Fatigue behaviour of Ti6Al4V alloy components manufactured by SLM subjected to HIP and residual stress relief

Abstract

Fatigue behaviour of HIPed and stress relieved Ti6Al4V alloy specimen's produced by SLM was analysed (Rε = -1). The HIP process caused a microstructural transformation decreasing the hardness and monotonic properties that not allowed fatigue strength increase. A bilinear behaviour in the elastic strain-fatigue life curve was observed, because of Young s modulus decrease during the cyclic elasto-plastic tests consequence of subgrains formation. The Smith-Watson-Topper and total strain energy density models showed a good concordance between predicted and experimental fatigue lives in notched samples.