A laser-induced shock wave high-precision forming method

Abstract

The present invention discloses a laser-induced shock wave high-precision forming method, which belongs to the field of laser shock forming technology. The method comprises the following steps: (1) determining the material, size, and structural dimensions of a part after forming; (2) drawing a three-dimensional model of the part, determining a laser shock forming processing scheme, and adjusting process parameters to ensure that the structural dimensions after forming meet the requirements; (3) using trajectory planning software to determine the processing trajectory of the first processing area, and impacting the first impact area according to the determined processing scheme and processing trajectory; (4) scanning the part after the impact of the first area, calculating the structural dimensions, and redrawing the three-dimensional model of the part; (5) determining the processing trajectory of the second impact area according to the newly drawn three-dimensional model of the part, and impacting the second impact area according to the determined processing scheme and processing path; and repeating the above process until all areas are processed. The method enables the laser to be accurately irradiated to the specified position, thereby improving the accuracy of laser shock forming.

Description

Technical Field

[0001] The present invention relates to the technical field of laser shock forming, and in particular to a laser-induced shock wave high-precision forming method. Background Art

[0002] Laser shock forming is an emerging material forming technology. Its principle is to first coat a sacrificial layer (usually aluminum foil or black tape) on the surface to be processed. When a high-energy short-pulse laser is irradiated on the surface of the material, the sacrificial layer on the surface of the part absorbs the laser energy and vaporizes into plasma in a very short time. The plasma continues to absorb energy and expands rapidly. Under the constraint of the outermost transparent constraint layer (usually water), a GPa-level stress wave is formed and propagates into the interior of the part. Under the impact of the high-pressure stress wave, the processing area produces plastic deformation. As the laser scans the surface of the part, the area of ​​the plastic deformation zone continues to increase, and it is finally processed into the desired shape.

[0003] During the laser shock forming process, the laser scans the processing area point by point, so the laser irradiation position has a significant impact on the final formed dimensions. Existing laser shock forming technology does not account for the deviation of processing position and processing angle caused by material deformation during processing. As a result, the actual processing position of subsequent processing points deviates from the designed processing position, which reduces the accuracy of laser shock forming and limits its application areas. Summary of the Invention

[0004] In order to address the problem of deviation between the actual processing position and the designed processing position due to material deformation in the existing laser shock forming process, the purpose of the present invention is to provide a regional laser-induced shock wave high-precision forming method that combines trajectory planning, numerical simulation and visual measurement, so that the laser can be accurately irradiated to the specified position and the laser shock forming accuracy can be improved.

[0005] To achieve the above object, the technical solutions adopted by the present invention are as follows:

[0006] A laser-induced shock wave high-precision forming method comprises the following steps:

[0007] (1) Determine the material type, initial structural dimensions, and structural dimensions after forming of the part;

[0008] (2) Use Solidwork software to draw the three-dimensional model of the part, and use finite element analysis software ABAQUS to perform numerical simulation analysis and determine the laser shock forming processing plan: import the laser energy, laser pulse width, spot shape and size, overlap rate, initial structural size parameters, processing area, and laser scanning direction of each area into ABAQUS software, use the Fabbro model and Johnson_Cook material constitutive model to calculate the structural size after shock forming, and adjust the process parameters to make the structural size after forming meet the requirements, thereby determining the processing plan;

[0009] (3) using trajectory planning software to determine the processing trajectory of the first processing area (i.e., the laser scanning trajectory), and impacting the first impact area according to the processing plan determined in step (2) and the processing trajectory of the first processing area generated;

[0010] (4) Use a laser scanning measuring instrument to scan the part after the impact in the first area, generate point cloud data, calculate the structural dimensions, and redraw the three-dimensional model of the part using Solidwork software;

[0011] (5) using trajectory planning software to determine the machining trajectory of the second impact area according to the newly drawn three-dimensional model of the part, and impacting the second impact area according to the machining parameters and the machining trajectory of the second impact area determined in step (2);

[0012] (6) Use a laser scanning measuring instrument to scan the part after the impact in the second area, generate point cloud data, calculate the structural dimensions, and redraw the three-dimensional model of the part using Solidwork software;

[0013] (7) Repeat steps (3) to (5) for subsequent processing areas until all processing areas are completed.

[0014] In step (2), the processing parameters determined are: laser energy, laser pulse width, spot shape and size, overlap rate, processing area, and laser scanning direction of each area.

[0015] In step (4), the scanning resolution is 0.1-0.3 mm.

[0016] The present invention has the following beneficial effects and advantages:

[0017] 1. The present invention uses numerical simulation to determine the processing plan, improves the accuracy of processing and reduces the time and cost of process testing, and has wide applicability in engineering applications.

[0018] 2. The present invention utilizes visual measurement and trajectory planning methods to impact each area, thereby reducing the deviation of the position of subsequent processing points caused by deformation during processing and improving processing accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is the laser shock forming operation process of the present invention.

[0020] Figure 2 These are the numerical simulation results after impacting areas 1, 2, and 3.

[0021] Figure 3 For processing area and laser scanning direction

[0022] Figure 4 The machining trajectory generated by trajectory planning for impact areas 1, 2, and 3.

[0023] Figure 5 The structural dimensions are visually measured after impacting areas 1, 2, and 3. DETAILED DESCRIPTION

[0024] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0025] Example 1:

[0026] This embodiment is a high-precision forming method for laser-induced shock waves in different regions that combines trajectory planning, numerical simulation, and visual measurement. The details are as follows:

[0027] 1. Determine the material type, initial dimensions, and structural dimensions after forming of the part. The material type is aluminum alloy 7050, the initial dimensions are 125×25×3mm, and the curvature radius after forming is required to be 260±5mm.

[0028] 2. Use Solidwork software to draw the three-dimensional model of the part. Use finite element analysis software ABAQUS to perform numerical simulation analysis to determine the laser shock forming scheme: import the laser energy, laser pulse width, spot shape and size, overlap rate, structural size parameters, processing area, and laser scanning direction of each area into ABAQUS software, and use the Fabbro model and Johnson_Cook material constitutive model to calculate the structural size after shock forming. By adjusting the process parameters to make the structural size after forming meet the requirements, the processing scheme is determined: laser energy 10J, laser pulse width 15ns, spot shape is square, spot size is 4mm, overlap rate 30%, processing area is 3, and the laser scanning direction of each area is a zigzag path along the long side of the specimen. The processing area and laser scanning direction are as follows: Figure 3 The numerical simulation results are shown in Figure 2As shown in the figure, the deformation of area 1 after impact is 3.04mm, and the curvature radius is 645mm. The deformation of area 2 after impact is 5.65mm, and the curvature radius is 349mm. The deformation of area 3 after impact is 7.50mm, and the curvature radius is 264mm.

[0029] 3. Use trajectory planning software to determine the processing trajectory of the first processing area (i.e. laser scanning trajectory), such as Figure 4 a) impacting the first impact area according to the processing plan determined in step (2) and the processing trajectory of the first processing area generated;

[0030] 4. Use a laser scanning measuring instrument to scan the parts after the impact in the first area with a scanning resolution of 0.1mm, generate point cloud data, calculate the structural dimensions, and the visual measurement results are as follows: Figure 5 As shown in (a), the deformation of area 1 after impact is 3.06 mm, and the curvature radius is 632 mm. The 3D model of the part is redrawn using Solidwork software.

[0031] 5. Use trajectory planning software to determine the processing trajectory of the second processing area (i.e. laser scanning trajectory), such as Figure 4 b) impacting the second impact area according to the processing plan determined in step (2) and the processing trajectory of the second processing area generated;

[0032] 6. Use a laser scanning measuring instrument to scan the parts after impact in the second area with a scanning resolution of 0.1mm, generate point cloud data, calculate the structural dimensions, and the visual measurement results are as follows: Figure 5 As shown in (b), the deformation of area 2 after impact is 5.7 mm, and the curvature radius is 338 mm. The 3D model of the part is redrawn using Solidwork software.

[0033] 7. Use trajectory planning software to determine the processing trajectory of the third processing area (i.e. laser scanning trajectory), such as Figure 4 c) impacting the third impact area according to the processing plan determined in step (2) and the processing trajectory of the third processing area generated;

[0034] 8. Use a laser scanning measuring instrument to scan the parts after impact in the third area with a scanning resolution of 0.1mm, generate point cloud data, calculate the structural dimensions, and the visual measurement results are as follows: Figure 5 As shown in (c), the deformation of area 2 after impact is 7.38 mm, and the curvature radius is 262 mm. The laser shock forming process of the part is completed.

Claims

1. A laser-induced shock wave high-precision forming method, characterized by: The method comprises the following steps: (1) Determine the material type, initial structural dimensions, and structural dimensions after forming of the part; (2) Use Solidwork software to draw the three-dimensional model of the part, and use finite element analysis software ABAQUS to perform numerical simulation analysis and determine the laser shock forming processing plan: import the laser energy, laser pulse width, spot shape, spot size, overlap rate, initial structural size parameters, processing area and laser scanning direction of each area into ABAQUS software, use the Fabbro model and Johnson_Cook material constitutive model to calculate the structural size after shock forming, and adjust the process parameters to make the structural size after forming meet the requirements, so as to determine the processing plan; (3) Using trajectory planning software to determine the machining trajectory of the first machining area, impacting the first impact area according to the machining plan determined in step (2) and the machining trajectory of the first machining area generated; (4) Use a laser scanning measuring instrument to scan the part after the impact in the first area with a scanning resolution of 0.1-0.3 mm, generate point cloud data, calculate the structural dimensions, and redraw the three-dimensional model of the part using Solidwork software; (5) Using trajectory planning software, determine the machining trajectory of the second impact area according to the newly drawn three-dimensional model of the part, and impact the second impact area according to the machining plan and the machining trajectory of the second impact area determined in step (2); (6) Use a laser scanning measuring instrument to scan the part after the impact in the second area, generate point cloud data, calculate the structural dimensions, and redraw the three-dimensional model of the part using Solidwork software; (7) Repeat steps (3) to (5) for subsequent processing areas until all processing areas are completed.

2. The laser-induced shock wave high-precision forming method according to claim 1, characterized in that: In step (2), the processing parameters in the determined processing plan are: laser energy, laser pulse width, spot shape, spot size, overlap rate, processing area and laser scanning direction of each area.

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