Structures and Properties of β-Titanium Doping Trace Transition Metal Elements: a Density Functional Theory Study

2020/04/29 by Jia Song, Song, Jia, Luyu Wang +9
Materials Science · Engineering · #Titanium Alloys Microstructure and Properties #Metal and Thin Film Mechanics #Advanced Materials Characterization Techniques

paper · pdf · doi:10.48550/arxiv.2004.13950

Abstract

We systematically calculate the structure, formation enthalpy, formation free energy, elastic constants and electronic structure of Ti_0.98X_0.02 system by density functional theory (DFT) simulations to explore the effect of transition metal X (X=Ag, Cd, Co, Cr, Cu, Fe, Mn, Mo, Nb, Ni, Pd, Rh, Ru, Tc, and Zn) on the stability mechanism of β-titanium. Based on our calculations, the results of formation enthalpy and free energy show that adding trace X is beneficial to the thermodynamic stability of β-titanium. This behavior is well explained by the density of state (DOS). However, the tetragonal shear moduli of Ti_0.98X_0.02 systems are negative, indicating that β-titanium doping with a low concentration of X is still elastically unstable at 0 K. Therefore, we theoretically explain that β-titanium doping with trace transition metal X is unstable in the ground state.

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