Effect of Mo Addition on Microstructures and Mechanical Properties of Ti₂AlNb Alloy

Effects of different Mo contents on microstructures and properties of Ti-22.5Al-20Nb-2V(at.%) were analyzed in this paper. Experimental results showed that the grain size was refined and the amounts of equiaxed α2 phases decreased with increase of Mo from 0.6at.% to 1.5at.%. The size of (O+B2) lath was refined when Mo from 0.6at.% to 1.2at.%. However, it seems that Mo easily segregate especially in grain boundary and become seriously with Mo increased. Compression tests showed that the yield strength and ultimate strength of alloys were obviously improved with Mo addition from 0.6at.% to 1.2at.%. Microhardness tests showed the same trend with compression yield and ultimate strength.