• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    Laser processing systems and methods are capable of moving a laser beam (110) while maintaining consistent laser beam characteristics at processing locations. The laser processing systems (120) produce a collimated laser beam having a constant Z-direction power density along at least a portion of a length of the laser beam and dithering the collimated laser beam in the X or Y direction. By dithering the collimated laser beam, a consistent laser processing on a three-dimensional surface is made possible, for example to provide a consistent application of a coating in a laser cladding process. A laser processing system may include a beam transmission system (130) that provides both collimation and dithering of the collimated laser and adjustment of the beam diameter of the collimated beam.
    公开号:CH710428B1
    申请号:CH00403/16
    申请日:2014-09-24
    公开日:2018-07-31
    发明作者:Leo Dallarosa Joseph；Amar Ben；Squires David
    申请人:Ipg Photonics Corp；
    IPC主号:
    专利说明:

    description
    FIELD OF DISCLOSURE The present invention relates to laser machining, and more particularly, to laser machining systems and methods that can dither a laser beam while maintaining uniform laser beam properties at machining locations, such as on a three-dimensional surface of a workpiece.
    Discussion of the General Prior Art Lasers are generally used to machine substrates or base materials (hereinafter referred to as workpieces) using a variety of different techniques. An example of laser processing is a laser cladding process in which the laser is used to heat the workpiece sufficiently to allow another material to adhere to the surface of the workpiece and thereby apply a coating to the surface of the workpiece. In one type of laser deposition welding process, powder particles are entrained in a rapidly flowing gas stream, which enables the particles to hit the workpiece in the heated area in such a way that the particles adhere through plastic deformation and bonding. Examples of the laser cladding process are described in even greater detail in international patent applications No. WO 2013/061 085 and No. WO 2013/061 086, which are incorporated into the present document by reference. Other examples of laser processing are laser beam welding and laser material removal or laser cleaning.
    One of the challenges in laser machining is the difficulty in moving the laser beam in a manner that allows the machining of more complex surfaces (e.g. three-dimensional surfaces) on work pieces while maintaining the desired properties of the laser beam (e.g. power density). With existing laser processing systems, it is not possible to move the laser beam with the desired response time and bundling. Laser processing systems that move the entire laser head, for example, do not provide a relatively fast response time. Some existing laser cladding systems simply scan in one direction, which takes longer and may not be effective on complex three-dimensional surfaces such as turbine blades.
    In addition, existing laser processing systems often focus the beam in such a way that the power density varies along the Z-axis of the beam. With a focused beam, the power density can vary significantly at different locations along the length of the beam because the power density is inversely proportional to the square of the radius of the light spot. The movement of the laser beam and / or the processing of three-dimensional surfaces thus leads to a considerable change in the laser beam properties, such as, for example, the power density, at different processing points on the workpiece, as a result of which the continuity of the laser processing is adversely affected. Galvo scanners have been used to scan laser beams in laser cladding systems, but it is often not possible with the systems that the beam maintains a constant power density at the processing points. For example, in certain laser deposition welding processes, the temperature profile provided by the laser before the powder should be precisely controlled. Changing the power density of the laser beam can change the temperature profile and prevent the coating from being applied with the desired continuity.
    Accordingly, there is a need for laser machining systems and methods that are capable of moving the laser beam while maintaining consistent laser beam properties at machining locations, for example on a three-dimensional surface of a workpiece.
    Summary [0006] In one embodiment, a method for laser machining a workpiece is provided. The method includes generating a collimated laser beam with a constant power density in the Z direction along at least a portion of a length of the collimated laser beam, aligning the collimated laser beam to a workpiece to form a light spot on the workpiece, moving the workpiece so that the light spot enables machining on the surface of the workpiece while the workpiece is moving, and dithering the collimated laser beam along the X or Y axis in such a way that the light spot is dithered on the workpiece while the workpiece is moving ,
    According to a further embodiment, a laser processing system comprises a glass fiber laser system and a beam transmission system, which are optically connected to a glass fiber laser output of the glass fiber laser system. The beam transmission system includes collimation lenses to generate a collimated laser beam, at least one of the collimation lenses being movable in the Z direction to change a diameter of the collimated beam. The laser processing system also includes a mechanism for moving the fiber optic laser output relative to the collimating lenses to dither the collimated laser beam in the X or Y direction, a workpiece carrier for carrying and moving a workpiece, and a motion control system for controlling the movement of the workpiece carrier and the mechanism, to move the fiber optic laser output relative to the collimation lenses.
    CH 710 428 B1 According to a further embodiment, an optical head comprises a housing, a glass fiber laser connection for connecting a glass fiber laser output to the housing at one end of the housing and a beam transmission system which is housed in the housing and is optically connected to the glass fiber laser output. The beam transmission system comprises first and second collimation lenses for providing a collimated laser beam and a last collimation lens for providing a final collimation of the collimated laser beam. At least one of the first and second lenses is movable in the Z direction to change a diameter of the collimated laser beam. The optical head further includes an X-Y stage of optics housed in the housing and carrying the collimating lenses for movement in the X and Y directions.
    According to one embodiment, an application of the method for laser processing is provided as a laser build-up welding process in order to apply a build-up welding layer to a workpiece. The laser deposition welding process includes generating a collimated laser beam that has a constant power density in the Z direction along at least a portion of a length of the collimated laser beam, aligning the collimated laser beam on a workpiece to form a spot on the workpiece, and aligning an overlay weld material the workpiece such that the surfacing material strikes the surface of the workpiece in an area heated by the light spot, and moving the workpiece such that the surfacing material forms an overlay layer on the surface of the workpiece while the workpiece is moving.
    According to a further embodiment, the use of a laser cladding system comprises a glass fiber laser system and a beam transmission system, which are optically connected to a glass fiber laser output of the glass fiber laser system. The beam transmission system includes collimation lenses to generate a collimated laser beam, at least one of the collimation lenses being movable in the Z direction to change a diameter of the collimated beam. The laser cladding system also includes a mechanism for moving the fiber optic laser output relative to the collimating lenses to dither the collimated laser beam in the X or Y direction, a workpiece carrier for carrying and moving a workpiece, and a motion control system for controlling the movement of the workpiece carrier and the mechanism, to move the fiber optic laser output relative to the collimation lenses. The laser build-up welding system further comprises a powder transfer system for transferring build-up welding powder to the workpiece such that the build-up welding powder hits the surface of the workpiece in an area that is heated by the collimated laser beam.
    According to a further embodiment, use of the optical head as an integrated optical laser welding head comprises a housing, a glass fiber laser connection for connecting a glass fiber laser output to the housing at one end of the housing and a beam transmission system which is housed in the housing and is optically connected to the glass fiber laser output , The beam transmission system comprises first and second collimation lenses for providing a collimated laser beam and a last collimation lens for providing a final collimation of the collimated laser beam. At least one of the first and second lenses is movable in a Z direction to change a diameter of the collimated laser beam. The integrated optical laser deposition welding head further comprises an X-Y stage of optics, which is accommodated in the housing and carries the collimation lenses for movement in the X and Y directions. The integrated optical laser build-up welding head further comprises a powder transfer system, which has a powder transfer nozzle attached to the housing and is intended for transferring build-up welding powder to the workpiece in such a way that the build-up welding powder hits the surface of the workpiece in an area which is heated by the collimated laser beam.
    Brief Description of the Drawings These and other features and advantages will be better understood from the following detailed description in conjunction with the drawings. It shows:
    1A shows a laser processing system in a schematic perspective view and a method for dithering a collimated laser beam on a three-dimensional surface of a workpiece according to embodiments of the present disclosure;
    1B shows a laser light spot on the workpiece shown in FIG. 1A in a schematic plan view;
    Fig. 1C in a schematic side view of a collimated laser beam, which is shown in Fig. 1A
    Workpiece moves and has a constant power density in the Z direction;
    2A-2D illustrate examples of laser machining patterns formed by dithering a laser light spot on a workpiece while providing coordinated movement of the workpiece, in accordance with embodiments of the present disclosure;
    3A is a schematic perspective view of a laser processing system that includes a beam transmission system for providing a collimated laser beam that can be dithered by moving optics, in accordance with some aspects of the present disclosure;
    CH 710 428 B1
    3B is a schematic perspective view of a laser processing system that includes a beam transmission system for providing a collimated laser beam that can be dithered through a movable glass fiber laser output, according to further embodiments of the present disclosure;
    4 shows a perspective view of an embodiment of the beam transmission system for providing a collimated laser beam that can be dithered;
    FIG. 5 shows the beam transmission system shown in FIG. 4 in a side view;
    FIG. 6 shows the beam transmission system shown in FIG. 4 in a second cross-sectional view;
    7 shows a schematic side view of a laser cladding welding system which has a beam transmission system for providing a collimated laser beam capable of dithering, according to embodiments of the present disclosure;
    8 shows a perspective view of an embodiment of an integrated optical laser deposition welding head for use in a laser deposition welding system;
    9 shows the integrated optical laser deposition welding head shown in FIG. 8 in a partial side cross-sectional view;
    FIG. 10 shows an integrated optical head in the integrated optical laser deposition welding head shown in FIG. 9 in a bottom view; FIG.
    11 shows the integrated optical laser deposition welding head in a cross-sectional view along the line
    XI-XI of Fig. 9;
    12 shows the integrated optical laser deposition welding head in a cross-sectional view along the line
    XII-Xll of Fig. 9;
    13 is a perspective view of an embodiment of a laser cladding welding system that the in
    8-12 shows an integrated optical laser deposition welding head, fastened in a housing together with a workpiece carrier.
    Detailed Description Laser processing systems and methods according to the embodiments described herein are capable of moving a laser beam while maintaining consistent laser beam properties at machining sites. The laser processing systems generate a collimated laser beam that has a constant power density in the Z direction along at least a portion of a length of the laser beam, and dither the collimated laser beam in the X or Y direction. The dithering of the collimated laser beam enables constant laser processing on a three-dimensional surface, for example in order to provide a constant application of a coating in a laser deposition welding process. A laser processing system may include a beam transmission system that provides both collimation and dithering of the collimated laser and adjustment of the beam diameter of the collimated beam.
    The laser processing systems and methods according to the configurations described herein can be used for a whole range of applications and three-dimensional surfaces. Laser processing applications include, for example, laser deposition welding, laser beam welding, laser cleaning, material removal, surface hardening and machining (e.g. scribing, cutting or shaping). Workpieces with three-dimensional surfaces that can be machined include, but are not limited to, turbine blades, valve seats, and pipes.
    As used herein, "collimated laser beam" refers to a laser beam that has a relatively low beam divergence (eg, a beam with a diameter of 10 mm and a divergence less than or equal to 1 mrad) so that the radius of the beam is none is subject to significant changes within moderate range distances. A “collimated laser beam” does not require an exact or perfect collimation with zero divergence. As used herein, "constant power density in the Z direction" refers to power per area of a laser beam that does not vary more than ± 6% along a Z axis of the laser beam in a 300 mm working area. A “constant power density in the Z direction” does not require a power density that is exactly the same along the Z axis of the beam. As used herein, "workpiece" refers to an object or objects that are processed by a laser beam; the term can include several objects that are processed together (e.g. by welding together). As used herein, "three-dimensional surface" refers to a non-flat surface that extends in the X, Y, and Z directions. As used herein, "dithering" refers to the reciprocation of a laser beam over a relative
    CH 710 428 B1 short distance (e.g. ± 10 mm or less) along an axis while the beam remains substantially perpendicular to the workpiece.
    1A-1C, a collimated laser beam 110 is used in a laser processing method and a laser processing system 100 according to the configurations described herein in order to process a workpiece 102, for example with a three-dimensional surface 104. The laser processing system 100 generally includes a laser system 120 that generates a laser output and a beam transmission system 130 that collimates the laser output coming from the laser system 120 and transmits the collimated laser beam 110 to the workpiece 102. The laser processing system 100 may further include a workpiece carrier 140 that can hold or carry a workpiece and can move the workpiece 102 during laser processing. The workpiece carrier 140 may further include linear and / or rotating stages that can move the workpiece 102 in several different directions.
    The collimated laser beam 110 is directed onto the surface 104 of the workpiece 102 and forms a light spot 112 on the surface 104, as shown in FIG. 1B. The energy emitted by the laser beam 110 at the light spot 112 is used to process the surface 104 of the workpiece 102, for example by heating the workpiece sufficiently so that build-up welding material adheres or material is welded or removed. In one example, the collimated laser beam 110 has a Gaussian beam profile. The laser wavelength, the beam power, the beam power density and the beam profile can change and generally depend on the application, the material or materials of the workpiece and / or other materials used in laser processing.
    The collimated laser beam 110 provides a constant power density in the Z direction in order to maintain constant laser beam properties at different processing locations, for example at different locations on the three-dimensional surface 104 that are touched by the laser light spot 112. As shown in FIG. 1C, the collimated laser beam 110 with the light spot 112 at one processing point essentially provides, for example, the same power density on the surface 104 of the workpiece 102 as a collimated laser beam 110a with a light spot 112a at another processing point. In an example with a beam diameter of 2 mm and a power of 6 kW, the power density would be approximately 191 kW / cm 2 . In this example, the power density of the collimated laser beam 110, 110a at the processing point of the light spot 112 and at the processing point of the light spot 112a should be approximately 191 kW / cm 2 . Thus, the collimated laser beam 110 can provide a constant power density in the Z direction over a relatively long working distance, thereby offering an advantage over laser processing systems that use a focused beam with a power density that changes significantly along the Z axis of the beam.
    The laser system 120 may include a laser of any suitable wavelength and power to provide the desired laser processing. In particular, laser system 120 may include a fiber optic laser that is capable of generating a laser beam with a relatively high power. In one example of a laser cladding system, laser system 120 includes an ytterbium glass fiber laser system that is capable of generating a laser beam with a wavelength of 1.07 pm and an output power in the range of 500 W to 50 kW, such as the YLS-3000CT by IPG Photonics Corporation. For most applications, laser system 120 provides a continuous wave laser output (CW laser output), although modulated or pulsed lasers can be used for some laser processing applications, for example to provide a textured surface.
    The collimated laser beam 110 may be dithered along the X-axis or Y-axis, as indicated by the arrows, to allow laser processing in multiple directions and along multiple axes. For example, in a laser cladding application, dithering can be used to provide a desired temperature profile in a wider area of the workpiece 104 before the cladding powder is applied to the workpiece. The dithering of the collimated laser beam 110 can also be used to enable a continuous multi-directional cladding process. In a laser beam welding application, dithering can be used to allow welding over an area that is wider than the beam diameter. The direction, the speed and the extent of the dithering can vary depending on the application and / or shape of the surface 104 of the workpiece 102. In one example, dithering can be provided in a range of ± 10 mm with a relatively fast response time from 10 Hz to 100 Hz. As will be described in more detail below, the beam transmission system 130 can include various types of mechanisms for dithering the collimated laser beam 110.
    The diameter of the collimated laser beam 110 (and thus the diameter of the light spot 112) can also be changed, for example for different machining applications, for different workpieces or for different areas on a single workpiece. For example, as shown in FIG. 1B, the diameter of the collimated beam 110 may be increased to provide a light spot 112b with a larger diameter. In one example, the diameter can be changed in a range from approximately 2 mm to 10 mm. As will be described in more detail below, the beam transmission system 130 may further include collimation optics that are capable of changing the diameter of the collimated laser beam 110.
    The workpiece carrier 140 may also be able to move the workpiece 102 along the X-axis, the Y-axis and / or the Z-axis and / or to rotate the workpiece 102 about one of these axes. Laser processing5
    CH 710 428 B1 system 100 further includes a motion control system 150 to control the dithering of the collimated laser beam 110 and / or the movement of the workpiece 102. The motion control system 150 may include any type of programmable motion control system (e.g., a programmed computer) that is used to control linear and / or rotating stages. The dithering of the collimated laser beam 110 and the movement of the workpiece 102 can be coordinated by the motion control system 150 to produce a variety of laser machining patterns (i.e., other than straight lines) on the surface 104 of the workpiece 102.
    Examples of patterns that can be generated by dithering the collimated laser beam 110 with a coordinated movement of the workpiece 102 are illustrated in FIGS. 2A-2D. As shown in FIG. 2A, the laser beam can be dithered to move the light spot 112 in the direction of arrow 108 while the workpiece is moving in the direction of arrow 106 to form a serpentine pattern. This type of pattern can be used in a welding application, for example to bridge the gap between two objects that are welded together (e.g. thick plates that are butt welded). In other words, the dithering causes the light spot 112 to move over the gap in such a way that the base material is drawn into the weld seam. FIG. 2B shows a further modification of this snake-like pattern, in which the extent of the dithering in the direction of the arrow 108 is gradually increased while the workpiece is moving in the direction of the arrow 106. The extent of dithering can also be changed in other ways to create other variations of this pattern.
    As shown in Fig. 2C, the laser beam can be dithered to move the light spot 112 in the direction of arrow 108 or arrow 109 while the workpiece is being moved in the direction of arrows 106,107 to form a spiral or vortex-shaped pattern form. This type of pattern can be used in a laser deposition welding application, for example to apply a coating that starts in the middle of the workpiece and then works outwards. In other words, this type of pattern can be used advantageously to apply a multi-directional coating with a relatively continuous motion, rather than using the conventional one-way raster pattern where the system must be stopped and followed up. 2D shows a further modification of a pattern from a series of circles formed by dithering the beam in the direction of arrow 108 or arrow 109 while the workpiece is being moved in the direction of arrows 106, 107. The dithering of the collimated laser beam thus enables patterns that dynamically provide a build-up coating on a large number of different types of surfaces, including three-dimensional surfaces.
    3A and 3B show different configurations of a laser processing system 300, 300 'with different mechanisms for dithering an adjustable collimated laser beam 310. In both laser processing systems 300, 300', the beam transmission system 330 comprises collimation lenses 332, 334, 336. A pair of adjustable ones Lenses 332, 334 (e.g., as used in a telescope assembly) provides a collimated beam 310, the diameter of which can be adjusted by moving one or both lenses 332, 334. A final collimation lens 336 is fixed and provides the final collimation of the collimated laser beam 310. In one example, the first collimation lens 332 is adjustable in a range of approximately 8 mm and the second collimation lens 334 is adjustable in a range of approximately 40 mm in order to provide an adjustability of the beam diameter in a range of approximately 2 mm to 10 mm , In one example, the first collimation lens 332 may be a convex lens and the second collimation lens 334 may be a concave lens. Other types of lenses capable of collimating the laser beam can also be used.
    In one embodiment, shown in Fig. 3A, the adjustable collimated laser beam 310 is dithered by moving the optics of the beam transmission system 330 without moving the fiber optic laser output. In this configuration, the optics of the beam transmission system 330 are moved by moving a support structure 331 which carries the collimation lenses 332, 334336. In particular, the support structure 331 is attached to an X-Y stage 360 of the optics, which provides a linear movement along the X and Y axes and thereby causes the linear movement of the collimation lenses 332, 334, 336 along the X and Y axes.
    A fiber optic laser termination block 324 is optically connected to the beam transmission system 330 through a termination block connector 326 and attached so that the collimating lenses 332, 334, 336 move without the fiber optic laser output moving. Moving the collimating lenses 332, 334, 336 in a direction either along the X-axis or the Y-axis relative to the glass fiber laser output causes the output of the collimated laser beam 310 output by the beam transmission system 330 to optically in moves an opposite direction along the X-axis and the Y-axis, respectively. The X-Y stage 360 of the optics moves the collimation lenses 332, 334, 336, for example, in an area sufficient to move the collimated laser beam 310 in an area of ± 10 mm. If only the optics are moved without the entire head including the glass fiber laser output being moved, the collimated laser beam 310 can be dithered with a relatively fast response time.
    In a further embodiment, which is shown in Fig. 3B, the adjustable collimated laser beam 310 is dithered by moving the glass fiber laser output directly without moving the optics. The fiber optic laser output can be moved directly by moving a termination block 324 that terminates an optical fiber laser, or by moving an termination block connector 326 that connects the termination block 324 to the beam transmission system 330. In this embodiment, an X-Y stage 328 of the fiber optic output is connected to either the termination block 324 or the termination block connector 326 to provide the motion that causes the dithering of the fiber optic output from the termination block 324. In one example, the degree6
    CH 710 428 B1 block 324 around a quartz block and with the termination block connection 326 around a quartz block holder connection (QBH connection). In one example, the X-Y stage 328 of the fiber optic laser output includes one or more piezoelectric motors or actuators (PZT motors or actuators). Thus, if the termination block 324 or termination block connector 326 is moved to directly move the fiber optic laser output, an even faster response time can be provided.
    The dithering of the collimated laser beam 310 by exclusively moving the optics or by exclusively moving the glass fiber laser output, as described above, also helps to maintain the collimation of the beam during processing. Thus, the constant power density in the Z direction of the collimated laser beam 310 can be maintained when the laser beam is dithered during processing. Even if the illustrated embodiments are capable of dithering in the X direction or in the Y direction, stages can be used in further embodiments which provide linear movement only along one axis.
    [0030] In both configurations, the dithering of the collimated laser beam 310 can be coordinated with the movement of the workpiece 302. In the system shown in FIG. 3A, a motion control system 350 is connected to an XY stage 340 of the workpiece carrier and to the XY stage 360 of the optics to control the movement of the stages 340, 360 and the dithering of the collimated laser beam 310 with the Coordinate movement of workpiece 302. In the system shown in FIG. 3B, a motion control system 350 is connected to both the XY stage 338 of the fiber optic laser output and the XY stage 340 of the workpiece carrier to control the movement of the stages 338, 340 and the dithering of the collimated laser beam 310 coordinate with the movement of workpiece 302.
    4-6, an embodiment of a beam transmission system 430 with movable optics will now be described in detail. The beam transmission system 430 comprises a support structure 431, which supports the collimation lenses 432, 434, 436. The collimation lenses 432, 434, 436 are secured in frames and carried by the support structure 431 in such a way that the collimation lenses 432, 434, 436 are aligned such that the laser beam can pass through from the first collimation lens 432 to the last collimation lens 436. As illustrated in this embodiment, the first and second adjustable lenses 432, 434 may include water-cooled lenses to prevent gaps due to laser energy.
    The support structure 431 is supported on a linear X-Y step 460 to allow movement in the X-Y direction as described above. Linear X-Y stage 460 includes a first direction linear actuator 462 to provide linear movement in the X direction and a second direction linear actuator 464 to provide movement in the Y direction. In the illustrated embodiment, linear actuators 462, 464 include a carriage that slides along a motorized lead screw. In further embodiments, the linear actuators can include any type of actuator capable of providing linear motion with the desired response time, including, but not limited to, a linear motor or a piezoelectric (PZT) motor.
    The adjustable collimation lenses 432, 434 are attached to Z-axis carriages 433 and 435 for movement in the Z direction. The Z-axis carriages 433, 435 are slidably supported by the support structure 431 and moved by the linear actuators 437 and 439, respectively, which are attached to the support structure 431 (see FIG. 6). In the illustrated embodiment, the linear actuators 437, 439 comprise motorized lead screws. In other configurations, other types of linear actuators can be used.
    Referring to FIG. 7, a laser cladding system 700 according to embodiments of the present disclosure is shown and described. The laser build-up welding system 700 comprises a build-up material transmission system 770, which is attached to an optical housing 780, which encloses a beam transmission system 730, as described above, for example. The output fiber 722 of an optical fiber is connected to the optical housing 780 with an end block connector 726 such that the optical fiber output (i.e., an optical fiber end block 724) is aligned with and optically connected to the beam transmission system 730 in the optical housing 780.
    In this embodiment, the application material transfer system 770 comprises a nozzle 772 for transferring an application powder material together with a high-speed gas to the workpiece, as described, for example, in the international patent applications publication numbers WO 2013/061 085 and WO 2013/061 086, which are described by reference in this document is inserted. The application material transfer system 770 is connected to a powder transmission line 774 and a gas transmission line 776 to supply the application powder material or gas. In other configurations, the application material transfer system can be configured to transfer other forms of application material, such as a wire.
    The optical housing 780 also encloses an X-Y stage 760 of the optics in order to move the beam transmission system 730 in the X direction or Y direction as described above. Alternatively, the housing 780 can enclose an X-Y stage 728 of the fiber optic laser output to move either the fiber termination block connector 726 or the fiber termination block 724. A motion control system 750 may control the movement of the X-Y stage 760 of the optics or the X-Y stage 728 of the fiber optic laser output to control the movement of the workpiece 702 in coordination with the dithering of the collimated laser beam 710 as discussed above.
    CH 710 428 B1 In operation, the beam transmission system 730 can direct the collimated laser beam 710 onto the workpiece in front of the powder material and can be dithered to provide a desired temperature profile on the workpiece 702. The collimated laser beam 710 can also be dithered in coordination with the movement of the workpiece 702 on the workpiece 702 in order to apply the coating in different patterns, which, for example, enable the deposition welding on three-dimensional surfaces.
    With reference to FIGS. 8-12, an embodiment of an integrated optical laser welding head 800 will now be described in detail. The integrated optical laser application welding head 800 comprises an application powder transmission system 870, which is attached at an angle 871 to an optical housing 880, which encloses a beam transmission system 830 (see FIG. 11). In this embodiment, beam transmission system 830 includes movable optics for dithering a collimated laser beam, as shown in FIGS. 4-6 and described above. A quartz block holder connector (QBH connector) 826 is connected to the optical housing 880 such that a quartz block 824 is aligned with and optically connected to the beam transmission system 830 (see FIG. 11). A sacrificial window 882 is located at the opposite end of the optical housing 880 to allow the collimated laser beam to be directed out of the optical housing 880 onto a workpiece.
    The applicator powder transfer system 870 includes a nozzle 872 for transferring the applicator powder material along with a heated gas at high speed. Although the nozzle 872 is fixed relative to the optical housing 880, the dithering of the collimated laser beam provided by the beam transmission system 830 enables the laser beam to be moved relative to the powder hitting the workpiece.
    In this embodiment, a monitoring system housing 890 is also attached to the optical housing 880. The monitoring system housing 890 encloses monitoring systems for monitoring the surfacing, such as a pyrometer for monitoring the temperature of the processing area.
    As shown in Fig. 13, the integrated optical laser build-up welding head 800 can be fixed in a housing 899 relative to a workpiece carrier 840 which carries and moves a workpiece. In the illustrated embodiment, workpiece carrier 840 is a robot arm that can rotate the workpiece and move the workpiece in the X, Y, and Z directions. Thus, the integrated optical laser deposition welding head 800 remains attached while the workpiece is being moved by the workpiece carrier 840 and / or the collimated laser beam is dithered in the optical housing 880.
    Accordingly, laser processing systems and methods according to the embodiments described herein are capable of processing more complex three-dimensional surfaces by dithering the laser beam while maintaining consistent laser beam properties at processing locations.
    While the principles of the invention have been described herein, it will be understood by those skilled in the art that this description is given by way of example only and does not limit the scope of the invention. In addition to the exemplary configurations which are shown and described here, further configurations are conceivable within the scope of the present invention. Changes and replacements by those of ordinary skill in the art are deemed to be within the scope of the present invention, which should not be limited except as by the following claims.
    权利要求:
    Claims (40)
    [1]
    claims
    1. A method for laser machining a workpiece, which comprises:
    Generating a collimated laser beam with a constant power density in the Z direction along at least a section of a length of the collimated laser beam,
    Directing the collimated laser beam onto a workpiece to form a light spot on the workpiece, moving the workpiece such that the light spot enables machining on the surface of the workpiece while the workpiece is moving, and
    Dithering the collimated laser beam along the X or Y axis such that the light spot on the workpiece is dithered while the workpiece is being moved.
    [2]
    2. The method of claim 1, wherein generating the collimated laser beam comprises directing a laser output through at least two collimation lenses.
    [3]
    3. The method according to claim 2, wherein at least one of the collimation lenses is movable in the Z direction in order to change a diameter of the light spot on the workpiece.
    [4]
    4. The method according to claim 1, wherein the laser processing is carried out as build-up welding.
    [5]
    5. The method according to claim 1, wherein the laser processing is carried out as welding.
    [6]
    6. The method of claim 1, wherein the laser processing is performed as a surface cleaning.
    [7]
    7. The method of claim 1, wherein the workpiece has a three-dimensional surface and wherein the collimated laser beam provides the constant power density in the Z direction at different processing points on the three-dimensional surface.
    [8]
    8. The method of claim 7, wherein the laser processing is carried out on a turbine blade.
    CH 710 428 B1
    [9]
    9. The method of claim 7, wherein the laser processing is performed on a valve seat.
    [10]
    10. The method of claim 1, wherein dithering the collimated laser beam comprises moving optics in a beam transmission system without moving a laser output optically connected to the beam transmission system.
    [11]
    11. The method of claim 1, wherein dithering the collimated laser beam comprises moving an optical fiber laser output without moving an optic of a beam transmission system optically connected to the optical fiber laser output.
    [12]
    12. The method of claim 1, wherein the collimated laser beam is dithered in coordination with movement of the workpiece so that the light spot moves on the surface of the workpiece such that a continuous pattern is formed.
    [13]
    13. The method of claim 12, wherein the pattern is a serpentine pattern.
    [14]
    14. The method of claim 12, wherein the pattern is a spiral pattern.
    [15]
    15. A laser processing system for performing the method according to any one of claims 1 to 14, comprising: a glass fiber laser system, a beam transmission system that is optically connected to a glass fiber laser output of the glass fiber laser system, the beam transmission system comprising collimation lenses to generate a collimated laser beam, at least one of which Collimation lenses can be moved in the Z direction in order to change a diameter of the collimated beam,
    Means for moving the fiber optic laser output relative to the collimation lenses to dither the collimated laser beam in the X or Y direction, a workpiece carrier for carrying and moving a workpiece, and a motion control system for controlling the movement of the workpiece carrier and the means for moving the fiber optic laser output relative to the collimation lenses.
    [16]
    16. The laser processing system of claim 15, wherein the means for moving the optical fiber laser output relative to the collimating lenses comprise an X-Y stage of the optics for moving the collimating lenses without moving the optical fiber laser output.
    [17]
    17. The laser processing system of claim 15, wherein the means for moving the fiber optic laser output relative to the collimating lenses comprise an X-Y stage of the fiber optic laser output for moving the fiber optic laser output without moving the collimating lenses.
    [18]
    18. An optical head for a laser processing system according to any one of claims 15 to 17, comprising: a housing, a glass fiber laser connector for connecting a glass fiber laser output to the housing at one end of the housing, a beam transmission system which is housed in the housing and optically connected to the glass fiber laser output the beam transmission system comprising:
    first and second collimation lenses for providing a collimated laser beam, at least one of the first and second collimation lenses being movable in the Z direction to change a diameter of the collimated laser beam, and a last collimation lens for providing a final collimation of the collimated laser beam and an XY- Stage of the optics, which is housed in the housing and the collimation lenses for movement in X and
    Y direction.
    [19]
    19. The optical head of claim 18, further comprising a sacrificial window located at another end of the housing to allow the collimated laser beam to be directed out of the housing.
    [20]
    20. The optical head of claim 18, further comprising a support structure and first and second lens carriages that are slidably mounted on the support structure for movement in the Z direction on the support structure, wherein the first and second collimation lenses are attached to the first and second lens carriages and wherein the support structure is attached to the XY stage of the optics.
    [21]
    21. The optical head according to claim 18, wherein the first and second collimation lenses comprise concave and convex lenses, respectively.
    [22]
    22. Application of the method for laser processing according to one of claims 1 to 4 in a laser deposition welding method for applying an overlay layer on a workpiece, the method comprising:
    Generating a collimated laser beam with a constant power density in the Z direction along at least a section of a length of the collimated laser beam,
    Directing the collimated laser beam onto a workpiece to provide a spot of light on the workpiece, directing a cladding material onto the workpiece such that the cladding material strikes the surface of the workpiece in an area heated by the point of light, and
    CH 710 428 B1
    Moving the workpiece such that the surfacing material forms a surfacing layer on the surface of the workpiece while the workpiece is moving.
    [23]
    23. The application of claim 22, further comprising: dithering the collimated laser beam along the X or Y axis such that the light spot on the workpiece is dithered while the workpiece is being moved.
    [24]
    24. Application according to claim 23, wherein the workpiece has a three-dimensional surface and wherein the collimated laser beam provides the constant power density in the Z direction at different processing points on the three-dimensional surface.
    [25]
    25. Application according to claim 22, wherein the workpiece has a three-dimensional surface and wherein the collimated laser beam provides the constant power density in the Z direction at different processing points on the three-dimensional surface.
    [26]
    26. Application claim 25, wherein the workpiece is a turbine blade.
    [27]
    27. The application of claim 22, wherein generating the collimated laser beam comprises directing a laser output through at least two collimation lenses.
    [28]
    28. Use according to claim 27, wherein at least one of the collimation lenses is movable in the Z direction in order to change a diameter of the light spot on the workpiece.
    [29]
    29. The application of claim 22, wherein the dithering of the collimated laser beam comprises moving an optic in a beam transmission system without moving a laser output optically connected to the beam transmission system.
    [30]
    30. The application of claim 22, wherein dithering the collimated laser beam comprises moving a fiber optic laser output without moving an optic of a beam transmission system optically connected to the fiber optic laser output.
    [31]
    31. Use according to claim 22, wherein the collimated laser beam is dithered in coordination with movement of the workpiece such that the light spot moves in a continuous pattern on the surface of the workpiece.
    [32]
    32. Use according to claim 31, wherein the pattern is a spiral pattern.
    [33]
    33. Application according to claim 22, wherein the build-up welding material is powder which is entrained in a gas stream.
    [34]
    34. Use of the laser processing system according to one of claims 15 to 17 as a laser build-up welding system, additionally comprising a powder transfer system for transferring build-up welding powder to the workpiece such that the build-up welding powder strikes the surface of the workpiece in an area which is heated by the collimated laser beam.
    [35]
    35. Use according to claim 34, wherein the means for moving the optical fiber laser output relative to the collimating lenses comprise an X-Y stage of the optics for moving the collimating lenses without moving the optical fiber laser output.
    [36]
    36. Use according to claim 34, wherein the means for moving the glass fiber laser output relative to the collimation lenses comprise an X-Y stage of the glass fiber laser output for moving the glass fiber laser output without moving the collimation lenses.
    [37]
    37. Use according to claim 34, further comprising an optical housing that encloses the beam transmission system, the powder transmission system being attached to the optical housing to form an integrated optical laser deposition welding head.
    [38]
    38. Use of the optical head according to one of claims 18 to 21 as an integrated optical laser welding head, additionally comprising a powder transfer system that has a powder transfer nozzle attached to the housing and is intended for transferring welding powder to the workpiece in such a way that the welding powder on the surface of the Workpiece hits an area that is heated by the collimated laser beam.
    [39]
    39. Use according to claim 38, further comprising a sacrificial window located at another end of the housing to allow the collimated laser beam to be directed out of the housing.
    [40]
    40. Use according to claim 38, further comprising a support structure and first and second lens carriages, which are attached to the support structure on the support structure for movement in the Z direction, wherein the first and second collimation lenses are attached to the first and second lens carriages and the support structure is attached to the XY stage of the optics.
    CH 710 428 B1
    Fig.1A
    CH 710 428 B1
    Fig.IB
    Fig.IC
    ^ .y
    106 ί i " sii
    Fig. 2A
    Fig. 2B
    CH 710 428 B1
    114
    Fig. 2C
    Fig.2D
    CH 710 428 B1
    Fig.3A
    CH 710 428 B1
    Fig. 3 B
    CH
    710 428 0 ^
    Fig · 4
    CH 710 428 B1
    Illustration 5
    CH 710 428 B1
    CH 710 428 B1
    700
    770
    750
    Fig. 7
    CH 710 428 B1 ^ -870
    Fig. 8
    CH 710 428 B1
    Fig. 9
    CH 710 428 B1
    800
    Fig. 10
    CH 710 428 B1
    Fig. 12
    CH 710 428 B1
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    CN105579185A|2016-05-11|
    EP3049212A4|2017-05-31|
    WO2015048111A1|2015-04-02|
    JP6594861B2|2019-10-23|
    AU2014326818A1|2016-04-21|
    CN105579185B|2020-11-17|
    CA2924823A1|2015-04-02|
    US20160228988A1|2016-08-11|
    ZA201601996B|2017-06-28|
    US11141815B2|2021-10-12|
    EP3049212A1|2016-08-03|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    US4328410A|1978-08-24|1982-05-04|Slivinsky Sandra H|Laser skiving system|
    DE2943107C2|1979-10-25|1984-07-26|Robert 6600 Saarbrücken Langen|Procedure for derusting|
    IT1179061B|1984-08-20|1987-09-16|Fiat Auto Spa|PROCEDURE FOR CARRYING OUT A TREATMENT ON METAL PIECES WITH THE ADDITION OF A VALUE MATERIAL AND WITH THE USE OF A POWER LASER|
    FR2577052B1|1985-02-05|1988-09-09|Bertin & Cie|METHOD AND DEVICE FOR MOVING THE POINT OF IMPACT OF A LASER BEAM ON A WORKPIECE|
    JPH04167986A|1990-11-01|1992-06-16|Nec Corp|Laser beam machining apparatus|
    US5160822A|1991-05-14|1992-11-03|General Electric Company|Method for depositing material on the tip of a gas turbine engine airfoil using linear translational welding|
    JP3060813B2|1993-12-28|2000-07-10|トヨタ自動車株式会社|Laser processing equipment|
    US6615470B2|1997-12-15|2003-09-09|General Electric Company|System and method for repairing cast articles|
    CA2284759C|1998-10-05|2006-11-28|Mahmud U. Islam|Process for manufacturing or repairing turbine engine or compressor components|
    US6791060B2|1999-05-28|2004-09-14|Electro Scientific Industries, Inc.|Beam shaping and projection imaging with solid state UV gaussian beam to form vias|
    US6838638B2|2000-07-31|2005-01-04|Toyota Jidosha Kabushiki Kaisha|Laser beam machining method|
    JP3686317B2|2000-08-10|2005-08-24|三菱重工業株式会社|Laser processing head and laser processing apparatus provided with the same|
    US6639177B2|2001-03-29|2003-10-28|Gsi Lumonics Corporation|Method and system for processing one or more microstructures of a multi-material device|
    KR100387488B1|2001-04-25|2003-06-18|현대자동차주식회사|Using the laser cladding process of valve seat manufacturing method|
    JP2003048095A|2001-08-06|2003-02-18|Mitsubishi Heavy Ind Ltd|Laser beam machining head and method for machining using the head|
    JP3905732B2|2001-08-30|2007-04-18|三菱重工業株式会社|Laser processing head, laser cutting apparatus and laser cutting method using the same|
    JP2003251484A|2002-03-01|2003-09-09|Mitsubishi Heavy Ind Ltd|Laser beam machining head and laser beam machining device equipped therewith|
    DE10213044B3|2002-03-22|2004-01-29|Freie Universität Berlin, Körperschaft des öffentlichen Rechts|Processes for material processing and / or material analysis with lasers|
    US6706999B1|2003-02-24|2004-03-16|Electro Scientific Industries, Inc.|Laser beam tertiary positioner apparatus and method|
    JP4038724B2|2003-06-30|2008-01-30|トヨタ自動車株式会社|Laser cladding processing apparatus and laser cladding processing method|
    DE102004001276A1|2004-01-08|2005-08-04|Mtu Aero Engines Gmbh|Method for heating components|
    US7199330B2|2004-01-20|2007-04-03|Coherent, Inc.|Systems and methods for forming a laser beam having a flat top|
    US20060153996A1|2005-01-13|2006-07-13|Stanek Jennifer M|Method and system for laser cladding|
    WO2007022567A1|2005-08-23|2007-03-01|Hardwear Pty Ltd|Powder delivery nozzle|
    US7864408B2|2007-06-20|2011-01-04|Cubic Corporation|Beam deflection using PZT resonance|
    US7898729B2|2007-06-20|2011-03-01|Cubic Corporation|Combinational PZT and MEMS beam steering|
    US8053704B2|2008-05-27|2011-11-08|Corning Incorporated|Scoring of non-flat materials|
    JP5309890B2|2008-10-27|2013-10-09|株式会社Ｉｈｉ|Welding apparatus and welding method|
    JP5331586B2|2009-06-18|2013-10-30|株式会社日立ハイテクノロジーズ|Defect inspection apparatus and inspection method|
    DE102009049518A1|2009-10-15|2011-04-21|Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V.|Method and device for welding workpieces made of heat-resistant superalloys|
    JP5527526B2|2010-02-24|2014-06-18|マツダ株式会社|Laser welding method|
    CN201693291U|2010-03-31|2011-01-05|苏州市博海激光科技有限公司|Focal spot oscillating laser texturing device for roller surface|
    US8309883B2|2010-05-20|2012-11-13|Ipg Photonics Corporation|Methods and systems for laser processing of materials|
    KR101137394B1|2010-07-05|2012-04-20|삼성모바일디스플레이주식회사|Laser beam irradiation apparatus and substrate sealing apparatus comprising the same|
    CN110039173B|2010-10-22|2021-03-23|伊雷克托科学工业股份有限公司|Laser machining system and method for beam dithering and skiving|
    JP2012137350A|2010-12-27|2012-07-19|Hitachi High-Technologies Corp|Defect inspection method and device|
    US20120199564A1|2011-02-09|2012-08-09|Coherent, Inc.|Powder-delivery apparatus for laser-cladding|
    GB201118698D0|2011-10-28|2011-12-14|Laser Fusion Technologies Ltd|Deposition of coatings on subtrates|
    JP5789527B2|2012-01-18|2015-10-07|株式会社アマダホールディングス|Laser processing apparatus and laser oscillation control method|
    CN202877731U|2012-09-14|2013-04-17|武汉市凯瑞迪激光技术有限公司|Laser texturing processing device with focusing light dot controlled to be deflected|EP3310521A4|2015-06-19|2019-03-13|IPG Photonics Corporation|Laser cutting head with controllable collimator having movable lenses for controlling beam diameter and/or focal point location|
    DE102015212284A1|2015-07-01|2017-01-05|Siemens Aktiengesellschaft|Apparatus and method for powder-based laser deposition welding|
    US10702951B2|2015-07-03|2020-07-07|Murata Machinery, Ltd.|Laser machine, laser machining method, planar-member machining system, and planar-member machining method|
    KR101801028B1|2016-07-11|2017-12-20|에이티아이 주식회사|Laser patterning apparatus for 3-dimensional object|
    CN106181062B|2016-07-29|2018-09-25|讯创电子有限公司|A kind of intelligent manufacturing system of all -fiber three-dimensional laser engraving antenna|
    KR102263215B1|2016-12-16|2021-06-09|미쓰비시덴키 가부시키가이샤|Shape change and laser processing equipment|
    LU100281B1|2017-06-09|2018-12-18|Highyag Lasertechnologie Gmbh|Holder for optical fiber connector|
    CN109175677A|2018-10-18|2019-01-11|深圳市斯普莱特激光科技有限公司|A kind of high accurancy and precision automatized three-dimensional laser process equipment|
    TWI706614B|2018-11-10|2020-10-01|鴻超環保能源股份有限公司|Laser light source module|
    FR3092509B1|2019-02-13|2022-03-04|Safran Aircraft Engines|THREE-DIMENSIONAL PRINTING DEVICE|
    WO2021150691A1|2020-01-21|2021-07-29|Ipg Photonics Corporation|System and method for laser metal powder deposition|
    法律状态:
    2020-09-30| PFA| Name/firm changed|Owner name: IPG PHOTONICS CORPORATION, US Free format text: FORMER OWNER: IPG PHOTONICS CORPORATION, US |
    优先权:
    申请号 | 申请日 | 专利标题
    US201361881666P| true| 2013-09-24|2013-09-24|
    PCT/US2014/057186|WO2015048111A1|2013-09-24|2014-09-24|Laser processing systems capable of dithering|
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