Synthesis of TiAl-(TiB2+Ti2AlN) composites by HIP reactive sintering

Intermetallic compound TiAl-base composites have been prepared by the hot i sostatic pressing (HIP) reactive sintering technique. These composites have been synthesized from a powder mixture of titanium, aluminum and boron nit ride, and contain Ti2AlN and TiB2 strengthening particles. Nearly spherical particles of Ti3Al and Ti2AlN of about 20 mu m in diameter have been embed ded in the TiAl phase. The composite has been found with a dual phase matri x structure. The Ti2AlN phase is composed of about 300-500 nm grains and in cludes dispersion of nano scaled TiB2 particles (about 50-100 mm). Both com pression tests and hardness measurements have revealed that this composite material attains higher strength as compared with non-reinforced TiAl. The insufficient bending ductility, however, hinders its bending fracture stren gth at ambient temperature.