( P120-P0007) First-principles study on effects of alloying elements on phase stabilities in Ti-X solid solution (X= Mo, Al, Sn, Zr, and Nb)

摘要

In Ti alloys different alloying elements are added to control the stability of β phase. First-principles calculationis an effective method to clarify the role of the alloying elements. But one of the difficulties in applying themethod to Ti alloys is to model the random distribution of alloying elements in the bcc Ti matrix. The specialquasirandom structures (SQS) model has been successful in analyzing the properties of the solid solution.First-principles calculations were applied to evaluate the structural stabilities of bcc Ti-X alloys (X= Mo, Al, Sn,Zr, and Nb). Phase stability depending on alloying element concentration (atomic fraction ranged from 0 to 0.5)and configuration (ordered and solid solution systems) in bcc TiX alloys were calculated. The specialquasirandom structures (SQS) model was employed to emulate solution state of the alloys.