Embodiments of this disclosure relate generally to gas turbines, and more specifically, to a method and apparatus that ablates or clears holes in an article of a gas turbine assembly.
Rotary machines such as gas turbines contain numerous parts that must be resurfaced and/or coated as part of fabrication and/or maintenance. Resurfacing and coating these parts often results in situations in which holes or apertures within the part are covered or otherwise obstructed by the coating. The holes often provide cooling to the article or other parts of the rotary machine. As a result, the holes must be cleared of all debris in the form of any leftover or excess coating.
Generally, computer-controlled cutting devices (e.g., lasers) are configured to clear debris from the numerous holes. However, this process is difficult and time consuming when numerous holes must be cleared on a variety of complex, contoured surfaces of the part, requiring movement and reorientation of the laser for each hole.
Because of the often large number of cooling holes on a gas turbine part that must be cleared after a coating operation, it becomes important that the hole clearing operation be performed in as efficient a means as possible in order to minimize process time and maximize part throughput. The physical movement of either the cutting devices or the part itself, in preparation for the next process step, often increases the overall process inefficiency as the cutting device typically does not operate during this portion of the process.
As a result, there exists a need for an apparatus and a method of cleaning debris and obstructions from numerous holes of a part that does not require substantial time and effort and does not negatively impact the part or coating thereon.
The following presents a simplified summary of the disclosed subject matter in order to provide a basic understanding of some aspects of the various embodiments described herein. This summary is not an extensive overview of the various embodiments. It is not intended to exclusively identify key features or essential features of the claimed subject matter set forth in the Claims, nor is it intended as an aid in determining the scope of the claimed subject matter. Its sole purpose is to present some concepts of the disclosure in a streamlined form as a prelude to the more detailed description that is presented later.
In accordance with one embodiment, a method of ablating one or more holes in an article with a laser is provided. The method includes an establishing step that establishes an ablation characteristic. The ablation characteristic includes a synchronized machine motion characteristic. An ablating step ablates the one or more holes with the laser based on the synchronized machine motion characteristic. The synchronized machine motion characteristic synchronizes a laser beam emitted from the laser with a location of the one or more holes.
In accordance with another embodiment, a system for ablating one or more holes in an article with a laser is provided. The system comprises a memory storing a set of machine motion synchronization data, and at least one processor executing instructions that cause the at least one processor to perform a plurality of steps. An establishing step establishes an ablation characteristic. The ablation characteristic includes a synchronized machine motion characteristic. An ablating step ablates the one or more holes with the laser based on the synchronized machine motion characteristic. The synchronized machine motion characteristic synchronizes a laser beam emitted from the laser with a location of the one or more holes.
In accordance with an alternate embodiment, a non-transitory, computer-readable medium stores instructions that, when executed by at least one processor, causes the at least one processor to perform a plurality of steps. An establishing step establishes an ablation characteristic, and the ablation characteristic includes a synchronized machine motion characteristic. An ablating step ablates one or more holes with a laser based on the synchronized machine motion characteristic. The synchronized machine motion characteristic synchronizes a laser beam emitted from the laser with a location of the one or more holes.
The present invention will be better understood from reading the following description of non-limiting embodiments, with reference to the attached drawings, wherein below:
Example embodiments of the present method and system will be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all embodiments are shown. Indeed, the present method and system may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Like numbers may refer to like elements throughout.
The term “ablate” or “ablation” as used herein, refers to the removal of material. This is accomplished by removing the material with a tool or cutting device. The method and system disclosed herein discuss the removal of material from a series of holes with a cutting device that emits laser pulses. The method and system disclosed herein can be applied to other methods involving ablation of material from edges, surfaces, and/or holes.
Turning now to the figures,
Referring to
Referring to
Referring back to
The laser ablation characteristic may also vary based on a specific region to be ablated. For example, a first laser ablation characteristic may be used to ablate regions of hole 14 (see
Referring to
In some embodiments, the control system 24 establishes a cooling hole characteristic that is configured to evaluate a material thermal capability of an article 10 to minimize damage to the article 10. The cooling hole characteristic includes a dimension of a hole 14, a thermal response of a material of the article 10, an overall three-dimensional shape of a desired cooling hole 14, a ceramic fill, a metallic fill, and/or thermal characteristics of a cooling hole including finished, partially ablated, and fully coated holes. The control system 24 may also evaluate the material properties of any surface coatings and/or substrates added to the exterior surface 12 of the article 10 to also minimize damage caused by the laser 22. One example of the control system 24 changing a characteristic to prevent damage to the article 10 is when the ablation pattern dictates ablating a first hole 14 in the batch of holes to a thermal threshold and then ablating a second hole 14 in the batch of holes while the first hole 14 cools. In some embodiments, specific holes 14 from each batch are targeted in order to efficiently remove material from multiple different batches at once, minimizing the thermal impact on the article 10. In other words, referring to
An exemplary embodiment of a method 600 of laser ablation for restoration of a series of holes 14 in an article 10 is illustrated in the flow diagram in
The method 600 includes an optional step of moving 612 the article 10 and/or laser 22 from an initial position to a following position, and vice versa, and repeating the steps of ablating 608, 610 and moving 612 the article 10. In some embodiments, the method includes moving the laser 22 and/or the article 10 during the step of ablating 608, 610 the at least one work zone. The established ablation characteristic can be changed 614 by the control system 24, as set forth above, and the method 600 creates 604 the laser path plan according to the changed ablation characteristic without requiring movement of the laser 22. For example, in step 604, a first ablation pattern may be used, and the method proceeds through steps 606-610, 614, and then a second ablation pattern (different from the first ablation pattern) is selected in step 614 and the second ablation pattern is then used in steps 604-610, or only in step 610. The laser ablation characteristic may also be changed between steps 608 and 610, so that a first laser ablation characteristic is used when ablating a first working zone, and a different, second laser ablation characteristic is used to ablate a second working zone.
The laser path plan is a function of the laser characteristic, the working zone characteristic, the cooling hole characteristic, and the synchronized machine motion characteristic for the article 10 for the first working zone and at least one second working zone. The laser path plan accommodates a number of following working zones and a number of following positions. The laser path plan may evaluate the capabilities of the laser 22 to determine an appropriate or efficient time scale for operation of the laser 22.
The method 600 synchronizes the motion of the laser and/or the article 10 relative to one another by considering characteristics including, but not limited to, linear and rotational acceleration of the laser 22 and/or the article 10, linear and rotational speed of the laser 22 and/or the article 10, repeatability and accuracy, and any additional characteristics relevant for a working zone and an effective working zone (e.g., laser inputs, field of view, a minimum and/or a maximum working distance, a minimum and/or a maximum effective working distance, spot size variation, energy efficiency, etc.). The synchronized machine motion characteristic includes, but is not limited to, motion and laser data in the form of a global and local position synchronization of the laser 22 and/or the article 10, an acceleration and/or deceleration notification, and includes control system latency versus motion of the article and/or laser. The method 600 allows for a dynamic relationship between the laser 22 and the article 10 to efficiently remove debris or obstructions from holes 14 and/or diffuser sections 19. The synchronized machine motion characteristic allows for tracking and monitoring of the location of the laser 22 and the article 10 without the need for registration holes or other zeroing of the device. However, incorporating of registration holes or zeroing the laser 22 during and/or after completion of the method 600 does not depart from the invention disclosed herein.
In some embodiments, the step of creating 604 a laser path plan targets ablation of a cooling hole 14 in a low thermal conductivity zone in a manner so as to enable ablation in a non-optimal working zone by reducing thermally induced damage to the substrate. The step of creating 604 a laser path plan may target ablation where an extremity of the cooling hole is irregular to smooth the transition into and out of the cooling hole. In some embodiments, the laser path plan targets known data regions and difficult ablation zones and layers while the regions, zones, and/or layers are in a peak effective ablation zone for the laser delivery system 20. In some embodiments, the step of creating a laser path plan establishes laser paths that are optimized for a working zone that moves across the article 10 while the article 10 is in motion. The laser path plan may also consider the debris cloud created when the laser 22 is ablating each hole 14 and may minimize or otherwise control the debris cloud to decrease or eliminate damage to the article 10.
The laser path plan is capable of operating in a time scale less than the time in which plasma forms to generate an ablation efficiency. This ablation efficiency can be evaluated and maintained above and/or below an ablation threshold. In some embodiments, the laser path plan operates in a time scale in a femtosecond or picosecond time regime. Here, the femtosecond time regime is defined as between 1 femtosecond and 1,000 femtoseconds. The picosecond time regime is defined as between 1 picosecond and 1,000 picoseconds. The nanosecond time regime is defined as between 1 nanosecond and 1,000 nanoseconds. The microsecond time regime is defined as between 1 microsecond and 1,000 microseconds.
As shown in
The one or more memory device(s) 706 can store information accessible by the one or more processor(s) 704, including computer-readable instructions 708 that can be executed by the one or more processor(s) 704. The instructions 708 can be any set of instructions that when executed by the one or more processor(s) 704, cause the one or more processor(s) 704 to perform operations, such as any of the operations described herein. For instance, the methods provided herein can be implemented in whole or in part by the computing system 700. The instructions 708 can be software written in any suitable programming language or can be implemented in hardware. Additionally, and/or alternatively, the instructions 708 can be executed in logically and/or virtually separate threads on processor(s) 704. The memory device(s) 706 can further store data 710 that can be accessed by the processor(s) 704. For example, the data 710 can include models, databases, machine motion synchronization data, etc.
The computing device(s) 702 can also include a network (or communication) interface 712 used to communicate, for example, with the other components of the laser system 20 (e.g., via a network). The network interface 712 can include any suitable components for interfacing with one or more network(s), including for example, transmitters, receivers, ports, antennas, and/or other suitable components.
The technology discussed herein makes reference to computer-based systems and actions taken by and information sent to and from computer-based systems. One of ordinary skill in the art will recognize that the inherent flexibility of computer-based systems allows for a great variety of possible configurations, combinations, and divisions of tasks and functionality between and among components. For instance, processes discussed herein can be implemented using a single computing device or multiple computing devices working in combination. Databases, memory, instructions, and applications can be implemented on a single system or distributed across multiple systems. Distributed components can operate sequentially or in parallel.
The above description of illustrated embodiments of the subject disclosure, including what is described in the Abstract, is not intended to be exhaustive or to limit the disclosed embodiments to the precise forms disclosed. While specific embodiments and examples are described herein for illustrative purposes, various modifications are possible that are considered within the scope of such embodiments and examples, as those skilled in the relevant art can recognize. For example, parts, components, steps and aspects from different embodiments may be combined or suitable for use in other embodiments even though not described in the disclosure or depicted in the figures. Therefore, since certain changes may be made in the above-described invention, without departing from the spirit and scope of the invention herein involved, it is intended that all of the subject matter of the above description shown in the accompanying drawings shall be interpreted merely as examples illustrating the inventive concept herein and shall not be construed as limiting the invention.
In this regard, while the disclosed subject matter has been described in connection with various embodiments and corresponding figures, where applicable, it is to be understood that other similar embodiments can be used or modifications and additions can be made to the described embodiments for performing the same, similar, alternative, or substitute function of the disclosed subject matter without deviating therefrom. Therefore, the disclosed subject matter should not be limited to any single embodiment described herein, but rather should be construed in breadth and scope in accordance with the appended claims below. For example, references to “one embodiment” of the present invention are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features.
In the appended claims, the terms “including” and “in which” are used as the plain-English equivalents of the respective terms “comprising” and “wherein.” Moreover, in the following claims, terms such as “first,” “second,” “third,” “upper,” “lower,” “bottom,” “top,” etc. are used merely as labels, and are not intended to impose numerical or positional requirements on their objects. The terms “substantially,” “generally,” and “about” indicate conditions within reasonably achievable manufacturing and assembly tolerances, relative to ideal desired conditions suitable for achieving the functional purpose of a component or assembly. Further, the limitations of the following claims are not written in means-plus-function format and are not intended to be interpreted as such, unless and until such claim limitations expressly use the phrase “means for” followed by a statement of function void of further structure.
What has been described above includes examples of systems and methods illustrative of the disclosed subject matter. It is, of course, not possible to describe every combination of components or methodologies here. One of ordinary skill in the art may recognize that many further combinations and permutations of the claimed subject matter are possible. Furthermore, to the extent that the terms “includes,” “has,” “possesses,” and the like are used in the detailed description, claims, appendices and drawings, such terms are intended to be inclusive in a manner similar to the term “comprising” as “comprising” is interpreted when employed as a transitional word in a claim. That is, unless explicitly stated to the contrary, embodiments “comprising,” “including,” or “having” an element or a plurality of elements having a particular property may include additional such elements not having that property. Moreover, articles “a” and “an” as used in the subject specification and annexed drawings should generally be construed to mean “one or more” unless specified otherwise or clear from context to be directed to a singular form.
This written description uses examples to disclose several embodiments of the invention, including the best mode, and also to enable one of ordinary skill in the art to practice the embodiments of invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to one of ordinary skill in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.
Further aspects of the invention are provided by the subject matter of the following clauses:
A method of ablating one or more holes in an article with a laser is provided. The method comprises an establishing step that establishes an ablation characteristic. The ablation characteristic includes a synchronized machine motion characteristic. An ablating step ablates the one or more holes with the laser based on the synchronized machine motion characteristic. The synchronized machine motion characteristic synchronizes a laser beam emitted from the laser with a location of the one or more holes.
The method of the previous clause, wherein the ablating step further comprises moving at least one of the article and the laser during the ablating step.
The method of any previous clause, wherein the ablating step further comprises moving the article during the ablating step.
The method of any previous clause, wherein the ablating step further comprises moving the laser during the ablating step.
The method of any previous clause, wherein the ablation characteristic also comprises at least one of, laser pulse width or pulse duration, laser frequency, laser pulse peak power, wavelength, average laser power, laser beam quality, repetition rate, pulse energy, laser spot size, and focal distance.
The method of any previous clause, wherein the laser pulse width is in a picosecond range, or within a 1 picosecond to 1,000 picosecond range, or within a 1 picosecond to 15 picosecond range.
The method of any previous clause, wherein laser operating parameters are at least one of, a repetition rate is in a range of 10 KHz to 10 MHz, an average laser power is in a range of 25 W to 250 W.
The method of any previous clause, wherein the synchronized machine motion characteristic includes at least one of a linear and a rotational acceleration, a linear and a rotational speed, and a field of view.
The method of any previous clause, further comprising moving at least one of the laser and the article when transitioning from a first working zone to a second working zone.
A system for ablating one or more holes in an article with a laser, the system comprising, a memory storing a set of machine motion synchronization data; and at least one processor executing instructions that cause the at least one processor to perform a series of steps. An establishing step establishes an ablation characteristic, and the ablation characteristic includes a synchronized machine motion characteristic. An ablating step ablates the one or more holes with the laser based on the synchronized machine motion characteristic. The synchronized machine motion characteristic synchronizes a laser beam emitted from the laser with a location of the one or more holes.
The system of the previous clause, wherein the ablating step further comprises, moving at least one of the article and the laser during the ablating step.
The system of any previous clause, wherein the ablating step further comprises, moving the article during the ablating step, or moving the laser during the ablating step.
The system of any previous clause, wherein the ablation characteristic also comprises at least one of, laser pulse peak power, laser pulse width, laser frequency, average laser power, center wavelength, average output power, pulse energy, output peak power, laser spot size, and focal distance.
The system of any previous clause, wherein laser operating parameters are at least one of, laser pulse width is in a picosecond range, or within a 1 picosecond to 1,000 picosecond range, or within a 1 picosecond to 15 picosecond range, a repetition rate is in a range of 10 kHz to 10 MHZ, average laser power is in a range of 25 W to 250 W.
The system of any previous clause, wherein the synchronized machine motion characteristic includes at least one of a linear and a rotational acceleration, a linear and a rotational speed, and a field of view.
The system of any previous clause, further comprising moving at least one of the laser and the article when transitioning from a first working zone to a second working zone.
A non-transitory, computer-readable medium storing instructions that, when executed by at least one processor, causes the at least one processor to perform a plurality of steps. An establishing step establishes an ablation characteristic, and the ablation characteristic includes a synchronized machine motion characteristic. An ablating step ablates one or more holes with a laser based on the synchronized machine motion characteristic. The synchronized machine motion characteristic synchronizes a laser beam emitted from the laser with a location of the one or more holes.
The non-transitory, computer-readable medium of the previous clause, wherein the ablating step further comprises, moving at least one of the article and the laser during the ablating step.
The non-transitory, computer-readable medium of any previous clause, wherein the ablating step further comprises, moving the article during the ablating step.
The non-transitory, computer-readable medium of any previous clause, wherein the ablating step further comprises, moving the laser during the ablating step.