Influence of Cr on the microstructure and mechanical properties of Ti–Si Eutectic Alloys

Abstract

Abstract As promising candidates for new high-temperature structural materials, Ti – Si eutectic alloys are required for the next generation of advanced aircraft engines. In this paper, microstructures of the Ti – Si eutectic alloys with various Cr contents were investigated by means of X-ray diffraction, scanning electron microscopy and light optical microscopy. The results show that with the increase of Cr content up to 9 wt.%, β-Ti (Si, Cr)ss matrix and Ti5Si3 form in the as cast alloy, however, the α-Ti (Si, Cr)ss phase disappears. Cr element solute in β-Ti and Ti5Si3 can significantly change the morphology and distribution of Ti5Si3 intermetallic phase. This greatly affects the fracture behavior and mechanical properties of as-cast Ti – Si eutectic alloys.