Influence of yttrium on microstructure, mechanical properties and deformability of Ti-43Al-9V alloy

The influences of rare earth metal (Y) on microstructure, mechanical properties and deformability of Ti-43A1-9V alloy are reported. The results show that Ti-43Al-9V-0.3Y alloy is composed of γ, α2, B2 and YAl2 phases. Adding 0.3at.% Y refines the grain size, decreases α2/γ/B2 lamellar thickness of Ti-43Al-9V alloy, and promotes the formation of fine α2/γ lamellae. Mechanical property tests show that adding 0.3at.% Y can apparently enhance strength and plastic property of Ti-43Al-9V alloy. The hot deformation experiment at 1200 °C indicates that adding 0.3at.% Y can improve deformability of Ti-43Al-9V alloy, because Ti-43Al-9V-0.3Y alloy has smaller grain size, lower resistance to deformation, and fine and uniform recrystallized grains.