This description relates to a magnetic production system, and more particularly to a continuous production system for magnetically processed materials.
Materials can be customized for specific applications by adjusting their properties. Magnetic treatment of materials can alter material characteristics. For example, magnetic treatment can be used to alter structural, magnetic, electrical, optical, acoustical, and tribological properties.
Magnetic treatment of materials can be applied in different forms as described next. Magnetic treatment can replace many existing treatments of materials. For example, hardening of materials, which is generally performed by heat treatment, can be done by magnetic treatment. For many materials, magnetic treatment can be used where other forms of treatment are not feasible. For example, alloys where solubility of certain materials is restricted due to thermodynamic limitations can be formed using magnetic treatments. In some applications, conventional heat treatment may not be useful to achieve desired material characteristics of microstructure and composition. Applications that require materials with particular strength, wear, ductility, and magnetic permeability may not be achievable by non-magnetic treatment such as heat treatment.
Magnetic treatment of materials has been used to vary material characteristics. Magnetic treatment can also be combined with existing treatment of materials to achieve specific material characteristics. For example, in U.S. Pat. No. 7,161,124 Kisner et al. describe techniques for altering characteristics of a workpiece which includes an electrically-conductive material. Further, the Kisner patent describes dual use of magnetic and thermal treatment on a workpiece to alter its material characteristics.
A material processing system for achieving specific material characteristics is described. Input materials or parts are treated in a magnetic field or a thermomagnetic zone. The magnetic field is of high strength, e.g., above 2 Tesla. The input materials or feed stock parts are continuously moved over a transport mechanism like a conveyor belt. The parts can be positioned in the treatment chamber using grips and can also be positioned using rotational, translational or other motion source. A quenching mechanism can be used to quench parts after the thermomagnetic treatment. The quenching mechanism can be integrated with the thermomagnetic processing system and the conveyor belt that moves the parts.
The feed stock 12 can be of different physical and structural forms. For example, feed stock 12 could be separate parts, linked parts, or continuous materials such as rods, bar stock, wire, plate, chain, sheet, etc. An example of the feed stock 12 could be steel (SAE 8600 series or other), that is magnetically treated using the system and process described here to achieve improvements in mechanical properties of a transmission gear formed using the steel feed stock. The transmission gear characteristics can be improved using magnetic treatment. For example, the gear's mechanical properties such tensile strength and wear can be improved by magnetic treatment.
Feed stock 12 can be sourced as a relatively lower cost material to achieve characteristics of relatively higher cost materials. For example, feed stock 12 can be relatively low cost steel, e.g., SAE 1215, which when magnetically treated in a continuous manner as described here yields improved characteristics of magnetic permeability, low magnetic coercivity and improved magnetic saturation that are comparable to more expensive grades of electrical steel.
Other examples of feed stock 12 that can be used are described next. For example, the feed stock 12 can be tool steel which when processed in a magnetic field will provide relatively superior temperature performance, e.g., improved creep resistance. In another example, the feed stock 12 can be stainless steel or cast iron that when continuously magnetically processed will yield better application performance for applications that use the treated stainless steel or cast iron. Other examples of alloys that can be treated include alloys of nickel, copper, and cobalt which when processed will generate unique microstructures and properties for a desired application.
The feed stock 12 can be a variety of materials, for example, the feed stock 12 can be ferrous or non-ferrous materials that can be treated magnetically to achieve desired characteristics for such materials. Feed stock 12 can be ferromagnetic, non-ferromagnetic, other magnetic state types, compounds, alloys, variable gradient materials, surface engineered gradient-compound materials, metals, non-metals, semiconductors, insulators, ceramics, engineered materials, nano-materials, composite materials, magnetic particle materials, crystalline and poly-crystalline materials having crystal plane orientation and anisotropic properties of materials, inorganic materials, organic and polymer materials, crystalline and amorphous materials, etc. Those skilled in the art will appreciate that above examples illustrate the use of continuous magnetic treatment described here, while other applications are also possible.
The treatment chamber 14 can be used to achieve magnetic or the other kinds of processing. The treatment chamber 14 can be used for magnetic, thermomagnetic, induction hardening, heat treatment, integrated, non-integrated, quenched or other kinds of standard material processing treatments. These treatments can be applied as stand-alone treatments or be used in combination with other treatments.
Magnetic treatment of the feed stock 12 is described next. Magnetic field processing of materials requires treating of target materials in a magnetic field. One approach to achieving the required magnetic field strength is by the use of electromagnets. Solenoid coils 16 form an electromagnet when the coils are energized. High magnetic fields, e.g., about 2 to 30 Tesla or higher, are used to alter material properties in the magnetic processing system 10. In one approach, such high magnetic field can be generated by a superconducting solenoid coil (cooled using a cryostat system). The feedstock 12 can be subject to pre-cleaning or other preparatory processes.
A treatment chamber 14 provides a chamber for magnetic treatment of the feed stock 12. The treatment chamber 14 includes solenoid coils 16 that generate magnetic field. The treatment chamber 14 includes mechanism to move the feed stock 12 through the treatment chamber 14. Any mechanism (not shown) can be used to move the feed stock 12 through the treatment chamber 14. For example, conveyors, worm-gear drives or linear actuators could be used. During the movement process, the feed stock 12 can be treated magnetically to alter its material properties. The feed stock 12 departs the magnetic chamber 14 as exit stock 18. The continuous treatment of the feed stock 12 through the treatment chamber 14 is used to alter the material properties of the feed stock 12 to achieve the exit stock 18.
The treatment chamber 14 forms part of an extraction system that continuously moves workpieces or samples of the feed stock 12 through the magnetic field. The extraction forces (not shown) can be up to 2000 pounds or more depending on: (1) the rate of passage of the materials or parts through the magnetic field, and (2) the strength of the magnetic field in the treatment chamber 14. The role of extraction forces is to overcome the magnetic field imposed on the part being processed. The extraction forces in the treatment chamber 14 will depend on sample geometry and size among other factors. Axial and cross-axis extraction forces would need to be controlled through continuous sample handling. Extraction forces can be supplied via electrical motor/actuation, hydraulic motor/actuation, or electro-hydraulic motor/actuation.
Continuous magnetic treatment processing reduces processing time as compared to treating each workpiece individually. This in turn leads to lower cost for treating materials or parts. Continuous magnetic treatment process as described here can be used to treat basic materials to create wires, rods and other such materials that facilitate further forming processes (e.g., forging, machining, bending, etc). The wires, rods and other such materials can be further treated magnetically in a continuous manner to improve formability. These improved materials and parts would require lower forming temperatures, lower energy consumption and longer tool life. Another example would be continuous billet casting process that uses the continuous magnetic treatment system described here. The billets casted with magnetic treatment will reduce segregation of inclusions and provide relatively more uniform microstructure and isotropic mechanical properties of the billets.
Alloys where solubility of some elements is restricted due to thermodynamic limitations can be made under the continuous magnetic processing described here. However, in certain cases where temperatures exceed the Curie temperatures in field operations, the magnetic treatment is inapplicable. The continuous magnetic treatment can be combined with or used in conjunction with other standard deformation methods, hardening methods, post treatment methods, etc, operating under a magnetic field or outside the magnetic field.
The thermomagnetic system 24 continuously provides twin treatments of thermal and magnetic forces to the representative parts 22a-22c as described next. Temperatures for induction hardening, induction heating and phase transformation within thermomagnetic processing can range from low temperatures (e.g, about 200 degree Fahrenheit) for quench mechanism, tempering, low temperature transformation or low temperature thermomagnetic transformation, to high temperatures (e.g, about 2000 degree Fahrenheit) for thermomagnetic transformations. The thermomagnetic system 24 can be used for processing cryogenic temperatures in combination with cryo-treatment of the materials. This cryogenic treatment can be applied for both ferrous and non-ferrous materials.
A conveyor 26 moves the parts 22a-22c through the thermomagnetic system 24. Those skilled in the art will appreciate that the conveyor 26 is only illustrative of different mechanisms that can be used to transport the parts 22a-22c through the thermomagnetic system 24. The conveyor 26 moves the parts 22a-22c continuously through the thermomagnetic system 24, which process the parts 22a-22c continuously through a magnetic fields and heated zones or areas.
The representative parts shown here, 22a-22c, are shown as cylinders for exemplary purpose, any other kind of parts can be processed through the thermomagnetic system 24. The exemplary parts 22a-22c show how relatively smaller parts can be continuously processed in the thermomagnetic processing system 24. As the parts 22a-22c exit through the thermomagnetic processing system 24's magnetic field, magnetic forces that were operating on the parts 22a-22c are overcome. The thermomagnetic processing system 24's magnetic field can be generated using a superconducting magnet (not shown). The superconducting magnet's magnetic field would keep the part at the center of that field through that magnetic force. Therefore, extraction forces are required and are provided by the conveyer mechanism to move that part out of the magnetic field area.
Control of heat treatment enables creation of materials with variable properties in their different dimensions. Certain applications require complex heat treatment, e.g., having different hardness in different regions of a part. For example, a gear (not shown) can require certain hardness for its teeth on the OD (Outer Diameter) and different hardness for splines on the ID (Inner Diameter). The thermomagnetic system 24 can include induction coils (not shown) that enable treatment to create parts like the last mentioned gear with variable hardness mentioned last using different frequencies.
The thermomagnetic system 24 can be used for continuous treatment of surface coatings and coated deposits. For example, some of the surface coating treatments that can be continuously treated are: Chemical Vapor Deposition (CVD), Physical Vapor Deposition (PVD), laser deposition, plasma transfer arc deposition, plating, plasma deposition, evaporation deposition, sputtering, ion beam deposition, reactive plasma deposition, or chemical beam epitaxial deposition. Surface coating treatment can be done as a function of the heat treatment, thermomagnetic processing or magnetic processing. For example, treatment of the surface coating could be a coating that gets transformed for improved performance (wear, ductility, lubricity, etc.). Those skilled in the art will appreciate that the surface coatings mentioned here are exemplary and other surface coating treatment using the continuous treatment are possible.
The conveyor 26 supports teeth 34 that engage with locking teeth 36. The locking teeth 36 support the rod 30. The teeth 34 and locking teeth 36 together form an interlocking system that is used to transport the rod 30 through the thermomagnetic system 24. During the transport, the rod 32 gets magnetically treated to alter its characteristics. The speed of movement of the conveyor 24 is controlled by the interlocking teeth mechanism formed by the teeth 34 and the locking teeth 36. The mechanically engaged magnetic treatment system 32 overcomes the magnetic forces through extraction forces as the rod 30 is transported out of the thermomagnetic system 24. The role of extraction forces is to overcome the magnetic field imposed on the part being processed. The rod 30 needs to be clamped, held or attached to the conveyor 26 so that it can be extracted from the magnetic field. If the rod 30 is not so clamped, held or attached to the conveyor 26, then to remove it from the magnetic field, the magnetic field will have to be switched-off. Hence, by clamping, holding or attaching the rod 30 to the conveyor 26 continuous magnetic or thermomagnetic processing can be achieved.
The forces for translational, rotational, gripping or other workpiece manipulation can be provided by electric motor, electrical actuation, electro-hydraulic actuation, hydraulic actuation, etc. The forces provided by such sources can be used to orient the rod 30 or similar workpiece in various angles, directions or positions to achieve targeted treatment for the desired material characteristics. The forces for translational, rotational, gripping enable the workpieces to be extracted out of the magnetic field of the magnetic treatment system 38. The magnetic treatment system 38 can be used in conjunction with a thermal treatment system (not shown) to provide thermomagnetic treatment. The thermal treatment can be provided simultaneously with the magnetic treatment of the magnetic treatment system 38 or sequentially.
Workpiece handling described above enables specific material properties to be engineered in the workpieces. For example, rotational and/or translational manipulation of the workpiece in the magnetic field described above allows hardening and treatment of gear teeth, filet features, wear areas, ductile areas, surface treatment, bulk treatment on relatively complicated geometry workpieces
Quenching process is used in conjunction with the combined heat and magnetic treatment of the exemplary rod 30 workpiece as described next. The quenching mechanism 50 is shown in a horizontal orientation. However, a vertical quenching mechanism is also possible with the thermomagnetic system 24, the conveyor 26, the quenching transporters 52a-52b and the sprinklers 54a-54b being oriented vertically as contrasted with the horizontal orientation shown in the
The placement of the quenching transporters 52a-52b and sprinklers 54a-54b within the quenching system 48 will depend on the configuration as described next. The quenching transporters 52a-52b and the sprinklers 54a-54b can be located at different positions in the quenching system 48. For example, they can be located in-situ with the thermomagnetic system 24, in a magnetic field associated with thermomagnetic processing (See
Temperature and magnetic profile can be varied along the continuous movement of the workpieces (shown here as the exemplary rod 30) on the conveyor 26. This enables proper transformation of the workpiece properties. Further, quenching process can be controlled with rapid or slower cooling to attain specific material properties in the workpieces. Continuous processing involves controlling movement rates and speeds of the workpieces through the temperature zones and magnetic profiles for specific times to provide the desired treatment characteristics.
Various aspects of the invention have been described in the foregoing specification, and it is believed that various alterations and modifications of the invention will become apparent to those skilled in the art from a reading and understanding of the specification. It is intended that all such alterations and modifications are included in the invention, insofar as they come within the scope of the appended claims.
This application is a U.S. National Stage Entry under 35 U.S.C. §371 of PCT/IB2009/006118 (now published as WO2010/001223 A1) filed on Jun. 30, 2009, which claims priority from U.S. Provisional Patent Application No. 61/133,540, filed on Jun. 30, 2008. Both priority applications are incorporated by reference herein in their entirety
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/IB2009/006118 | 6/30/2009 | WO | 00 | 3/1/2011 |
Number | Date | Country | |
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61133540 | Jun 2008 | US |