Mechanical properties and microstructural response of 2A14 aluminum alloy subjected to multiple laser shock peening impacts

Abstract Detailed analysis on mechanical properties and microstructural evolution of 2A14 aluminum alloy subjected to multiple Laser Shock Peening (LSP) impacts has been conducted. The tensile test and in-depth microhardness measurement were utilized in analyzing the mechanical properties, while Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) examinations were also conducted to characterize the microstructural response. Experimental results demonstrated that the strength and micro-hardness of 2A14 aluminum alloy were improved with increasing the numbers of LSP impacts. After 3 LSP impacts, the tensile strength, and surface micro-hardness reached 525 MPa and 262 HV respectively, which received an increase of 20.69% and 72.37% compared with the untreated sample. And high-density of dislocation structures were also found in surface layer of the specimen subjected to 3 LSP impacts. With regards to the microstructural characteristics of 2A14 aluminum alloy, the enhancement of its mechanical properties was mainly contributed to the beneficial microstructure evolution induced by multiple LSP impacts.