Low cycle fatigue properties of Ti-6Al-4V alloy fabricated by high-power laser directed energy deposition: Experimental and prediction

Abstract

The low cycle fatigue (LCF) properties of Ti-6Al-4V parts fabricated by high-power laser directed energy deposition were investigated. The results show that the parts after solution treatment and aging exhibit superior LCF lives to those of other reported AM Ti-6Al-4V parts, as well as are comparable to those of the wrought counterparts at intermediate strain amplitudes (from 0.8% to 1.1%). Cyclic softening behaviors were found at various strain amplitudes (from 0.65% to 1.7%). In addition, a microstructure-based multistage fatigue model was used to predict their LCF lives and shows good agreement with the experimental data.