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 the adding small amounts of 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 doped with trace transition metal X is unstable in the ground state.

中文翻译：

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微量过渡金属掺杂β-钛合金的结构与性能：密度泛函理论研究

摘要

我们通过密度泛函理论（DFT）模拟系统地计算Ti _0.98 X _0.02体系的结构，形成焓，形成自由能，弹性常数和电子结构，以探索过渡金属X（X = Ag，Cd，Co，Cr （Cu，Fe，Mn，Mo，Nb，Ni，Pd，Rh，Ru，Tc和Zn）对β-钛稳定机理的影响。根据我们的计算，形成焓和自由能的结果表明，少量X的加入有利于β-钛的热力学稳定性。状态密度（DOS）很好地解释了此行为。但是，Ti的四方剪切模量为_0.98 X _0.02 系统为负，表明低浓度X掺杂的β-钛在0 K时仍然是弹性不稳定的。因此，我们从理论上解释说，掺杂痕量过渡金属X的β-钛在基态下是不稳定的。