基于密度泛函理论和局域密度近似的第一性原理方法,进行了Al晶界的第一性原理拉伸试验.得到Al晶界的理论拉伸强度为9·5GPa,对应的应变为16%.根据价电荷密度、键长和原子构型随应变的变化,我们证实断裂发生在晶界面,其特征是所有界面键的断裂.同时还发现在周围原子键的数目减少的情况下,界面重构的Al-Al原子键具有共价键的性质.因此Al晶界依然保持着较高的界面强度. Based on the first principle method of density functional theory and local density approximation, the first principle tensile test of Al grain boundary was carried out. The theoretical tensile strength of Al grain boundary was 9.5GPa and the corresponding strain was 16 %. Based on the valence charge density, bond length and atomic configuration as a function of strain, we demonstrate that the fracture occurs at the grain boundary and is characterized by the rupture of all the interface bonds. It is also found that in the event that the number of surrounding atomic bonds decreases, the interface The reconstructed Al-Al atomic bond has the property of covalent bond, so the Al grain boundary still maintains a high interfacial strength.