The role of microstructure in the stress relaxation and tempering of laser clad Ti-6Al-4V

In this work a heat treatment procedure was performed on laser clad Ti-6Al-4V, which resulted in a reduction of tensile residual stresses in the clad samples as well and a decrease in the hardness of the clad layer with an increasing heat treatment time. The reduction in the residual stress was attributed to inter-phase stress relaxation brought about by the growth of the β phase. The reduction in hardness was attributed to an increase in the volume fraction of the soft β phase. Both the reduction in residual stress and hardness due to this heat treatment makes it an attractive method to heat treat both laser clad and additively manufactured Ti-6Al-4V components for improved mechanical properties.