Microstructure and Mechanical Properties of TA15 Alloy Produced by Electron Beam Melting

A series of TA15 specimens with different process parameters were built by electron beam melting in this paper to systematically investigate the relationship of material-process-microstructure-mechanical properties. A quantitative mathematical model of yield strength and Vickers hardness with respect to α lath thickness was established. Microstructure analysis results showed that the microstructure of TA15 titanium alloy were basketweave microstructure, lamellar microstructure and bimodal microstructure depending on process. In general, the yield strength, Vickers hardness and α plate thickness are correlated with the Hall-Petch equation, but the mathematical model established in this paper has a better fitting effect. Process parameters affect the mechanical properties of the TA15 titanium alloy by affecting α lath thickness, and speed factor has the greatest influence on α lath thickness. The tensile properties of TA15 titanium alloy are as well as, if not better than, that of TA15 titanium alloys with tri-modal microstructure. Graphic abstract