CN115945776A - Device and method capable of realizing multiple laser shot blasting forming under rigid constraint layer - Google Patents

Abstract

The invention provides a device and a method capable of realizing multiple laser shot peening forming under a rigid constraint layer, and the device comprises a motion system, a laser shot peening system, a laser heating and warming system, a particle flowing system and a working groove, wherein a workpiece to be processed is arranged in the working groove, the working groove is communicated with the particle flowing system to form a closed loop, and charged black paint particles are adsorbed on the surface of the workpiece to be processed through the particle flowing system; the laser heating system is used for enabling the charged black paint particles to form a black paint deposition layer on the surface of the workpiece to be processed; the laser shot blasting strengthening system is used for carrying out laser shot blasting on the surface of a workpiece to be processed. The invention utilizes the characteristic that charged small particles are easy to be adsorbed on the metal surface, and adopts a nanosecond pulse laser heating method to melt and deposit the tiny black paint particles at the appointed position, thereby realizing the timely supplement of the absorption layer and the accurate control of the thickness of the absorption layer.

Description

Device and method capable of realizing multiple laser shot blasting forming under rigid constraint layer

Technical Field

The invention relates to the field of laser shock forming, in particular to a device and a method capable of realizing multiple times of laser shot blasting forming under a rigid constraint layer.

Background

The laser shot-peening forming is a new flexible precise die-free forming method, which uses high-energy laser beam to impact the plate material point by point, the impact of the vapor generated by laser ablation on the metal material makes the metal material generate compression plastic deformation, and the plastic extension deformation characteristic of the metal material is used to form macroscopic large deformation by small product. Has been widely applied to the fields of aerospace, space science, marine ships and the like.

Theories and practices prove that the constraint layer can greatly increase the pressure of the laser shock wave and prolong the duration time of the laser shock wave by blocking the escape of the vapor, and better forming benefits can be obtained.

Common constraining layers are classified into liquid constraining layers, flexible constraining layers, and rigid constraining layers, wherein the initial state of the high pressure gas mass can be maintained for a long time since the rigid constraining layers are not deformed, and then the vapor is diffused from the gap between the constraining layers and the workpiece.

Although the rigid constraining layer has the best effect on the vapor constraint, the rigid constraining layer is not usually adopted in the laser peening currently because the following difficulties cannot be solved:

1. the generation of the laser shot peening is that colored vapor adheres to the surface of the rigid absorption layer, and the laser beam is prevented from irradiating the surface of the metal workpiece by multiple impacts, so that irreparable damage is caused to the constraint layer.

2. Because laser shot blasting can generate pits and the center of the workpiece can generate a pit after being formed, the gap between the rigid constraint layer and the absorption layer is too large to be beneficial to the constraint of the vapor, and the impact force and the duration can be greatly reduced.

3. The absorbing layer is too thick, so that impact force is not transmitted to the surface of a workpiece, and when the absorbing layer is too thin, if the absorbing layer needs to be replaced for multiple times of laser shot blasting, the process is complicated.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides a device and a method for realizing multiple times of laser shot-peening forming under a rigid restraint layer, which utilize the characteristic that charged small particles are easy to be adsorbed on the surface of metal, and adopt a nanosecond pulse laser heating method to melt and deposit tiny black paint particles at an appointed position, thereby realizing timely supplement to an absorption layer and accurate control on the thickness of the absorption layer, and adopt femtosecond pulse laser to perform multiple times of shot-peening forming, so that the forming precision is extremely high; the heating and temperature rising system is combined with high-speed flowing air flow to melt and flexibly remove black paint impurities attached to the surface of the optical glass, the optical glass is not damaged, and the benefit of next laser shot blasting is not influenced.

The present invention achieves the above-described object by the following technical means.

A device capable of realizing multiple laser shot peening forming under a rigid constraint layer comprises a motion system, a laser shot peening strengthening system, a laser heating system, a particle flowing system and a working groove,

a workpiece to be processed is arranged in the working groove, the working groove is communicated with the particle flowing system to form a closed loop, and charged black paint particles are adsorbed on the surface of the workpiece to be processed through the particle flowing system; the laser heating system is used for enabling the charged black paint particles to form a black paint deposition layer on the surface of the workpiece to be processed; the laser shot blasting strengthening system is used for carrying out laser shot blasting on the surface of a workpiece to be processed; the motion system is used for enabling the laser shot peening system, the laser heating system and the workpiece to be processed to move.

Further, the particle flowing system comprises a shell, an electronic ejector, an electronic storage cavity, a high-speed fan, a refrigeration rod, a particle crusher, a particle storage box, a pressure sensor probe and a pneumatic pump;

a working groove is arranged in a closed flow passage of the shell, optical glass is arranged on the shell above the working groove, and the closed flow passage is sequentially provided with a particle crusher, a particle storage box, a high-speed fan, an electronic storage cavity and a workpiece to be processed according to the flow direction; the particle storage box is used for storing black paint particles, and the refrigeration rod is used for cooling the recycled vaporized black paint; the particle crusher is used for crushing the cooled black paint into black paint particles; the outlet of the particle crusher is provided with a pneumatic pump used for keeping pressure in the closed flow passage;

the upper half part of one side wall surface of the particle storage box is of a mesh structure, and the lower half part of one side wall surface of the particle storage box is a closed boundary; the other side wall surface of the particle storage box is a double-layer baffle, one layer of baffle is a mesh baffle, and the other layer of baffle is a movable closed baffle; the particle storage box is provided with a movable pressure plate mechanism which is used for dividing the particle storage box into a circulation area and a black paint particle area; the upper side and the lower side of the electronic storage cavity are of a net structure, and an electronic ejector is mounted on the electronic storage cavity and used for enabling free electrons to be generated in the electronic storage cavity.

Further, the laser heating system comprises a nanosecond laser, a second reflector and a second focusing mirror; the laser beam emitted by the nanosecond laser is reflected by the second reflecting mirror and then focused on the surface of the workpiece to be processed through the second focusing mirror, so that charged black paint particles form a black paint deposition layer on the surface of the workpiece to be processed; when the height of the black paint deposition layer is increased, the focal position of the second focusing lens is changed, so that the laser beam is focused on the black paint particle adsorption layer on the upper surface of the black paint deposition layer; the laser shot peening strengthening system comprises a femtosecond laser, a first reflecting mirror and a first focusing mirror; and laser beams emitted by the femtosecond laser are reflected by the first reflecting mirror and then focused to the upper surface of the black paint deposition layer through the first focusing mirror.

Further, the motion system comprises a first slide rail, a first slide block, a second slide rail, a third slide block and a mobile platform, wherein the first slide block and the second slide block are respectively arranged on the first slide rail; the first sliding block is connected with the first reflector, and the second sliding block is connected with the second reflector; the third sliding block is arranged on the second sliding rail; the third sliding block is connected with the second focusing mirror and is used for changing the focal position of the second focusing mirror; and a workpiece to be processed is placed on the moving platform.

The device further comprises a three-dimensional information collector, a pressure sensor and a displacement sensor, wherein the three-dimensional information collector is aligned to the lower surface of the optical glass and is used for capturing whether black paint vapor is attached to the lower surface of the optical glass or not; the displacement sensor is used for detecting the thickness of the black paint deposition layer and the distance between the black paint deposition layer and the optical glass; the pressure sensor is used for detecting the pressure in the closed flow passage.

A method for realizing a device for multiple times of laser shot peening forming under a rigid constraint layer comprises the following steps:

filling high-pressure gas in the closed flow channel through a pneumatic pump, and closing the pneumatic pump after the pressure sensor reaches a first set value;

the black paint particles in the particle storage box circularly flow in the closed flow passage by controlling the high-speed fan to start; the black paint particles pass through the electronic storage cavity and then are charged through the electronic ejector; the charged black paint particles are adsorbed on the surface of a workpiece to be processed;

controlling the second sliding block to move, so that the light of the nanosecond laser is reflected by the second reflector to reach the surface of the workpiece to be processed; aligning a black paint particle layer adsorbed on the surface of a workpiece to be processed through a laser focus to form a black paint deposition layer; when the thickness of the black paint deposition layer is determined to reach a design value through the displacement sensor, the nanosecond laser is turned off;

controlling the first sliding block to move, so that the light of the femtosecond laser is reflected by the first reflecting mirror to reach the surface of the black paint deposition layer; dividing the particle storage box into a circulation area and a black paint particle area by moving the pressure plate mechanism; controlling the movable sealing baffle plate to enable the circulation area to be communicated with the sealing flow channel; performing laser shot blasting on the black paint deposition layer by laser generated by a femtosecond laser;

capturing whether attached black paint vapor exists on the lower surface of the optical glass or not through a three-dimensional information collector, and focusing laser generated by a nanosecond laser on the lower surface of the optical glass for laser cleaning when the attached black paint vapor exists; and controlling the wind speed of the high-speed fan, and blowing off the melted or gasified black paint attachments by utilizing the airflow flow in the closed flow channel.

Further, the method also comprises the following steps:

in the laser shot blasting process, the displacement sensor monitors the thickness of the black paint deposition layer in real time, when the thickness of the black paint deposition layer is smaller than a second set value, laser shot blasting processing is stopped, the movable sealing baffle is controlled to enable the black paint particle area to be communicated with the sealing flow channel, and the high-speed fan is controlled to start, so that the black paint particles with charges are adsorbed on the surface of the black paint deposition layer to be subjected to laser shot blasting; controlling the light of the nanosecond laser to be reflected by the second reflector to reach the surface of the black paint deposition layer; the laser focus is aligned to the black paint particle layer adsorbed on the surface of the black paint deposition layer, and the black paint particle layer is used for supplementing the black paint deposition layer.

Further, controlling the position of a nanosecond laser focus point according to the monitoring value of the displacement sensor to enable the thickness of the black paint deposition layer to be 1-100 mu m; controlling the moving platform to enable the distance between the black paint deposition layer and the optical glass to be 5-20 mu m; the particle diameter in the particle storage box is within 1 mu m; and the black paint pulverizer pulverizes the cooled blocky black paint into particles with the diameter less than 1 mu m.

Further, the electron jet flow rate of the electron jet is far greater than the instantaneous flow rate of the particles in the closed flow channel passing through the high-speed fan; when a nanosecond laser heats black paint particles to form a black paint deposition layer, the flow rate of the high-speed fan is 1-10 mm/s, and the movable sealing baffle is controlled to move downwards to increase the flow cross section;

when a femtosecond laser performs laser shot blasting on the black paint deposition layer, the flow rate of the high-speed fan is 10-100 mm/s, and the movable sealing baffle is controlled to move upwards to reduce the flow cross section;

when the laser generated by the nanosecond laser cleans the lower surface of the optical glass, the flow velocity of the high-speed fan is 100-1000 mm/s, and the movable sealing baffle is controlled to move upwards to reduce the flow cross section.

Furthermore, the nanosecond laser adopts square light spots, the side length of each light spot is 0.1-1mm, the laser energy is 0.03-5 mJ, and the laser pulse width is 5-10ns;

the femtosecond laser adopts a circular light spot, the diameter of the light spot is 3-5mm, the laser energy is 3-15 mJ, and the laser pulse width is 300-500fs.

The invention has the beneficial effects that:

1. the device and the method can realize multiple laser shot blasting forming under a rigid constraint layer, can form a particle film on the surface of a deposition layer through flowing fine charged black paint particles, can timely supplement pits generated by laser shot blasting and central depression generated by workpiece deformation by combining a nano laser heating technology, can perform accurate repair, and avoid the attenuation of impact benefits caused by surface appearance change.

2. The device and the method can realize multiple times of laser shot blasting forming under the rigid constraint layer, and the infrared distance meter can detect the thickness of the black paint deposition layer and the distance between the black paint deposition layer and the rigid constraint layer in real time, thereby effectively ensuring the constraint effect of the constraint layer on the vapor and reducing the attenuation of impact force along the deposition layer.

3. The device and the method can realize multiple laser shot-peening formation under the rigid constraint layer, can detect the attachment condition of the gas on the surface of the rigid constraint layer in real time through the three-dimensional information collector, can timely clean and remove the rigid constraint layer by the control system, avoid the absorption of stains on laser energy, improve the utilization rate of the laser energy, reduce the damage of the rigid constraint layer and ensure that the laser shot-peening effect is basically unchanged every time.

4. The invention can realize the device and the method for forming the rigid restraint layer by multiple laser shot blasting, the black paint particles are gasified and condensed in the closed space for circulation, and the condensed blocky black paint can be ground into particles meeting the requirement by a particle grinder so as to be recycled.

5. According to the device and the method for realizing multiple times of laser shot blasting forming under the rigid constraint layer, during laser shot blasting forming, the black paint vapor can be taken away by airflow flowing in the absorption layer and the constraint layer, and the influence on shot blasting effect due to solidification on the surface of the optical glass is avoided.

6. According to the device and the method for realizing multiple times of laser shot blasting forming under the rigid constraint layer, the temperature and the pressure of the target surface are accumulated in the laser pulse process, and an unbalanced Knudsen layer is formed. The pressure of the knudsen layer is released rapidly, so that the overpressure is exponentially attenuated in the evolution process of the shock wave. The attenuation of the overpressure is due to the relatively low density and high compressibility of the air. The laser ablation product works with constant compression of air, resulting in irreversible energy loss. The pneumatic pump ensures that the initial environment of the laser shot blasting forming area is in a high-pressure state, the density is increased, the compressibility is reduced, the peak value before the pressure release of the Knudsen layer can be increased, the speed of air extrusion by the vapor is reduced, and the attenuation speed of overpressure is reduced, so that the peak value and the duration of impact force are improved, and the laser shot blasting forming area has promotion benefit.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below, and the drawings in the following description are some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained from the drawings without creative efforts.

FIG. 1 is an assembly view of an apparatus for performing multiple laser peening operations under a rigid constraining layer in accordance with the present invention.

FIG. 2 is a process flow diagram of the processing method of the present invention for achieving multiple laser peening formations under a rigid constraining layer.

In the figure:

1-a first slide rail; 2-a first slide block; 3-a second slide block; 4-femtosecond laser; 5-a first mirror; 6-a second mirror; a 7-nanosecond laser; 8-a computer; 9-a three-dimensional information collector; 10-a first focusing mirror; 11-a second focusing mirror; 12-a second slide rail; 13-a third slide; 14-optical glass; 15-a displacement sensor; 16-a housing; 17-black paint particles; 18-a motion controller; 19-black paint deposition; 20-a workpiece to be processed; 21-a mobile platform; 22-electron injector; 23-an electronic storage chamber; 24-free electrons; 25-high speed fan; 26-a refrigeration stick; 27-a particle grinder; 28-a particle storage tank; 29-wind speed controller; 30-a moving platen mechanism; 31-a pressure sensor; 32-a damper controller; 33-pneumatic pump.

Detailed Description

The invention will be further described with reference to the following figures and specific examples, but the scope of the invention is not limited thereto.

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

In the description of the present invention, it is to be understood that the terms "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "axial," "radial," "vertical," "horizontal," "inner," "outer," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the present invention and for simplicity in description, and are not intended to indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and are not to be considered limiting. Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

In the present invention, unless otherwise explicitly stated or limited, the terms "mounted," "connected," "fixed," and the like are to be construed broadly and may, for example, be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

As shown in fig. 1, the apparatus capable of achieving multiple times of laser shot peening formation under a rigid constraint layer according to the present invention includes a motion system, a laser shot peening system, a laser heating system, a particle flow system and a working tank, wherein a workpiece 20 to be processed is installed in the working tank, the working tank and the particle flow system are communicated to form a closed loop, and charged black paint particles 17 are adsorbed on the surface of the workpiece 20 to be processed through the particle flow system; the laser shot peening strengthening system and the laser heating system are respectively positioned above the workpiece 20 to be processed, and the laser heating system is used for enabling the charged black paint particles 17 to form a black paint deposition layer 19 on the surface of the workpiece 20 to be processed; the laser shot peening strengthening system is used for performing laser shot peening on the surface of the workpiece 20 to be processed; the motion system is used for moving the laser shot peening system, the laser heating and warming system and the workpiece 20 to be processed. The invention utilizes the characteristic that charged small particles are easy to be adsorbed on the surface of metal, and adopts a nanosecond pulse laser heating method to melt and deposit the tiny black paint particles at the designated position, thereby realizing the timely supplement of the absorption layer and the accurate control of the thickness of the absorption layer; the heating and temperature rising system is combined with high-speed flowing air flow to melt and flexibly remove black paint impurities attached to the surface of the optical glass, the optical glass is not damaged, and the benefit of next laser shot blasting is not influenced.

The particle flowing system comprises a shell 16, an electronic ejector 22, an electronic storage cavity 23, a high-speed fan 25, a refrigeration rod 26, a particle crusher 27, a particle storage box 28, a pressure sensor probe 31 and a pneumatic pump 33; a working groove is arranged in a closed flow channel of the shell 16, optical glass 14 is arranged on the shell above the working groove, and a particle crusher 27, a particle storage box 28, a high-speed fan 25, an electronic storage cavity 23 and a workpiece 20 to be processed are sequentially arranged in the closed flow channel according to the flow direction; black paint particles are stored in the particle storage box 28, and the refrigeration rod 26 is used for cooling the recycled vaporized black paint; the particle crusher 27 is used for crushing the cooled black paint into black paint particles; an air pressure pump 33 is arranged at the outlet of the particle crusher 27 and used for keeping pressure in the closed flow channel; the upper half part of one side wall surface of the particle storage box 28 is of a mesh structure, and the lower half part of one side wall surface of the particle storage box 28 is a closed boundary; the other side wall surface of the particle storage box 28 is a double-layer baffle, one layer of baffle is a mesh baffle, and the other layer of baffle is a movable closed baffle; the particle storage tank 28 is provided with a movable platen mechanism 30 for dividing the particle storage tank 28 into a circulation area and a black paint particle area; the upper side and the lower side of the electronic storage cavity 23 are of a net structure, and the electronic storage cavity 23 is provided with an electronic ejector 22 for generating free electrons 24 inside the electronic storage cavity 23.

The laser heating system comprises a nanosecond laser 7, a second reflector 6 and a second focusing mirror 11; the laser beam emitted by the nanosecond laser 7 is reflected by the second reflecting mirror 6 and then focused on the surface of the workpiece 20 to be processed through the second focusing mirror 11, so that the charged black paint particles 17 form a black paint deposition layer 19 on the surface of the workpiece 20 to be processed; when the height of the black paint deposition layer 19 is increased, the laser beam is always focused on the black paint particle 17 adsorption layer on the upper surface of the black paint deposition layer 19 by changing the focal position of the second focusing lens 11; the laser shot peening strengthening system comprises a femtosecond laser 4, a first reflecting mirror 5 and a first focusing mirror 10; the laser beam emitted by the femtosecond laser 4 is reflected by the first reflecting mirror 5 and then focused to the upper surface of the black paint deposition layer 19 through the first focusing mirror 10.

The motion system comprises a first slide rail 1, a first slide block 2, a second slide block 3, a second slide rail 12, a third slide block 13 and a mobile platform 21, wherein the first slide block 2 and the second slide block 3 are respectively arranged on the first slide rail 1; the first sliding block 2 is connected with a first reflector 5, and the second sliding block 3 is connected with a second reflector 6; the third sliding block 13 is mounted on the second sliding rail 12; the third sliding block 13 is connected with the second focusing mirror 11, and the position of a focus relative to the black paint deposition layer 19 and the optical glass 14 is changed in real time by driving the second focusing mirror 11 to move up and down so as to change the focus position of the second focusing mirror 11; the workpiece 20 to be processed is placed on the moving platform 21, the moving platform 21 is connected with the motion controller 18, and the maximum distance between the optical glass 14 and the moving platform 21 can reach 10mm.

The device capable of realizing multiple times of laser shot blasting forming under the rigid constraint layer further comprises a three-dimensional information collector 9, a pressure sensor 31 and a displacement sensor 15, wherein the three-dimensional information collector 9 is aligned to the lower surface of the optical glass and used for capturing whether black paint vapor is attached to the lower surface of the optical glass 14 or not; the displacement sensor 15 is used for detecting the thickness of the black paint deposition layer 19 and the distance between the black paint deposition layer 19 and the optical glass 14; the pressure sensor 31 is used for detecting the pressure in the closed flow passage.

The computer 8 controls the first slide block 2, the second slide block 3, the femtosecond laser 4, the nanosecond laser 7, the three-dimensional information collector 9, the third slide block 13, the displacement sensor 15, the motion controller 18, the electronic ejector 22, the wind speed controller 29, the pressure sensor 30, the baffle controller 32 and the pneumatic pump 33. The wind speed controller 29 is used to control the wind speed of the high-speed fan 25. The damper controller 32 is used to control the movable closure damper on the particle storage tank 28. The motion controller 18 is used to control the movement of the moving platform 21.

As shown in fig. 2, the processing method of the apparatus capable of implementing multiple times of laser peening forming under rigid constraint layer according to the invention comprises the following steps:

the closed flow channel is filled with high-pressure gas through a pneumatic pump 33, and the pneumatic pump 33 is closed when the pressure sensor 31 reaches a first set value;

the black paint particles 17 in the particle storage tank 28 circularly flow in the closed flow passage by controlling the high-speed fan 25 to be started; the black paint particles 17 pass through the electron storage cavity 23 and then are charged by the electron ejector 22; the charged black paint particles 17 are adsorbed on the surface of the workpiece 20 to be processed;

controlling the second slide block 3 to move, so that the light of the nanosecond laser 7 is reflected by the second reflector 6 to reach the surface of the workpiece 20 to be processed; the black paint particle layer absorbed on the surface of the workpiece 20 to be processed is focused by laser to form a black paint deposition layer 19; when the thickness of the black paint deposition layer 19 is determined to reach a design value through the displacement sensor 15, the nanosecond laser 7 is turned off;

controlling the first slide block 2 to move, so that the light of the femtosecond laser 4 is reflected by the first reflector 5 to reach the surface of the black paint deposition layer 19; the particle storage tank 28 is divided into a circulation area and a black paint particle area by moving the platen mechanism 30; controlling the movable sealing baffle plate to enable the circulation area to be communicated with the sealing flow channel; performing laser shot blasting on the black paint deposition layer 19 by laser generated by the femtosecond laser 4;

capturing whether attached black paint vapor exists on the lower surface of the optical glass 14 or not through the three-dimensional information collector 9, and focusing laser generated by the nanosecond laser 7 on the lower surface of the optical glass 14 for laser cleaning when the attached black paint vapor exists; the speed of the high-speed fan 25 is controlled, and the melted or gasified black paint attachment is blown away by the airflow flowing in the closed flow channel.

In the laser shot blasting process, the displacement sensor 15 monitors the thickness of the black paint deposition layer 19 in real time, when the thickness of the black paint deposition layer 19 is smaller than a second set value, laser shot blasting processing is stopped, the movable sealing baffle is controlled to enable a black paint particle area to be communicated with the closed flow channel, and the black paint particles 17 with charges are adsorbed on the surface of the black paint deposition layer 19 to be detected by controlling the high-speed fan 25 to be started; controlling the light of the nanosecond laser 7 to be reflected by the second reflecting mirror 6 to reach the surface of the black paint deposition layer 19; the layer of black paint particles adsorbed on the surface of the black paint deposition layer 19 is focused by laser to replenish the black paint deposition layer 19.

Controlling the position of a focusing point of a nanosecond laser 7 according to a monitoring value of a displacement sensor 15 to enable the thickness of the black paint deposition layer 19 to be 1-100 mu m; the distance between the black paint deposition layer 19 and the optical glass 14 is 5-20 mu m by controlling the moving platform 21, so that the optical glass 14 is guaranteed to play a role in restraining laser shot blasting and is not easy to break; the maximum distance between the moving platform 21 and the optical glass 14 is 10mm, so that the flowing of the black paint particles 17 and the deposition of the black paint deposition layer 19 are facilitated. The particle diameter in the particle storage tank 28 is within 1 μm; the black paint pulverizer 27 pulverizes the block-shaped black paint after cooling into particles with the diameter less than 1 μm.

When the nanosecond laser 7 heats the black paint particles 17 to form the black paint deposition layer 19, the flow rate of the high-speed fan 25 is 1-10 mm/s, and the movable sealing baffle is controlled to move downwards to increase the flow cross section; when the femtosecond laser 4 carries out laser shot blasting on the black paint deposition layer 19, the flow rate of the high-speed fan 25 is 10-100 mm/s, and the movable sealing baffle is controlled to move upwards to reduce the flow cross section; when the laser generated by the nanosecond laser 7 cleans the lower surface of the optical glass 14, the flow rate of the high-speed fan 25 is 100-1000 mm/s, and the movable sealing baffle is controlled to move upwards to reduce the flow cross section.

The nanosecond laser 7 adopts a square light spot, the side length of the light spot is 0.1-1mm, the laser energy is 0.03-5 mJ, and the laser pulse width is 5-10ns; the femtosecond laser device 4 adopts a circular light spot, the diameter of the light spot is 3-5mm, the laser energy is 3-15 mJ, and the laser pulse width is 300-500fs.

The electron jet 22 jets electron flow far larger than the instantaneous flow of the particles in the closed flow channel through the high-speed fan 25, so that more than 95% of the black paint particles 17 are ensured to be attached with electron with electronegativity and can be adsorbed on the surface of the metal workpiece to form a thin black paint particle layer of 1-3 s for a short time, because the particles are repelled in an isotropic way when being charged; when the particle electrons are changed into uncharged particles by the metal workpiece, the black paint particles 17 can be blown away by high-speed high-pressure fluid without the action of adsorption force, so that the mutual adhesion of the black paint particles 17 is avoided, and the point-by-surface repair and layer-by-layer quick deposition of the black paint deposition layer 19 with high precision are facilitated. When the black paint particles 17 are heated and melted to become the black paint deposition layer 19, the contact between the black paint deposition layer 19 and the metal workpiece for more than 3 seconds can become electrically neutral, and the black paint deposition layer 19 can adsorb the black paint particles 17 for 1 to 3 seconds.

The method for realizing multiple times of laser shot peening forming under the rigid constraint layer in the embodiment 1 comprises the following steps:

s1: and a workpiece 20 to be machined is arranged in the working groove, and the workpiece 20 to be machined is a metal workpiece. Typically micro/nano-scale, mechatronics and MEMS products. Opening the pneumatic pump 33 to fill the closed flow channel with high-pressure gas, and closing the pneumatic pump 33 when the pressure sensor 30 reaches 2-5 atm;

s2: the computer 8 controls the electronic ejector 22, the air speed controller 29, the refrigerating rod 26 and the particle crusher 27 to be started, so that the black paint particles 17 in the particle storage box 28 circularly flow in the closed flow channel, the black paint particles 17 are negatively charged after passing through the electronic storage cavity 23, and the charged black paint particles 17 have a transient adsorption effect when passing through the surface of the metal workpiece;

s3: the computer 8 controls the second sliding block 3 to move, so that light of the nanosecond laser 7 is reflected by the second reflecting mirror 6 to reach the coordinate origin of a processing area, at the moment, the nanosecond laser 7, the motion controller 18, the third sliding block 13 and the non-contact infrared distance meter are started, the motion controller 18 controls the moving platform 21 to move in three dimensions, a laser focus is aligned with a black paint particle layer temporarily adsorbed on the surface of the metal workpiece 20 to be melted and gradually accumulated to form a black paint deposition layer 19, the thickness of the black paint deposition layer 19 is observed by the non-contact infrared distance meter, the nanosecond laser 7, the third sliding block 13 and the wind speed controller 29 are closed after the proper thickness is reached, the second reflecting mirror 3 is started to control the second reflecting mirror 6 to be far away from the upper part of the working table, and the motion controller 18 controls the moving platform 21 to return to the position and rise for a certain distance, so that the distance between the black paint deposition layer and the optical glass 14 is proper;

s4: the computer 8 controls the first sliding block 2 to move, so that the light of the femtosecond laser 4 is reflected by the first reflector 5 to reach the coordinate origin of the processing area, the movable pressure plate mechanism 30 is started to divide the particle storage box 28 into a circulation area and a black paint particle area, and the movable sealing baffle is controlled to enable the circulation area to be communicated with the sealing flow channel; the air flow rate is controlled by controlling the air speed controller 29 to reach a proper flow rate, and at the moment, the femtosecond laser 4, the motion controller 18 and the three-dimensional information collector 9 are started to realize multiple laser shot blasting on the black paint deposition layer 19;

s5: monitoring the thicknesses of different sections on the whole plane of the black paint deposition layer 19 by the non-contact infrared distance meter at any time, and repeating the S3 operation to directionally supplement the black paint deposition layer 19 when the thickness of a certain section is lower than a certain range;

s6: the three-dimensional information collector 9 captures whether black paint vapor is attached to the lower surface of the optical glass 14 at any time, if yes, the second sliding block 3, the nanosecond laser 7, the motion controller 18, the third sliding block 13, the wind speed controller 29 and the baffle controller 32 are started, proper laser parameters are selected to enable a laser focus to be focused on a black area to enable the black paint attachment to be melted or gasified, the baffle controller 32 controls the baffle to be higher than the particle storage height in the particle storage box 28, and the wind speed controller 29 controls the wind speed of the high-speed fan 25 to enable pure high-pressure airflow in the pipeline to flow at a high speed to blow away the melted or gasified black paint attachment;

s7: and (4) circulating S4-S6, completing laser shot peening forming of the workpiece, and closing all equipment.

It should be understood that although the present description has been described in terms of various embodiments, not every embodiment includes only a single embodiment, and such description is for clarity purposes only, and those skilled in the art will recognize that the embodiments described herein may be combined as suitable to form other embodiments, as will be appreciated by those skilled in the art.

The above-listed detailed description is only a specific description of a possible embodiment of the present invention, and they are not intended to limit the scope of the present invention, and equivalent embodiments or modifications made without departing from the technical spirit of the present invention should be included in the scope of the present invention.

Claims (10)

1. A device capable of realizing multiple times of laser shot peening forming under a rigid constraint layer is characterized by comprising a motion system, a laser shot peening strengthening system, a laser heating system, a particle flowing system and a working tank,

a workpiece (20) to be processed is arranged in the working groove, the working groove is communicated with the particle flow system to form a closed loop, and charged black paint particles (17) are adsorbed on the surface of the workpiece (20) to be processed through the particle flow system; the laser heating temperature rising system is used for enabling charged black paint particles (17) to form a black paint deposition layer (19) on the surface of a workpiece (20) to be processed; the laser shot blasting strengthening system is used for carrying out laser shot blasting on the surface of a workpiece (20) to be processed; the motion system is used for enabling the laser shot peening system, the laser heating temperature rising system and the workpiece (20) to be processed to move.

2. Device capable of achieving multiple laser shot peening formations under rigid constraining layers according to claim 1, characterized in that the particle flow system comprises a housing (16), an electronic ejector (22), an electronic storage chamber (23), a high speed fan (25), a refrigeration rod (26), a particle crusher (27), a particle storage tank (28), a pressure sensor probe (31) and a pneumatic pump (33);

a working groove is arranged in a closed flow channel of the shell (16), optical glass (14) is arranged on the shell above the working groove, and a particle crusher (27), a particle storage box (28), a high-speed fan (25), an electronic storage cavity (23) and a workpiece (20) to be processed are sequentially arranged in the closed flow channel according to the flow direction; the particle storage box (28) is internally provided with black paint particles, and the refrigeration stick (26) is used for cooling the recycled vaporized black paint; the particle crusher (27) is used for crushing the cooled black paint into black paint particles; the outlet of the particle crusher (27) is provided with a pneumatic pump (33) for keeping the pressure in the closed flow channel; the upper half part of one side wall surface of the particle storage box (28) is of a mesh structure, and the lower half part of one side wall surface of the particle storage box (28) is a closed boundary; the other side wall surface of the particle storage box (28) is a double-layer baffle, one layer of baffle is a mesh baffle, and the other layer of baffle is a movable closed baffle; the particle storage tank (28) is provided with a movable platen mechanism (30) which is used for dividing the particle storage tank (28) into a circulation area and a black paint particle area; the upper side and the lower side of the electronic storage cavity (23) are of a net structure, and an electronic ejector (22) is mounted on the electronic storage cavity (23) and used for generating free electrons (24) in the electronic storage cavity (23).

3. Device capable of achieving multiple laser shot peening under a rigid constraining layer according to claim 1, characterized in that the laser heating temperature raising system comprises a nanosecond laser (7), a second mirror (6) and a second focusing mirror (11); the laser beam emitted by the nanosecond laser (7) is reflected by the second reflecting mirror (6) and then focused on the surface of the workpiece (20) to be processed through the second focusing mirror (11) to form a black paint deposition layer (19) on the surface of the workpiece (20) to be processed by the black paint particles (17) with charges; when the height of the black paint deposition layer (19) is increased, the laser beam is focused on the black paint particle (17) adsorption layer on the upper surface of the black paint deposition layer (19) by changing the focal position of the second focusing lens (11); the laser shot peening system comprises a femtosecond laser (4), a first reflecting mirror (5) and a first focusing mirror (10); and laser beams emitted by the femtosecond laser (4) are reflected by the first reflector (5) and then focused to the upper surface of the black paint deposition layer (19) through the first focusing mirror (10).

4. The device capable of achieving multiple times of laser shot peening forming under the rigid constraint layer is characterized in that the motion system comprises a first slide rail (1), a first slide block (2), a second slide block (3), a second slide rail (12), a third slide block (13) and a moving platform (21), wherein the first slide block (2) and the second slide block (3) are respectively installed on the first slide rail (1); the first sliding block (2) is connected with the first reflector (5), and the second sliding block (3) is connected with the second reflector (6); the third sliding block (13) is arranged on the second sliding rail (12); the third sliding block (13) is connected with the second focusing mirror (11) and is used for changing the focus position of the second focusing mirror (11); and a workpiece (20) to be processed is placed on the moving platform (21).

5. The device capable of realizing multiple times of laser shot peening forming under the rigid constraint layer is characterized by further comprising a three-dimensional information collector (9), a pressure sensor (31) and a displacement sensor (15), wherein the three-dimensional information collector (9) is aligned to the lower surface of the optical glass and is used for capturing whether black paint vapor is attached to the lower surface of the optical glass (14); the displacement sensor (15) is used for detecting the thickness of the black paint deposition layer (19) and the distance between the black paint deposition layer (19) and the optical glass (14); the pressure sensor (31) is used for detecting the pressure in the closed flow channel.

6. A method for processing an apparatus capable of achieving multiple times of laser peening forming under a rigid constraint layer according to any one of claims 1 to 5, comprising the steps of:

the closed flow channel is filled with high-pressure gas through a pneumatic pump (33), and the pneumatic pump (33) is closed when the pressure sensor (31) reaches a first set value;

the black paint particles (17) in the particle storage box (28) circularly flow in the closed flow passage by controlling the high-speed fan (25) to be started; the black paint particles (17) pass through the electronic storage cavity (23) and then are charged through the electronic ejector (22); the charged black paint particles (17) are adsorbed on the surface of a workpiece (20) to be processed;

controlling the second sliding block (3) to move, so that the light of the nanosecond laser (7) is reflected by the second reflecting mirror (6) to reach the surface of the workpiece (20) to be processed; aiming at the black paint particle layer absorbed on the surface of the workpiece (20) to be processed through the laser focus to form a black paint deposition layer (19); when the thickness of the black paint deposition layer (19) is determined to reach a design value through the displacement sensor (15), the nanosecond laser (7) is turned off;

controlling the first sliding block (2) to move, so that the light of the femtosecond laser (4) is reflected by the first reflecting mirror (5) to reach the surface of the black paint deposition layer (19); dividing a particle storage tank (28) into a circulation area and a black paint particle area by moving a platen mechanism (30); controlling the movable sealing baffle plate to enable the circulation area to be communicated with the sealing flow channel; performing laser shot blasting on the black paint deposition layer (19) by laser generated by a femtosecond laser (4);

whether black paint vapor attached to the lower surface of the optical glass (14) exists or not is captured through the three-dimensional information collector (9), and when the black paint vapor exists, laser generated by the nanosecond laser (7) is focused on the lower surface of the optical glass (14) for laser cleaning; the air speed of the high-speed fan (25) is controlled, and melted or gasified black paint attachments are blown away by the flowing of air flow in the closed flow channel.

7. The method for processing an apparatus capable of performing multiple laser peening forming under a rigid constraint layer according to claim 6, further comprising the steps of:

in the laser shot blasting process, the displacement sensor (15) monitors the thickness of the black paint deposition layer (19) in real time, when the thickness of the black paint deposition layer (19) is smaller than a second set value, laser shot blasting processing is stopped, the movable sealing baffle is controlled to enable the black paint particle area to be communicated with the sealing flow channel, and the high-speed fan (25) is controlled to start, so that the black paint particles (17) with charges are adsorbed on the surface of the black paint deposition layer (19); controlling the light of the nanosecond laser (7) to be reflected by the second reflector (6) to reach the surface of the black paint deposition layer (19); the black paint particle layer adsorbed on the surface of the black paint deposition layer (19) is focused by laser to supplement the black paint deposition layer (19).

8. The processing method of the device capable of realizing multiple times of laser shot peening forming under the rigid constraint layer is characterized in that the position of a focus point of a nanosecond laser (7) is controlled according to a monitoring value of a displacement sensor (15), so that the thickness of the black paint deposition layer (19) is 1-100 μm; controlling a moving platform (21) to enable the distance between the black paint deposition layer (19) and the optical glass (14) to be 5-20 mu m; the particle diameter in the particle storage tank (28) is within 1 mu m; and the black paint crusher (27) crushes the blocky black paint after temperature reduction into particles with the diameter less than 1 mu m.

9. The machining method of the device capable of realizing multiple times of laser shot peening under the rigid constraint layer is characterized in that the electron jet (22) jets the electron flow rate which is far larger than the instantaneous flow rate of particles in the closed flow channel through the high-speed fan (25); when the nanosecond laser (7) heats the black paint particles (17) to form a black paint deposition layer (19), the flow rate of the high-speed fan (25) is 1-10 mm/s, and the movable sealing baffle is controlled to move downwards to increase the flow cross section; when the femtosecond laser (4) carries out laser shot blasting on the black paint deposition layer (19), the flow rate of the high-speed fan (25) is 10-100 mm/s, and the movable sealing baffle is controlled to move upwards to reduce the flow cross section; when the laser generated by the nanosecond laser (7) cleans the lower surface of the optical glass (14), the flow rate of the high-speed fan (25) is 100-1000 mm/s, and the movable sealing baffle is controlled to move upwards to reduce the flow cross section.

10. The processing method of the device capable of realizing the multiple laser shot peening forming under the rigid constraint layer according to claim 6, wherein the nanosecond laser (7) adopts a square light spot, the side length of the light spot is 0.1-1mm, the laser energy is 0.03-5 mJ, and the pulse width of the laser is 5-10ns; the femtosecond laser (4) adopts a circular light spot, the diameter of the light spot is 3-5mm, the laser energy is 3-15 mJ, and the laser pulse width is 300-500fs.

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