System, apparatus, and method for monitored thermal spraying

BACKGROUND OF THE INVENTION

The invention relates generally to the spraying of a substance onto a surface. More specifically, the invention is a plasma transferred wire arc system, apparatus, and method for monitored thermal spraying (collectively, the “system”).

A. Plasma

There are four “states of matter” in physics. Matter can take the form of: (1) a solid; (2) a liquid; (3) a gas; or (4) a plasma. Plasma is an ionized gas consisting of positive ions and free electrons in equal proportions resulting in essentially no overall electric charge. Like a gas, plasma does not have a definitive shape or volume. It will expand to fill the space available to it. Unlike gases, plasmas are electrically conductive. Plasma conducts electricity, produces magnetic fields, and responds to electromagnetic forces. In plasma, positively charged nuclei travel in a space filled of freely moving disassociated electrons. These freely moving electrons allow matter in a plasma state to conduct electricity.

Although the term “plasma” is not commonly used outside the context of science and engineering, there are many common examples of plasma that people encounter in everyday life. Lightning, electric sparks, fluorescent lights, neon lights, and plasma televisions are all examples of plasma. Gas is typically converted into a state of plasma through heat (e.g. high temperatures) or electricity (e.g. a high voltage difference between two points).

B. Thermal Spraying

Thermal spraying is a process by which material is sprayed onto a surface with the purpose of improving the surface that is being sprayed. There are many different types of thermal spraying, including, but not limited to: plasma spraying; detonation spraying; wire arc spraying; plasma transferred wire arc spraying; flame spraying; high velocity oxy-fuel coating spraying (“HVOF”); warm spraying; and cold spraying.

Two of these thermal spraying techniques involve the use of plasma, plasma spraying and plasma transferred wire arc spraying. Plasma spraying involves the introduction of feedstock, which can be in the form of a powder, a liquid, a ceramic feedstock that is dispersed in a liquid suspension, or a wire that is introduced into a plasma jet created by a plasma torch. Plasma transferred wire arc (“PTWA”) spraying is plasma spraying when the feedstock is electrically part of the circuit and is in the form of a wire.

C. PTWA

PTWA can be used to enhance the surface properties of components. Treated components can be protected against extreme heat, abrasion, corrosion, erosion, abrasive wear, and other environmental and operational conditions that would otherwise limit the lifespan and effectiveness of the treated component. Overall durability is enhanced, while at the same time PTWA can also be used to achieve the following advantages with respect to treated components: (1) reductions in weight; (2) cost savings; (3) reduction in friction; (4) and a reduction of stress. In the context of vehicles such as automobiles, PTWA treatment of engine components such as cylinder bores can result in increased fuel economy and lower emissions. PTWA can also be useful in refurbishing old parts as well as in enhancing new parts.

The inputs of a PTWA system are electricity, gas, and consumable feedstock. The output of a PTWA system is a plasma arc between a cathode and an anode, where the anode is an open end of a consumable wire. The plasma spray is what enhances the surface properties of a component or surface being treated. Feedstock in a PTWA system is delivered to the plasma torch in the form of the wire. Electric current travels through the wire as the free end of the wire is moved to where the generated plasma exits the nozzle of the plasma torch. In many PTWA systems, the torch assembly revolves around a longitudinal axis of the wire feedstock while maintaining an electrical connection, a plasma arc, between the cathode of the plasma torch and the open end of the wire feedstock. In some embodiments, there is an offset between the longitudinal axis of the wire feedstock and the center of revolution (from the perspective of a cathode revolving around a center point) or the center of rotation (from the perspective of a cathode and surrounding empty space rotating around a center point). See U.S. Pat. No. 8,581,138 which discloses a thermal spray technology “wherein the method includes the steps of offsetting the central axis of a consumable wire with respect to an axial centerline of a constricting orifice.”

PTWA can provide highly desirable benefits in the treatment of components used in a wide variety of different industries, including but not limited to: aerospace; automotive; commercial vehicles; heavy industrial equipment; and rail.

D. Operating Parameters

The correct functioning of a PTWA system typically requires the coordination of: (1) a straight and rapidly traveling feed wire between about 100-500 inches/minute; (2) stable current traveling through the rapidly traveling feed wire; and (3) a consistent gas flow/pressure sufficient for sustaining stable plasma temperatures typically between 6,000 and 20,000 degrees Celsius. If one or more of the parameters of a PTWA system fall outside the desired ranges, inconsistent melting of the feed wire can result. Such inconsistency can negate the desired advantages of PTWA spraying. In extreme cases, such inconsistencies can result in a waste of the feedstock and the component being sprayed.

The correct functioning of a PTWA system requires the coordination of different variables under substantially tight constraints. Operations outside those constraints are not necessarily visible to the human eye unless the undesirable effects are severe. For example, a PTWA system functioning outside of desired parameters can result in “spitting” because the system will project large molten globules instead of finely atomized particles onto the surface being treated by the PTWA system. Even before visible “spitting” occurs, the operation of a PTWA system with even one parameter outside of an acceptable range can be highly undesirable.

E. Monitoring Patterns in the Data

Prior art PTWA systems may monitor certain parameters such as voltage measurements in the electrical pathway that are used to sustain a plasma arc. However, prior art PTWA systems do not analyze data for patterns in the data collected over time, i.e. process the data captured over time as waveforms. The failure to process a series of data as a waveform means that such systems can experience undesirable performance degradations that are not noticed by human operators until after the fact.

The prior art misses some valuable opportunities to proactively identify undesirable operating conditions before such conditions result in undesirable outcomes because the prior art fails to look for patterns in the sensor data. Prior art approaches do not process at least some of the sensor data as a waveform.

The system can be further understood as described in the Summary of the Invention section set forth below.

SUMMARY OF THE INVENTION

The system can utilize one or more of a variety of different sensors. Such sensors can capture one or more of a wide variety of different sensor measurements. The system can process some or all of such data as being part of a pattern or waveform.

Electrical measurements captured along the electrical pathway that supports the plasma arc can be particularly useful in the proactive monitoring of the system. The inclusion of other additional types of data can expand the types of conditions that can be proactively monitored.

Different embodiments of the system can be configured to provide different types of responses to different types of conditions identified through different types of sensor data. Responses can include: (1) one or more warnings; and/or (2) one or more automatic adjustments to the operation of the system. The monitoring, archiving, and subsequent analysis of such data opens up future possibilities of even more proactive error detection and/or correction.

The system can be implemented in a wide variety of different ways using a wide variety of different components and configurations. Virtually any PTWA system in the prior art can incorporate and benefit from the monitoring of electrical data as a waveform.

The system can be further understood in terms of the drawings described below.

BRIEF DESCRIPTION OF THE DRAWINGS

Many features and inventive aspects of the system are illustrated in the Figures which are described briefly below. However, no patent application can disclose through text descriptions or graphical illustrations all of the potential embodiments of an invention. In accordance with the provisions of the patent statutes, the principles and modes of operation of the system are explained and illustrated with respect to certain preferred embodiments. However, it must be understood that the components, configurations, and methods described above and below may be practiced otherwise than is specifically explained and illustrated without departing from its spirit or scope. Each of the various elements described in the glossary set forth in Table 1 below can be implemented in a variety of different ways while still being part of the spirit and scope of the invention.

FIG. 1a is an abbreviated cross-section diagram illustrating an example of certain components in a prior art PTWA system. The illustration shows a free end of a wire in a position for the creation of a plasma arc between the cathode and the free end of the wire.

FIG. 1b is an abbreviated cross-section diagram illustrating an example of a plasma arc from the cathode to the free end of the wire being created by a prior art PTWA system. As illustrated in FIG. 1b, the cathode (along with the rest of the torch assembly which is not displayed in the figure) rotates around the center which in this diagram is marked by the position of the wire.

FIG. 1c is an abbreviated cross-section diagram similar to FIG. 1b, except that the rotational position of the cathode of the prior art PTWA system is 180 degrees from the position illustrated in FIG. 1b.

FIG. 1d is an abbreviated top planar view diagram illustrating an example of a prior art PTWA system that includes a cathode (the rest of the torch assembly which is not displayed in the figure) rotating around the longitudinal axis of the wire. The magnitude of the “gap” between the cathode and the free end of the wire is ideally identical at each spot in the rotational path of the cathode.

FIG. 1e is an abbreviated block diagram showing a prior art PTWA system with a direct current circuit connecting the power source to the wire, the wire to the gap in which the plasma arc is created, the gap to the cathode of the torch assembly, and the torch assembly back to the power source.

FIG. 2a is a block diagram illustrating an example of a view of the system organized into three interacting subsystems.

FIG. 2b is a block diagram illustrating an example of the functionality that can be performed by a data capture subsystem.

FIG. 2c is a block diagram illustrating an example of the functionality that can be performed by a data analysis subsystem.

FIG. 2d is a hierarchy diagram illustrating different examples of operating conditions that can be identified using a waveform of electrical measurements.

FIG. 2e is a hierarchy diagram illustrating an example of different categories and subcategories of measurements that can be utilized by the system.

FIG. 2f is a hierarchy diagram illustrating an example of different categories and subcategories of waveform attributes that a processor can utilize as inputs to trigger a particular response.

FIG. 2g is a chart diagram illustrating a potentially undesirable operating condition and the corresponding waveform attribute(s) that can potentially be used to identify the particular operating condition.

FIG. 2h is a hierarchy diagram illustrating an example of different categories and subcategories of responses that can be generated by the system.

FIG. 2i is a waveform diagram illustrating an example of certain waveform attributes.

FIG. 3a is an abbreviated and exaggerated side view diagram illustrating an example of how a bent wire can result in different “gap” distances between the cathode and the wire as the cathode (along with the rest of the torch assembly which is not displayed in the figure) is rotated around the center (which in FIG. 3a is the position of the wire). As illustrated in FIG. 1e, such variances in the “gap” distance will typically result in voltage or other electrical measurement variances.

FIG. 3b is an abbreviated side view diagram illustrating an example of how variances in the velocity of the wire feed can impact the magnitude of the “gap” between the wire and the cathode. As illustrated in FIG. 1e, such variances in “gap” distance will typically result in voltage or other electrical measurement variances.

FIG. 3c is an abbreviated circuit diagram illustrating an example of how a momentary open circuit at virtually any location in the circuit can impact electrical measurements across the circuit. It is believed that a bad contact tip connecting the wire to the power supply is a likely scenario of such a momentary open circuit condition.

FIG. 3d is a diagram illustrating an example of how variances in gas flow and direction can result in variances in a particle stream as well as the plasma arc.

FIG. 3e is a diagram illustrating an example of a top view of a cathode revolving around a center (which may or may not be the wire) and positional differences between a plasma plume involving plasma distortion and a plasma plume without plasma distortion.

FIG. 4a is a block diagram illustrating an example of a system that includes an electrical sensor that transmits electrical measurements to a processor. The system can selectively generate a response to such measurements.

FIG. 4b is a block diagram illustrating an example of a system that uses a sensor from one of a variety of potentially different locations along the applicable DC (direct current) circuit.

FIG. 4c is a flow chart diagram illustrating an example of a processor utilizing electrical measurements in the form of a waveform to trigger a response to the operating conditions of the system.

FIG. 5a is a waveform diagram illustrating an example of a waveform of voltage measurements falling within a range of threshold values.

FIG. 5b is a graph of waveform characteristics illustrating an example of how a bent wire can impact a peak-to-peak voltage waveform.

FIG. 5c is a waveform diagram illustrating an example of different peak-to-peak voltages.

FIG. 5d is a waveform diagram illustrating an example of torch rotation measurements.

FIG. 5e is a waveform diagram illustrating an example of a poor electrical contact.

FIG. 5f is a waveform diagram illustrating an example of a rotationally-dependent poor electrical contact.

FIG. 6a is a block diagram illustrating an example of the different assemblies that can make up the system. The system can accommodate a wide variety of different assembly configurations, including virtually any prior art PTWA power delivery assembly, gas delivery assembly, wire delivery assembly, torch assembly, and IT assembly.

FIG. 6b is a schematic diagram illustrating an example of the system.

FIG. 6c is an enlarged representation of a portion of FIG. 6b.

The drawings described briefly above can be further understood in accordance with the Detailed Description section set forth below.

DETAILED DESCRIPTION

The invention relates generally to the spraying of a substance onto a surface. More specifically, the invention is a plasma transferred wire arc (“PTWA”) system, apparatus, and method for monitored thermal spraying (collectively, the “system” 100).

All component numbers referenced in the text below are listed in Table 1 along with an element name and definition.

I. Overview

The system 100 can be implemented and used with respect to virtually any prior art PTWA apparatus 50. The addition of a sensor 610 and a processor 710 can transform a prior art PTWA apparatus 50 into a system 100.

The system 100 uses one or more sensors 610 to capture one or more series of measurements 650 over time that can be processed as one or more waveforms 750. Using at least a subset of one or more waveforms 750, the processor 710 can generate a response 770 such as a warning 772 and/or an automatic adjustment 790.

It is anticipated that at least one of the sensors 610 will be an electrical sensor 611 used to capture electrical measurements 652 such as voltage measurements 654 or current measurements 653. Other types of measurements 650 captured by other types of sensors 610 can be factored into the processing of the processor 710 used to generate responses 770. By way of example, the list of inputs used by the processor 710 to generate a single response 770 as an output can include measurements 650 such as: (1) wire measurements 660 (such as wire position 662 and/or wire speed 664); (2) plasma measurements 670 (such as plasma flow rate 672 and/or plasma pressure 674); and/or (3) electrical measurements (such as voltage measurements 654, current measurements 653, and/or frequency measurements 656). Not all measurements 650 used as inputs to the processor 710 for creating a response 770 must be in the form of a waveform 750. It is anticipated that utilizing electrical measurements 652 as waveforms 750 will be particularly useful to the system 100 in identifying operating conditions 800 that would benefit from the triggering of a response 770 (such as a warning 772 and/or an automatic adjustment 790) in an automated manner without human intervention.

FIG. 2g is a chart that discloses different types and combinations of attributes of a waveform 750 created from electrical measurements 652 that can be used to enable a processor 710 to identify an operating condition 800 of the system 100. Other types of additional measurements 650 can be used in addition to the inputs identified in FIG. 2g.

As illustrated in FIG. 2a, the system 100 can be conceptualized as three subsystems that interact with each other. An operations subsystem 1010 that creates and sustains a plasma arc 60, a data capture subsystem 1020 that captures sensor measurements 650 from the conditions 800 of the operations subsystem 1010, and a data analysis subsystem 1030 that processes at least some of the sensor measurements 650 in the form of a waveform 750.

A. Operations

The operations subsystem 1010 is essentially any prior art apparatus 50 used to create and sustain a plasma arc 60. The operations subsystem 1010 can include a variety of different assemblies such as a torch assembly 200, a wire delivery assembly 300, a power delivery assembly 400, and a gas delivery assembly 500. The operating conditions 800 of the operations subsystem 1010 are the attributes being monitored by the system 100. The system 100 monitors the conditions 800 (which can also be referred to as operating parameters) that can impact the creation and sustaining of a plasma arc 60 for the purposes of creating a particle stream 70 directed to the desired surface 80 of a substrate 84.

B. Data Capture

A data capture subsystem 1020 can include one or more sensor assemblies 600. One or more sensors 610 can be used to capture sensor measurements 650 relating to the conditions 800 of the operations subsystem 1010. The function of the data capture subsystem 1020 is to create sensor measurements 650 that can serve as inputs for a data analysis subsystem 1030.

Electrical measurements 652 such as voltage measurements 654 captured along the electrical pathway 492 used to supply the plasma arc 60 with electricity 490, can be particularly useful in monitoring the operating conditions 800 of the operations subsystem 1010. Electrical measurements 652 captured by a high speed electrical sensor 612 can be particularly helpful in the monitoring of operating conditions 800 because the operations subsystem 1010 includes a cathode 212 that rapidly moves in a substantial circular orbit 280 around a rotational centerline 206. It is thus desirable for at least some sensor measurements 650 to be captured in a sufficiently rapid manner so that multiple measurements 650 are captured within a single orbit 280 of the cathode 212.

FIG. 2b illustrates the processing of a data capture subsystem 1020 that can repeat on a continuous or periodic basis. One or more sensors 610 can rapidly capture repeated measurements 650. Measurements 650 can be captured on a continuous, substantially continuous, or less frequent basis. Such measurements 650 provide data to the data analysis subsystem 1030 that is processed as a waveform 750.

FIG. 2e illustrates examples of different categories and subcategories of measurements 650 that can be captured by different sensors 610.

C. Data Analysis

The purpose of the data analysis subsystem 1030 is to selectively create a response 770 when conditions 800 merit the creation of a response 770. The system 100 seeks to proactively monitor the operations subsystem 1010 such that future problems are resolved before they actually generate problematic or even merely undesirable results.

The data analysis subsystem 1030 is comprised of an IT assembly 700 that includes a processor 710. The processor 710 can automatically and selectively generate a response 770 from one or more inputs. Inputs that can trigger a response 770 will typically include a series of electrical measurements 652 in the form of a waveform 750.

The system 100 can detect undesirable conditions 800 through the monitoring of measurements 650. The processing of rapidly obtained electrical measurements 652 over time as a waveform 750 can be particularly desirable in identifying undesirable operating conditions 800. By capturing measurements 650 rapidly over time, the system 100 can detect undesirable conditions 800 and determine which undesirable condition is specifically occurring. The innovative PTWA system 100 can generate a response 770 to a detected undesirable condition 800 without any human intervention.

FIG. 2c illustrates an example of a process that can be performed on a continuous or repeated basis by a data analysis subsystem 1030. Measurements 650 in the form of a waveform 750 can be processed by a processor 710 to selectively generate a response 770 when such a response 770 is justified by the underlying processing rules of the system 100.

Inputs to the processor 710 can include one or more waveforms 750 of measurements 650, measurements 650 not the form of a waveform 750, threshold values 740 for comparison purposes, and even historical data 734 stored on a database 732.

D. Waveform

FIG. 2i is a graphical illustration of a waveform 750. The attributes of an average value 758, a period 753, and a peak-to-peak value 751 are illustrated in the Figure. A waveform 750 is a collection of data points collected over time such that relationships between the data points such as patterns can be detected or analyzed. Waveforms 750 possess a wide range of attributes such as absolute amplitude, relative amplitude, maximum points, minimum points, frequency/period, etc. While a waveform 750 can be and often is illustrated in a visual manner, a waveform 750 is the underlying data that is capable of being visually represented in the shape of a wave. Thus a graph of a waveform 750 is a waveform 750, but the same underlying data without a visual representation of the data is also a waveform 750. Measurements 650, such as electrical measurements 652, can be put into the form of a waveform 750 by the sensor 610, the processor 710, or some other component of the system 100. The processor 710 can analyze all or some electrical measurements 652 in the form of a waveform 750, with attributes such as amplitude, frequency, and variations thereof. Examples of attributes associated with a waveform 750 can include, but are not limited to: (a) a peak-to-peak attribute 751; (b) a rate-of-change-in-peak-to-peak attribute 752; (c) a period 753; (d) a rate-of-change-in-period 754; (e) a discontinuity 755 (such as a periodic discontinuity 756 or a non-periodic discontinuity 757); and (f) an average value 758 and a rate-of-change-in-average value 759.

E. Response

The purpose of a monitored system 100 is the selective and automatic generation of a response 770 triggered by the applicable input or combination of inputs. One or more threshold values 740 can be used in the determination by the processor 710 of whether a response 770 is to be triggered. One or more different attributes of a waveform 750 can be used to trigger a response 770 by a processor 710.

FIG. 2h is a hierarchy diagram illustrating different categories and subcategories of responses 770 that can be generated by the system 100. A warning 772 is a response 770 that is limited to the communication of a problem to a human operator. An automatic adjustment 790 is a response 770 that includes a change to the operations of the operations subsystem 1010 that is triggered by the system 100 without human intervention. As indicated in FIG. 2h, warnings 772 can pertain to specific assemblies relating to the undesirable operating condition 800. Examples of warnings 772 can include but are not limited to: (a) a wire warning 773; (b) a gas warning 774; (c) a power warning 775; and (d) a plasma distortion warning 776. Examples of automatic adjustments 790 can include but are not limited to: (1) a change feed rate 791; (2) a modify wire feed process 792; and (3) a shutdown 799.

F. Operating Conditions

FIG. 2d illustrates examples of different categories and subcategories of operating conditions 800 that can be detected through the analysis of electrical measurements 652 captured over time that are processed as a waveform 750. Many embodiments of the system 100 will use a high speed electrical sensor 612 such as a high speed voltage sensor 614 to capture electrical measurements 652 such as voltage measurements 654 in rapid succession over time. Such electrical measurements 652 can be processed as a waveform 750 so that patterns and other relationships between the data points can be used to identify undesirable operating conditions 800 before such conditions 800 manifest themselves in undesirable outcomes.

FIG. 2g is chart that associates certain conditions 800 with the aspects of a waveform 750 of electrical measurements 652 that can be used to identify certain undesirable parameters of certain conditions 800.

Electrical measurements 652 are useful variables to track because sustaining a plasma arc 60 for the operation of the system 100 requires that electricity 490 jump across a gap 61 between a cathode 212 and a free end 370 in the wire 310. Electrical measurements 652 can be captured at any location in an electrical pathway 492 that includes the gap 61.

The electrical measurements 652 can reveal certain torch-related undesirable conditions 800 such as: (1) a wire curvature 801 (which causes a cyclical gap 61 between a free end 370 of a wire 310 and a cathode 212 that impacts the electrical measurements 652); (2) a wire curvature rate of change 802; (3) torch RPM 803; (4) torch RPM rate of change 804; (5) wire feed motion 805; (6) poor electrical contact 806; (7) rotationally-dependent poor electrical contact 807; (8) plasma distortion 808; and (9) plasma distortion rate of change 809.

Undesirable operating conditions 800 can be detected before a stream 70 of spit 71 or even non-atomized particles 72 can be otherwise detected by the operators of the apparatus 50. Such conditions 800 go undetected in a prior art apparatus 50 because the prior art apparatus 50 does not capture electrical measurements 652 over time as a waveform 750. The conditions 800 ultimately relate to the electrical pathway 492 that requires connectivity across the gap 61.

In many instances the system 100 can determine more than just the presence of a particular condition 800. The magnitude and the specific attributes or orientation of the condition 800 can be identified in some embodiments of the system 100. This can result in more specific warnings 772 and more opportunities for automated adjustments 790.

1. Wire Curvature (e.g. Bent Wire or Wire Position)

FIG. 3a illustrates an example of a condition 800 referred to as wire curvature 801. The extent of such curvature is exaggerated in FIG. 3a to better illustrate the ramifications of wire curvature 801. Wire curvature 801 can also be referred to as a “bent wire” or “wire position” because such variations each involve a portion of the free end 370 of the wire 310 being consumed by the plasma arc 60 in a position that is at least to some extent undesirable.

FIG. 3a illustrates how a bent wire 310 changes the magnitude of the “gap” 61 so that it is either a smaller gap 61A or a larger gap 61B than a desired gap 61. Wire curvature 801 can result in non-atomized particles 72 or even spit 71 being sprayed onto a substrate 84. As illustrated in FIG. 3a, the cathode 212 rotates around the free end 370 of the wire 310 while the plasma arc 60 is sustained. Thus the gap 61 in a bent wire condition 801 will often cycle between being larger than desired and shorter than desired within a single revolution of the cathode 212.

Some embodiments of the system 100 can determine the orientation of the bend in the wire 310 in addition to the presence of a bent wire 310. A waveform 750 of electrical measurements can be used to determine the magnitude and direction of the bend in the shape of the wire 310. Such information can be used to describe orientation in terms of magnitude of the bend and in the direction/angle of the bend. Other embodiments of the system 100 may describe the bend in terms of X-Y coordinates.

As disclosed in the incorporate references, the rotational centerline 206 can be the desired position of the wire 310 or the rotational centerline 206 can be offset from the position of the wire 310 so that the wire 310 is not the center around which the cathode 212 rotates.

The wire curvature rate of change condition 802 is the time derivative (rate of change over time) of the wire curvature 801.

2. Wire Feed Motion (e.g. Velocity and Acceleration)

FIG. 3b illustrates how variations and/or discrepancies in the speed and/or acceleration of the wire feed (e.g. wire feed motion 805) can impact the magnitude of the gap 61. At a typical speed 352 (which can also be referred to as an acceptable speed 352) the gap 61 is smaller than the gap 61C that results from a lagging speed 352C or a gap 61D that results from a leading speed 352D. Unlike wire curvature condition 801 which can both increase and decrease the distance of the gap 61, wire feed motion 805 only increases the gap 61. Both the lagging gap 61C and the leading gap 61D are longer than the desired gap 61 that results from wire feed motion 805 within desired parameters.

3. Poor Electrical Contact

FIG. 3c illustrates an example of how an open circuit 450 anywhere in the electrical pathway 492 of the prior art apparatus 50 can impact the ability of the prior art apparatus 50 to sustain the plasma arc 60 across the gap 61. A poor electrical contact 806 can exist at virtually any spot along the PTWA circuit 492, but a bad contact 450 at the contact tip 422 (typically made of a copper alloy) is a particularly likely cause of the problem. The intermittent loss of connectivity can be distinguished from other undesired conditions 800 through a pattern of electrical measurements 652.

Some instances of poor electrical contact 806 are rotationally dependent because they relate to the rotation of the cathode 212 around a rotational centerline 206. Such instances can be referred to as rotationally-dependent poor electrical contact 807.

4. Plasma Distortion

FIGS. 3d and 3e illustrate examples of plasma distortion 808. Such distortion can be embodied in a plasma plume 62E that is not properly oriented (FIG. 3e) or a plume 62 that is either too large or too small (FIG. 3d). As illustrated in FIG. 2g, plasma distortion 808 is a condition 800 that can be identified by looking at the waveform 750 of electrical measurements 652. Plasma distortion rate of change 809 is a time derivative (rate of change over time) of the plasma distortion 808.

The supply and/or direction of gas 510 to the torch assembly 200 can also result in an undesirable condition 800 such as plasma distortion 808. If there is insufficient gas 510, then there will likely be insufficient plasma for the plasma arc 60 to be sustained across the gap 61. This interruption in connectivity can be detected from the electrical measurement 652 captured by the sensor 650.

II. Alternative Embodiments

The system 100 can be implemented with respect to virtually any prior art apparatus 50. The system 100 can be implemented using a wide variety of different components and component configurations. The system 100 can also be implemented using a wide variety of different sensors 610 to capture a wide variety of different sensor measurements 650. The processor 710 used to trigger automated responses 770 without human intervention can trigger such responses 770 based on a single input or a complex heuristic involving many different inputs.

Different embodiments of the system 100 can trigger different responses 770 to different conditions 800 using different sensor measurements 650. Different embodiments of the system 100 can utilize different processing rules for the triggering of responses 770.

Many embodiments of the system 100 will involve measurements 650 captured over time so that patterns and trends in the data can be identified. Some but not all of the data processed by the IT assembly 700 can be in the form a waveform 750.

No patent application can disclose through text descriptions or graphical illustrations all of the potential embodiments of an invention. In accordance with the provisions of the patent statutes, the principles and modes of operation of the system are explained and illustrated with respect to certain preferred embodiments. However, it must be understood that the components, configurations, and methods described above and below may be practiced otherwise than is specifically explained and illustrated without departing from its spirit or scope. Each of the various components and assemblies elements described in the glossary set forth in Table 1 below can be implemented in a variety of different ways while still being part of the spirit and scope of the invention.

III. Incorporated References

The system 100 is an improvement to prior art apparatuses 50 that can be incorporated into virtually any prior art apparatus 50. Prior art PTWA technology is discussed in the following patent references, all of which are hereby incorporated by reference in their entirety (collectively, the “incorporated references”): (1) U.S. Pat. No. 5,808,270 (“Plasma transferred wire arc thermal spray apparatus and method” filed on Feb. 14, 1997); (2) U.S. Pat. No. 5,938,944 (“Plasma transferred wire arc thermal spray apparatus and method” filed on Apr. 9, 1998); (3) U.S. Pat. No. 6,372,298 (“High deposition rate thermal spray using plasma transferred wire arc” filed on Jul. 21, 2000); (4) U.S. Pat. No. 6,706,993 (“Small bore PTWA thermal spraygun” filed on Dec. 19, 2002); (5) U.S. Pat. No. 8,581,138 (“Thermal spray method and apparatus using plasma transferred wire arc” filed on Dec. 22, 2011); (6) U.S. Published Application 20150376759 (“Device for thermally coating a surface” filed on Dec. 19, 2013) and (7) U.S. Published Application 20160001309 (“Device for thermally coating a surface” filed on Dec. 18, 2013).

IV. Prior Art PTWA Apparatuses

FIGS. 1a-1d illustrate examples of prior art PTWA apparatuses 50 and the relationship between a plasma arc 60 across a gap 61 between a cathode 212 and a free end 370 of the wire 310. FIG. 1e illustrates that the gap 61 is part of the electrical pathway 492. FIGS. 3a-3e illustrate examples of undesirable operating conditions 800 that can be detected by processing electrical measurements 652 captured over time as a waveform 750. FIGS. 5a-5f illustrate examples of waveforms 750 that can be used to identify undesirable operating conditions 800 in a prior art PTWA apparatus 50.

A. Combination of Coordinated Processes

The purpose of a properly functioning prior art PTWA apparatus 50 is to melt and atomize the material in the free end 370 of the wire 310 so that the atomized particles 74 can form a stream 70 directed to a desired surface 80 on a desired substrate 84. As illustrated in FIG. 1a, the portion of the wire 310 that is exposed to being melted and atomized is a free end 370 of the wire 310 which includes the end tip 371.

This highly complex process of spraying a stream 70 of predominantly atomized particles 74 onto a surface 80 involves coordinating several processes under substantially tight tolerances. Such processes include: (1) sustaining a steady plasma arc 60 between a cathode 212 in the torch assembly 200 and a free end 370 of the wire 310; (2) moving the wire 310 toward the gap 61 as its free end 370 is atomized in the plasma arc 60; (3) the delivery of electricity 490 to the cathode 212; (4) the delivery of gas 510 to the cathode 212; and (5) rotating a cathode 212 around a central point of rotation that is either the location of the wire 310 or a center point that is slightly offset with respect to the position of the wire 310. The thermal spraying process can provide substantial benefits to a surface 80 being targeted with a stream of atomized particles 74 from a prior art PTWA apparatus 50. Unfortunately, if the underlying parameters of the apparatus 50 deviate from acceptable ranges, the output of the apparatus 50 is not a finely atomized particle 74 stream but rather is a stream which includes non-atomized particles 72. Such non-atomized particles 72 are molten, and if the globules of molten material are sufficiently large, they are commonly referred to as “spits” 71. The benefits of a PTWA apparatus 50 result from the spraying of a stream 70 of finely atomized particles 74, and not from the spraying of non-atomized particles 72. Moreover, the spraying of spits 71 can actually damage the substrate 84, resulting in a waste of time, money, and materials.

As illustrated in FIGS. 1d and 1e, the proper functioning of a prior art PTWA apparatus 50 requires connectivity in the form of a plasma arc 60 across a “gap” 61 of gas. The gap 61 is from the cathode 212 of the torch assembly 200 to a free end 370 of the wire 310. In the context of a DC circuit, a circuit or electrical pathway 492 distributes electricity 490 to the various components of the PTWA apparatus 50, and the gap 61 is a potential open in the circuit 492. Under normal conditions, air does not conduct electricity 490. Sufficient plasma, which is created through the use of gas 510 and the availability of electricity 490, is needed to create the conditions necessary in order to create and sustain the plasma arc 60 across the gap 61.

FIG. 1a is an abbreviated cross-section diagram illustrating an example of certain components in a prior art PTWA apparatus 50. The illustration shows a free end 370 of a wire 310 in position for the creation of a plasma arc 60 between the cathode 212 and the free end 370 of the wire 310.

The wire 310 is moved through rollers 340 and a guide tip 330 before reaching the position for the creation and sustaining of the plasma arc 60 where a free end 370 of the wire 310 is to be melted, atomized, and otherwise consumed by the plasma arc 60.

Gases 510 are provided from a gas assembly 500 through gas ports 530. A cathode 212 within the torch assembly 200 provides for creating and sustaining the plasma arc 60, contingent upon having access to the necessary inputs.

Not labelled in the abbreviated diagram of FIG. 1a is a nozzle 220 in the torch assembly 200 that helps to direct the plasma arc 60 and the resulting particle stream 70. Other components of the torch assembly 200, the wire delivery assembly 300, the gas delivery assembly 500, and the power delivery assembly 400 are discussed below, in Table 1, in FIGS. 6b and 6c, as well as in the incorporated references.

B. Rotational Movement of the Torch Assembly

FIG. 1b is an abbreviated cross-section diagram illustrating an example of a plasma arc 60 from the cathode 212 to the free end 370 of the wire 310 being created by a prior art PTWA apparatus 50. As illustrated in FIG. 1b, the cathode 212 (along with the rest of the torch assembly 200 which is not displayed in the figure) rotates around the longitudinal axis of the wire 310 (i.e. the rotational centerline 206). This movement is important because the plasma arc 60 must be sustained in all of the different positions of the torch assembly 200. The operating conditions 800 of bent wire 801 and wire feed motion 805 are triggered by variances in the magnitude of the gap 61 that results from the underlying variance of geometric position. FIG. 1c is an abbreviated cross-section diagram similar to FIG. 1b, except that the rotational position of the cathode 212 of the prior art PTWA apparatus 50 is 180 degrees from the position illustrated in FIG. 1b.

FIG. 1d is an abbreviated top planar view diagram illustrating an example of a prior art PTWA apparatus 50 that includes a cathode 212 (along with the rest of the torch assembly 200 which is not displayed in the figure) rotating around the rotational centerline 206 (a center of rotation) that is the same position as the wire 310. If the wire 310 is perfectly straight, then the magnitude of the “gap” 61 between the cathode 212 and the free end 370 of the wire 310 is identical at each spot in a rotational path 280 of the cathode 212. In the case of bent wire condition 801 and/or wire feed motion condition 805, differences will arise in the various gaps 61 at different locations along the rotational path 280.

C. PTWA Circuit/Electrical Pathway

FIG. 1e is an abbreviated block diagram showing a prior art PTWA apparatus 50 with a direct current circuit 492 connecting the power source 410 to the wire 310, the wire 310 to the gap 61 in which the plasma arc 60 is created, from the gap 61 to the cathode 212 of the torch assembly 200, and the torch assembly 200 back to the power source 410.

The difference between a prior art PTWA apparatus 50 and the applicant's inventive system 100 is the use of a sensor 610 such as an electrical sensor 611 or a high speed electrical sensor 612 to capture electrical measurements 652 over time that are subsequently processed by a processor 710 as a waveform 750. One or more attributes of the waveform 750 can be used by a processor 710 to automatically trigger a response 770 to an undesirable operating condition 800. An electrical sensor 611 can be positioned at any location in the electrical pathway 492 that includes the gap 61 across which the plasma arc 60 is formed and sustained in the operation of the system 100. The processor 710 can similarly be located virtually anywhere in an apparatus 110 or even outside the apparatus 110.

V. Undesirable Conditions, Waveforms, and Responses

The intended purpose of a prior art apparatus 50 as well as the innovative system 100 and apparatus 110 is to create a suitable plasma arc 60 across a gap 61 within desired parameters. Such a plasma arc 60 is intended to create a desired particle stream 70 comprised substantially of atomized particles 74 originating from the wire 310. It is not desired for the particle stream 70 to be comprised largely of non-atomized particles 72, although the inclusion of some such material is to some extent inevitable. The system 100 can avoid the concentration of non-atomized particles 72 from becoming too large in the particle stream 70 by identifying the underlying conditions 800 that can fall out of tolerance. The system 100 can rectify the problems through warnings 772 or even automatic adjustments 790.

A. Conditions

FIGS. 2d and 2g illustrate examples of undesirable conditions 800 that can be detected by processing electrical measurements 652 as a waveform 750.

To project atomized particles 74 instead of molten globules 72, it is required that the wire 310 be melted and atomized in the plasma arc 60, with the particulate matter being projected in the desired particle stream 70 onto a desired surface 80. The benefits of such a process can be substantial. However, it is a process with tight operating parameters such as the parameters relating to the electricity 490 that “jumps” across the gap 61. If one of the underlying processes is not functioning properly, the output of the system 100 will be an undesirable condition 800, not a stream 70 of well atomized particles 74 suitable for spraying.

The further the operating parameters become out of tolerance, the more likely non-atomized particles 72 and even a spit 71 is to be sprayed onto the desired surface 80 of the substrate 84. Spit 71 occurs when a large molten globule 72 is formed out of the wire 310 and propelled to the substrate 84 or surface 80 that is the target of the spraying process. Spit 71 results in waste. Wasted time in running the system 100 without generating useful results. Wasted materials in terms of the wire 310, the surface 80 on which the particle stream 70 was to enhance, and in terms of the electricity 490 and gas 510 used by the prior art apparatus 50. In contrast, a monitored system 100 can avoid such waste.

Potential responses 770 can include warnings 772 as well as automatic adjustments 790 that are made by the system 100. As illustrated in FIG. 2d, there are at least several categories of relevant conditions 800 that can be detected using a waveform 750 of electrical measurements 652 captured over time. Some conditions 800 relate to the wire delivery assembly 300 such as wire curvature 801, wire curvature rate-of-change 802, and wire feed motion 805. Other conditions 800 relate to the movement of the cathode 212 in its orbit 280 around a rotational centerline 206, such as torch RPM 803 or torch RPM rate-of-change 804. Other conditions 800 relate to the movement of electricity 490 along the electrical pathway 492 such as a poor electrical contact 806 or a rotationally-dependent poor electrical contact 807. Still other conditions 800 relate to the gas 510 that is heated and delivered across the gap 61, such as plasma distortion 808 or the plasma distortion rate-of-change 809. Many of these conditions 800 can result in spit 71 or other forms of waste if not corrected in a proactive manner.

FIG. 3a illustrates a context of a system 100 that is experiencing the condition 800 of undesirable wire curvature 801. FIG. 3b illustrates a context of a system 100 that is experiencing undesirable wire feed motion 805. FIG. 3c illustrates a context of a system 100 that is experiencing poor electrical contact 806. FIGS. 3d and 3e illustrate examples of a system 100 that is experiencing plasma distortion 808.

B. Waveforms

Examples of waveforms 750 and waveform attributes are illustrated in FIGS. 2i and 5a-5f. FIG. 2g is a chart that serves to associate certain attributes of waveforms 750 (which are comprised of electrical measurements 652) to certain detectable conditions 800. FIG. 2i discloses a waveform 750 that has attributes such as a peak-to-peak value 751, a period 753, and an average value 758.

FIG. 5a reveals an example of voltage measurements 654 within a range of acceptable threshold values 740. Such results suggest a system 100 operating where the gap 61 is not varying significantly with the orbit 280 of the cathode 212. Contrast FIG. 1d where the gap 61 is constant with FIG. 3a which illustrates an example of a relatively larger gap 61B and a relatively smaller gap 61A caused by a bend in the free end 370 of the wire 310.

FIG. 5b is a waveform analysis that relates to the wire curvature 801. FIG. 5c illustrates how peak-to-peak values 751 can be used to differentiate the operations of the system 100. FIG. 5d discloses a potential relationship between a period rate of change attribute 754 and a torch RPM condition 803. FIGS. 5e and 5f illustrate examples of poor electrical contact 806 and rotationally-dependent poor electrical contact 807.

C. Responses

FIG. 2h illustrates an example of different categories and subcategories of responses 770 that can be generated by the system 100. Responses 770 can also correspond with different aspects of the system 100. For example, warnings 772 can relate to an attribute of: (1) the wire delivery assembly 300 (a wire warning 773); (2) the gas delivery assembly 500 (a gas warning 774); (3) the power delivery assembly 400 (a power warning 775); or (4) the torch assembly 200 (a plasma distortion warning 776). Automatic adjustments 790 can similarly be implemented for different assemblies as an output to different combinations of inputs.

Responses 770 can also correlate or otherwise be mapped to/correspond with different identified operating conditions 800. Each of the conditions 800 in FIGS. 2d and 2g can be associated with a particular warning 772 and/or automatic adjustment 790.

VI. Method of Thermal Spraying

FIG. 4c is a flow chart diagram illustrating an example of a method 900 of thermal spraying in which a sensor 610 is used to capture sensor readings 650 that can trigger a processor 710 to generate a response 770 without any human intervention. In FIG. 4c, steps 910 through 940 reflect processes performed by a prior art apparatus 50 and steps 950 through 970 illustrate processes that are not performed by a prior art apparatus 50. The system 100 can transform a prior art apparatus 50 through the use of one or more sensors 610 such as an electrical sensor 611 used to capture electrical measurements 652 over time. Such measurements 652 can be processed as a waveform 750 by the processor 710 to selectively generate a response 770 automatically without human intervention.

At 910, gas 510 is delivered to a torch assembly 200. This is typically achieved by the movement of gas 510 from a gas source 520 through a gas port 530 to a torch assembly 200.

At 920, the wire 310 is moved towards the torch assembly 200. This involves a movement of a free end 370 of the wire 310 through the rollers 340 and through a guide tip 330 towards the position of the gap 61 and the desired plasma arc 60.

At 930, electricity 490 is delivered from a power source 410. The electrical pathway 492 includes the power source 410, the cathode 212, a contact tip 422, and the wire 310.

At 940, a plasma arc 60 is created and sustained across the gap 61 between the cathode 212 and the free end 370 of the wire 310.

At 950, an electrical measurement 652 is captured with an electrical sensor 611.

At 960, the electrical measurement 652 is sent to a processor 710.

At 962, the processor 710 processes the measurements 650 as a waveform 750. The waveform 750 can be analyzed at 962 to determine at 965 whether or not there is a problematic condition 800 that merits a response 770. That determination can be made on a selective basis by processing a waveform 750 of the electrical measurements 652. FIG. 2c compares the most recent electrical measurement 652 in the context of prior electrical measurements 652, one or more threshold values 740, and other operating parameters of the system 100. FIG. 2g discloses a chart of conditions 800 and corresponding attributes of a waveform 750 in the context of electrical measurements 652.

If the processor 710 at 965 determines that the torch assembly 200 is operating within acceptable parameters, the process returns to 910 with the continued sustaining of the plasma arc 60.

If the processor 710 at 965 determines that the torch assembly 200 is not operating within acceptable parameters, a response 770 is generated at 970.

The response 770 may constitute a warning 772 and/or an automatic adjustment 790. The plasma arc 60 and the operation of the torch assembly 200 may or may not continue after the response 770.

V. System and Apparatus Embodiments

The system 100 will often, but not necessarily always, be implemented in the form of an integrated apparatus 110. FIGS. 4a-4b and 6a-6c illustrate various embodiments of systems 100 and apparatuses 110 at various levels of detail.

A. FIG. 4a

FIG. 4a is a block diagram illustrating an example of a system 100 that utilizes an electrical sensor 611 to capture electrical measurements 652 which can be processed by a processor 710 as a waveform 750 to generate a response 770.

The electrical sensor 611 can be positioned potentially anywhere along a circuit 492 through which electricity 490 travels. The power supply 410 provides current that travels through the circuit 492 which includes the gap 61 between the cathode 212 and the free end 370 of the wire 310.

B. FIG. 4b

FIG. 4b is a block diagram illustrating an example of an apparatus 110 that utilizes a sensor 610 (often a high speed voltage sensor 614) to capture electrical measurements 652 over time which can be used by a processor 710 to generate a response 770 from a waveform 750 of such electrical measurements 652.

Gas 510 is delivered from a gas source 520 to a gas port 530, making the gas 510 accessible to the torch assembly 200.

The power supply 410 provides electricity 490 that travels through an electrical pathway 492. The electrical pathway 492 includes the portion of the wire 310 from the contact tip 422 to the free end 370 of the wire 310 and the cathode 212 in the torch assembly 200.

C. FIG. 6a

FIG. 6a is a block diagram illustrating different assemblies that can be included in the system 100 and apparatus 110.

A power delivery assembly 400 provides the electricity 490 to the torch assembly 200 so that torch assembly 200 can create and sustain a plasma arc 60 across the gap 61. The power delivery assembly 400 can deliver electricity 490 across an electrical pathway 492 using components such as a power supply 410 (typically a DC power source 412), a lead/contact 420, a contact tip 422 in contact with the wire 310, an insulating object 430 (such as a rubber ring 432 or an insulating block 434), and other electrical subassemblies, components, and parts known in the art.

A gas delivery assembly 500 provides gas 510 to the torch assembly 200 so that torch assembly 200 can create and sustain a plasma arc 60 across the gap 61. The gas delivery assembly 500 can provide for delivering different types of gases 510, including a plasma gas 512 that is transformed into an ionized plasma gas 516 as well as a secondary gas 518 such as air. The gas delivery assembly 500 can include multiple gas sources 520 such as a primary gas source 522 for the primary plasma gas 512 and a secondary gas source 524 for the secondary gas 518. The assembly 500 can also include a variety of ports 530, manifolds 550 and 560, plates such as a baffle plate 552, bores 562 to facilitate the movement of gas 510, and other subassemblies, components, and parts known in the art.

A wire delivery assembly 300 provides a free end 370 of a wire 310 to the torch assembly 200 so that torch assembly 200 can create and sustain a plasma arc 60 across the gap 61. Wire 310 is moved to the torch assembly 200 through rollers 340 that are powered by a speed-controlled motor 350. The wire 310 moves through a guide tip 330 to position the free end 370 of the wire 310 in the proper position for the plasma arc 60.

A torch assembly 200 takes the inputs of electricity 490, gas 510, and wire 310 to create and sustain a plasma arc 60 across the gap 61. The torch assembly 200 includes a cathode subassembly 210 that includes a cathode 212, a cathode holder 214, and gas ports 216 to facilitate the movement of plasma gas 512. The torch assembly 200 is typically enclosed in a surface referred to as a torch body 202. Within the torch body 202 is also a nozzle 220 such as an anode nozzle or plasma nozzle 222.

A sensor assembly 600 captures one or more sensor readings 650 from one or more sensors 610. The sensor readings 650 are sent to the IT assembly 700. The one or more sensors 610 can include voltage sensors 613 such as high speed voltage sensors 614, current sensors 615, frequency sensors 617, and other types of sensors 610. The range of sensor measurements 650 is commensurate with the range of different sensors 610, including voltage measurements 654, current measurements 653, frequency measurements 656, and/or potentially other types of measurements 650.

An IT assembly 700 can selectively identify operating conditions 800 and selectively trigger a response 770 to address the applicable operating condition 800. The IT assembly 700 can include one or more processors 710, running one or more applications/programs 712 and accessing data through a memory/RAM component 720. Data such as sensor measurements 650 can also be stored on a storage component 730, which may organize the data using a database 732. Historical data 734 can be stored on the database 732, and used to create and update threshold values 740 used by the processor 710 in identifying operating conditions 800. The IT Assembly 700 is responsible for generating responses 770 such as warnings 772 and automatic adjustments 790. An automatic adjustment 790 can impact the operation of any of the assemblies identified above, including the gas delivery assembly 500, the power delivery assembly 400, the wire delivery assembly 300, and the torch assembly 200.

D. FIGS. 6b and 6c

FIG. 6b shows a schematic representation of a PTWA apparatus 110 that can include a sensor 610 such as a high speed voltage sensor 614 for capturing voltage measurements 654 that can be used by a processor 710 to create a response 770 to undesirable operating conditions 800. The sensor 610 can be positioned anywhere in the electrical pathway 492 within the apparatus 110. FIG. 6c is an enlarged representation of an anode nozzle 222 and a free end 370 of a wire 310 illustrated in FIG. 6b.

The apparatus 110 includes a torch body 202 containing a plasma gas port 532 and a secondary gas port 534. The torch body 202 is typically formed of an electrically conductive metal. The plasma gas 512 is connected by means of a plasma gas port 532 to a cathode holder 214 through which the plasma gas 512 flows into the inside of the cathode subassembly 210 and exits through gas ports 216 located in the cathode holder 214. The plasma gas 512 forms a vortex flow between the outside of the cathode subassembly 210 and the internal surface of the plasma nozzle 222, and then it exits through the constricting orifice 224. The plasma gas vortex provides substantial cooling of the heat being generated by the functioning of the cathode.

Secondary gas 518 enters the torch assembly 200 through secondary gas ports 534 which direct the secondary gas 518 to a gas manifold 550 (a cavity formed between a baffle plate 552 and the torch body 202 and then through bores 562). The secondary gas 518 flow is uniformly distributed through the equi-angularly spaced bores 562 concentrically surrounding the outside of the constricting orifice 224.

Wire feedstock 320 is used supply the plasma arc 60 with the material that is sprayed onto the surface 84. The wire 310 is directed by rollers 340 that are powered by a speed-controlled motor 350. The wire 310 moves through a wire contact tip 422 which is in electrical contact to the wire 310 as it slides through the wire contact tip 422. In this embodiment, the wire contact tip 422 is composed of two pieces, 422a and 422b, held in spring or pressure load contact with the wire 310 by means of a rubber ring 432 or other suitable means. The wire contact tip 422 is made of high electrically conducting material. As the wire 310 exits the wire contact tip 422, it enters a wire guide tip 330 for guiding the wire 310 into precise alignment with the axial centerline 204 of the constricting orifice 224. The wire guide tip 330 can be supported in a wire guide tip block within an insulating block 434 which provides electrical insulation between the main body 202, which is held at a negative electrical potential, while the wire guide tip block 332 and the wire contact tip 422 are held at a positive potential. In other embodiments, the wire guide tip 330 can be structurally integral with the nozzle 220. A small port 536 in the insulator block 434 allows a small amount of secondary gas 518 to be diverted through the wire guide tip block 332 in order to provide heat removal from the block 332. This can also be done via a bleed gas 510 around or through the nozzle 220. In some embodiments, the wire guide tip block 332 can be maintained in pressure contact with the plasma nozzle 222 to provide an electrical connection between the plasma nozzle 222 and the wire guide tip block 332. Electrical connection is made to the main body 202 and thereby to the cathode subassembly 210 (having cathode 212) through the cathode holder 214 from the negative terminal of the power supply 410. In some embodiments, the power supply 410 may contain both a pilot power supply and a main power supply operated through isolation contactors. Positive electrical connection can be made to the wire contact tip 422 from the positive terminal of the power supply 410. Wire 310 is fed toward the axial centerline 204 of the constricting orifice 224, which is also the axis of the plasma plume 62. Concurrently, the cathode subassembly 210 is electrically energized with a negative charge and the wire 310, as well as the plasma nozzle 222 although the plasma nozzle 222 can be isolated, it can be electrically charged with a positive charge. The wire guide tip 330 and wire 310 can be positioned relative to the plasma nozzle 222 by many different methods. In one embodiment, the plasma nozzle 222 itself can have features for holding and positioning of the wire guide tip 330. The torch body 202 may be desirably mounted on a power rotating support (not shown) which revolves the torch around the wire axis to coat the interior of bores.

To initiate operation of the apparatus 110, plasma gas 512 at an inlet gas pressure of between 50 and 140 psig is caused to flow through the plasma gas ports 532, creating a vortex flow of the plasma gas 512 about the inner surface of the plasma nozzle 222 and then, after an initial period of time of typically two seconds, high-voltage DC power or high frequency power is connected to the electrodes creating the plasma arc 60. Wire 310 is fed by means of wire feed rollers 340 into the plasma arc 60 sustaining it even as the free end 370 is melted off by the intense heat of the plasma arc 60 and its associated plasma 68 which surrounds the plasma arc 60. Molten metal particles 72 are formed on the free end 370 of the wire 310 and are atomized into fine, particles 74 by the viscous shear force established between the high velocity, ionized plasma gas 516 and the initially, stationary molten droplets. The molten particles 72 are further atomized and accelerated by the much larger mass flow of secondary gas 518 through bores 562 which converge at a location or zone 64 beyond the melting of the wire free end 370, now containing the finely atomized particles 74, which are propelled to the substrate surface 80 to form a deposit 82 on a desired substrate 84.

In the most stable condition of the apparatus 110 as shown in FIG. 6c but also including some components which are not pictured in FIG. 6c, wire 310 will be melted and particles 70 will be formed and immediately carried and accelerated by vector forces 66 in the same direction as the ionized plasma gas 516; a uniform dispersion 70 of fine particles 74, without aberrant globules 72, will be obtained. The vector forces 66 are the axial force components of the plasma arc energy and the high level converging secondary gas 518 streams. However, under some conditions, instabilities occur where particles from the melted wire free end 370 are not uniformly melted as the cathode subassembly 210 is rotated around the rotational centerline 206 of the wire 310 whereby some part of the wire free end 370 is accelerated away from the free end 370 in larger droplets 72 which are not atomized into fine particles 74. These large particles or droplets 72 are propelled as large agglomerate masses toward the substrate 84 and are included into the coating (i.e. deposit 82) as it is being formed, resulting in coating of poor quality.

As indicated earlier, high velocity secondary gas 518 is released from equi-angularly spaced bores 562 to project a curtain of gas 510 streams about the plasma arc 60. The supply 524 of secondary gas 518, such as air, is introduced into the chamber 550 under high flow, with a pressure of about 20-120 psi. The chamber 550 (i.e. gas manifold 550) acts as a plenum to distribute the secondary gas 518 to the series of equi-angularly spaced bores 562 which direct the secondary gas 518 as a concentric converging stream which assists the atomization and acceleration of the particles 70. Each bore 562 has an internal diameter of about 0.040-0.090 inches and projects a high velocity air flow at a flow rate of about 10-60 scfm from the total of all of the bores 562 combined. The plurality of bores 562, typically ten in number, are located concentrically around the constricting orifice 224, and are radially and substantially equally spaced apart. To avoid excessive cooling of the plasma arc 60, these streams are radially located so as not to impinge directly on the wire free end 370. The bores 562 are spaced angularly apart so that the wire free end 370 is centered midway between two adjacent bores 562, when viewed along the axial centerline 204 of the constricting orifice 224. Thus, as shown in FIG. 6c, bores 562 will not appear because the section plane is through the wire 310. FIG. 6b shows the bores 562 only for illustration purposes and it should be understood they are shown out of position (typically 18 degrees for a plasma nozzle 222 with 10 radial bores 562) and are not in the section plane for this view. The converging angle of the gas 510 streams is typically about 30 degrees relative to the axial centerline 204 of the constricting orifice 224, permitting the gas 510 streams to engage the particles 70 downstream of the wire-plasma intersection zone 64.

VII. Glossary/Index

Table 1 below is comprised of a chart that cross-references element numbers, element names, and element definitions/descriptions.

Element

Number
Element Name
Element Definition/Descriptions

50
Prior Art
A prior art PTWA (plasma transferred

Apparatus
wire arc) thermal spraying apparatus.

60
Plasma Arc
An arc forming between a cathode 212

and a free end 370 of a wire 310. The

arc is comprised of a jet of very hot

plasma produced from electric current

490 traveling through ionized plasma

gas 516 in the space between the

cathode 212 and the wire 310.

61
Gap
The space between the cathode 212

and the free end 370 of the wire.

62
Plasma Plume
The area surrounding a plasma arc 60

where non-atomized particles 72 are

atomized.

64
Zone
An area or location beyond the melting

of the free end 370 of the wire 310. The

zone 64 can also be referred to as a

wire-plasma intersection zone.

66
Vector Forces
Forces pushing particles 70 in the same

direction of the ionized plasma gas 516.

68
Associated
Plasma that surrounds the plasma

Plasma
plume 62.

70
Particles or
The system 100 atomizes the particles

Particle Stream
70 in the wire 310 and sprays them

towards a surface 80. The particles 70

projected towards the surface 80 are

originally solid, in the form of the wire

310. A free end 370 of the wire 310 is

melted into non-atomized particles 72

and then atomized into atomized

particles 74 which are then sprayed on

the desired surface 80. The purpose of

the system 100 is to generate a particle

stream 70 of atomized particles 74.

Realistically, some quantity of non-

atomized particles 72 will be included in

the particle stream 70. The further from

optimal the operation of the system 100

becomes, the greater the ratio of non-

atomized particles 72 to atomized

particles 74.

71
Spit
A more extreme example of non-

atomized particles 72 in the particle

stream 70 that is visible to the human

eye. The existence of spit 71 in the

particle stream 70 means that operation

of the system 100 is likely not

satisfactory.

72
Non-Atomized
Particles 70 from the wire that have

Particles
been melted or partially melted, but not

fully atomized. In the theoretically

optimal and aspirational operation of the

system 100, the particle stream 70 is

comprised entirely of atomized particles

74. Realistically however, there will also

be non-atomized particles 72 in the

particle stream 70. As the operation of

the system 100 falls further away from

optimal, the non-atomized particles 72

can be in the form of spit 71. Non-

atomized particles 72 can also often be

referred to as molten metal particles

since at the applicable temperature, the

metal material from the wire 310 will be

in a molten or at least substantially

molten form.

74
Atomized
Particles 70 from the wire that are in a

Particles
sufficiently fine form as to be suitable

for spraying on the surface 80 of the

substrate 84.

80
Surface
The exterior face or boundary of the

substrate 84 which is being sprayed with

particles 70 from the system 100.

82
Deposit
In a properly functioning system 100,

the deposit 82 is the buildup of atomized

particles 74 sprayed onto the surface 80

by the system 100 or apparatus 110.

Realistically, the deposit 82 is likely to

include some quantity of non-atomized

particles 72. A deposit 82 of spit 71 is

typically unacceptable.

84
Substrate
The material being sprayed on by the

system 100 or apparatus 110. The

deposit 82 is formed from spraying the

particles 70 onto the surface 80 of the

substrate 84.

100
Plasma Arc
A PTWA (plasma transferred wire arc)

Thermal Spray
system for projecting (i.e. spraying)

System
atomized particles 74 onto a surface 80

of a substrate 84 that utilizes one or

more sensors 610 to monitor the

operations of the system 100, e.g. the

“system” 100. The system 100 can be

implemented in a wide variety of

embodiments, including a variety of

different apparatuses 110 and methods

900.

110
Plasma Arc
A plasma arc thermal spray system 100

Thermal Spray
in the form of an at least substantially

Apparatus
integrated apparatus 110.

200
Torch Assembly
An aggregate configuration of

subassemblies, components, and parts

that provide for the creation and

sustaining of a plasma arc 60 from the

cathode 212 to a free end 370 of a wire

310. The inputs for the torch assembly

200 are electricity 490 from a power

delivery assembly 400, a wire 310 from

a wire delivery assembly 300, and a gas

510 from a gas delivery assembly 500.

202
Torch Body
The torch assembly 200 enclosed in an

exterior surface.

204
Axial Centerline
A central axis of the constricting orifice

224.

206
Rotational
A central axis around which the cathode

Centerline
212 revolves around in an orbit 280 that

is typically at least substantially circular

in shape. In some embodiments, the

rotational centerline 206 is the position

of the wire 310. In other embodiments,

there is an offset between the position of

the wire 310 and the rotational

centerline 206 (see U.S. Pat. No.

8,581,138).

210
Cathode
An aggregate configuration of

Subassembly
components and parts that support the

functionality of the cathode 212 within

the torch assembly 200.

212
Cathode
A negatively charged electrode used to

form the plasma arc 60.

214
Cathode Holder
A structure that secures the position of

the cathode 212 relative to the other

components of the torch assembly 200

and the various inputs delivered to the

torch assembly 200.

216
Gas Port
An opening in the cathode holder 214 or

torch body 202 through which gas 510

exits. The gas port 216 allows for the

delivery of gas 510 to the cathode 212.

Gas 510 travelling to the cathode 212

through the gas port 216 is an important

input for the creation of the plasma arc

60.

220
Nozzle
A projecting spout through which

something flows in an outward direction.

222
Anode Nozzle or
A nozzle 220 through which plasma gas

Plasma Nozzle
512 exits.

224
Constricting
An opening or passageway that narrows

Orifice
as the plasma gas 512 travels through

it.

280
Orbit
A pathway around a rotational centerline

206 that is typically at least substantially

circular in shape. Much of the literature

on prior art PTWA 50 describes this

movement as a rotation around the

rotational centerline 206 by the cathode

212.

300
Wire Delivery
An aggregate configuration of

Assembly
components that provide for the

movement of the wire 310 towards the

position where a free end 370 of the

wire 310 is positioned for the plasma arc

60. The wire delivery assembly 300 can

also be referred to as a wire assembly

300.

310
Wire
A metallic material in the shape of a

slender, string-like piece or filament.

The wire 310 is comprised of the matter

from which the atomized particles 74 are

derived and directed to the surface 80 of

the substrate 84.

320
Feedstock
A portion of the wire 310 that is the

opposite end to the free end 370.

Feedstock 320 can also be referred to

as the wire base or wire supply.

Feedstock 320 is the portion of the wire

310 that is not yet within the rollers 340,

the contact tip 422, or the guide tip 330.

The feedstock 320 is where the supply

of wire 310 is positioned and stored until

the speed-controlled motor 350 moves

the particular portion of the wire 310.

330
Guide Tip
A hollow structure through which the

wire 310 moves. The guide tip 350 is

often the final structure that helps

position the wire 310 and more

specifically the free end 370 of the wire

310 at the desired position for the

creation and sustaining of a plasma arc

60.

332
Guide Tip Block
This structure provides support for the

guide tip 330. It is typically contained

within an insulating object 430.

340
Rollers
Rotating structures that are at least

substantially cylindrically shaped.

Rollers 340 are powered by the speed-

controlled motor 350. Rollers 340 move

the wire 310 towards the guide tip 330.

350
Speed-Controlled
An engine that moves a free end 370 of

Motor
the wire 310 (with the rest of the wire

310 following) through the wire delivery

assembly 300 to the desired position for

the plasma arc 60. The speed-

controlled motor 350 moves the wire

310 by powering the rollers 340.

352
Wire Speed
The velocity at which the wire 370

moves towards the gap 61. Wire speed

352 is controlled primarily by the motor

350.

370
Free End
An end portion of the wire 310 that is

melted and atomized within a proper

plasma arc 60. The free end 370 of the

wire 310 is opposite to the feedstock

320 end. The free end 370 of the wire

310 includes an end tip 371 as well as

the portions/lengths of the wire prior to

the end tip 371. The free end 370 of the

wire 310 is from the end tip 371 to

portions of the wire 310 that have just

passed through the guide tip 330.

371
End Tip
The portion of the free end 370 that is

the precise end position.

400
Power Delivery
An aggregate configuration of

Assembly
subassemblies, components, and parts

that collectively provide the electricity

490 used to sustain the plasma arc 60.

In most embodiments of the system

100, the power delivery assembly 400

provides for supplying electricity 490

in the form of direct current (DC)

electricity 490. The power delivery

assembly 400 can also be referred to

as a power assembly 400.

410
Power Supply
A device that provides the electricity 490

for forming the plasma arc 60 from the

cathode 212 to the free end 370 of the

wire 310.

412
DC Power Source
A power supply 410 that provides for

directing electricity 490 in the form of

direct current (DC) along the electrical

pathway 492.

420
Lead/Contact
An electrical connection comprising a

length of wire or a metal conductive

pad. The power delivery assembly 400

can utilize a wide variety of different

leads/contacts 420 to direct electricity

490 throughout the power delivery

assembly 400.

422
Contact Tip
A lead 420 in direct physical contact

with the wire 310 that provides for

routing electricity 490 to the wire 310.

In some embodiments, the contact tip

422 can be made up of two or more

pieces such as 422A and 422B, held

in spring or pressure load contact with

the wire 310 by a rubber ring 432 or

other similar structure.

430
Insulating Object
A structure that does not conduct

electricity 490. The system 100 may

use various insulating objects 430 to

direct electricity 490 through the desired

electrical pathway 492.

432
Rubber Ring
An insulating object 430 typically used

to hold the contact tip 422 together with

the wire 310 so that the portion of the

wire 310 in contact with the contact tip

422 to the free end 370 becomes part of

the electrical pathway 492.

434
Insulating Block
An insulating object 430 that insulates

the portion of the wire 310 between the

contact tip 422 and the free end 370.

450
Open Circuit
An unintentional gap in the electrical

pathway 492 that can negatively impact

the performance of the system 100. An

open circuit 450 can also be referred to

as a bad contact 450.

490
Electricity
A form of energy resulting from the

existence of charged particles (such as

electrons or protons), either statically as

an accumulation of charge or

dynamically as a current. Electricity 492

is a necessary input for creating and

sustaining a plasma arc 60.

492
Circuit or
A route that the electricity 490 forming

Electrical
the plasma arc 60 travels from the

Pathway
power supply 410 to the plasma arc 60

and back again.

500
Gas Delivery
An aggregate configuration of

Assembly
subassemblies, components, and parts

that collectively provide the gas 510 or

gasses 510 used to sustain the plasma

arc 60. The gas delivery assembly 500

can also be referred to as a gas

assembly 500.

510
Gas
A non-solid, non-liquid and non-ionized

material supplied to the torch assembly

200.

512
Plasma Gas
A gas 510 that will become ionized to

create and sustain the plasma arc 60.

An example of a suitable plasma gas

512 is Ar—H2 65/35.

516
Ionized
Plasma gas 512 in a sufficiently

Plasma Gas
heated, ionized, and in a high velocity

state (often supersonic) that it is suitable

for atomizing the material in the free end

370 of the wire 310.

518
Secondary Gas
A gas 510 that is not plasma gas 512.

A secondary gas 518 is typically

introduced into the gas manifold 550

under high flow. Secondary gas 518 is

typically used to direct the atomized

particles 74 of the wire 310 in the

desired direction. Secondary gas 518 is

used to further atomize and accelerate

the particles 70.

520
Gas Source
A subassembly or component that

supplies one or more gases 510 to the

system 100 or apparatus 110.

522
Primary Gas
The gas source 520 for plasma gas 512.

Source/Plasma

Gas Source

524
Secondary Gas
The gas source 520 for secondary gas

Source
518.

530
Gas Port
A passageway through which gas 510

can travel and is directed to travel from

one location within the system 100 to

another location.

532
Plasma Gas Port
A port 530 that provides for the delivery

of plasma gas 512 to the cathode holder

214.

534
Secondary
A port 530 that provides for the delivery

Gas Port
of secondary gas 518 to the gas

manifold 550.

536
Insulator Block
A port 530 within the insulator block

Gas Port
434 that provides for a small amount

of secondary gas 518 to be directed

through the insulator block 424 to

facilitate the removal of heat from the

insulator block 434.

550
Gas Manifold
A cavity or chamber formed between the

baffle plate 552 and the torch body 202.

The gas manifold 550 is used in the

process of directing the flow of

secondary gas 518. The gas manifold

550 can also be referred to as a first

manifold 550.

552
Baffle Plate
A surface that along with the torch body

202 forms the walls of the gas manifold

550.

560
Second Manifold
A cavity or chamber that secondary gas

518 is directed to after the initial gas

manifold 550. Secondary gas 518

moves from the first manifold 550 to the

second manifold 560 through bores 562

connecting the two chambers.

562
Bores
Openings such as holes that facilitate

the movement of gas 510.

600
Sensor Assembly
An aggregate configuration of

components that provide for capture of

sensor readings 650 from a sensor 610,

and the transmission of sensor readings

650 to the IT assembly 700. The

system 100 can have a varying number

of sensors 610 and types of sensors

610.

610
Sensor
A device that is used to capture sensor

readings 650. Sensors 610 are often

defined with respect to the types of

sensor measurements 650 that are

captured by the sensor 610. The

system 100 can include a wide variety of

different sensors 610, including, but not

limited to, electrical sensors 611, wire

sensors 620, plasma sensors 624, and

virtually any other type of sensor 610

that can be used to capture

measurements 650 that would be useful

to the monitoring of the system 100.

611
Electrical Sensor
A sensor 610 that is used to capture

measurements 650 relating to attributes

of electricity 490 and electrical pathways

492. The system 100 includes at least

one electrical sensor 611. An electrical

sensor 611 captures an electrical

measurement 652. Examples of

electrical sensors 611 include voltage

sensors 613, current sensors 615, and

frequency sensors 617.

612
High Speed
An electrical sensor 611 that can

Electrical Sensor
capture an electrical measurement 652

at a high speed. The speed capability of

the sensor 610 should be sufficient with

respect to the rotational speed of the

cathode 212 that a waveform 750 of

data can be provided to the processor

710. A high speed electrical sensor 612

can capture an electrical measurement

652 about at least every 10 ms.

613
Voltage Sensor
An electrical sensor 611 that is used to

capture voltage measurements 654 over

time.

614
High Speed
A voltage sensor 613 that can take

Voltage Sensor
many voltage measurements 654 in a

short period of time. In many

embodiments, a high speed voltage

sensor 614 can operate in a highly

precise manner with about a minimum

of +/− 10 mV accuracy in capturing

measurements at least about every 10

ms.

615
Current Sensor
An electrical sensor 611 that is used to

capture a current measurement 653.

616
High Speed
A high speed electrical sensor 612 that

Current Sensor
is used to a capture a current

measurement 653.

617
Frequency
An electrical sensor 611 that is used to

Sensor
capture a frequency measurement 656.

618
High Speed
A high speed electrical sensor 612 that

Frequency
is used to a capture a frequency

Sensor
measurement 656.

620
Wire Sensor
A sensor 610 that is used to capture

information about the wire delivery

assembly 300, such as wire position 662

or wire speed 664.

624
Plasma Sensor
A sensor 610 that is used to capture

information about the gas 510 delivered

to the cathode 212, such as plasma flow

rate 672 and plasma pressure 674.

650
Sensor Reading
Information captured by a sensor 610.

or Measurement
Measurements 650 can also be called

sensor readings 650. Sensor

measurements 650 are used by the

system 100 to identify out of tolerance

operating conditions 800.

652
Electrical
A measurement 650 relating to the flow

Measurement
of electricity 490 along the electrical

pathway 492. Examples of electrical

measurements 652 can include: current

measurements 653; voltage

measurements 654; frequency

measurements 656; and other similar

metrics known in the art. Electrical

measurements 652 can be analyzed as

a waveform 750 by the processor 710.

By capturing electrical measurements

652 over time, the system 100 can

monitor the operating status of the

system 100 by monitoring electrical

measurements 652 as a waveform 750.

653
Current
An electrical measurement 652 of a flow

Measurement
of electric charge. Current

measurements 653 can be captured by

current sensors 615.

654
Voltage
An electrical measurement 652 of a

Measurement
difference in electric potential energy

between two points per unit electric

charge. Voltage measurements 654

can be captured by a voltage sensor

613. By capturing voltage

measurements 654 over time, the

system 100 can monitor the operating

status of the system 100 by monitoring

voltage measurements 654 as a

waveform 750.

656
Frequency
An electrical measurement 652 relating

Measurement
to frequency. Frequency measurements

656 can be captured by a frequency

sensor 617.

660
Wire
A measurement 650 pertaining to the

Measurement
wire 310. Examples can include wire

position 662, wire speed 664 and other

measurements 650 relating to the wire

310.

662
Wire Position
A wire measurement 660 pertaining to

the position of a free end 370 of the wire

310.

664
Wire Speed
A wire measurement 660 pertaining to

the velocity of the wire 310.

670
Plasma
A measurement 650 that pertains to the

Measurements
gas 510 that is delivered to the area of

the plasma arc 60. Examples of plasma

measurements 670 include plasma flow

rate 672 and plasma pressure 674.

672
Plasma
The velocity of gas 510 used to create

Flow Rate
the plasma arc 60.

674
Plasma Pressure
Force per unit area of the gas 510 used

to create the plasma arc 60.

700
IT Assembly
An aggregate configuration of

components that provide for the

processing of data and the

communication of components. The IT

assembly 700 can also be referred to as

a computer system 700.

710
Processor
A machine that is capable of being

programmed, either through hardware

or software. Processors 710 are

sometimes referred to as

microprocessors. Most processors 710

are silicon-based.

712
Application/
Instructions that are provided to the

Program
processor 710. Such instructions can

be implemented through hardware

and/or software means.

720
Memory/RAM
A memory device that is accessible to

the processor 710 and provides for the

accessing of information in any order.

730
Storage
A device that can be used by the

Component
processor 710 to create, store, retrieve,

update, and/or delete data.

732
Database
A collection of data stored in a storage

component 730 that is easily accessible

to the processor 710. Many but not all

databases 732 are relational databases

utilizing system query language (SQL).

734
Historical Data
A potential large library of data that can

include past sensor readings 650, past

operating parameter data, and past

operator assessments relating to one or

more systems 100 and/or apparatuses

110.

740
Threshold Value
A numerical value that can be

selectively or non-selectively used by

the processor 710 for the purposes of

assessing sensor readings 650.

Different embodiments of the system

100 as well as different operating

conditions 800 can involve differing use

of one or more threshold values 740.

Threshold values 740 can be the sole

and dispositive factor in triggering a

particular response 770, a primary factor

that weighs heavily in triggering a

particular response 770, a relatively

minor factor with little weight in

triggering a response 770, or totally

irrelevant to the triggering of a response

770. Threshold values 740 can be set

by the operators of the system 100, or

can be determined by heuristics that

“factor in” the historical data 734 of the

system 100. Threshold values 740 can

relate to different attributes of a

waveform 750. Some threshold values

740 can be in the forms of ranges, with

both maximum and minimum values.

Other threshold values 740 involve only

a minimum, a maximum, or some other

unitary comparison metric.

750
Waveform
A collection of data points collected over

time such that relationships between the

data points such as patterns can be

detected or analyzed. Waveforms 750

possess a wide range of attributes such

as absolute amplitude, relative

amplitude, maximum points, minimum

points, frequency/period, etc. While a

waveform 750 can be and often is

illustrated in a visual manner, a

waveform 750 is the underlying data

that is capable of being visually

represented in the shape of a wave.

Thus a graph of a waveform 750 is a

waveform 750, but the same underlying

data without a visual representation of

the data is also a waveform 750.

Measurements 650, such as electrical

measurements 652, can be put into the

form of a waveform 750 by the sensor

610, the processor 710, or some other

component of the system 100. The

processor 710 can analyze all or some

electrical measurements 652 in the form

of a waveform 750, with attributes such

as amplitude, frequency, and variations

thereof. Examples of attributes

associated with a waveform 750 can

include, but are not limited to, a peak-to-

peak 751, a peak-to-peak rate-of-

change 752, a period 753, a period rate-

of-change 754, a discontinuity 755 (such

as a periodic discontinuity 756 or a non-

periodic discontinuity 757), an average

value 758 and an average value rate-of-

change 759.

751
Peak-to-Peak
The magnitude of the difference

Attribute
between a minimum measurement 650

and a maximum measurement 650 in a

waveform 750 with respect to a

particular attribute, such as voltage,

current, or some other type of data. A

peak-to-peak attribute 751 can also be

referred to as a peak-to-peak value 751

or simply a peak-to-peak 751.

752
Rate-of-Change-
A time derivative (the rate of change

in-Peak-to-
over time) of the peak-to-peak attribute

Peak Attribute
751, such as voltage, current, or some

other type of data. A rate-of-change-in-

peak-to-peak attribute 752 can also be

referred to as a rate-of-change-in-peak-

to-peak 752 or a peak-to-peak rate-of-

change 752.

753
Period
The time that it takes for a pattern

within the waveform to repeat itself.

The period corresponds with a single

revolution of the torch cathode 212.

The period 753 is inversely proportional

to frequency. Waveforms 750 generated

by measurements 650 of the system 100

can be impacted by the rotation of the

cathode 212 around a central axis of

space which is typically either the

position of the wire 310 or a position that

is slightly offset from the position of the

wire 310.

754
Rate-of-
A time derivative (the rate of change

Change-in-
over time) of the period 753. A rate-of-

Period
change-in-period 754 can also be

referred to as a period rate-of-change

754.

755
Discontinuity
A substantial change in the shape of the

waveform 750. Discontinuities 755 can

be periodic 756 and non-periodic 757.

756
Periodic
A discontinuity 755 that repeats itself

Discontinuity
with a given frequency.

757
Non-Periodic
A discontinuity 755 that does not appear

Discontinuity
to repeat itself with a given frequency.

758
Average Value
An average value the measurements

650 making up the waveform 750.

759
Rate-of-
A time derivative (the rate of change

Change-in-
over time) in the change of average

Average Value
value 757. A rate-of-change-in-

average-value 759 can also be referred

to as an average value rate-of-change

759.

770
Response
A reaction to one or more sensor

readings 650 generated by the

processor 710. Responses 770 can

include one or more warnings 772 and

one or more automatic adjustments 790.

772
Warning
A response 770 that is comprised of a

communication. Warnings 772 serve to

notify operators of the system 100 as

well as for management.

773
Wire Warning
A warning 772 that relates to the

delivery of wire 310 to the plasma arc

60.

774
Gas Warning
A warning 772 that relates to the

delivery of gas 510 to the cathode 212.

775
Power Warning
A warning 772 that relates to the flow of

electricity 490 through the electrical

pathway 492.

776
Plasma
A warning 772 that relates to the shape,

Distortion
location, and the consistency of the

Warning
plasma plume 62.

790
Automatic
A response 770 by the system 100 or

Adjustment
apparatus 110 that is beyond that of

communication. An automatic

adjustment 790 involves a modification

in the operation of the system 100 or

apparatus 110. Examples of automatic

adjustments 790 can include, but are

not limited to, a change in feed rate 791,

a modification of the wire feed process

792, and a shutdown 799.

791
Change
The speed/velocity of the wire 310 can

Feed Rate
be adjusted by the processor 710 by

instructing the speed-controlled motor

350 to either speed up or slow down.

792
Modify Wire
A bent wire condition 801 can be

Feed Process
addressed by adjusting the operation of

the wire delivery assembly 300 so that

the wire 310 is straightened.

799
Shutdown
The system 100 or apparatus 110 can

be automatically shut down to avoid

waste or damage.

800
Operating
An operating parameter 800 of the

Condition
system 100. An operating condition 800

can be within acceptable tolerances,

outside of acceptable tolerances, and/or

identified as likely to move outside of

acceptable tolerances. In many

contexts, assessment of the particular

condition 800 can involve assessing the

magnitude of the condition, as well as

other attributes of the condition 800.

801
Wire Curvature
An operating condition 800 that is

indicative of a wire 310 being curved

instead of straight. Some embodiments

of the system 100 can assess the

magnitude and orientation of the bend in

the wire 310.

802
Wire Curvature
The time derivative (rate of change over

Rate of Change
time) of the wire curvature 801.

803
Torch RPM
The speed at which the torch assembly

200 revolves around a central point.

RPM stands for rotations per minute.

804
Torch RPM
The time derivative (rate of change over

Rate of Change
time) of the torch RPM 803.

805
Wire Feed
The motion of the wire 310 towards the

Motion
gap 61. Wire Feed Motion 805 can

encompass both velocity and

acceleration.

806
Poor Electrical
A point in the electrical pathway 492

Contact
where electricity 490 does not readily

flow.

807
Rotationally-
A poor electrical contact 806 problem

Dependent Poor
that is periodic with the revolution of the

Electrical
torch assembly 200 around a center

Contact
point.

808
Plasma
When the plasma gas 512 exits the

Distortion
plasma nozzle 222 in a manner that is

not intended.

809
Plasma Distortion
A time derivative (rate of change over

Rate of Change
time) of the plasma distortion 808.

900
Method
A process of steps for detecting out of

tolerance operating conditions 800 in

the thermal spray process and

selectively generating a response 770.

1010
Operations
A collection of assemblies, structures,

Subsystem
activities, and information that relate to

the creation of a plasma arc 60 across a

gap 61.

1020
Data Capture
A collection of assemblies, structures,

Subsystem
activities, and information that relate to

the capture of measurements 650 from

the operations subsystem 1010.

1030
Data Analysis
A collection of assemblies, structures,

Subsystem
activities, and information that relate to

the analyzing of a waveform 750

resulting from the measurements 650.

Number	Name	Date	Kind
4122327	Vogts	Oct 1978	A
5528010	Herwig	Jun 1996	A
6134005	Smith, Jr.	Oct 2000	A
6680456	Adams	Jan 2004	B2
6703579	Rice	Mar 2004	B1
8013994	Vattiat	Sep 2011	B1
8581138	Kowalsky	Nov 2013	B2

System, apparatus, and method for monitored thermal spraying

Information

Patent Number

Date Filed

Date Issued

Inventors

Examiners

CPC

Field of Search

US

CPC

International Classifications

Abstract

Description

Claims

US Referenced Citations (7)

Related Publications (1)