Interlayer laser shot peening strengthening device embedded in melting process of laser powder bed

Abstract

The invention belongs to the technical field of laser application devices, and particularly relates to an interlayer laser shot peening strengthening device embedded in the melting process of a laser powder bed, the interlayer laser shot peening strengthening device comprises a powder supply and recovery module, a laser scanning forming module and a pulse laser shock peening module, the laser scanning forming module is used for covering the metal powder particles in the printing bin with high-energy laser through reflection, and melting forming of the metal powder particles is achieved; pulse laser in the pulse laser shock peening module acts on the part under construction after melting of the metal powder particles, so that each layer of the part is strengthened in the manufacturing process; according to the laser shock peening device, laser shock peening can be carried out after each layer of metal powder particles are melted through laser, and the processing performance of parts produced through the laser powder bed melting technology is further improved by refining crystal grains and reducing defects.

Description

Technical Field

[0001] The invention belongs to the technical field of laser application devices, and in particular relates to an interlayer laser shot peening strengthening device embedded in a laser powder bed melting process. Background Art

[0002] Laser powder bed melting technology is a typical additive manufacturing technology that uses a high-energy laser beam to melt metal powder and accumulate it layer by layer, which can quickly and directly form metal parts with complex shapes. However, the defects contained in the laser powder bed melting process itself include columnar grains formed by crystal epitaxial growth, pore defects caused by gas entrapment or unfused, and residual tensile stress, which requires additional post-processing to meet the requirements of actual engineering applications. At present, the production and post-processing strengthening of parts produced by traditional laser powder bed melting equipment are two separate stages, that is, the surface is strengthened after the parts are produced. However, the strengthening area of ​​this method is limited to the surface of the part, and the inside of the part is not strengthened, so the overall strengthening effect of the part is not significant.

[0003] For example, the invention patent with application number 202411033831.9 discloses a method for improving the fatigue performance of titanium alloy by microscale laser strengthening, the method comprising: using a laser powder bed fusion process for additive manufacturing to obtain a titanium alloy; cutting the titanium alloy and then heat treating it; cleaning the titanium alloy after heat treatment, and performing multiple microscale laser strengthening treatments on the residual tensile stress layer on the surface of the titanium alloy with unfused defects; this method solves the problem of removing microcracks and unfused defects, etc., and introducing a residual compressive stress layer, thereby achieving the purpose of improving fatigue performance. This method first uses a laser powder bed fusion process for additive manufacturing, and then uses a pulsed laser to strengthen the surface of the titanium alloy with unfused defects, but this only strengthens the surface of the part and cannot improve the grains and pore defects inside the part. Summary of the invention

[0004] In view of the shortcomings of the prior art, the purpose of the present invention is to provide an interlayer laser shot peening strengthening device embedded in the laser powder bed melting process to solve the problem that the existing laser shock peening equipment only strengthens the near-surface layer while the internal strengthening effect of the parts is limited, and how to further improve the mechanical properties of parts produced by laser powder bed melting technology. The device can not only refine each layer of grains, reduce / close pore defects, and improve residual stress during the molding process, but also construct a grain grading microstructure from the micron or even nanometer level by adjusting the laser parameters of the pulsed laser source in this process, thereby achieving grain refinement and the transformation of columnar crystals to equiaxed crystals, so as to meet higher requirements for additive manufacturing materials.

[0005] In order to achieve the above-mentioned object, the present invention adopts the following technical scheme: an interlayer laser shot peening strengthening device embedded in a laser powder bed melting process, comprising an outer shell, a powder supply and recovery module, a laser scanning forming module, a pulse laser shock strengthening module, a powder supply and recovery module, a laser scanning forming module, and a pulse laser shock strengthening module fixed on the outer shell;

[0006] The powder supply and recovery module lays the metal powder particles in the printing chamber for laying the metal powder particles and recovering the excess metal powder particles. The laser scanning and forming module reflects the high-energy laser and covers it on the metal powder particles in the printing chamber for melting and forming the metal powder particles. The pulse laser in the pulse laser shock strengthening module acts on the parts under construction after the metal powder particles are melted, for strengthening each layer of the parts during the manufacturing process.

[0007] The powder supply and recovery module includes a powder supply bin, a printing bin, a powder recovery bin, and a powder scraper moving mechanism. The scraper on the powder scraper moving mechanism scrapes the metal powder particles in the powder supply bin onto a circular substrate in the printing bin, and the excess metal powder particles enter the powder recovery bin.

[0008] The powder supply bin lifts the metal powder particles to the top of the powder supply bin through the powder bin moving mechanism; the printing bin drives the circular substrate to move downward through the printing bin moving mechanism.

[0009] The laser scanning forming module includes a laser powder bed melting laser source, a first laser reflector, a second laser reflector, and a laser reflector moving mechanism. The laser powder bed melting laser source is arranged on the side wall of the outer shell. The laser reflector moving mechanism is provided with two groups, which are slidably connected to the top of two fixed plates fixedly connected to the inner wall of the outer shell. The laser reflector moving mechanism drives the first laser reflector and the second laser reflector to move to the top of the printing chamber. The laser powder bed melting laser source emits high-energy laser, which can cover the entire circular substrate in the printing chamber after being reflected by the first laser reflector and the second laser reflector, and melt the metal powder particles to form the required parts.

[0010] The pulse laser shock strengthening module includes a constraint layer mechanism and a pulse laser source. The constraint layer mechanism is slidably connected to an intermediate plate fixedly connected to an outer shell and is located on the left side of a powder recovery bin. The constraint layer mechanism includes a glass plate moving mechanism and a transparent glass plate. A transparent glass plate is provided above the glass plate moving mechanism. When laser shock strengthening is performed, the glass plate moving mechanism drives the transparent glass plate to cover the top of the printing bin. The pulse laser source adjusts its position above the printing bin through a light source driving device fixed on the top plate of the outer shell, and the pulse laser acts on the parts of the printing bin through the transparent glass plate.

[0011] A powder supply bin, a printing bin and a powder recovery bin are provided between the middle plate of the outer shell and the bottom plate of the outer shell, and the printing bin is located between the powder recovery bin and the powder supply bin; a powder scraper moving mechanism is located above the powder supply bin, and two groups of powder scraper moving mechanisms are provided, which are respectively slidably connected to the bottom of two fixed plates arranged on the inner wall of the outer shell; the bottoms of the two groups of powder scraper moving mechanisms are connected to the scraper to drive the scraper to move.

[0012] The scraper includes a top seat, a scraper plate and a gathering block. The top seat is fixed on two groups of powder scraper moving mechanisms. The scraper plate is located at the bottom center of the top seat and is used for laying powder. A chamfered corner is provided on one side of the scraper plate involved in laying powder. Gathering blocks fixed on the top seat are provided on both sides of the scraper plate, and the scraper plate protrudes from the outer side of the gathering block.

[0013] The laser reflector moving mechanism comprises two groups of reflector moving components and a connecting plate, wherein the reflector moving components are slidably connected above the fixing plate;

[0014] A first laser reflector and a second laser reflector are provided on the top of the connecting plate. The first laser reflector is connected to the output shaft of the motor V through the connecting block, and the motor V adjusts the angle of the first laser reflector; the second laser reflector is connected to the coupling V connected to the motor VI through the motor frame III fixed on the connecting plate, and the motor VI adjusts the angle of the second laser reflector.

[0015] The light source driving device comprises a motor VIII and a motor IX. Two slide rails IV are arranged on the top plate of the outer shell. Each of the two slide rails IV has a slider IV. The slider IV is connected to the movable plate I. The motor VIII is fixed to the top plate of the outer shell through a motor frame V. The output shaft of the motor VIII is connected to the ball screw VI through a coupling VII. The screw slider on the ball screw VI is connected to the slider IV. The motor VIII drives the movable plate I to move left and right.

[0016] Two slide rails V are fixed under the moving plate I, each of the two slide rails V is provided with a slider V, the slider V is connected to the moving plate II, the motor IX is fixed to the moving plate I through the motor frame VI, the output shaft of the motor IX is connected to the ball screw VII through the coupling VIII, the bottom of the screw slider on the ball screw VII is provided with a moving plate II, a pulse laser source is fixed on the moving plate II, and the motor IX drives the moving plate II and the pulse laser source to move forward and backward.

[0017] The beneficial effects of the present invention are:

[0018] The interlayer laser shot peening strengthening device embedded in the laser powder bed melting process of the present invention can perform laser shock strengthening after laser melting each layer of metal powder particles, further improve the process performance of parts produced by laser powder bed melting technology by refining grains and reducing defects, and construct a grain grading microstructure from micron to nanometer level by adjusting pulse laser parameters during each strengthening to meet higher requirements for materials. The various mechanisms of the device cooperate closely, the structure is relatively simple, the operation is convenient, and the practicability is strong. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of the present invention;

[0020] Figure 2 A top view of the powder supply and recovery module of the present invention;

[0021] Figure 3 for Figure 2 AA section view;

[0022] Figure 4 It is a schematic diagram of the structure of the laser scanning forming module of the present invention;

[0023] Figure 5 It is a schematic diagram of the structure of the pulse laser shock peening module of the present invention;

[0024] Figure 6 It is a structural schematic diagram of the scraper of the present invention;

[0025] In the figure, 1, outer shell; 111, powder supply bin; 112, printing bin; 113, powder recovery bin; 2, motor II; 3, coupling II; 4, ball screw II; 5, powder supply bin fixing plate; 6, connecting rod I; 7, lower bottom plate I; 8, upper top plate I; 9, motor III; 10, coupling III; 11, ball screw III; 12, printing bin fixing plate; 13, connecting rod II; 14, lower bottom plate II; 1 5. Top plate II; 16. Round base plate; 17. Motor I; 18. Motor frame I; 19. Fixed plate; 20. Slide rail I; 21. Slider I; 22. Scraper; 2201. Top seat; 2202. Scraper plate; 2203. Gathering block; 23. Ball screw I; 24. Coupling I; 25. Motor IV; 26. Motor frame II; 27. Slide rail II; 28. Slider II; 29. ​​Screw slider I; 30. Connecting plate; 31. Ball screw IV; 32. Coupling IV; 33. Laser source for laser powder bed melting; 34. Bottom plate of outer shell; 35. First laser reflector; 36. Connecting block; 37. Motor V; 38. Motor frame III; 39. Motor VI; 40. Second laser reflector; 41. Coupling V; 42. Intermediate plate; 43. Slide rail III; 44. Slider III; 45. Transparent glass plate; 46 , screw slider II; 47, ball screw V; 48, coupling VI; 49, motor VII; 50, motor frame IV; 51, outer shell top plate; 52, slide rail IV; 53, slider IV; 54, moving plate I; 55, coupling VII; 56, motor VIII; 57, motor frame V; 58, slide rail V; 59, slider V; 60, moving plate II; 61, motor IX; 62, motor frame VI; 63, pulse laser source. DETAILED DESCRIPTION

[0026] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0027] like Figures 1 to 6 As shown, an interlayer laser shot peening strengthening device embedded in the laser powder bed melting process includes an outer shell 1, a powder supply and recovery module, a laser scanning forming module and a pulse laser shock strengthening module, wherein the powder supply and recovery module, the laser scanning forming module and the pulse laser shock strengthening module are fixed in the outer shell 1; the powder supply and recovery module lays metal powder particles in the printing bin 112, which is used for laying metal powder particles and recovering excess metal powder particles, the laser scanning forming module covers the metal powder particles in the printing bin through reflection with high-energy laser, which is used for melting and forming the metal powder particles, and the pulse laser in the pulse laser shock strengthening module acts on the parts under construction behind the metal powder particles, which is used for strengthening each layer of the parts during the manufacturing process.

[0028] The powder supply and recovery module includes a powder supply bin 111, a printing bin 112, a powder recovery bin 113, and a powder scraper moving mechanism. An intermediate plate 42 is provided in the outer shell 1. The powder supply bin 111, the printing bin 112, and the powder recovery bin 113 are provided between the intermediate plate 42 of the outer shell 1 and the bottom plate 34 of the outer shell. The printing bin 112 is located between the powder recovery bin 113 and the powder supply bin 111. A rectangular feed port is provided on the top right side of the powder recovery bin 113; the powder scraper moving mechanism is located above the powder supply bin 111, and the powder scraper moving mechanism is slidably connected to the bottom of two fixed plates 19 provided on the inner wall of the outer shell 1. A powder bin moving mechanism is provided in the powder supply bin 111, and the powder bin moving mechanism lifts the metal powder particles to the top of the powder supply bin 111. The powder bin moving mechanism includes a motor Ⅱ2, a coupling Ⅱ3, a ball screw Ⅱ4, and a connecting rod mechanism Ⅰ. The motor Ⅱ2 is fixed to the bottom plate of the outer shell. 34, the motor Ⅱ2 is connected to the ball screw Ⅱ4 through the coupling Ⅱ3, the end of the ball screw Ⅱ4 is connected to the powder supply bin fixing plate 5 fixed on the powder supply bin 111 bin body, the powder supply bin fixing plate 5 is provided with circular holes Ⅰ around it to cooperate with the connecting rod member Ⅰ, and metal powder particles are laid on the top of the connecting rod member Ⅰ, and the motor Ⅱ2 drives the connecting rod member Ⅰ and the metal powder particles to move upward; the connecting rod member Ⅰ includes four connecting rods, a lower bottom plate and an upper top plate, and the connecting rod Ⅰ6 of the connecting rod member Ⅰ is inserted into the circular hole Ⅰ of the powder supply bin fixing plate 5, one end of the connecting rod Ⅰ6 is connected to the upper top plate Ⅰ8, and the other end is connected to the lower bottom plate Ⅰ7 connected to the screw slider of the ball screw Ⅱ4, and powder is placed on the upper top plate Ⅰ8; the lower bottom plate Ⅰ7 moves upward with the rotation of the ball screw Ⅱ4 and the constraint of the powder supply bin fixing plate 5, and pushes the upper top plate Ⅰ8 upward through the connecting rod Ⅰ6, so as to push the metal powder particles on the upper top plate Ⅰ8 out of the powder supply bin 111;

[0029] A printing chamber moving mechanism is provided in the printing chamber 112, and a circular substrate 16 is provided on the top of the printing chamber moving mechanism. Parts are placed on the circular substrate 16. During the 3D printing process, the substrate provides stable support for the parts, and is convenient for removing the finished product after printing is completed. At the same time, heat conduction can be used to prevent the parts from warping or deformation caused by temperature difference. The printing chamber moving mechanism drives the parts on the circular substrate 16 to move downward. The printing chamber moving mechanism includes a motor III9, a coupling III10, a ball screw III11, and a connecting rod mechanism II. The motor III9 is ​​fixed on the bottom plate 34 of the outer shell. The motor III9 is ​​connected to the ball screw III11 through the coupling III10. The end of the ball screw III11 is connected to the printing chamber fixing plate 12 fixed on the printing chamber 112. There are circular holes Ⅱ around the print bin fixing plate 12, which cooperate with the connecting rod component Ⅱ. A circular substrate 16 is provided on the top of the connecting rod mechanism Ⅱ. The motor Ⅲ9 drives the connecting rod mechanism Ⅱ and the parts on the circular substrate 16 to move downward; the connecting rod mechanism Ⅱ includes four connecting rods, a lower bottom plate and an upper top plate. The connecting rod Ⅱ13 of the connecting rod component Ⅱ is inserted into the circular hole Ⅱ on the print bin fixing plate 12. One end of the connecting rod Ⅱ13 is connected to the upper top plate Ⅱ15. The circular substrate 16 is placed above the upper top plate Ⅱ15, and the other end is connected to the lower bottom plate Ⅱ14 connected to the screw slider of the ball screw Ⅲ11. With the rotation of the ball screw Ⅲ11 and the constraint of the print bin fixing plate 12, the lower bottom plate Ⅱ14 moves downward and drives the upper top plate Ⅱ15 and the circular substrate 16 to move downward through the connecting rod Ⅱ13.

[0030] The powder scraper moving mechanism scrapes the metal powder particles onto the circular substrate 16 in the printing chamber 112, and the excess metal powder particles enter the powder recovery chamber 113 through the rectangular feed port. The powder recovery chamber 113 is responsible for recycling the excess metal powder particles.

[0031] The powder scraper moving mechanism is provided with two groups, which are respectively slidably connected to the bottom of two fixed plates 19 arranged on the inner wall of the outer shell; the bottom of the two groups of powder scraper moving mechanisms are connected to the scraper 22, driving the scraper 22 to move; the powder scraper moving mechanism includes a motor Ⅰ17, a motor frame Ⅰ18, a slide rail Ⅰ20, a slider Ⅰ21, a ball screw Ⅰ23, and a coupling Ⅰ24. The motor Ⅰ17 is fixed to the end of the fixed plate 19 through the motor frame Ⅰ18, and the motor Ⅰ17 is connected to the ball screw Ⅰ23 through the coupling Ⅰ24; a slide rail Ⅰ20 is provided at the bottom of the fixed plate 19, and a slider Ⅰ21 is provided on the slide rail Ⅰ20, and the slider Ⅰ21 is connected to the screw slider on the ball screw Ⅰ23; the slider Ⅰ21 of the two groups of powder scraper moving mechanisms is connected to the scraper 22 at the bottom, and the motor Ⅰ17 drives the slider Ⅰ21 and the scraper 22 to move to spread the powder.

[0032] The scraper 22 includes a top seat 2201, a scraper plate 2202 and a gathering block 2203. The top seat 2201 is fixed on a slider Ⅰ21 of two groups of powder scraper moving mechanisms. The scraper plate 2202 is located at the bottom center of the top seat 2201 and is used for laying powder. A chamfer is provided on one side of the scraper plate 2202 involved in laying powder. Gathering blocks 2203 fixed on the top seat 2201 are provided on both sides of the scraper plate 2202. The outer side of the gathering block 2203 protrudes from the scraper plate 2202 to achieve the gathering of metal powder particles and prevent the metal powder particles from overflowing and causing waste.

[0033] The laser scanning forming module includes a laser powder bed melting laser source 33, a first laser reflector 35, a second laser reflector 40, and a laser reflector moving mechanism. The laser reflector moving mechanism is slidably connected to the top of two fixed plates 19 fixedly connected to the inner wall of the outer shell 1. The laser reflector moving mechanism is provided with a first laser reflector 35 and a second laser reflector 40. The laser reflector moving mechanism includes two groups of reflector moving components and a connecting plate 30. The reflector moving components are slidably connected above the fixed plate 19. A connecting plate is connected between the two groups of reflector moving components. Connecting plate 30, the reflector moving assembly includes motor IV25, coupling IV32, motor frame II26, ball screw IV31, slider II28, and slide rail II27. Motor IV25 is fixed to the other end of the fixed plate 19 through motor frame II26. Slide rail II27 is fixed above the fixed plate 19. Slide rail II27 is provided with slider II28. The side of slider II28 is connected to the screw slider I29 of the ball screw IV31. A connecting plate 30 is provided on the top of the two sliders II28. The ball screw IV31 is driven to rotate by motor IV25, thereby driving the connecting plate 30 to move.

[0034] The laser powder bed melting laser source 33 is arranged on the side wall of the outer shell 1 perpendicular to the fixed plate 19, and can emit high-energy laser with required process parameters. The laser reflector moving mechanism moves on the fixed plate 19 to move the first laser reflector 35 and the second laser reflector 40 above the printing chamber 112. The first laser reflector 35 and the second laser reflector 40 are provided on the top of the connecting plate 30. The first laser reflector 35 is connected to the output shaft of the motor V37 through the connecting block 36, and the motor V37 adjusts the angle of the first laser reflector 35; the second laser reflector 40 is connected to the coupling V41 connected to the motor VI39 through the motor frame III38 fixed on the connecting plate 30, and the motor VI39 adjusts the angle of the second laser reflector 40 That is, the motor IV25 drives the ball screw IV31 to rotate, thereby driving the slider II28 to move on the slide rail II27, so that the connecting plate 30 drives the first laser reflector 35 and the second laser reflector 40 to move above the printing chamber 112; the laser powder bed melting laser source 33 emits a high-energy laser, which hits the first laser reflector 35 after the first reflection, and the motor V37 adjusts the angle of the first laser reflector 35 through the connecting block 36. The second laser reflector 40 rotates through the rotation of the motor VI39 and can receive the laser reflected from the first laser reflector 35 for a second reflection. After two reflections, the high-energy laser can cover the entire circular substrate 16 in the printing chamber 112, melt the metal powder particles to form the required parts.

[0035] A pulse laser shock strengthening module is provided on the top of the printing chamber 112 to strengthen each layer of parts during the manufacturing process. The pulse laser shock strengthening module includes a constraint layer mechanism and a pulse laser source 63. The constraint layer mechanism is slidably connected to the middle plate 42 fixedly connected to the outer shell 1 and is located on the left side of the powder recovery chamber 113. The constraint layer mechanism includes a glass plate moving mechanism and a transparent glass plate 45. A transparent glass plate 45 is provided above the glass plate moving mechanism. When laser shock strengthening is performed, the glass plate moving mechanism drives the transparent glass plate 45 to cover the top of the printing chamber 112. The glass plate moving mechanism includes a motor VII 49. The motor VII49 is connected to the ball screw V47 through a coupling VI48, and the motor VII49 is fixed to the middle plate 42 through a motor frame IV50. The middle plate 42 is provided with two slide rails III43, and each of the two slide rails III43 has a slider III44. A transparent glass plate 45 is provided above the slider III44, and the screw slider II46 on the ball screw V47 is connected to the transparent glass plate 45. The pulse laser source 63 adjusts its position above the printing chamber 112 through a light source driving device fixed on the top plate 51 of the outer shell, and the pulse laser emitted by the pulse laser source 63 acts on the parts in the printing chamber 112 through the transparent glass plate 45.

[0036] The light source driving device includes a motor VIII 56 and a motor IX 61. Two slide rails IV 52 are provided on the top plate 51 of the outer shell. Each of the two slide rails IV 52 has a slider IV 53. The slider IV 53 is connected to the moving plate I 54. The motor VIII 56 is fixed to the top plate 51 of the outer shell through a motor frame V 57. The output shaft of the motor VIII 56 is connected to the ball screw VI through a coupling VII 55. The screw slider on the ball screw VI is connected to the slider IV 53. The motor VIII 56 drives the moving plate I 54 to move left and right.

[0037] Two slide rails V58 are fixed under the movable plate I54, and each of the two slide rails V58 has a slider V59, and the slider V59 is connected to the movable plate II60. The motor IX61 is fixed to the movable plate I54 through the motor frame VI62, and the output shaft of the motor IX61 is connected to the ball screw VII through the coupling VIII. The bottom of the screw slider on the ball screw VII is provided with a movable plate II60, and a pulse laser source 63 is fixed on the movable plate II60. The motor IX61 drives the movable plate II60 and the pulse laser source 63 to move forward and backward.

[0038] The following describes a one-time use process of the present invention in conjunction with the accompanying drawings:

[0039] Start motor Ⅱ2, and drive ball screw Ⅱ4 to rotate through coupling Ⅱ3. Under the constraint of powder supply bin fixing plate 5 fixed on the bin body, lower bottom plate Ⅰ7 connected to ball slider moves upward, and supported by connecting rod Ⅰ, upper top plate Ⅰ8 pushes powder out of powder supply bin 111; start motor Ⅰ17, and drive ball screw Ⅰ23 to rotate through coupling Ⅰ24. The screw slider on ball screw Ⅰ23 is connected to slider Ⅰ21 and moves along slide rail Ⅰ20. Scraper 22 fixed on slider Ⅰ21 moves toward printing bin 112 through the rotation of motor Ⅰ17, spreads the powder pushed out by upper top plate Ⅰ8 onto circular substrate 16, and brings excess metal powder particles into powder recovery bin 113. Then motor Ⅰ17 reverses and scraper 22 returns to its initial position.

[0040] Start the motor IV25, and drive the ball screw IV31 to rotate through the coupling IV32. The screw slider I29 on the ball screw IV31 is connected to the slider II28 and moves along the slide rail II27. The connecting plate 30 fixed on the slider II28 moves to the top of the printing chamber 112 through the rotation of the motor IV25. Turn on the laser powder bed melting laser source 33 to emit high-energy laser, which is reflected for the first time on the first laser reflector 35. The first laser reflector 35 is connected to the output shaft of the motor V37 through the connecting block 36, and can swing with the rotation of the output shaft of the motor V37 to adjust the laser route. After receiving the reflected laser, the second laser reflector 40 can rotate through the rotation of the motor VI39 to reflect the laser for the second time. After two reflections and multiple angle adjustments, the high-energy laser covers the entire circular substrate 16 for processing. After scanning one layer, the laser powder bed melting laser source 33 is turned off, the motor IV25 is reversed, and the connecting plate 30 returns to the initial position.

[0041] Start motor VII49, drive ball screw V47 to rotate through coupling VI48, and drive slider III44 along slide rail III43 by screw slider II46. Transparent glass plate 45 fixed on slider III44 moves toward printing chamber 112 through the rotation of motor VII49, covering the opening of printing chamber 112. Start motor VIII 56, drive ball screw VI to rotate through coupling VII 55, the screw slider on ball screw VI drives slider IV 53 to move along slide rail IV 52, and movable plate I 54 fixed on slider IV 53 can move left and right through the rotation of motor VIII 56; start motor IX 61, drive ball screw VII to rotate through coupling VIII, the screw slider on ball screw VII drives slider V 59 to move along slide rail V 58, and movable plate II 60 fixed on slider V 59 can move back and forth through the rotation of motor IX 61, turn on pulse laser source 63, emit pulse laser, and impact strengthen the parts in printing chamber 112, and turn off pulse laser source 63 after completion, and motor VII 49 reverses to drive transparent glass plate 45 back to its original position, so as to strengthen the parts after each layer of metal powder particles is melted, refine each layer of grains, reduce / close pore defects, and improve residual stress.

[0042] The present invention can not only refine each layer of grains, reduce / close pore defects, and improve residual stress during the molding process, but also construct a grain hierarchical microstructure from the micron level to the nanometer level by adjusting the pulse laser parameters in this process, thereby achieving grain refinement and the transformation of columnar crystals to equiaxed crystals, so as to meet higher requirements for additive manufacturing materials.

[0043] The solutions in the embodiments are not intended to limit the patent protection scope of the present invention. All equivalent implementations or changes that do not deviate from the present invention are included in the patent scope of this case.

Claims

1. An interlayer laser shot peening strengthening device embedded in a laser powder bed melting process, characterized in that: It includes an outer shell, a powder supply and recovery module, a laser scanning forming module, and a pulse laser shock strengthening module, wherein the powder supply and recovery module, the laser scanning forming module, and the pulse laser shock strengthening module are fixed on the outer shell; The powder supply and recovery module lays the metal powder particles in the printing chamber for laying the metal powder particles and recovering the excess metal powder particles. The laser scanning and forming module reflects the high-energy laser and covers it on the metal powder particles in the printing chamber for melting and forming the metal powder particles. The pulse laser in the pulse laser shock strengthening module acts on the parts under construction after the metal powder particles are melted, for strengthening each layer of the parts during the manufacturing process.

2. The interlayer laser shot peening strengthening device embedded in the laser powder bed melting process according to claim 1 is characterized in that: The powder supply and recovery module includes a powder supply bin, a printing bin, a powder recovery bin, and a powder scraper moving mechanism. The scraper on the powder scraper moving mechanism scrapes the metal powder particles in the powder supply bin onto a circular substrate in the printing bin, and the excess metal powder particles enter the powder recovery bin.

3. The interlayer laser shot peening strengthening device embedded in the laser powder bed melting process according to claim 1 is characterized in that: The laser scanning forming module includes a laser powder bed melting laser source, a first laser reflector, a second laser reflector, and a laser reflector moving mechanism. The laser powder bed melting laser source is arranged on the side wall of the outer shell. The laser reflector moving mechanism is provided with two groups, which are slidably connected to the top of two fixed plates fixedly connected to the inner wall of the outer shell. The laser reflector moving mechanism drives the first laser reflector and the second laser reflector to move to the top of the printing chamber. The laser powder bed melting laser source emits high-energy laser, which can cover the entire circular substrate in the printing chamber after being reflected by the first laser reflector and the second laser reflector, and melt the metal powder particles to form the required parts.

4. The interlayer laser shot peening strengthening device embedded in the laser powder bed melting process according to claim 1 is characterized in that: The pulse laser shock strengthening module includes a constraint layer mechanism and a pulse laser source. The constraint layer mechanism is slidably connected to an intermediate plate fixedly connected to an outer shell and is located on the left side of a powder recovery bin. The constraint layer mechanism includes a glass plate moving mechanism and a transparent glass plate. A transparent glass plate is provided above the glass plate moving mechanism. When laser shock strengthening is performed, the glass plate moving mechanism drives the transparent glass plate to cover the top of the printing bin. The pulse laser source adjusts its position above the printing bin through a light source driving device fixed on the top plate of the outer shell, and the pulse laser acts on the parts of the printing bin through the transparent glass plate.

5. The interlayer laser shot peening strengthening device embedded in the laser powder bed melting process according to claim 2 is characterized in that: A powder supply bin, a printing bin and a powder recovery bin are provided between the middle plate of the outer shell and the bottom plate of the outer shell, and the printing bin is located between the powder recovery bin and the powder supply bin; a powder scraper moving mechanism is located above the powder supply bin, and two groups of powder scraper moving mechanisms are provided, which are respectively slidably connected to the bottom of two fixed plates arranged on the inner wall of the outer shell; the bottoms of the two groups of powder scraper moving mechanisms are connected to the scrapers to drive the scrapers to move.

6. The interlayer laser shot peening strengthening device embedded in the laser powder bed melting process according to claim 2 is characterized in that: The powder supply bin lifts the metal powder particles to the top of the powder supply bin through the powder bin moving mechanism; the printing bin drives the circular substrate to move downward through the printing bin moving mechanism.

7. The interlayer laser shot peening strengthening device embedded in the laser powder bed melting process according to claim 5 is characterized in that: The scraper includes a top seat, a scraper plate and a gathering block. The top seat is fixed on two groups of powder scraper moving mechanisms. The scraper plate is located at the bottom center of the top seat and is used for laying powder. A chamfered corner is provided on one side of the scraper plate involved in laying powder. Gathering blocks fixed on the top seat are provided on both sides of the scraper plate, and the scraper plate protrudes from the outer side of the gathering block.

8. The interlayer laser shot peening strengthening device embedded in the laser powder bed melting process according to claim 3 is characterized in that: The laser reflector moving mechanism comprises two groups of reflector moving components and a connecting plate, wherein the reflector moving components are slidably connected above the fixing plate; A first laser reflector and a second laser reflector are provided on the top of the connecting plate. The first laser reflector is connected to the output shaft of the motor V through the connecting block, and the motor V adjusts the angle of the first laser reflector; the second laser reflector is connected to the coupling V connected to the motor VI through the motor frame III fixed on the connecting plate, and the motor VI adjusts the angle of the second laser reflector.

9. The interlayer laser shot peening strengthening device embedded in the laser powder bed melting process according to claim 4 is characterized in that: The light source driving device comprises a motor VIII and a motor IX. Two slide rails IV are arranged on the top plate of the outer shell. Each of the two slide rails IV has a slider IV. The slider IV is connected to the movable plate I. The motor VIII is fixed to the top plate of the outer shell through a motor frame V. The output shaft of the motor VIII is connected to the ball screw VI through a coupling VII. The screw slider on the ball screw VI is connected to the slider IV. The motor VIII drives the movable plate I to move left and right. Two slide rails V are fixed under the moving plate I, each of the two slide rails V is provided with a slider V, the slider V is connected to the moving plate II, the motor IX is fixed to the moving plate I through the motor frame VI, the output shaft of the motor IX is connected to the ball screw VII through the coupling VIII, the bottom of the screw slider on the ball screw VII is provided with a moving plate II, a pulse laser source is fixed on the moving plate II, and the motor IX drives the moving plate II and the pulse laser source to move forward and backward.

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