Influence of process parameters on temperature and residual stress distributions of the deposited part by a Ti-6Al-4V wire feeding type direct energy deposition process

Abstract

Distributions of temperature and residual stress of the deposition bead and the substrate during a wire feeding type direct energy deposition (DED) process are crucial to avoid undesired thermal effects and premature failure of the fabricated part due to repeated heating and cooling cycles during successive deposition. The goal of the paper is to investigate the influence of process parameters on distributions of temperature and residual stress of the deposited bead and the substrate for a single layer deposition through thermo-mechanical finite element analyses (FEAs). Ti-6Al-4V is chosen as the material of the wire. The effects of the power of the laser, the travel speed of the table and the length of the bead on the formation of the heat affected zone (HAZ) and the stress influenced region (SIR) are quantitatively examined using the results of FEAs. From the results of the examination, an appropriate gap between adjacent beads for successive deposition is proposed to reduce undesirable thermal effects and residual stress of the part fabricated by the Ti-6Al-4V wire feeding type DED process.