阅读说明：本技术 一种激光抛光方法及激光抛光设备 (Laser polishing method and laser polishing equipment ) 是由 赵振宇 肖永山 张玉洁 董志君 罗博伟 周浩 帅词俊 尹杰 李凯 于 2021-07-08 设计创作，主要内容包括：本发明涉及一种激光抛光方法及激光抛光设备,使用连续激光对金属材料进行粗抛光,在此过程中利用超声振动控制连续激光束的焦点上下移动,使金属材料的表面受到的连续激光束的能量产生间歇性波动,这种间歇性波动不像脉冲激光那样间歇性运作,而是保持着连续激光时刻都有激光输出的特性,只是降低了激光能量,减少金属材料表面的热量积累,更好的控制激光能量大小,使金属材料表面的平整度更高,粗抛光完成后使用脉冲激光对金属材料进行精抛光,由于已经使用过连续激光束进行抛光,因此金属材料表面的温度还很高,脉冲激光束只需要较小的功率即可使金属材料达到熔点,材料凝固时,重力、表面张力等力处于平衡状态,抛光效果好,还能节省能耗。(The invention relates to a laser polishing method and a laser polishing device, wherein a metal material is roughly polished by using continuous laser, the focus of the continuous laser beam is controlled to move up and down by using ultrasonic vibration in the process, so that the surface of the metal material is subjected to energy generation of the continuous laser beam to generate intermittent fluctuation, the intermittent fluctuation does not work intermittently like pulse laser, but keeps the characteristic that the continuous laser outputs laser at all times, only reduces the laser energy, reduces the heat accumulation on the surface of the metal material, better controls the laser energy, ensures that the surface of the metal material has higher flatness, uses the pulse laser to finely polish the metal material after the rough polishing is finished, because the continuous laser beam is used for polishing, the surface of the metal material has higher temperature, and the pulse laser beam only needs smaller power to ensure that the metal material reaches a melting point, when the material is solidified, the gravity, the surface tension and other forces are in a balanced state, the polishing effect is good, and the energy consumption can be saved.)

1. A laser polishing method applied to a laser polishing apparatus for polishing a metal material, the laser polishing method comprising:

emitting continuous laser beams to the surface of the metal material for rough polishing, wherein the focus of the continuous laser beams is controlled to move up and down by ultrasonic vibration in the process of emitting the continuous laser beams so that the surface of the metal material is subjected to intermittent fluctuation by energy of the continuous laser beams;

a pulsed laser beam is emitted to the surface of a metal material to perform finish polishing.

2. The laser polishing method according to claim 1, characterized in that: the vibration frequency of the ultrasonic vibration is greater than or equal to 5000HZ and less than or equal to 35000 HZ.

3. The laser polishing method according to claim 2, wherein said emitting a continuous laser beam to the surface of the metal material for rough polishing further comprises:

and controlling the focus of the continuous laser beam to move on the surface of the metal material so as to adjust the rough polishing area.

4. The laser polishing method according to claim 3, characterized in that: the rough polishing area is more than or equal to 100mm²。

5. The laser polishing method according to claim 3, characterized in that: the moving speed of the focal point of the continuous laser beam is greater than or equal to 10 mm/s.

6. The laser polishing method according to claim 3, wherein said emitting a pulse laser beam to the surface of the metal material for finish polishing further comprises:

and controlling the focus of the pulse laser beam to move on the surface of the metal material so as to adjust the fine polishing area.

7. The laser polishing method according to claim 5, characterized in that: the fine polishing area is more than or equal to 100mm²。

8. The laser polishing method according to claim 3, characterized in that: the moving speed of the focal point of the pulse laser beam is greater than or equal to 10 mm/s.

9. The laser polishing method according to any one of claims 1 to 8, wherein: before the emitting the continuous laser beam to the surface of the metal material for rough polishing, the method further comprises the following steps:

and inputting inert gas into the environment where the metal material is located.

10. A laser polishing apparatus for polishing an external metal material by the laser polishing method according to any one of claims 1 to 9, comprising:

a frame;

the continuous laser is arranged on the rack and used for generating continuous laser beams;

the pulse laser is arranged on the frame and used for generating a pulse laser beam;

the first galvanometer is arranged on the rack and comprises a first refractive lens group, a first focusing lens and an ultrasonic vibration piece, the continuous laser beam is refracted to the first focusing lens through the first refractive lens group and focused to the surface of the external metal material through the first focusing lens, and the ultrasonic vibration piece is connected with the first focusing lens and used for driving the first focusing lens to move up and down so as to enable the focus of the continuous laser beam to move up and down;

and the second vibrating mirror is arranged on the rack and comprises a second refraction lens group and a second focusing lens, and the pulse laser beam is refracted to the second focusing lens by the second refraction lens group and focused to the surface of the external metal material by the second focusing lens.

Technical Field

The invention relates to the field of laser processing, in particular to a laser polishing method and laser polishing equipment.

Background

The laser polishing technique has a selectable polishing speed, no chemical contamination, and a polishing process detectability, and is a non-contact processing method, and thus is widely used for polishing the surface of a metal material.

Laser polishing techniques involve the application of a focused laser beam spot to the surface of a roughened metallic material to cause the melting and evaporation of a thin raised layer on the surface of the material. The melted material flows under the action of surface tension and gravity of the material, fills the concave part of the surface of the material and solidifies, and finally obtains the ideal surface of the polishing material.

In the prior art, a continuous laser is mostly adopted to polish a metal material, the thermal stress generated due to large temperature gradient is large, so that cracks are easily generated on the surface of the metal material, and when the molten material is solidified, the forces such as gravity, surface tension and the like are always in an unbalanced state, so that the surface flatness of the metal material is poor, and the polishing effect is poor.

Disclosure of Invention

The technical problem to be solved by the embodiments of the present invention is to provide a laser polishing method and a laser polishing apparatus, so as to solve the problems in the prior art that when a continuous laser is used to polish a metal material, thermal stress generated due to a large temperature gradient is large, so that cracks are easily generated on the surface of the metal material, and when a molten material is solidified, forces such as gravity and surface tension are often in an unbalanced state, so that the surface flatness of the metal material is poor, and the polishing effect is poor.

In a first aspect, an embodiment of the present invention provides a laser polishing method, which is applied to a laser polishing apparatus to polish a metal material, and is characterized in that the laser polishing method includes: emitting continuous laser beams to the surface of the metal material for rough polishing, wherein the focus of the continuous laser beams is controlled to move up and down by ultrasonic vibration in the process of emitting the continuous laser beams so that the surface of the metal material is subjected to intermittent fluctuation by energy of the continuous laser beams; a pulsed laser beam is emitted to the surface of a metal material to perform finish polishing.

Further, the vibration frequency of the ultrasonic vibration is greater than or equal to 5000HZ and less than or equal to 35000 HZ.

Further, the emitting a continuous laser beam to the surface of the metal material for rough polishing further includes: and controlling the focus of the continuous laser beam to move on the surface of the metal material so as to adjust the rough polishing area.

Further, the rough polishing area is more than or equal to 100mm²。

Further, the moving speed of the focal point of the continuous laser beam is equal to or greater than 10 mm/s.

Further, the emitting a pulse laser beam to the surface of the metal material for finish polishing further includes: and controlling the focus of the pulse laser beam to move on the surface of the metal material so as to adjust the fine polishing area.

Further, the fine polishing area is more than or equal to 100mm²。

Further, the moving speed of the focal point of the pulse laser beam is 10mm/s or more.

Further, before emitting the continuous laser beam to the surface of the metal material for rough polishing, the method further comprises: and inputting inert gas into the environment where the metal material is located.

In a second aspect, an embodiment of the present invention further provides a laser polishing apparatus, including a frame; the continuous laser is arranged on the rack and used for generating continuous laser beams; the pulse laser is arranged on the frame and used for generating a pulse laser beam; the first galvanometer is arranged on the rack and comprises a first refractive lens group, a first focusing lens and an ultrasonic vibration piece, the continuous laser beam is refracted to the first focusing lens through the first refractive lens group and focused to the surface of an external metal material through the first focusing lens, and the ultrasonic vibration piece is connected with the first focusing lens and used for driving the first focusing lens to move up and down so as to enable the focus of the continuous laser beam to move up and down; and a second galvanometer mounted on the frame, the second galvanometer including a second refractive lens group and a second focusing lens, the pulse laser beam being refracted by the second refractive lens group to the second focusing lens and focused by the second focusing lens to the surface of the external metal material, wherein the laser polishing apparatus polishes the metal material by using the laser polishing method according to any one of the first aspect.

The embodiment of the invention has the beneficial effects that: the metal material is roughly polished by using the continuous laser, the focus of the continuous laser beam is controlled to move up and down by using ultrasonic vibration in the rough polishing process, the moving up and down of the focus can lead the surface of the metal material to be subjected to energy generation intermittent fluctuation of the continuous laser beam, the intermittent fluctuation does not operate intermittently like pulse laser, but keeps the characteristic of the continuous laser, laser output is realized immediately, only laser energy is reduced, heat accumulation on the surface of the metal material is reduced, the laser energy is better controlled, the flatness of the surface of the metal material is higher, the pulse laser is used for finely polishing the metal material after rough polishing is finished, and the temperature of the surface of the metal material is still high when the pulse laser beam is used for polishing, so the pulse laser beam only needs smaller power to lead the metal material to reach a melting point, when the material is solidified, the forces such as gravity, surface tension and the like are in a balanced state, so that the metal material is finely polished, the polishing effect is good, the energy consumption can be saved, and the polishing method is very environment-friendly.

Drawings

The following detailed description of embodiments of the invention will be made with reference to the accompanying drawings and examples, in which:

FIG. 1 is a flow chart of a laser polishing method of an embodiment of the present invention;

FIG. 2 is a detailed flow chart of a laser polishing method according to an embodiment of the present invention;

FIG. 3 is a detailed flow chart of a laser polishing method according to an embodiment of the present invention;

FIG. 4 is a schematic view of the overall structure of a laser polishing apparatus according to an embodiment of the present invention;

FIG. 5 is a partial schematic structural view of a laser polishing apparatus according to an embodiment of the present invention;

FIG. 6 is a partial schematic structural view of a laser polishing apparatus according to an embodiment of the present invention;

the figures are numbered:

1. laser polishing equipment; 11. a frame; 12. a continuous laser; 13. a pulsed laser; 14. a first galvanometer; 141. a focusing lens; 142. an ultrasonic vibrator; 15. a second galvanometer; 16. a control computer; 17. a water cooling mechanism; 18. sealing the cabin; 19. a lifting platform; 10. a beam expander; 200. a metal material; 300. an inert gas bottle.

Detailed Description

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

The embodiment of the invention provides a laser polishing method, which is applied to a laser polishing device 1 to polish metal materials, and as shown in fig. 1, 4 and 5, the laser polishing method comprises the following steps:

step S110: emitting a continuous laser beam to the surface of the metal material 200 for rough polishing, wherein the focus of the continuous laser beam is controlled to move up and down by using ultrasonic vibration in the process of emitting the continuous laser beam so that the energy of the continuous laser beam received by the surface of the metal material 200 generates intermittent fluctuation;

step S120: a pulsed laser beam is emitted to the surface of the metal material 200 to perform finish polishing.

By implementing the embodiment, the continuous laser is firstly used for melting the surface of the metal material 200 into liquid, the liquid state flows under the action of surface tension and gravity, so that the concave part of the surface of the metal material 200 is filled and solidified, then the pulse laser is used for finely polishing the metal material 200, and as the continuous laser beam is used for polishing, the temperature of the surface of the metal material 200 is very high when the pulse laser beam is used for polishing, so that the pulse laser beam only needs less power to enable the metal material 200 to reach a melting point, and when the material is solidified, the gravity, the surface tension and other forces are in a balanced state, so that the fine polishing of the metal material 200 is completed, and the polishing effect is good, the energy consumption can be saved, and the polishing device is very environment-friendly.

Specifically, the laser polishing aims to reduce the surface roughness, but the defects such as bulges and ripples are easily generated during the polishing process, the embodiment also controls the focus of the continuous laser beam to move up and down by using ultrasonic vibration during the continuous laser beam emitting process, the energy of the continuous laser beam received by the surface of the metal material 200 can be intermittently fluctuated by the up and down movement of the focus, the energy received by the surface of the metal material 200 can be reduced when the focus is far away from the surface of the metal material 200, the energy received by the surface of the metal material 200 can be increased when the focus is close to the surface of the metal material 200, the ultrasonic vibration can make the focus move up and down continuously, so that the energy of the continuous laser beam received by the surface of the metal material 200 can generate intermittent fluctuation, the intermittent fluctuation does not operate intermittently like the pulse laser, but maintains the characteristic of the continuous laser, namely, laser output is provided all the time, so that the laser energy is reduced, the heat accumulation on the surface of the metal material 200 is reduced, the laser energy is better controlled, and the flatness of the surface of the metal material 200 is higher. Wherein the ultrasonic vibration has a vibration frequency of 5000Hz or more and 35000Hz or less, and the polishing effect is best in the range of 29000 and 31000 Hz.

In a specific embodiment, as shown in fig. 2 and 5, step S110 specifically includes: the focus of the continuous laser beam is controlled to move on the surface of the metal material 200 to adjust the rough polishing area.

Since the focus of the continuous laser beam is small and only point polishing can be performed, the present embodiment controls the focus of the continuous laser beam to move on the surface of the metal material 200, thereby performing rough polishing on a plane or a curved surface. Wherein the rough polishing area is preferably 100mm or more²Since the polishing area is too small, heat accumulation occurs, resulting in more molten material.

Preferably, the moving speed of the focal point of the continuous laser beam is greater than or equal to 10mm/s, and the moving speed of the focal point of the continuous laser beam can change the laser energy density, wherein the slower the speed, the higher the laser energy, and vice versa. The skilled person can adapt the speed of movement of the focal point of the continuous laser beam to different metallic materials 200.

In a specific embodiment, as shown in fig. 2 and 5, step S120 specifically includes: the focus of the pulse laser beam is controlled to move on the surface of the metal material 200 to adjust the fine polishing area.

Since the focus of the pulse laser beam is small and only point polishing can be performed, the present embodiment controls the focus of the pulse laser beam to move on the surface of the metal material 200, thereby performing finish polishing on a plane or a curved surface. Wherein the fine polishing area is preferably 100mm or more²Since the polishing area is too small, heat accumulation occurs, resulting in more molten material.

Preferably, the moving speed of the focal point of the pulse laser beam is equal to or greater than 10mm/s, and the moving speed of the focal point of the pulse laser beam can change the laser energy density, wherein the slower the speed, the higher the laser energy, and vice versa. The skilled person can adapt the moving speed of the focal point of the pulsed laser beam to different metallic materials 200.

Since different metal materials 200 have different melting points, the polishing power used is different, and for the metal material 200 with higher melting point, such as S136D die steel, the melting point is 1550 ℃, the power should be controlled between 180W-230W during continuous laser polishing, and between 15W-35W during pulsed laser polishing. The present invention does not specifically limit the polishing power, and the polishing power is adaptively adjusted for different metal materials 200.

In a specific embodiment, as shown in fig. 3 and 5, step S110 further includes step S1101: inert gas is introduced into the environment in which the metal material 200 is located.

Specifically, in order to prevent the surface of the metal material 200 from being oxidized during the polishing process, which results in irregular micro-cracks on the surface, the present embodiment further improves the polishing quality by suppressing the occurrence of micro-cracks by introducing an inert gas into the environment in which the metal material 200 is located. For example, when the die steel is polished, inert gas such as argon or gas such as nitrogen that does not chemically react with the steel material may be used, thereby improving the polishing quality of the die steel.

The embodiment of the invention discloses a laser polishing method, as shown in fig. 1 and 5, firstly, continuous laser is used for rough polishing of a metal material 200, the ultrasonic vibration is used for controlling the focus of the continuous laser beam to move up and down in the rough polishing process, the focus moves up and down to enable the energy of the continuous laser beam on the surface of the metal material 200 to generate intermittent fluctuation, the intermittent fluctuation does not operate intermittently like pulse laser, the characteristic of the continuous laser is maintained, the laser output is available at any moment, the laser energy is only reduced, the heat accumulation on the surface of the metal material 200 is reduced, the laser energy is better controlled, the flatness of the surface of the metal material 200 is higher, the pulse laser is used for finish polishing of the metal material 200 after the rough polishing is finished, because the continuous laser beam is used for polishing, when the pulse laser beam is used for polishing, the temperature of the surface of the metal material 200 is high, so that the pulse laser beam can enable the metal material 200 to reach a melting point only by small power, and when the material is solidified, the forces such as gravity, surface tension and the like are in a balanced state, so that the metal material 200 is finely polished.

An embodiment of the present invention further provides a laser polishing apparatus 1, and as shown in fig. 4 to 6, the laser polishing apparatus 1 includes: a frame 11, a continuous laser 12, a pulse laser 13, a first galvanometer 14, and a second galvanometer 15. A continuous laser 12 is mounted on the frame 11, the continuous laser 12 is configured to generate a continuous laser beam, a pulse laser 13 is mounted on the frame 11, and the pulse laser 13 is configured to generate a pulse laser beam. The first galvanometer 14 is mounted on the frame 11, the first galvanometer 14 includes a first refractive lens group (not shown), a first focusing lens 141 and an ultrasonic vibration element 142, the continuous laser beam is refracted to the first focusing lens 141 by the first refractive lens group and focused to the surface of the external metal material 200 by the first focusing lens 141, and the ultrasonic vibration element 142 is connected to the first focusing lens 141 and used for controlling the first focusing lens 141 to move up and down so as to move the focus of the continuous laser beam up and down. The second galvanometer 15 is mounted on the frame, and includes a second refractive lens group (not shown) and a second focusing lens (not shown), and the pulse laser beam is refracted by the second refractive lens group to the second focusing lens and focused by the second focusing lens to the surface of the external metal material 200.

By implementing the embodiment, the continuous laser 12 is firstly adopted to generate a continuous laser beam, the continuous laser beam is refracted to the first focusing lens 141 through the first refractive lens group and is focused on the surface of the external metal material 200 through the first focusing lens 141 to melt the surface of the metal material 200 into liquid, and the liquid flows under the action of surface tension and gravity, so that the concave part on the surface of the metal material is filled and solidified, and in the process, the ultrasonic vibration piece 142 drives the first focusing lens 141 to move up and down to enable the focus of the continuous laser beam to move up and down. The up-and-down movement of the focus can make the surface of the metal material 200 receive the energy of the continuous laser beam to generate intermittent fluctuation, the intermittent fluctuation does not operate intermittently like the pulse laser, but keeps the characteristic of the continuous laser, namely, laser output is provided all the time, only the laser energy is reduced, the heat accumulation on the surface of the metal material 200 is reduced, the laser energy is better controlled, the flatness of the surface of the metal material 200 is higher, then the pulse laser 13 is adopted to generate the pulse laser beam, the pulse laser beam is refracted to the second focusing lens by the second refraction lens set and focused to the surface of the external metal material 200 by the second focusing lens, because the continuous laser beam is used for polishing, the temperature of the surface of the metal material 200 is still high when the pulse laser beam is used for polishing, so the pulse laser beam only needs less power to make the metal material 200 reach the melting point, when the material is solidified, the forces such as gravity, surface tension and the like are in a balanced state, so that the metal material 200 is finely polished, the polishing effect is good, the energy consumption can be saved, and the environment is very environment-friendly.

In one embodiment, as shown in fig. 4-6, the first refractive lens set and the second refractive lens set each include a plurality of refractive lenses (not shown), and at least one of the refractive lenses is capable of moving relative to the other refractive lenses, so as to adjust the focus positions of the continuous laser beam and the pulse laser beam.

By implementing the embodiment, the focal positions of the continuous laser beam and the pulse laser beam can be adjusted by using the refractive lens, so that plane polishing and curved surface polishing are realized.

In an embodiment, as shown in fig. 4-6, the laser polishing apparatus 1 further comprises a control computer 16 connected to the continuous laser 12, the pulse laser 13, the first galvanometer 14, and the second galvanometer 15.

Specifically, the machining parameters such as the rough polishing area, the finish polishing area, the moving speed of the focal point of the continuous laser beam, the moving speed of the focal point of the pulsed laser beam, and the polishing power can be set by the control computer 16. Wherein the rough polishing area and the fine polishing area are preferably equal to or larger than 100mm²Since the polishing area is too small, heat accumulation occurs, resulting in more molten material. The moving speed of the focal point can change the laser energy density, the slower the speed, the higher the laser energy and vice versa, and preferably the moving speed of the focal point of the continuous laser beam and the moving speed of the focal point of the pulsed laser beam are equal to or greater than 10 mm/s. Different metals have different melting points, so the polishing power used is different, and for the metal material with higher melting point, such as S136D die steel, the melting point is 1550 ℃, so the power should be controlled at 180W-2 during continuous laser polishing30W, and the power of the pulse laser polishing is controlled between 15W and 35W. The present invention does not specifically limit the polishing power, and the polishing power is adaptively adjusted for different metal materials 200.

In the embodiment, the control computer 16 is also connected to the ultrasonic vibrator 142.

Specifically, the vibration frequency of the ultrasonic vibrator may be set by the control computer 16, wherein the vibration frequency is equal to or higher than 5000HZ and equal to or lower than 35000 HZ. And the polishing effect is best when the vibration frequency is in the range of 29000-31000HZ

In the embodiment, the laser polishing apparatus 1 further includes a water cooling mechanism 17 connected to the continuous laser 12, the pulse laser 13, the first galvanometer 14, and the second galvanometer 15.

Specifically, when the laser polishing apparatus 1 operates, the continuous laser 12, the pulse laser 13, the first vibrating mirror 14, and the second vibrating mirror 15 generate a large amount of heat, and in this embodiment, the water cooling mechanism 17 is adopted to cool the continuous laser 12, the pulse laser 13, the first vibrating mirror 14, and the second vibrating mirror 15, so as to ensure that the continuous laser 12, the pulse laser 13, the first vibrating mirror 14, and the second vibrating mirror 15 can operate for a long time and are not damaged by high temperature.

In a particular embodiment, as shown in fig. 4-6, the laser polishing apparatus 1 further comprises a capsule 18. The hermetic chamber 18 is installed on the frame 11, the metal material is installed in the hermetic chamber 18, and the inert gas can be filled into the hermetic chamber 18 by using the inert gas bottle 300 during the process.

Specifically, in order to prevent the surface of the metal material 200 from being oxidized during polishing to cause irregular micro-cracks on the surface, the present embodiment further improves the polishing quality by filling the inside of the hermetic chamber 18 with an inert gas to suppress the occurrence of the micro-cracks. For example, when the die steel is polished, inert gas such as argon or gas such as nitrogen that does not chemically react with the steel material may be used, thereby improving the polishing quality of the die steel.

In an embodiment, as shown in fig. 4-6, the laser polishing apparatus 1 further includes a lifting table 19, the lifting table 19 is mounted on the frame, the first galvanometer 14 and the second galvanometer 15 are both mounted on the lifting table 19, and the lifting table 19 is used to drive the pulse laser 13 and the continuous laser 12 to ascend and descend.

Specifically, the lifting platform 19 can drive the first galvanometer 14 and the second galvanometer 15 to ascend and descend, so as to polish the metal materials 200 with different heights, and also polish the surfaces of the same metal material 200 with different heights, thereby increasing the universality of the laser polishing device 1. For example, the focus of the continuous laser beam emitted from the first galvanometer 14 is formed at a distance of 480mm from the first galvanometer, and the height of the first galvanometer 14 can be adjusted by the elevation table 19 so that the first galvanometer is 480mm away from the surface of the metal material 200.

In an embodiment, as shown in fig. 4-6, the laser polishing apparatus 1 further includes two beam expanders 10, and the two beam expanders 10 are respectively disposed on the optical path between the continuous laser 12 and the first galvanometer 14, and the optical path between the pulse laser 13 and the second galvanometer.

Specifically, the beam expander 10 can adjust the beam diameter and divergence angle to reduce the focused spot, and a smaller spot can achieve a higher energy density in laser polishing.

It should be understood that the above embodiments are only used for illustrating the technical solutions of the present invention, and not for limiting the same, and those skilled in the art can modify the technical solutions described in the above embodiments, or make equivalent substitutions for some technical features; and all such modifications and alterations should fall within the scope of the appended claims.