Strengthening Mechanisms upon Implantation of Nanoparticles in Materials Using Laser Shock Waves

The implantation of nanoparticles into materials using laser shock waves is an advanced method of surface strengthening of light metals and alloys. The strengthening is based on a combination of plastic deformation caused by the well-known laser shock peening and the high mechanical characteristics of solid nanoparticles. This article discusses specific interconnections between the strengthening mechanisms and the properties of the surface processed by laser shock waves. When such a technology is used, the strengthening effect is found to be provided by two main factors: the gradient microstructure caused by plastic deformation and the gradient depth distribution of implanted SiC particles. Three competing mechanisms affect the strengthening when a laser shock wave is applied to gradient reinforced layers: dispersion strengthening with SiC nanoparticles, grain refinement, and dislocation strengthening. The contribution of each strengthening mechanism to the total strengthening was studied using a modified Clyne computational model.