In situ synthesized Ti2AlNb-based composites produced by selective laser melting by addition of SiC-whiskers

Abstract

Ti2AlNb-based composites are attractive advanced materials for light-weight aero-space applications at high service temperatures since titanium orthorhombic alloys demonstrate an attractive combination of mechanical properties, low density, and are suitable for matrix materials. Additive Manufacturing is a promising way of producing SiC/Ti2AlNb composites because it offers a possibility to produce parts with a high degree of design-freedom and good mechanical properties. In this work, Ti2AlNb-based alloy powder was blended with 0–15 vol% SiC whiskers and used in Selective Laser Melting process with high-temperature substrate preheating to produce crack-free Ti2AlNb-based composites. Addition of SiC whiskers resulted in in situ formation of TiC phase and B2/β-grain refinement resulting in Ti2AlNb + B2 + TiC microstructure with microhardness up to 711 ± 15 HV1.0.