Comprehensive Analysis of Laser Peening Forming Effects on 5083 Aluminum Alloy

In order to investigate the laws of the laser peening forming process and the effects of laser peening on the surface quality and tensile properties of 5083 aluminum alloy, experiments were conducted utilizing various laser peening paths, energies, and plate thicknesses. Subsequently, laser peening forming experiments were performed on S-shaped and different shapes of aluminum alloy substrates. The impact of different laser peening durations on surface morphology and tensile properties was then analyzed. Results indicated that the largest bending deformation perpendicular to the laser peening path reached 12.5 mm. In cases where the laser peening path was inclined relative to the horizontal direction, torsional deformations were observed in the aluminum alloy plate. For laser energy levels of 5 J, 6 J, and 7 J, deformation amounts were 3.8 mm, 4.9 mm, and 5.4 mm, respectively. Plates with thicknesses of 4 mm exhibited convex deformation, while those with 2 mm thickness showed concave deformation. Furthermore, following one and two laser peening cycles, the residual stresses in the alloy plates were −80 MPa and −107 MPa, the surface hardness increased by 16 HV and 31 HV, the roughness increased by 2.495 μm and 3.615 μm, and the tensile strength increased by 9.5 MPa and 18.5 MPa, respectively.


Introduction
Alloy 5083 aluminum is extensively utilized in automotive, aircraft, and marine industries for its high strength-to-weight ratio, excellent resistance, and welding capabilities [1][2][3].The growing demand for metal parts in electronic products and microelectromechanical systems (MEMS) has drawn interest towards forming technologies associated with them.Nevertheless, conventional forming methods are characterized by high costs, lengthy cycle times, and limited precision [4].
In recent years, laser-shock-forming technology has emerged as a novel approach to address the aforementioned issues.Laser Shock Form (LSF) is a process used to shape plates by generating high strain-rate plastic deformation through the application of a laser shock wave [5].Hackel et al. [6] introduced the concept and methodology for plastic deformation of plates through laser peening.Hammersley et al. [7] proposed a laser peening forming technique that relies on pre-bending, where the plate undergoes initial elastic bending before being shaped through laser peening.This approach significantly enhances the level of plastic deformation in the plate.Ocana et al. [8] studied the deformation of a cantilever beam made of stainless-steel plate girder with a laser peening of 50 um thickness.They discovered that the overall deformation was a combination of the local concave surface at the focal point and the macroscopic bending deformation of the plate girder.Sagisaka et al. [9] conducted a laser peening forming method on SUS304 stainless steel to experiment out to remove internal stresses before conducting the experiments.The surface of th imen was ground and polished to remove the oxide film on the surface of the spe and greasy dirt was removed using acetone.

LSP Experiments
As shown in Figure 1, a third-generation laser blasting system (LSPT, Dubli USA, PROCUDO200) was used for the test.The key technical parameters were as fo all laser rods were YLF crystals, pump diode lifetime than 15 years, pulse energy 5 pulse maximum repetition frequency 20 Hz, pulse width 8-16 ns, spot size adjusta tween 2 mm and 8 mm, and laser wavelength 1053 nm.

Experimental Study of Laser Peening Forming Process Rules
To study the law of laser peening forming on 5083 aluminum alloy sheets, we a 300 mm × 100 mm × 4 mm sheet of this alloy as our research object.Figure 2 illu the three different laser-peening paths that were designed.To explore their impact forming trend of the aluminum alloy plate, we used a unilateral-bolt fixed constrain an impact area of 130 mm × 100 mm.Next, we selected the laser-peening path par the horizontal direction and conducted forming tests on 5083 aluminum alloy pl varying thicknesses: 2 mm, 4 mm, and 5 mm.This allowed us to analyze the influe different thicknesses on the bending deformation of the plates.Finally, we focused 4 mm thick 5083 aluminum alloy plate and performed laser-peening tests using la ergy levels of 5 J, 6 J, and 7 J.Our goal was to examine the effect of different laserlevels on the bending deformation of the aluminum alloy plate.

Experimental Study of Laser Peening Forming Process Rules
To study the law of laser peening forming on 5083 aluminum alloy sheets, we chose a 300 mm × 100 mm × 4 mm sheet of this alloy as our research object.Figure 2 illustrates the three different laser-peening paths that were designed.To explore their impact on the forming trend of the aluminum alloy plate, we used a unilateral-bolt fixed constraint with an impact area of 130 mm × 100 mm.Next, we selected the laser-peening path parallel to the horizontal direction and conducted forming tests on 5083 aluminum alloy plates of varying thicknesses: 2 mm, 4 mm, and 5 mm.This allowed us to analyze the influence of different thicknesses on the bending deformation of the plates.Finally, we focused on the 4 mm thick 5083 aluminum alloy plate and performed laser-peening tests using laser energy levels of 5 J, 6 J, and 7 J.Our goal was to examine the effect of different laser-energy levels on the bending deformation of the aluminum alloy plate.
To measure the degree of deformation of the plate, we considered the following dimensions: the thickness of the aluminum alloy plate is h, the thickness of the substrate is H, the length of the substrate is L (300 mm), the radius of curvature of the bent plate is R, the arc height for bending the plate is d, and the maximum distance between the bent plate and the substrate is D. We used the arc height to gauge the extent of deformation in the plate post-bending.In order to obtain the arc bow height, a coordinate measuring machine (CMM) was used to measure the coordinates of the plate after deformation and calculate the arc bow height.The CMM is shown in Figure 3a.The schematic diagram of the arc bow height is shown in Figure 3b.To measure the degree of deformation of the plate, we considered the following dimensions: the thickness of the aluminum alloy plate is h, the thickness of the substrate is H, the length of the substrate is L (300 mm), the radius of curvature of the bent plate is R, the arc height for bending the plate is d, and the maximum distance between the bent plate and the substrate is D. We used the arc height to gauge the extent of deformation in the plate post-bending.In order to obtain the arc bow height, a coordinate measuring machine (CMM) was used to measure the coordinates of the plate after deformation and calculate the arc bow height.The CMM is shown in Figure 3a.The schematic diagram of the arc bow height is shown in Figure 3b.

Effect of Laser Peening on Surface Quality and Tensile Properties of Aluminum Alloy Mate rials
A plate with a size of 300 mm × 100 mm × 4 mm was used for double-sided las peening treatment.The laser pulse frequency was set at 5 Hz, with a spot size of 3 m and a flat-top distribution beam.The remaining process parameters are specified in Tab

Effect of Laser Peening on Surface Quality and Tensile Properties of Aluminum Alloy Materials
A plate with a size of 300 mm × 100 mm × 4 mm was used for double-sided laser peening treatment.The laser pulse frequency was set at 5 Hz, with a spot size of 3 mm and a flat-top distribution beam.The remaining process parameters are specified in Table 1.X-ray testing was used to measure the residual stress of the aluminum alloy plate after laser-peening treatment.Specific measurements were made by the side-dipping fixed Ψ method, with the fixed-peak method being the mutual correlation method; the radiation was CuKα and the diffracted crystal plane (213).Microhardness and surface roughness were observed using a microhardness tester and a white light interferometer, respectively.Additionally, the surface morphology of the specimen was examined.The aluminum alloy plate was used to create the tensile specimen pieces, which were cut using wire cutting.The dimensions of these specimens are illustrated in Figure 4b.The tensile experiment was conducted utilizing an electronic universal testing machine (Bairoe, Shanghai, China, WDW-200), depicted in Figure 4a.The tensile speed was set at 2 mm/min, with a gauge length of 30 mm for the tensile specimen.Following tensile fracture, the fracture morphology was observed using a TM3030 benchtop microscope(Hitachi High-Tech, Schaumburg, IL, USA, TM3030).

Laser Peening Forming of Aluminum Alloy Plates for S-Shaped Profiles
A laser with an energy of 5 J, a pulse width of 16 ns, and a frequency of 5 Hz, focused on a 3 mm spot, was applied to the aluminum alloy plate; the resulting S-shaped laser peening effect is shown in Figure 5.The measured arc bow height is 5.1 mm.

Laser Peening Forming of Aluminum Alloy Plates for S-Shaped Profiles
A laser with an energy of 5 J, a pulse width of 16 ns, and a frequency of 5 Hz, focused on a 3 mm spot, was applied to the aluminum alloy plate; the resulting S-shaped laser-peening effect is shown in Figure 5.The measured arc bow height is 5.1 mm.treatment twice.

Laser Peening Forming of Aluminum Alloy Plates for S-Shaped Profiles
A laser with an energy of 5 J, a pulse width of 16 ns, and a frequency of 5 Hz, foc on a 3 mm spot, was applied to the aluminum alloy plate; the resulting S-shaped l peening effect is shown in Figure 5.The measured arc bow height is 5.1 mm.

Laser Peening Forming of Aluminum Alloys With Different-Shaped Substrates
The same laser-peening parameters were used to perform tests on plates with d ent initial shapes, as shown in Figure 6a-c.The results of the laser peening formin presented in Figure 6d-f.As illustrated in Figure 6d, the aluminum alloy substrate dominantly underwent bending deformation, whereas in Figure 6e,f, the substrate marily underwent torsional deformation.The maximum displacement of the hig point of the torsion-formed plate with respect to the horizontal plane was 11 mm.

Laser Peening Forming of Aluminum Alloys with Different-Shaped Substrates
The same laser-peening parameters were used to perform tests on plates with different initial shapes, as shown in Figure 6a-c.The results of the laser peening forming are presented in Figure 6d-f.As illustrated in Figure 6d, the aluminum alloy substrate predominantly underwent bending deformation, whereas in Figure 6e,f, the substrate primarily underwent torsional deformation.The maximum displacement of the highest point of the torsion-formed plate with respect to the horizontal plane was 11 mm.

Effect of Laser Peening Path on the Bending Deformation of Aluminum Alloy Plates and Its Analysis
For the laser peening forming experiments on 300 mm × 100 mm × 4 mm 5083 aluminum alloy plates, a laser energy of 5 J, a pulse width of 16 ns, a frequency of 5 Hz, and a spot size of 3 mm were selected.The effects of different laser peening paths are shown in Figure 7, and the impact of the laser peening path on the height of the arc bow is illustrated in Figure 8.As shown in Figures 7 and 8, under the same laser process parameters, a 4 mm minum alloy plate exhibited convex deformation relative to the direction of laser dence.Shock path 2 resulted in greater deformation of the plate, with an arc height of mm, compared to impact paths 1 and 3.This difference is primarily due to the form of residual stresses and bending moments around the X and Y axes in the region  As shown in Figures 7 and 8, under the same laser process parameters, a 4 mm aluminum alloy plate exhibited convex deformation relative to the direction of laser incidence.Shock path 2 resulted in greater deformation of the plate, with an arc height of 12.5 mm, compared to impact paths 1 and 3.This difference is primarily due to the formation of residual stresses and bending moments around the X and Y axes in the region of a As shown in Figures 7 and 8, under the same laser process parameters, a 4 mm aluminum alloy plate exhibited convex deformation relative to the direction of laser incidence.Shock path 2 resulted in greater deformation of the plate, with an arc height of 12.5 mm, compared to impact paths 1 and 3.This difference is primarily due to the formation of residual stresses and bending moments around the X and Y axes in the region of a single small spot.In Figure 9a, when laser peening was carried out along path 1, the path was parallel to the X-axis (the length direction of the plate), resulting in opposite bending moments around the Y-axis between neighboring spots, which reduced the bending deformation around the Y-axis.Conversely, in Figure 9b, when laser peening was performed along path 2, the bending moments around the Y-axis between neighboring spots were in the same direction, thereby enhancing the bending deformation around the Y-axis [14].Comparing impact paths 1 and 2, it is evident that the bending deformation was larger in the direction perpendicular to the impact path.As shown in Figure 9c, for the laser peening path inclined in the horizontal direction (path 3), a torsionally deformed part was obtained due to one-sided constraints on the plate, resulting in a larger superposition of bending moments perpendicular to the impact path.As shown in Figure 7c, the bending and twisting parts did not coincide with the flat plate at one vertex, with the measured distance being 2.9 mm.ing deformation around the Y-axis.Conversely, in Figure 9b, when laser peening was performed along path 2, the bending moments around the Y-axis between neighboring spots were in the same direction, thereby enhancing the bending deformation around the Y-axis [14].Comparing impact paths 1 and 2, it is evident that the bending deformation was larger in the direction perpendicular to the impact path.As shown in Figure 9c, for the laser peening path inclined in the horizontal direction (path 3), a torsionally deformed part was obtained due to one-sided constraints on the plate, resulting in a larger superposition of bending moments perpendicular to the impact path.As shown in Figure 7c, the bending and twisting parts did not coincide with the flat plate at one vertex, with the measured distance being 2.9 mm.

Effect of Different Laser Energies on the Bending Deformation of Aluminum Alloy Plate
The effect of different laser energies on the amount of bending deformation of the aluminum alloy plate is shown in Figure 10.As the laser energy increases, the bending deformation also increases.According to Fabbro's research [21], this is primarily due to the increase in shock-wave force and residual stress within the material, which strengthens the bending moment perpendicular to the laser peening path.The bending moments in other directions are limited or canceled out, leading to increased bending deformation perpendicular to the impact path as laser energy increases.Unlike the effect of the laser peening path on the amount of deformation, the impact path has a more significant influence on the amount of deformation.After laser peening, the black tape on the surface was removed, and the forming effect with 7 J laser energy is shown in Figure 11.On the surface, some micro-pits can be observed, indicating the impact of laser peening forming.

Effect of Different Laser Energies on the Bending Deformation of Aluminum Alloy Plate
The effect of different laser energies on the amount of bending deformation of the aluminum alloy plate is shown in Figure 10.As the laser energy increases, the bending deformation also increases.According to Fabbro's research [21], this is primarily due to the increase in shock-wave force and residual stress within the material, which strengthens the bending moment perpendicular to the laser peening path.The bending moments in other directions are limited or canceled out, leading to increased bending deformation perpendicular to the impact path as laser energy increases.Unlike the effect of the laser peening path on the amount of deformation, the impact path has a more significant influence on the amount of deformation.After laser peening, the black tape on the surface was removed, and the forming effect with 7 J laser energy is shown in Figure 11.On the surface, some micro-pits can be observed, indicating the impact of laser peening forming.

Effect of Thickness on Laser Peening Forming of Aluminum Alloy Plates
The effect of different thicknesses on the laser peening deformation of aluminum alloy plates is shown in Figure 12.Under the same laser process parameters, the arc bow height is 4.1 mm, 3.8 mm, and 3 mm for plate thicknesses of 2 mm, 4 mm, and 5 mm, respectively.The value of the arc height decreases as the thickness of the plate increases.For the 2 mm-thick aluminum alloy plate, concave deformation occurs relative to the direction of laser incidence, as shown in Figure 13.According to Yang et al. [22], the deformation pattern of the plates is consistent.This is mainly due to the fact that when the aluminum alloy plate is thin, a certain amount of laser energy results in minimal attenuation of the laser-induced shock wave through the entire thickness.Consequently, the bottom surface of the aluminum alloy plate also undergoes plastic deformation, generating a positive bending moment that causes concave deformation.When the thickness of the plate is 4 mm and 5 mm, residual stresses are formed in the laser shock area, a steep stress gradient is formed inside the plate due to the limitation of the surrounding material, and the amplitude gradually decreases, leading to the formation of convex deformation.

Effect of Thickness on Laser Peening Forming of Aluminum Alloy Plates
The effect of different thicknesses on the laser peening deformation of aluminum alloy plates is shown in Figure 12.Under the same laser process parameters, the arc bow height is 4.1 mm, 3.8 mm, and 3 mm for plate thicknesses of 2 mm, 4 mm, and 5 mm, respectively.The value of the arc height decreases as the thickness of the plate increases.For the 2 mm-thick aluminum alloy plate, concave deformation occurs relative to the direction of laser incidence, as shown in Figure 13.According to Yang et al. [22], the deformation pattern of the plates is consistent.This is mainly due to the fact that when the aluminum alloy plate is thin, a certain amount of laser energy results in minimal attenuation of the laser-induced shock wave through the entire thickness.Consequently, the bottom surface of the aluminum alloy plate also undergoes plastic deformation, generating a positive bending moment that causes concave deformation.When the thickness of the plate is 4 mm and 5 mm, residual stresses are formed in the laser shock area, a steep stress gradient is formed inside the plate due to the limitation of the surrounding material, and the amplitude gradually decreases, leading to the formation of convex deformation.

Effect of Thickness on Laser Peening Forming of Aluminum Alloy Plates
The effect of different thicknesses on the laser peening deformation of aluminum alloy plates is shown in Figure 12.Under the same laser process parameters, the arc bow height is 4.1 mm, 3.8 mm, and 3 mm for plate thicknesses of 2 mm, 4 mm, and 5 mm, respectively.The value of the arc height decreases as the thickness of the plate increases.For the 2 mm-thick aluminum alloy plate, concave deformation occurs relative to the direction of laser incidence, as shown in Figure 13.According to Yang et al. [22], the deformation pattern of the plates is consistent.This is mainly due to the fact that when the aluminum alloy plate is thin, a certain amount of laser energy results in minimal attenuation of the laser-induced shock wave through the entire thickness.Consequently, the bottom surface of the aluminum alloy plate also undergoes plastic deformation, generating a positive bending moment that causes concave deformation.When the thickness of the plate is 4 mm and 5 mm, residual stresses are formed in the laser shock area, a steep stress gradient is formed inside the plate due to the limitation of the surrounding material, and the amplitude gradually decreases, leading to the formation of convex deformation.

Surface Topography of the Material after Treatment With Different La Times
The surface morphology of different specimens after laser peening is sho 14, and the contour lines are presented in Figure 15.The surface morphology were 22 µm, 68 µm, and 96 µm for specimens 1, 2, and 3, respectively.The su ness values were 0.245 µm, 2.74 µm, and 3.86 µm for specimens 1, 2, and 3, as shown in Figure 16. Figure 15b,c shows the contour plots after 1 or 2 lase ments.The periodicity in the graphs is mainly related to the overlapping concave deformation in the center of the spot and a convex deformation in t area.It can be seen that with the increase in the number of laser shock tr surface morphology fluctuation of the specimen increases, and the surface r creases, which is consistent with the pattern obtained by Qiao et al. [23].In roughness increased with the increase in the number of laser shock peenin ness of the specimen increased from 0.05 µm to 0.37 µm after laser shock pe J laser pulse energy three times.The increase in surface roughness and mor tuation after laser peening is primarily due to the plastic deformation of the face caused by the shock-wave pressure exceeding the material's dynamic y

Surface Topography of the Material after Treatment With Different Laser Shock Times
The surface morphology of different specimens after laser peening is shown in Figure 14, and the contour lines are presented in Figure 15.The surface morphology fluctuations were 22 µm, 68 µm, and 96 µm for specimens 1, 2, and 3, respectively.The surface roughness values were 0.245 µm, 2.74 µm, and 3.86 µm for specimens 1, 2, and 3, respectively as shown in Figure 16. Figure 15b,c shows the contour plots after 1 or 2 laser shock treatments.The periodicity in the graphs is mainly related to the overlapping ratio, with a concave deformation in the center of the spot and a convex deformation in the rest of the area.It can be seen that with the increase in the number of laser shock treatments, the surface morphology fluctuation of the specimen increases, and the surface roughness increases, which is consistent with the pattern obtained by Qiao et al. [23].In their study roughness increased with the increase in the number of laser shock peening; the roughness of the specimen increased from 0.05 µm to 0.37 µm after laser shock peening with 9 J laser pulse energy three times.The increase in surface roughness and morphology fluctuation after laser peening is primarily due to the plastic deformation of the material surface caused by the shock-wave pressure exceeding the material's dynamic yield strength  The surface morphology of different specimens after laser peening is shown in Figure 14, and the contour lines are presented in Figure 15.The surface morphology fluctuations were 22 µm, 68 µm, and 96 µm for specimens 1, 2, and 3, respectively.The surface roughness values were 0.245 µm, 2.74 µm, and 3.86 µm for specimens 1, 2, and 3, respectively, as shown in Figure 16. Figure 15b,c shows the contour plots after 1 or 2 laser shock treatments.The periodicity in the graphs is mainly related to the overlapping ratio, with a concave deformation in the center of the spot and a convex deformation in the rest of the area.It can be seen that with the increase in the number of laser shock treatments, the surface morphology fluctuation of the specimen increases, and the surface roughness increases, which is consistent with the pattern obtained by Qiao et al. [23].In their study, roughness increased with the increase in the number of laser shock peening; the roughness of the specimen increased from 0.05 µm to 0.37 µm after laser shock peening with 9 J laser pulse energy three times.The increase in surface roughness and morphology fluctuation after laser peening is primarily due to the plastic deformation of the material surface caused by the shock-wave pressure exceeding the material's dynamic yield strength.

Material Hardness after Different Laser Shock Times
The depth-direction microhardness distribution of the laser-shocked and untreated specimens is shown in Figure 17.The hardness of the untreated 5083 aluminum alloy matrix was 89 HV.After one and two laser double-sided impacts, the hardness increased to 105 HV and 120 HV, respectively, representing increases of 16 HV and 31 HV.In the depth direction, the hardness of the laser-shocked specimens gradually decreased with increasing distance from the surface.Therefore, while laser peening strengthening has a diminishing effect with depth, the impact extends to a depth greater than 1.2 mm.This is due to the fact that a gradual work-hardening layer can easily be formed by the plastic deformation produced under the pressure of the laser shock wave.The intense plastic deformation of the specimen leads to high dislocation density and grain refinement, and the increase of grain boundaries after grain refinement enhances the intergranular bonding [24,25].

Material Hardness after Different Laser Shock Times
The depth-direction microhardness distribution of the laser-shocked and untreated specimens is shown in Figure 17.The hardness of the untreated 5083 aluminum alloy matrix was 89 HV.After one and two laser double-sided impacts, the hardness increased to 105 HV and 120 HV, respectively, representing increases of 16 HV and 31 HV.In the depth direction, the hardness of the laser-shocked specimens gradually decreased with increasing distance from the surface.Therefore, while laser peening strengthening has a diminishing effect with depth, the impact extends to a depth greater than 1.2 mm.This is due to

Material Hardness after Different Laser Shock Times
The depth-direction microhardness distribution of the laser-shocked and untreated specimens is shown in Figure 17.The hardness of the untreated 5083 aluminum alloy matrix was 89 HV.After one and two laser double-sided impacts, the hardness increased to 105 HV and 120 HV, respectively, representing increases of 16 HV and 31 HV.In the depth direction, the hardness of the laser-shocked specimens gradually decreased with increasing distance from the surface.Therefore, while laser peening strengthening has a diminishing effect with depth, the impact extends to a depth greater than 1.2 mm.This is due to the fact that a gradual work-hardening layer can easily be formed by the plastic deformation produced under the pressure of the laser shock wave.The intense plastic deformation of the specimen leads to high dislocation density and grain refinement, and the increase of grain boundaries after grain refinement enhances the intergranular bonding [24,25].The depth-wise distribution of residual stresses in both laser-peened and untreated specimens is depicted in Figure 18.The 5083-aluminum-alloy matrix surface exhibited an initial tensile stress of 58 MPa.Following double-sided laser impacts for one and two cy-

Residual Stresses in Materials after Laser Shock Peening
The depth-wise distribution of residual stresses in both laser-peened and untreated specimens is depicted in Figure 18.The 5083-aluminum-alloy matrix surface exhibited an initial tensile stress of 58 MPa.Following double-sided laser impacts for one and two cycles, the surface residual stresses shifted to −80 MPa and −107 MPa, respectively, transitioning from tensile to compressive stress states.This transition primarily arose from material plastic deformation induced by laser peening.Plastic deformation was confined to a localized region, counteracted by the surrounding material, resulting in residual compressive stresses.Residual stresses gradually diminished in the depth direction from the surface in laser-treated specimens [26,27].Consequently, the reinforcing effect of laser peening attenuated with increasing depth.

Residual Stresses in Materials after Laser Shock Peening
The depth-wise distribution of residual stresses in both laser-peened and untreated specimens is depicted in Figure 18.The 5083-aluminum-alloy matrix surface exhibited an initial tensile stress of 58 MPa.Following double-sided laser impacts for one and two cycles, the surface residual stresses shifted to −80 MPa and −107 MPa, respectively, transitioning from tensile to compressive stress states.This transition primarily arose from material plastic deformation induced by laser peening.Plastic deformation was confined to a localized region, counteracted by the surrounding material, resulting in residual compressive stresses.Residual stresses gradually diminished in the depth direction away from the surface in laser-treated specimens [26,27].Consequently, the reinforcing effect of laser peening attenuated with increasing depth.The Force-Displacement curves of the laser-peening-treated specimens are illustrated in Figure 19.Specimens 1, 2, and 3 are the specimens after 1, 2, and 3 laser impacts, respectively.The tensile test results are presented in Table 2.The tensile strengths of specimens 1, 2, and 3 were 208.5 MPa, 218 MPa, and 236.5 MPa, respectively.As can be seen from Table 2, the tensile strength of the specimen increased with the increase in the number of laser shocks.Laser peening treatment demonstrated a significant enhancement in the tensile strength of aluminum alloy materials.The Force-Displacement curves of the laser-peening-treated specimens are illustrated in Figure 19.Specimens 1, 2, and 3 are the specimens after 1, 2, and 3 laser impacts, respectively.The tensile test results are presented in Table 2.The tensile strengths of specimens 1, 2, and 3 were 208.5 MPa, 218 MPa, and 236.5 MPa, respectively.As can be seen from Table 2, the tensile strength of the specimen increased with the increase in the number of laser shocks.Laser peening treatment demonstrated a significant enhancement in the tensile strength of aluminum alloy materials.The fracture morphology of the 5083 aluminum alloy specimen is depicted in Figure 20.The tensile fracture exhibited numerous equiaxial dimples, with the dimple in unshocked specimen 1 being larger and unevenly distributed.In contrast, the dimples in the fracture of the laser-shocked specimen were smaller and exhibited a more uniform distribution, indicating refinement post-laser shock.This refinement of the dimple was mainly due to the large number of dislocations during laser shock peening.For specimen 3, the dimples increased and became finer and more pronounced; this is because each impact caused further plastic deformation, and the cumulative effect led to deeper dimples.In addition to this, the dimples of specimen 3 were more evenly distributed on the material surface.

Conclusions
Firstly, the effects of the laser peening path, laser energy, and plate thickness on the deformation trend and deformation amount of 5083 aluminum alloy plates were investigated.Secondly, the effects of different impact times on the surface quality and tensile properties of 5083 aluminum alloy were examined.In addition, laser peening forming experiments were conducted on aluminum alloy substrates of different shapes.Finally, the

Figure 5 .
Figure 5. Results of laser peening molding of S-shaped shaped parts.

Figure 5 .
Figure 5. Results of laser peening molding of S-shaped shaped parts.

Figure 6 .
Figure 6.Effect of LSP forming on different shapes of substrates.(a) Geometry of a C-shaped plate; (b) Geometry of a T-shaped plate; (c) Geometry of a Square-shaped plate; (d) Results of LSP on Cplate; (e) Results of LSP on T-plate; (f) Results of LSP on Square-plate.

3 .
Results and Discussion 3.1.Influence Law and Analysis of Process Parameters 3.1.1.Effect of Laser Peening Path on the Bending Deformation of Aluminum Alloy Plates and Its Analysis For the laser peening forming experiments on 300 mm × 100 mm × 4 mm 5083 alumi-

Figure 6 .
Figure 6.Effect of LSP forming on different shapes of substrates.(a) Geometry of a C-shaped plate; (b) Geometry of a T-shaped plate; (c) Geometry of a Square-shaped plate; (d) Results of LSP on C-plate; (e) Results of LSP on T-plate; (f) Results of LSP on Square-plate.

Figure 8 .
Figure 8.Effect of laser peening path on arc bow height.

Figure 8 .
Figure 8.Effect of laser peening path on arc bow height.

Figure 8 .
Figure 8.Effect of laser peening path on arc bow height.

Micromachines 2024 , 18 Figure 10 .
Figure 10.Effect of different laser energies on the bending deformation of aluminum alloy plate.

Figure 11 .
Figure 11.Aluminum alloy plate forming effect under laser energy 7 J.

Figure 10 . 18 Figure 10 .
Figure 10.Effect of different laser energies on the bending deformation of aluminum alloy plate.

Figure 11 .
Figure 11.Aluminum alloy plate forming effect under laser energy 7 J.

Figure 11 .
Figure 11.Aluminum alloy plate forming effect under laser energy 7 J.

Figure 12 .
Figure 12.Effect of thickness on laser peening deformation.

Figure 13 .
Figure 13.Effect of laser peening forming of aluminum alloy plate with a thickness o

Figure 13 .
Figure 13.Effect of laser peening forming of aluminum alloy plate with a thickness of 2 mm.

Figure 13 .
Figure 13.Effect of laser peening forming of aluminum alloy plate with a thickness of 2 mm.

3. 2 .
Effect of the Number of Laser Shocks on the Surface Quality of Aluminum Alloy Materials 3.2.1.Surface Topography of the Material after Treatment with Different Laser Shock Times

Figure 16 .
Figure 16.Surface roughness of different specimen pieces.

Figure 16 .
Figure 16.Surface roughness of different specimen pieces.

Figure 16 .
Figure 16.Surface roughness of different specimen pieces.

Figure 17 .
Figure 17.Hardness distribution of different specimen depth directions.

Figure 17 .
Figure 17.Hardness distribution of different specimen depth directions.

Figure 18 .
Figure 18.Residual stress distribution in different depth directions of specimens.Figure 18. Residual stress distribution in different depth directions of specimens.

Figure 18 .
Figure 18.Residual stress distribution in different depth directions of specimens.Figure 18. Residual stress distribution in different depth directions of specimens.

3. 3 .
Effect of Different Laser Shock Times on the Properties of Aluminum Alloy Materials 3.3.1.Tensile Properties

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