中文摘要：

从合金热力学的角度，采用一种普适化的三亚晶格热力学模型，辅助以第一性原理总能计算的方法，研究了常用于添加在L10-TiAl基金属间化合物中的12种过渡族金属元素的占位行为随Ti／Al比和温度的变化情况。结果表明，在1173K，合金化元素含量固定为2％（原子分数），Ti／Al比从0．6增加至1．4时，Ti和Al本身具有很强的占位有序性。当温度固定为1173K，Ti／Al比从0．6增加至1．4时，合金化元素按其占位行为可以分为两大类，其中，V，Ta，Mo，Mn，Cr，Zn和W元素随Ti/Al比的增加，其占位行为在Ti／Al=1附近出现了从占Ti位到Al位的突变；Zr，Nb，Tc，Co和Ag元素的占位行为随Ti／Al比变化没有明显变化。当Ti／Al=1，合金体系固定为Ti0.49Al0.49M0.02，温度从200K增加至2000K时，合金化元素按其占位行为同样可以分为两大类，其中，V，Ta，Mo，Te，Co，Mn，Cr，Zn和w元素随温度升高，其占位行为从完全无序转变为具有明显的占位倾向性；Zr，Nb和Ag元素的占位行为随温度升高没有显著变化。比较表明，Ti／Al比对合金化元素占位行为的影响大于温度的影响。该结果与大部分文献报道的实验和计算结果吻合。

英文摘要：

The site occupancy dependence of 12 transition metal elements on Ti/Al ratio and temperature usually used for the alloying of L10-TiAl were studied by thermodynamic model and first-principles calculation using a general three sublattice model. Ti and Al in the alloy with 2% （ atom fraction） alloying elements had very strong site preferences in the range of Ti/Al ratio from 0.6 to 1.4. The transition metals could be classified into two groups when the Ti/Al ratio changed from O. 6 to 1.4 at 1173 K. The site occupancies of V, Ta, Mo, Mn, Cr, Zn and W changed from Ti sublattice to Al sublattice around Ti/A1 = 1 and the site occupancies of Zr, Nb, Tc, Co and Ag did not change a lot. The transition metals could also be fall into two groups when the temperature changed from 200 K to 2000 K in Ti0.49Al0.49M0.02 with Ti/Al = 1. The site occupancies of V, Ta, Mo, Tc, Co, Mn, Cr, Zn and W changed from disorder to obvious site preferences, and the site occupancies of Zr, Nb and Ag did not change much. In contrast, the Ti/Al ratio had more effect than the temperature on the site occupancies of transition metals in L10-TiAl. The present predictions agreed well with the previous reports from both experimental and theoretical studies in the literature.