Laser shock processing as a method of decreasingudfatigue of a die-casting die made of maraging steel

摘要

Laser Shock Processing (LSP) is a process of laser treatment with a pulsed beam of high-power density. The process generates locally limited mechanical waves that increase the through-depth density of dislocations. This entails a change in mechanical properties, particularly at the workpiece surface. The treatment with laser-induced shock waves is suitable for structural parts and machine elements subjected to high thermo-dynamical loads. LSP can substantially improve the wear resistance, which is of exceptional significance to die-casting tools made of maraging steel. The paper describes the effects of LSP on chosen 12% Ni maraging steel, which is suitable also for the manufacture of tools for die casting of aluminium alloys. After laser treatment, measurements of residual stresses and microhardness and other properties, including surface defects at the micro level, were carried out. The results of the study confirmed that exceptionally favourable residual stresses and microhardness could be obtained.