Tial-based materials by in situ selective laser melting of ti/al reactive composites

Abstract

Additive manufacturing (AM) of refractory materials requires either a high laser power or the use of various easily melting binders. In this work, we propose an alternative—the use of spherical reactive Ti/Al composite particles, obtained by preliminary high-energy ball milling. These powders were used to produce high-temperature TiAl-based materials during the selective laser melting (SLM) process. When laser heating is applied, mechanically activated composite particles readily react with the release of a considerable amount of heat and transform into corresponding intermetallic compounds. The combustion can be initiated at relatively low temperatures, and the exothermic effect prevents the sharp cooling of as-sintered tracks. This approach allows one to produce dense intermetallic materials with a homogeneous structure in one step via SLM and eliminates the need for powerful lasers, binders, or additional post-processing and heat treatments.