Prediction of micro indention depth of TC4 titanium alloy during laser shock processing

摘要

Laser shock peening (LSP) is an effective surface treatment technology to regulate the residual stress and surface profiles of many metallic materials. The micro-indention produced on the metal surface after LSP is an important factor related to the surface profile. In this work, the micro-indention induced by LSP is investigated with theoretically and experimentally, and the residual stress in the micro-indention is also measured. The results show that the micro-indention is induced in the spot center, whose depth is proportional to the laser power density and laser pulse duration. It saturates with the number of impacts beyond 3. The micro-indention transfers materials in the spot center to the surroundings and induces convex deformation at the spot edge. The trend of the residual stress is similar to that of micro-indention depth. The micro-indention and convex deformation increase the peak-to-valley roughness R-z at the edge. (C) 2018 The Japan Society of Applied Physics