Utilizing laser peening in mitigating hydrogen embrittlement susceptibility of TC4 titanium alloy under varying hydrogenated conditions

Abstract

Hydrogen embrittlement (HE) sensitivity of laser-peened TC4 titanium alloy under various hydrogenation settings was examined in this study by analyzing the impact of laser peening (LP) generated compressive residual stress, refined grains, and dislocation density on hydrogen-induced surface changes, XRD phase shifts, microhardness, and tensile properties of the alloy under varying hydrogenation conditions. The results indicate that even at higher hydrogenation levels, LP significantly mitigated the effects of hydrogen-induced microstructural changes and alloy hardening rates. Moreover, an increase in laser pulse energy further limited the effects of hydrogen-induced negative surface properties, suggesting that hydrogen diffusion suppression is effective even at higher hydrogenation conditions. The LPed specimens showed enhanced toughness under higher laser pulse energy, and they were more resilient than the non-LPed ones for the different hydrogenation settings. Consequently, even at greater hydrogenation circumstances, LP can greatly lower the alloy’s hydrogen embrittlement index to increase its HE resistance.