Effect of Solution Time on Microstructures and Mechanical Properties of Ti-5553 Alloy

The effects of varied solution time on the microstructures and tensile properties in alpha+beta phase field of Ti-5553 alloy were studied. The volume fraction and Feret ratio distribution of primary alpha (alpha(p)) with varied solution time were emphatically analyzed. The microstructures of Ti-5553 alloy were observed by SEM. The orientation evolution of grain boundary primary alpha and intragranular alpha phase during solution was characterized by EBSD technique. The tensile properties were tested by an electronic universal testing machine. The results show that the volume fraction of alpha(p) decreases with the extension of solution time; meanwhile, the equiaxation and coarsening of alpha(p) decrease the resistance to dislocation movement, which result in the decrease of strength and the increase of plasticity. The grain boundary alpha(p) is truncated in the form of "hot trench" during solution process; however the truncated grain boundary alpha(p) maintains the same orientation.