Effects of Laser Shock Processing on Impact Toughness of Ti-17 Titanium Alloy

Abstract

AbstractTi-17 titanium alloy was treated with laser shock processing (LSP) and tested for impact toughness. Residual compressive stress, cross-section hardness, microstructure, and the impact toughness properties of the treated alloy samples were evaluated. The average impact toughness of the samples subjected to LSP increased by 10 J compared with that of the base material. The samples subjected to LSP remained connected after an impact test, whereas untreated samples completely ruptured. The location of fracture initiation shifted from the center to the side to the Charpy-V notch region because of the stress concentration induced by LSP. The stress concentration was induced by the uneven microhardness of the samples treated with LSP. The hardness of the irradiated surface increased compared with that of the base metal because of the higher dislocation density and smaller grains produced by LSP.