Influence of continuous laser treatment on microstructural evolution and mechanical properties of forged Ti-Zr alloy

Abstract

The influence of different continuous laser injection parameters on microstructure, phase evolution and mechanical properties of Ti-30Zr-5Al-3V (30Zr, wt%) is systematically investigated. The as-prepared 30Zr alloy consists of α and β phase, whereas the surface of 30Zr alloy is composed of α′, α and β phases after laser surface re-melting (LSR). The surface microstructure of laser-treated 30Zr alloys is significantly refined and nanocrystalline is observed in the outermost layer after LSR. The top surface hardness of laser-treated 30Zr alloys is mainly affected by the form of α′ phase and microstructural refinement. Herein, the higher laser power density and longer laser dwelling time resulted in a higher surface hardness of 30Zr alloy. The cross-sectional microhardness of laser-treated 30Zr alloys decreased with increasing distance from the alloy surface.