Microstructure and mechanical properties of a novel β titanium metallic composite by selective laser melting

Selective laser melting (SLM) is an additive manufacturing process in which functional, complex parts are produced by selectively melting consecutive layers of powder with a laser beam. This flexibility enables the exploration of a wide spectrum of possibilities in creating novel alloys or even metal metal composites with unique microstructures. In this research, Ti6A14V-ELI powder was mixed with 10 wt.% Mo powder. In contrast to the fully alpha ' microstructure of Ti6A14V after SLM, the novel microstructure consists of a beta titanium matrix with randomly dispersed pure Mo particles, as observed by light optical microscopy, scanning electron microscopy and X-ray diffraction. Most importantly, the solidification mechanism changes from planar to cellular mode. Microstructures after heat treatment indicate that the beta phase is metastable and locate the beta transus at similar to 900 degrees C, and tensile properties are equal to or better than conventional titanium alloys. (C) 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.