A novel titanium alloy manufactured by selective laser melting: Microstructure, high temperature oxidation resistance

A novel titanium alloy (Ti-5.5Al-3.4Sn-3.0Zr-0.7Mo-0.3Si-0.4Nb-0.35Ta) with a relative density of 9934% was produced by selective laser melting (SLM) under the condition of 140 W laser power and 400 mm/s scanning speed. The microstructure, high temperature oxidation resistance and micro-hardness were studied. The results showed that the acicular martensitic alpha' phase was about 0.5 mu m in width due to the high cooling rate during the SLM process. The comparative measurements showed that the as-SLMed sample had higher oxidation resistance and micro-hardness than those of the as-casted one. And the oxidation mechanism was proposed. (C) 2015 Elsevier Ltd. All rights reserved.