Controlled precipitation by thermal engineered laser shock peening and its effect on dislocation pinning: Multiscale dislocation dynamics simulation and experiments

Warm laser shock peening without coating induced phase transformations and pinning effect on fatigue life of low-alloy steel

“…The thickness of BK7 glass confinement layer is 1 mm. In this case, WLSP parameters are being tuned to get a match of shock impedance between confinement glass layer and decarburized surface steel, in order to attain peak pressure (Table 1) [5,14,[18][19][20]51,52]. The laser power density used for the current experimental process is 5.97 GW cm −2 .…”

“…In order to avoid fast cooling of the pre-heated specimen during WLSP experiments, the electrical dryers are used for continuous heating of target specimen holder surroundings. Subsequently, the WLSP treated specimen are slowly cooled from the processing temperature to avoid RS relaxation [14,[18][19][20]51,52]. The authors earlier work investigated that direct laser ablation on the mirror polished surface works efficiently but, an anisotropic problem during the shock wave production is identified [5,21,24,27].…”

“…The optimum working temperature for dual phase spring steel was evaluated for shot peening process [16][17]. The thermal engineering based warm laser shock peening (WLSP) has advantages such as dynamic strain aging (DSA), and dynamic precipitation (DP) hardening of low-alloy steel which contributes an extensive improvement in fatigue life cycle [14,[18][19][20]51,52]. LSPwC method of producing high compressive RS works efficiently with low energy lasers.…”

Surface topography evolution of Ni-based single crystal superalloy under laser shock: Formation of the nano-scale surface reliefs

“…Many researchers attributed the improvement of mechanical properties to the compressive residual stresses brought by LSP [10,11]. In addition, there were also many investigations that focused on the effect of microstructure modification induced by LSP on the improvement of material performances [6,12]. However, there is little information available in the literature about the relevance of material performances and the changes of surface integrity affected by LSP.…”

Laser shock processing on Ni-based superalloy K417 and its effect on thermal relaxation of residual stress

“…During LSP the specimen undergoes extremely high strain rate (greater than 10 6 s −1 ) in a extremely short period of time (dozens of ns) and is dynamically strengthened. The enhanced mechanical properties after LSP are mainly ascribed to the work-hardened layers and generation of compressive residual stress on the surface of processed materials due to the laser-induced ultra high strain rate plastic deformation [7,8]. However, residual stress induced by LSP relaxes obviously at elevated temperatures and the strengthening effect is weakened [9,10].…”