The effect of heat treatment on the residual stress levels within direct metal laser sintered Ti-6Al-4V as measured using the hole-drilling strain gauge method

Abstract

In Direct Metal Laser Sintering (DMLS) the presence of significant temperature gradients is capable of inducing high residual stresses. Since residual stresses are potentially detrimental to the structural integrity of cyclically loaded materials, there is incentive for identifying an effective residual stress alleviation technique. The effect of heat treatment on the residual stress levels within DMLS Ti-6Al-4V was evaluated using the hole-drilling strain gauge method (ASTM E837-08). Simple stress-relief treatment and a range of annealing processes were evaluated, from which recrystallization annealing proved most effective. In addition, the microstructural response to heat treatment was evaluated with the aim of identifying possible material property changes.