An investigation of the effect of warm laser shock peening on the surface modifications of [001]-oriented DD6 superalloy

Warm laser shock peening (WLSP) is a novel surface modification technology involving a combination of laser shock peening (LSP) and dynamic strain aging (DSA) technologies. Nickel-based single-crystal superalloy is one of the leading materials for aeroengine turbine blades. Hence, studying the surface modification effect of WLSP on [001]-oriented DD6 nickel-based single-crystal superalloy has a real significance in the aerospace field. Three experimental heating temperatures, 260 °C, 280 °C, and 300 °C, were selected in the vicinity of DD6 DSA temperature, and WLSP treatment was carried out on [001]-oriented DD6 specimens. Microstructure, FEM simulation of laser-induced compressive residual stress field, microhardness, and microstructural changes after the heat treatment of specimens were studied. The test results show that WLSP could generate plenty of stable dislocation structures in the impacted regions, and the effect of WLSP is positively correlated with the experimental temperature. Besides, both the WLSP-induced compressive residual stress and the microhardness in the impacted region tend to increase with the increase in WLSP temperature. The microstructure of a WLSP specimen varies at different annealing temperatures.