Processing of Ti–13Nb–13Zr powder by selective laser melting under a relatively high oxygen atmosphere

Abstract

Ti–13Nb–13Zr (TNZ) parts were produced by selective laser melting under an atmosphere with a relatively high O content using a comprehensive combination of laser powers and laser beam scanning velocities. The influence of processing conditions on the density, microstructure, interstitial element contents (N and O), and hardness of as-printed TNZ parts were studied. The N and O contents in the TNZ parts increased on increasing the energy density (ED). Despite the high O content in the chamber during laser processing, it was possible to obtain TNZ parts with high density and relatively low N and O contents, depending on the ED applied. Two different types of microstructure were observed in the TNZ parts: α′ martensite and α/α′ + β phases. Depending on its microstructure, the TNZ parts presented interstitial solid solution hardening and second phase hardening.