Effect of Laser Quenching on Surface Microstructures of TA15 Titanium Alloy

In order to improve the mechanical properties of the surface for TA15 titanium alloy, the microstructures evolution of alloys under different laser power were studied by analyzing the transformation of microstructures and the distribution of composition and hardness. The results show that the laser quenching can induce the martensite transformation of TA15 alloy, resulting in the formation of α-Ti and α’-Ti hardening phases on the surface. The morphologies of TA15 are composed of quenched layer, transition region and matrix after laser quenching. The formation of martensite α’-Ti results in the hardening layer and a hardness higher than 430 HV0.3 on the surface of TA15 alloy. The thickness and width of the hardening layer increase with the increase of laser quenching power. When the power is 800 W, there will be the maximum thickness and width of 777 μm and 2117 μm, respectively.