Laser-assisted micromachining system and method
First Claim
1. A laser-assisted micro-milling system adapted to perform a machining operation on a workpiece material, the system comprising:
- a spindle disposed so that said spindle and said workpiece material define a workspace therebetween;
a micro-milling tool held by said spindle;
a laser generating a laser beam;
means for fixturing said micro-milling tool and said laser in fixed positions relative to each other during the machining operation performed by the system;
a beam expander optically aligned with said laser and expanding said laser beam generated thereby to yield an expanded laser beam;
a focusing element optically aligned with said beam expander and optically aligned with said laser via said beam expander for focusing said expanded laser beam to yield a focused laser beam having a fixed position that is fixed by said fixturing means relative to said micro-milling tool, said focusing element being optically aligned with a target spot on the workpiece material and substantially adjacent to a working end of said micro-milling tool such that the workpiece material is locally preheated by said focused laser beam prior to machining locally preheated workpiece material with a cutting section of said micro-milling tool;
first and second mirrors located at least partially within said workspace and positioned with respect to said spindle so as to optically align said focusing element and said target spot such that said focused laser beam from said focusing element is reflected away from the workpiece material by said first mirror onto said second mirror and reflected by said second mirror toward the workpiece material to said target spot, said second mirror being oriented so that a final stage path of said focused laser beam has an angle of incidence of less than 30 degrees with a perpendicular of a surface of the workpiece material, said angle of incidence being fixed by said fixturing means relative to said micro-milling tool; and
means for moving the workpiece material relative to said micro-milling tool and said focused laser beam as said locally preheated workpiece material is being machined by said cutting section of said micro-milling tool.
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Accused Products
Abstract
A novel apparatus and method for laser-assisted micro-milling. The disclosed laser-assisted micro-milling system and method provides unique micro-milling capabilities for very difficult-to-machine materials, such as ceramics, high temperature alloys and composites. A low power laser beam is focused at a very small spot, thus producing a very high power density, the spot being located just ahead of a mechanical micro-milling cutter to preheat the material prior to machining. This localized heating thermally weakens the workpiece resulting in lower cutting forces, improved surface finish, and longer tool life. The system is capable of micro-milling difficult-to-machine materials that may be conductive or non-conductive with high material removal rates compared to existing systems and methods.
31 Citations
22 Claims
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1. A laser-assisted micro-milling system adapted to perform a machining operation on a workpiece material, the system comprising:
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a spindle disposed so that said spindle and said workpiece material define a workspace therebetween; a micro-milling tool held by said spindle; a laser generating a laser beam; means for fixturing said micro-milling tool and said laser in fixed positions relative to each other during the machining operation performed by the system; a beam expander optically aligned with said laser and expanding said laser beam generated thereby to yield an expanded laser beam; a focusing element optically aligned with said beam expander and optically aligned with said laser via said beam expander for focusing said expanded laser beam to yield a focused laser beam having a fixed position that is fixed by said fixturing means relative to said micro-milling tool, said focusing element being optically aligned with a target spot on the workpiece material and substantially adjacent to a working end of said micro-milling tool such that the workpiece material is locally preheated by said focused laser beam prior to machining locally preheated workpiece material with a cutting section of said micro-milling tool; first and second mirrors located at least partially within said workspace and positioned with respect to said spindle so as to optically align said focusing element and said target spot such that said focused laser beam from said focusing element is reflected away from the workpiece material by said first mirror onto said second mirror and reflected by said second mirror toward the workpiece material to said target spot, said second mirror being oriented so that a final stage path of said focused laser beam has an angle of incidence of less than 30 degrees with a perpendicular of a surface of the workpiece material, said angle of incidence being fixed by said fixturing means relative to said micro-milling tool; and means for moving the workpiece material relative to said micro-milling tool and said focused laser beam as said locally preheated workpiece material is being machined by said cutting section of said micro-milling tool. - View Dependent Claims (2)
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3. A laser-assisted mechanical micro-milling system adapted to perform a machining operation on a workpiece material, the system comprising:
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a machine frame having a spindle mounted thereon; a micro-milling tool held by said spindle; a laser generating a laser beam; a fixturing plate mounted to said machine frame and fixturing said micro-milling tool and said laser in fixed positions relative to each other during the machining operation performed by the system; a beam expander optically aligned with said laser and expanding said laser beam generated thereby to yield an expanded laser beam; a focusing element optically aligned with said beam expander and optically aligned with said laser via said beam expander for focusing said expanded laser beam to yield a focused laser beam having a fixed position that is fixed by said fixturing plate relative to said micro-milling tool, said focusing element being optically aligned with a target spot on the workpiece material and substantially adjacent to a working end of said micro-milling tool such that the workpiece material is locally preheated by said focused laser beam prior to machining locally preheated workpiece material with a cutting section of said micro-milling tool; and a controlled stage mounted to said frame for moving the workpiece material relative to said micro-milling tool and said focused laser beam as said locally preheated workpiece material is being machined by said cutting section of said micro-milling tool. - View Dependent Claims (4, 7, 8, 9, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
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5. A laser-assisted micro-milling method for perform a machining operation on a workpiece material, the method comprising:
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positioning a spindle having a micro-milling tool mounted thereto so that said spindle and said workpiece material define a workspace therebetween; moving the workpiece material relative to said micro-milling tool; producing a laser beam; expanding said laser beam generated by said laser to yield an expanded laser beam; and focusing said expanded laser beam to yield a focused laser beam on a target spot on the workpiece material so as to locally preheat the workpiece material at said target spot and then machining locally preheated workpiece material with said micro-milling tool; wherein the focused laser beam is optically aligning with first and second mirrors located at least partially within said workspace and positioned with respect to said spindle such that said focused laser beam is reflected away from the workpiece material by said first mirror onto said second mirror and reflected by said second mirror toward the workpiece material and onto said target spot, said second mirror being oriented so that a final stage path of said focused laser beam has an angle of incidence of less than 30 degrees with a perpendicular of a surface of the workpiece material; and wherein said micro-milling tool and said focused laser beam are in fixed positions relative to each other and the workpiece material moves relative to said micro-milling tool and said focused laser beam during the machining operation. - View Dependent Claims (6, 10)
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Specification