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 beta phase. The reduction in hardness was attributed to an increase in the volume fraction of the soft beta 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.