Laser-assisted polishing device for metallographic specimen polishing machine and using method

Abstract

The invention discloses a laser-assisted polishing device for a metallographic specimen polishing machine and a using method, the laser-assisted polishing device comprises a box-type mounting rack, a horizontal moving device is arranged at the top of the box-type mounting rack, an upper moving body is arranged at the moving end of the horizontal moving device, and a vertical moving device is arranged on the upper moving body; a rotatable polishing platform is arranged at the moving end of the vertical moving device, a polishing machine is arranged below the polishing platform, a sample block detachably installed on the polishing platform is matched with the polishing machine in a polishing mode, and a laser auxiliary device with a variable focus is arranged on one side of the box type installation frame. The focus of the laser auxiliary device is always aligned with the closest contact position of the sample block and the polishing machine, and the situation that positive and negative defocusing causes heat input to affect the material property, and consequently the polishing effect is affected is avoided.

Description

Technical Field

[0001] The invention relates to the technical field of mechanical processing, in particular to a laser-assisted polishing device for a metallographic sample polishing machine and a use method thereof. Background Art

[0002] Metallographic sample preparation is a key step in material analysis, and the quality of the polishing process directly determines the accuracy of microstructure observation.

[0003] Traditional manual polishing machines have long faced three major technical bottlenecks: First, the operator needs to control the polishing pressure, path and time parameters throughout the entire process. This experience-based dependence leads to reproducibility differences of more than 30% between different operators; second, fluctuations in manual force during continuous operation cause thermal damage to the sample surface as high as 12%, seriously affecting the pass rate of high-precision samples; third, the procurement cost of existing fully automatic polishing systems is 8-12 times higher than that of manual equipment, making it difficult to upgrade equipment in small and medium-sized laboratories.

[0004] When dealing with difficult-to-machine materials (hard and brittle materials), traditional polishing methods suffer from slow removal speeds and long processing cycles due to the extremely high hardness of hard and brittle materials. Mechanical stress can easily cause microcracks, chipping, and breakage (especially brittle fracture), making surface roughness difficult to control. The subsurface damage layer can also reduce the fatigue strength of the material. Laser-assisted polishing increases processing speed by locally softening or melting the material surface, while effectively reducing brittle fractures and inhibiting microcracks and chipping. However, defocus during laser-assisted polishing has a significant impact on the polishing effect. For example, excessive positive defocus may result in insufficient heat input, making it impossible to effectively smooth the surface; negative defocus may cause deep thermal damage.

[0005] Therefore, there is an urgent need for a laser-assisted polishing device for metallographic sample polishing machines, which uses laser-assisted processing to improve the machinability of hard and brittle difficult-to-process materials and achieve controllable thermal softening and efficient removal of the surface of difficult-to-process materials. Summary of the Invention

[0006] The present invention provides a laser-assisted polishing device and a method of use for a metallographic sample polishing machine, aiming to solve the above-mentioned problems that the existing laser-assisted polishing equipment is prone to positive and negative defocus when facing hard and brittle materials, thereby affecting the material properties and polishing effect, and has poor auxiliary self-control and applicability.

[0007] In order to solve the above technical problems, the technical solution adopted by the present invention is: A laser-assisted polishing device for a metallographic sample polishing machine includes a box-type mounting frame, a horizontal moving device is provided on the top of the box-type mounting frame, an upper moving body is provided on the moving end of the horizontal moving device, a vertical moving device is provided on the upper moving body, a rotatable polishing platform is provided on the moving end of the vertical moving device, a polishing machine is provided below the polishing platform, and a sample block detachably mounted on the polishing platform forms a polishing cooperation with the polishing machine. A laser-assisted device with variable focus is provided on one side of the box-type mounting frame, and the focus of the laser-assisted device is always aligned with the contact point between the closest sample block and the polishing machine.

[0008] Preferably, a motor seat is provided on the top of the box-shaped mounting frame for mounting a horizontal moving device, and an angle iron is provided on one side of the box-shaped mounting frame for mounting a laser auxiliary device.

[0009] More preferably, the horizontal moving device includes a first motor installed on a motor seat, a lead screw is provided on the top of the box-type mounting frame, one end of the lead screw forms a linkage fit with the output shaft of the first motor, the other end of the lead screw forms a rotation fit with the vertical seat through a bearing, the vertical seat is fixed on the box-type mounting frame, an upper support seat is installed on the lead screw through a lead screw nut, circular guide rails with a sliding direction parallel to the axial direction are provided on both sides of the lead screw, and guide rail sliders are slidably installed on the circular guide rails, and the upper moving body forms a lead screw fit with the lead screw through the upper support seat and the guide rail slider.

[0010] Furthermore, the upper movable body includes a horizontal plate arranged horizontally, the bottom of the horizontal plate is fixedly matched with the top of the upper support seat and the guide rail slider, and a number of vertical plates arranged vertically are arranged at the bottom of the horizontal plate and extend into the box-type mounting frame. The vertical plates are connected to the horizontal plates through angle irons, and the vertical plates cooperate with the horizontal plates to form a hollow frame, and a vertical moving device is installed on the vertical plate.

[0011] Furthermore, the vertical moving device includes a ball screw and an optical axis arranged vertically parallel to the vertical plate, one end of the optical axis is vertically fixed on the horizontal plate, and the other end of the optical axis is fixedly mounted on the vertical plate through an optical axis support seat, an optical axis slide is slidably mounted on the optical axis, a screw slider is mounted on the ball screw through a screw nut, a second motor is provided on the horizontal plate, the output shaft of the second motor forms a linkage cooperation with the ball screw through a coupling, and the polishing platform forms a screw cooperation with the ball screw through the screw slider and the optical axis slide.

[0012] Specifically, the polishing platform includes a motor slider, which is fixedly matched with the screw slider and the optical axis slide. A third motor is provided on the motor slider, and the output shaft of the third motor is vertically downward. A transmission shaft is provided on the output shaft of the third motor through a coupling, and a sample fixture is detachably installed on the other end of the transmission shaft.

[0013] More specifically, the sample fixture includes a mounting plate, a fixed shaft is provided at the top of the middle axis of the mounting plate, a threaded head is provided at the bottom end of the transmission shaft, a mounting screw mouth is provided at the top of the fixed shaft and is threadedly engaged with the threaded head, mounting holes are provided on the mounting plate at equal intervals around the axis, and a fastening screw hole is provided on the outer wall of the mounting plate corresponding to each mounting hole, and a fastening screw is threadedly engaged with the fastening screw hole, the bottom of the sample block is exposed and embedded in the mounting hole, and the sample block is pressed and fixed in the corresponding mounting hole by the fastening screw.

[0014] In detail, the laser-assisted device includes a slide module that is drivable and slidable and is mounted on an angle iron. A laser frame is mounted on the movable end of the slide module. The laser frame slides in a vertical direction. A light pulse laser emitter, a helium-neon laser emitter, and a beam merging module are mounted on the laser frame. A synchronously moving convex lens holder is slidably mounted on the laser frame. Each convex lens holder is equipped with a convex lens to form a convex lens group. The light emitted by the light pulse laser emitter and the helium-neon laser emitter is merged by the beam merging module and then focused by the convex lens group on the contact point between the sample block closest to the focus and the polishing machine. A laser displacement sensor is provided at the front end of the laser frame. The sensing end of the laser displacement sensor forms a distance measurement cooperation with the contact point between the closest sample block and the polishing machine. The convex lens bracket forms a lead screw cooperation with the trapezoidal lead screw in the laser frame. The trapezoidal lead screw is driven by the stepper motor on the laser frame and rotates synchronously. A controller is provided on one side of the laser frame. The stepper motor forms a linkage cooperation with the laser displacement sensor through the controller. The focus position is adjusted by moving the convex lens bracket so that the focus is always located at the contact point between the closest sample block and the polishing machine.

[0015] In more detail, the helium-neon laser emitter in the laser-assisted device emits visible light with a wavelength of 632.8nm, which enters the beam merging module. After two reflections, it enters the dichroic mirror in the beam merging module at an incident angle of 45° and is reflected. The light pulse laser emitter emits a laser with a wavelength of 1064nm, which directly passes through the dichroic mirror and coincides with the reflected visible light beam.

[0016] A method for using a laser-assisted polishing device for a metallographic sample polishing machine, using the laser-assisted polishing device for a metallographic sample polishing machine to continuously laser soften and polish a sample block, comprising the following steps: S1. Before polishing, debug the laser-assisted device to ensure that the optical axis coincides with the center of the convex lens holder. Manually move the convex lens holder to the middle position and record the laser displacement sensor ±10mm to observe whether the change in the laser displacement sensor value is linear. S2. The metallographic specimen block to be polished is placed in the specimen fixture on the polishing platform and is clamped by screwing the fastening screws into the fastening screw holes of the specimen fixture; S3. The first motor-driven screw of the horizontal moving device drives the upper movable body to slide on the circular guide rail to a set position and stops. At this time, the sample fixture is located just above the polishing range of the polishing machine; S4. Position the polishing cloth as needed, turn on the polishing machine, and adjust the metallographic polishing machine to the appropriate speed. The second motor of the vertical movement device drives the ball screw to rotate the specimen block against the polishing cloth. At the same time, the third motor of the polishing platform drives the specimen fixture and the polishing plate to rotate in opposite directions via the drive shaft. S5. When polishing begins, the slide module drives the laser frame downward to the set position, and the fiber pulse laser emitter is aligned with the contact point closest to the sample block being polished and the polishing cloth. The fiber pulse laser emitter and the helium-neon laser emitter are turned on and the beams are merged by the beam merging module. The focus falls on the contact point between the sample block and the polishing cloth for auxiliary polishing. At the same time, the laser displacement sensor monitors the surface height of the sample in real time. When the defocus amount exceeds ±100 microns, the stepper motor is driven to adjust the position of the two convex lens brackets. When the laser distance is shorter than the set value, the convex lens bracket is moved backward to move the focus backward. When the laser distance is longer than the set value, the convex lens bracket is moved forward to move the focus forward, so that the focus always falls on the surface of the sample block.

[0017] Beneficial effects of the present invention: (1) The device uses a laser-assisted device and a polishing machine to automatically polish and improve the efficiency of polishing. The laser-assisted device can always focus on the surface of the sample to ensure the auxiliary effect and polishing effect; (2) The device is relatively compact, occupies a small area, is easy to move, and is convenient for laboratory operation; (3) The laser auxiliary device controls the up and down movement through the slide module to ensure that the laser can irradiate the sample being polished. The helium-neon laser emitter emits visible light into the beam merging module. After two reflections, it enters the dichroic mirror in the beam merging module at an incident angle of 45° and is reflected. The light pulse laser emitter emits laser light that directly passes through the dichroic mirror and coincides with the reflected visible light beam, which makes it easier to observe the polishing process and focus. At the same time, the laser auxiliary device monitors the height change of the sample surface through the laser displacement sensor and transmits it to the controller. The controller calculates the defocus amount based on the change in the sample surface height to determine whether to drive the stepper motor to adjust the position of the convex lens. When the defocus amount exceeds 100 microns, the controller drives the stepper motor to adjust the two convex lens brackets to move away from the light source. When the defocus amount exceeds -100 microns, the controller drives the stepper motor to adjust the two convex lens brackets to move toward the light source, thereby improving self-control, strong adaptability, and good polishing effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention; Figure 2 It is a schematic diagram of the box of the present invention; Figure 3 is a schematic diagram of a horizontal moving device of the present invention; Figure 4 is a schematic diagram of the upper moving body of the present invention; Figure 5 is a schematic diagram of a vertical moving device of the present invention; Figure 6 is a schematic diagram of a polishing platform of the present invention; Figure 7 is a schematic diagram of the laser-assisted device of the present invention; Figure 8 Schematic diagram of the motor controlling the movement of the convex lens holder in the laser-assisted device of the present invention; Figure 9 Schematic diagram of clamping of the sample block of the present invention; In the figure: 1. Box-type mounting frame; 11. Motor base; 2. Horizontal moving device; 21. First motor; 22. Circular guide rail; 23. Guide rail slider; 24. Lead screw; 25. Vertical seat; 26. Upper support seat; 3. Upper moving body; 31. Horizontal plate; 32. Vertical plate; 4. Vertical moving device; 41. Second motor; 42. Optical axis; 43. Optical axis support seat; 44. Optical axis slide; 45. Ball screw; 46. Screw slider; 5. Polishing platform; 51. Third motor; 52. Motor slider; 53. Drive shaft; 54. Sample fixture; 541. Fixed shaft; 542. Threaded head; 543. Mounting plate; 544. Mounting hole; 545. Fastening screw hole; 546. Fastening screw; 547. Mounting screw hole; 6. Laser assist device; 61. Slide module; 62. Laser frame; 63. Light pulse laser emitter; 64. Convex lens holder; 65. Stepper motor; 66. Laser displacement sensor; 67. Controller; 68. Beam merging module; 69. Helium-neon laser emitter; 610. Lead screw; 7. Polishing machine; 8. Sample block. DETAILED DESCRIPTION

[0019] As follows, embodiments are further described with reference to the accompanying drawings.

[0020] As a preferred embodiment 1, Figure 1As shown, a laser-assisted polishing device for a metallographic sample polishing machine includes a box-type mounting frame 1, a horizontal moving device 2 is provided on the top of the box-type mounting frame 1, an upper moving body 3 is provided on the moving end of the horizontal moving device 2, a vertical moving device 4 is provided on the upper moving body 3, a rotatable polishing platform 5 is provided on the moving end of the vertical moving device 4, a polishing machine 7 is provided below the polishing platform 5, and a sample block 8 detachably mounted on the polishing platform 5 forms a polishing cooperation with the polishing machine 7, a laser-assisted device 6 with variable focus is provided on one side of the box-type mounting frame 1, and the focus of the laser-assisted device 6 is always aligned with the contact point between the closest sample block 8 and the polishing machine 7.

[0021] like Figure 1 and Figure 2 As shown, the top of the box-type mounting frame 1 is provided with a motor seat 11 for installing the horizontal moving device 2, and one side of the box-type mounting frame 1 is provided with an angle iron for installing the laser auxiliary device 6. It is convenient for the installation of the device.

[0022] like Figure 3 As shown, the horizontal moving device 2 includes a first motor 21 installed on the motor seat 11, and a screw 24 is provided on the top of the box-type mounting frame 1. One end of the screw 24 forms a linkage fit with the output shaft of the first motor 21, and the other end of the screw 24 forms a rotation fit with the vertical seat 25 through a bearing. The vertical seat 25 is fixed on the box-type mounting frame 1, and an upper support seat 26 is installed on the screw 24 through a screw nut. Both sides of the screw 24 are provided with circular guide rails 22 whose sliding direction is parallel to the axial direction, and guide rail sliders 23 are slidably installed on the circular guide rails 22. The upper moving body 3 forms a screw fit with the screw 24 through the upper support seat 26 and the guide rail slider 23.

[0023] The horizontal moving device 2 is used to control the position of the upper movable body 3 to ensure that the ideal polishing position is obtained. It mainly controls the movement of the screw 24 through the first motor 21, drives the upper support seat 26 to move axially, and limits it through the guide rail slider 23. The guide rail slider 23 is used to connect the upper support seat 26 to the upper movable block 3 to ensure the stability of the movement.

[0024] like Figure 4 As shown, the upper movable body 3 includes a horizontal plate 31 arranged horizontally, the bottom of the horizontal plate 31 is fixedly matched with the upper support seat 26 and the top of the guide rail slider 23, and a plurality of vertical plates 32 are arranged vertically at the bottom of the horizontal plate 31 and extend into the box-type mounting frame 1. The vertical plates 32 are connected to the horizontal plate 31 through angle irons, and the vertical plates 32 cooperate with the horizontal plates 31 to form a hollow frame, and a vertical moving device 4 is installed on the vertical plate 32.

[0025] The upper moving block 3 is formed by connecting a horizontal plate 31 and a vertical plate 32, and the lower end of the vertical plate 32 and the other side of the horizontal plate 31 are connected using angle iron.

[0026] like Figure 5 As shown, the vertical moving device 4 includes a ball screw 45 and an optical axis 42 arranged vertically parallel to the vertical plate 32. One end of the optical axis 42 is vertically fixed on the horizontal plate 31, and the other end of the optical axis 42 is fixedly installed on the vertical plate 32 through an optical axis support seat 43. An optical axis slide 44 is slidably installed on the optical axis 42, and a screw slider 46 is installed on the ball screw 45 through a screw nut. A second motor 41 is provided on the horizontal plate 31, and the output shaft of the second motor 41 forms a linkage cooperation with the ball screw 45 through a coupling. The polishing platform 5 forms a screw cooperation with the ball screw 45 through the screw slider 46 and the optical axis slide 44.

[0027] The second motor 41 of the vertical movement device 4 is mounted on the horizontal plate 31. One end of the optical axis 42 is fixed to the horizontal plate 31, and the other end is fixed to the vertical plate 32 via an optical axis support 43. The optical axis slider 44 and the lead screw slider 46 connected to the ball screw 45 are connected to the motor slider 52. The movement of the ball screw 45 drives the lead screw slider 46 to move horizontally, and the optical axis slider 44 is used to limit the position, ensuring the stable up and down movement of the polishing platform 5.

[0028] like Figure 6 As shown, the polishing platform 5 includes a motor slider 52, which is fixedly matched with the lead screw slider 46 and the optical axis slide 44. A third motor 51 is provided on the motor slider 52, and the output shaft of the third motor 51 is vertically downward. A transmission shaft 53 is provided on the output shaft of the third motor 51 through a coupling, and a sample fixture 54 is detachably installed on the other end of the transmission shaft 53.

[0029] The polishing platform 5 drives the transmission shaft 53 to rotate through the motor 51 , wherein the transmission shaft 53 is threadedly connected to the sample holder 54 after processing, so that the sample holder 54 rotates to obtain a better polishing effect.

[0030] like Figure 9 As shown, the sample fixture 54 includes a mounting plate 543, a fixed shaft 541 is provided at the top of the middle axis of the mounting plate 543, a threaded head 542 is provided at the bottom end of the transmission shaft 53, and a mounting screw 547 is provided at the top of the fixed shaft 541, which is threadedly matched with the threaded head 542 to facilitate installation and disassembly and ensure fastening. Mounting holes 544 are evenly spaced around the axis on the mounting plate 543, and a fastening screw hole 545 is provided on the outer wall of the mounting plate 543 corresponding to each mounting hole 544. A fastening screw 546 is threadedly matched in the fastening screw hole 545, and the bottom of the sample block 8 is exposed and embedded in the mounting hole 544, and the sample block 8 is pressed and fixed in the corresponding mounting hole 544 by the fastening screw 546 to ensure the fastening of the sample.

[0031] Preferably, the tightening direction of the threaded head 542 is the same as the rotation direction of the third motor 51 to prevent it from falling off during rotation.

[0032] like Figure 7 and Figure 8 As shown, the laser auxiliary device 6 includes a slide module 61 that is drivable and slidable and is provided on an angle iron. A laser frame 62 is provided on the movable end of the slide module 61. The laser frame 62 slides in the vertical direction. A light pulse laser emitter 63, a helium-neon laser emitter 69 and a beam merging module 68 are provided on the laser frame 62. A synchronously moving convex lens holder 64 is slidably mounted on the laser frame 62. Each convex lens holder 64 is equipped with a convex lens to form a convex lens group. The light pulse laser emitter 63 and the helium-neon laser emitter 69 emit light, which is merged by the beam merging module 68 and then focused by the convex lens group on the contact point between the sample block 8 and the polishing machine 7 closest to the focus. A laser displacement sensor 66 is provided at the front end of the laser frame 62. The sensing end of the laser displacement sensor 66 forms a distance measurement cooperation with the contact point between the closest sample block 8 and the polishing machine 7. The convex lens bracket 64 forms a screw cooperation with the trapezoidal screw 610 in the laser frame 62. The trapezoidal screw 610 is driven by the stepping motor 65 on the laser frame 62 and rotates synchronously. A controller 67 is provided on one side of the laser frame 62. The stepping motor 65 forms a linkage cooperation with the laser displacement sensor 66 through the controller 67. The focus position is adjusted by moving the convex lens bracket 64 so that the focus is always located at the contact point between the closest sample block 8 and the polishing machine 7.

[0033] The helium-neon laser emitter 69 in the laser assist device 6 emits visible light with a wavelength of 632.8 nm, which enters the beam merging module 68. After two reflections, the light enters the dichroic mirror in the beam merging module 68 at an incident angle of 45° and is reflected. The light pulse laser emitter 63 emits a laser with a wavelength of 1064 nm, which directly passes through the dichroic mirror and overlaps with the reflected visible light beam.

[0034] The laser auxiliary device 6 controls the up and down movement through the slide module 61 to ensure that the laser can irradiate the sample being polished. The helium-neon laser emitter 69 emits visible light with a wavelength of 632.8nm and enters the beam merging module 68. After two reflections, it enters the dichroic mirror in the beam merging module 68 at an incident angle of 45° and is reflected. The light pulse laser emitter emits a laser with a wavelength of 1060nm, which directly transmits the dichroic mirror and coincides with the reflected visible light beam, making it easier to observe the polishing process and for focusing. At the same time, the laser auxiliary device 6 monitors the change in the surface height of the sample through the laser displacement sensor 66 and transmits it to the controller 67. The controller 67 calculates the defocus amount based on the change in the surface height of the sample to determine whether to drive the stepper motor 65 to adjust the position of the convex lens. When the defocus amount exceeds 100 microns, the controller drives the stepper motor 65 to adjust the two convex lens brackets 64 to move away from the light source. When the defocus amount exceeds -100 microns, the controller drives the stepper motor 65 to adjust the two convex lens brackets 64 to move toward the light source.

[0035] As a preferred embodiment 2, a method for using a laser-assisted polishing device for a metallographic sample polishing machine, using the aforementioned laser-assisted polishing device for a metallographic sample polishing machine to continuously laser soften and polish a sample block 8, comprises the following steps: S1. Before polishing, debug the laser-assisted device 6 to ensure that the optical axis coincides with the center of the convex lens holder 64. Manually move the convex lens holder 64 to the middle position, record the laser displacement sensor 66) reading, move the convex lens holder 64±10mm, and observe whether the laser displacement sensor 66 value changes linearly; S2. The metallographic specimen block 8 to be polished is placed in the sample holder 54 in the polishing platform 5, and is clamped by screwing the fastening screw 545 into the fastening screw 546 of the sample holder 54; S3. The first motor 21 of the horizontal moving device 2 drives the lead screw 24 to drive the upper movable body 3 to slide on the circular guide rail 22 to a set position and stop. At this time, the sample holder 54 is located just above the polishing range of the polishing machine 7; S4. Place the polishing cloth as needed, turn on the polishing machine 7, adjust the metallographic polishing machine to the appropriate speed, the second motor 41 of the vertical moving device 4 drives the ball screw 45 to rotate the specimen block 8 to press the polishing cloth, while the third motor 51 of the polishing platform 5 drives the specimen holder 54 and the polishing disc to rotate in the opposite direction through the drive shaft 53; S5. When polishing begins, the slide module 61 drives the laser frame 62 to move downward to the set position, and the fiber pulse laser emitter 63 is aligned with the contact point closest to the sample block 8 being polished and the polishing cloth. The fiber pulse laser emitter 63 and the helium-neon laser emitter 69 are turned on, and the beams are merged by the beam merging module 68, and the focus falls on the contact point between the sample block 8 and the polishing cloth for auxiliary polishing. At the same time, the laser displacement sensor 66 monitors the surface height of the sample in real time. When the defocus amount exceeds ±100 microns, the stepping motor 65 is driven to adjust the position of the two convex lens brackets 64. When the laser distance is shorter than the set value, the convex lens bracket 64 is moved backward to move the focus backward. When the laser distance is longer than the set value, the convex lens bracket 64 is moved forward to move the focus forward, so that the focus always falls on the surface of the sample block 8.

Claims

1. A laser-assisted polishing device for a metallographic sample polishing machine, comprising a box-type mounting frame (1), characterized in that: A horizontal moving device (2) is provided on the top of the box-type mounting frame (1), an upper moving body (3) is provided on the moving end of the horizontal moving device (2), a vertical moving device (4) is provided on the upper moving body (3), a rotatable polishing platform (5) is provided on the moving end of the vertical moving device (4), a polishing machine (7) is provided below the polishing platform (5), and a sample block (8) detachably mounted on the polishing platform (5) forms a polishing match with the polishing machine (7), and a laser auxiliary device (6) with a variable focus is provided on one side of the box-type mounting frame (1), and the focus of the laser auxiliary device (6) is always aligned with the contact point between the closest sample block (8) and the polishing machine (7).

2. The laser-assisted polishing device for a metallographic sample polishing machine according to claim 1, characterized in that: A motor seat (11) is provided on the top of the box-shaped mounting frame (1) for mounting the horizontal moving device (2), and an angle iron is provided on one side of the box-shaped mounting frame (1) for mounting the laser auxiliary device (6).

3. The laser-assisted polishing device for a metallographic sample polishing machine according to claim 2, characterized in that: The horizontal moving device (2) includes a first motor (21) mounted on a motor base (11), a screw (24) is provided on the top of the box-type mounting frame (1), one end of the screw (24) forms a linkage fit with the output shaft of the first motor (21), the other end of the screw (24) forms a rotation fit with a vertical seat (25) through a bearing, the vertical seat (25) is fixed to the box-type mounting frame (1), an upper support seat (26) is mounted on the screw (24) through a screw nut, both sides of the screw (24) are provided with circular guide rails (22) whose sliding direction is parallel to the axial direction, and a guide rail slider (23) is slidably mounted on the circular guide rail (22), and the upper moving body (3) forms a screw fit with the screw (24) through the upper support seat (26) and the guide rail slider (23).

4. The laser-assisted polishing device for a metallographic sample polishing machine according to claim 3, characterized in that: The upper movable body (3) includes a horizontal plate (31) arranged horizontally, the bottom of the horizontal plate (31) is fixedly matched with the upper support seat (26) and the top of the guide rail slider (23), and a plurality of vertical plates (32) arranged vertically are arranged at the bottom of the horizontal plate (31) and extend into the box-type mounting frame (1). The vertical plates (32) are connected to the horizontal plate (31) through angle irons, and the vertical plates (32) cooperate with the horizontal plate (31) to form a hollow frame body, and a vertical moving device (4) is installed on the vertical plate (32).

5. The laser-assisted polishing device for a metallographic sample polishing machine according to claim 4, characterized in that: The vertical moving device (4) comprises a ball screw (45) and an optical axis (42) arranged vertically parallel to the vertical plate (32), one end of the optical axis (42) is vertically fixed to the horizontal plate (31), and the other end of the optical axis (42) is fixedly mounted on the vertical plate (32) via an optical axis support seat (43), an optical axis slide (44) is slidably mounted on the optical axis (42), a screw slider (46) is mounted on the ball screw (45) via a screw nut, a second motor (41) is provided on the horizontal plate (31), an output shaft of the second motor (41) forms a linkage with the ball screw (45) via a coupling, and the polishing platform (5) forms a screw with the ball screw (45) via the screw slider (46) and the optical axis slide (44).

6. The laser-assisted polishing device for a metallographic sample polishing machine according to claim 5, characterized in that: The polishing platform (5) includes a motor slider (52), which is fixedly matched with the lead screw slider (46) and the optical axis slide (44). A third motor (51) is provided on the motor slider (52), and the output shaft of the third motor (51) is vertically downward. A transmission shaft (53) is provided on the output shaft of the third motor (51) through a coupling, and a sample fixture (54) is detachably installed on the other end of the transmission shaft (53).

7. The laser-assisted polishing device for a metallographic sample polishing machine according to claim 6, characterized in that: The sample fixture (54) includes a mounting plate (543), a fixed shaft (541) is provided at the top of the middle shaft of the mounting plate (543), a threaded head (542) is provided at the bottom end of the transmission shaft (53), a mounting screw (547) is provided at the top of the fixed shaft (541) and is threadedly engaged with the threaded head (542), mounting holes (544) are provided on the mounting plate (543) at equal intervals around the shaft, and a fastening screw hole (545) is provided on the outer wall of the mounting plate (543) corresponding to each mounting hole (544), and a fastening screw (546) is threadedly engaged in the fastening screw hole (545), the bottom of the sample block (8) is exposed and embedded in the mounting hole (544), and the sample block (8) is pressed and fixed in the corresponding mounting hole (544) by the fastening screw (546).

8. The laser-assisted polishing device for a metallographic sample polishing machine according to claim 7, characterized in that: The laser auxiliary device (6) includes a slide module (61) that is drivable and slidable and is arranged on an angle iron. A laser frame (62) is arranged on the movable end of the slide module (61). The laser frame (62) slides in a vertical direction. A light pulse laser emitter (63), a helium-neon laser emitter (69) and a beam merging module (68) are arranged on the laser frame (62). A synchronously moving convex lens holder (64) is slidably mounted on the laser frame (62). Convex lenses are mounted on the convex lens holder (64) to form a convex lens group. The light pulse laser emitter (63) and the helium-neon laser emitter (69) emit light, which is combined by the beam merging module (68) and then focused by the convex lens group on the contact point between the sample block (8) closest to the focus and the polishing machine (7). A laser displacement sensor (66) is provided at the front end of the laser frame (62), and the sensing end of the sensor of the laser displacement sensor (66) forms a distance measurement cooperation with the contact point between the closest sample block (8) and the polishing machine (7). The convex lens bracket (64) forms a screw cooperation with the trapezoidal screw (610) in the laser frame (62), and the trapezoidal screw (610) is driven by the stepping motor (65) on the laser frame (62) and rotates synchronously. A controller (67) is provided on one side of the laser frame (62), and the stepping motor (65) forms a linkage cooperation with the laser displacement sensor (66) through the controller (67). The focus is adjusted by moving the convex lens bracket (64) so that the focus is always located at the contact point between the closest sample block (8) and the polishing machine (7).

9. The laser-assisted polishing device for a metallographic sample polishing machine according to claim 8, characterized in that: The helium-neon laser emitter (69) in the laser auxiliary device (6) emits visible light with a wavelength of 632.8 nm, which enters the beam merging module (68). After two reflections, the light enters the dichroic mirror in the beam merging module (68) at an incident angle of 45° and is reflected. The light pulse laser emitter (63) emits laser light with a wavelength of 1064 nm, which directly passes through the dichroic mirror and overlaps with the reflected visible light beam.

10. A method for using a laser-assisted polishing device for a metallographic sample polishing machine, characterized in that: Continuous laser softening and polishing of a sample block (8) using a laser-assisted polishing device for a metallographic sample polishing machine as claimed in claim 9 comprises the following steps: S1. Before polishing, debug the laser auxiliary device (6) to ensure that the optical axis coincides with the center of the convex lens holder (64). Manually move the convex lens holder (64) to the middle position, record the reading of the laser displacement sensor (66), move the convex lens holder (64) ±10mm, and observe whether the change in the value of the laser displacement sensor (66) is linear; S2. The metallographic specimen block (8) to be polished is placed in the specimen holder (54) in the polishing platform (5), and is clamped by screwing the fastening screw (546) into the fastening screw hole (545) of the specimen holder (54); S3. The first motor (21) of the horizontal moving device (2) drives the lead screw (24) to drive the upper moving body (3) to slide on the circular guide rail (22) to a set position and stop. At this time, the sample holder (54) is located just above the polishing range of the polishing machine (7); S4. Place the polishing cloth as needed, turn on the polishing machine (7), adjust the metallographic polishing machine to a suitable speed, and drive the ball screw (45) by the second motor (41) of the vertical moving device (4) to rotate so that the sample block (8) is pressed against the polishing cloth. At the same time, the third motor (51) of the polishing platform (5) drives the sample fixture (54) and the polishing disc to rotate in the opposite direction through the transmission shaft (53); S5. When polishing begins, the slide module (61) drives the laser frame (62) to move downward to the set position, and the fiber pulse laser emitter (63) is aligned with the contact point closest to the sample block (8) being polished and the polishing cloth. The fiber pulse laser emitter (63) and the helium-neon laser emitter (69) are turned on and the beams are merged by the beam merging module (68). The focus falls on the contact point between the sample block (8) and the polishing cloth for auxiliary polishing. At the same time, the laser displacement sensor (66) monitors the surface height of the sample in real time. When the defocus amount exceeds ±100 microns, the stepper motor (65) is driven to adjust the position of the two convex lens brackets (64). When the laser distance is shorter than the set value, the convex lens bracket (64) is moved backward to move the focus backward. When the laser distance is longer than the set value, the convex lens bracket (64) is moved forward to move the focus forward, so that the focus always falls on the surface of the sample block (8).

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