NiAl晶体中点缺陷的模拟

利用嵌入原子法（ＥＡＭ）势函数，通过分子静态弛豫方法ＮｉＡｌ合金中各种点缺陷的形成能进行了模拟计算。结果表明，从点缺陷的形成能来看，在ＮｉＡｌ晶格中很难形成Ｎｉ反位置缺陷，而Ａｌ原子亚点阵位置总是被占据。当合金富Ｎｉ时，Ｎｉ占据Ａｌ位置形成Ａｌ的反位置缺陷；当合金富Ａｌ时，形成Ｎｉ空位。点缺陷周围原子的位移情况及双空位形成能与空位之间间距的关系的研究表明，随着两个空位之间距离的增大，其交互作用逐渐

Simulation on Point Defects in NiAl Intermetallics

Using embedded atom potentials, the formation energies of vacancies, antisites, di vacancies in NiAl alloy were calculated and the displacements of atoms around the defects were studied. The results show that in NiAl alloy, it is very difficult to form Ni antisite and to form vacancies with the same type of atoms in the nearest neighbor. The Al sublattice is always occupied. When the alloy is Ni rich, Ni atom resides at Al sublattice and forms Al antisite; however, if the alloy is Al rich, Ni vacancies are formed. Only atoms limited in 2 3 lattice parameter around the point defects have displacements. The interaction between the point defects and grain boundary shows that the grain boundary will absorb the point defects to lower their energy, to keep their stochemical composition order, and to relax the distortions caused by the point defects.