Effect of Zr and Si addition on high temperature mechanical properties of near-α Ti-Al-Zr-Sn based alloys

The mechanical properties and microstructural evolution of Ti-Al-Zr-Sn based near α-Ti alloys with various amounts of Zr and Si have been systematically investigated. The compression test results reveal that higher contents of Zr and Si can improve the yielding strength both at room temperature and high temperature (650 °C). The enhanced yield strength was found to be contributed mainly by fine silicide precipitates (Ti5Si3). Zr was enriched in the silicide formed at α-lath boundaries. The microstructural characterization of the alloys with various alloying elements has been studied using transmission electron microscopy (TEM).