Fig. 1. Schematic of LSP principle^[12]

Fig. 2. Schematic of RCS and SPD generation^[12]

Fig. 3. Residual stress distribution near the hole at laser power densities of 4.7 GW/cm² and 6.6 GW/cm²^[14]. (a) Contour map of residual stress distribution; (b) residual stress distribution along the AB line

Fig. 4. Impact of RCS at different overlap ratios. (a) Ref. [16]; (b) Ref. [17]

Fig. 5. Impact test results^[19]. (a) Average grain size of each sample; (b) cross-sectional microhardness distribution curves for each sample

Fig. 6. Cross-sectional grain morphology of the original sample^[21]. (a) Semi-circular melt pool boundary; (b) refined morphology in the blue dashed-line region; (c) pores

Fig. 7. Cross-sectional grain morphology of LSP-ed sample^[21]. (a) Deformed layer; (b) refined microstructure within the blue dashed-line frame; (c) microhardness of the original and LSP-ed samples

Fig. 8. Fatigue crack initiation and fatigue crack growth in LSP-treated Ti6Al4V titanium alloy^[30]. (a) Crack length variation with cycle numbers at different laser shock intensities; (b)values of C and m for different sets of materials derived from the Paris equation fitting; (c)‒(f) functional relationship between FCG rate and crack length, as well as the relationship between FCG rate and ΔK; (g) (h) enlarged images of localized regions

Fig. 9. S-N curves of LSP and HT ^[33]

Fig. 10. Influence of different processing methods on sample cracks^[33]. (a) Macroscopic appearance of the fracture surface of high-temperature specimens; (b) unmelted powder with stress of 400 MPa and 8.29×10⁴ cycles; (c) regions exhibiting incomplete fusion with stress of 340 MPa and 2.78×10⁵ cycles; (d) clusters of α-phase with stress of 280 MPa and 5.52×10⁸ cycles; (e) stress of 370 MPa and 3.57×10⁷ cycles

Fig. 11. Comparative charts before and after using LSPwC^[43]. (a) S_a; (c) R_a; (b)(d) surface roughness profile