【摘要】 用密度泛函理论计算了大量He原子存在时He在金属铝中不同位置的能量,并在理论上预测了铝中的氦原子行为.结果表明,铝晶胞内He原子择优占位区是空位,而在整个晶体范围,最有利于容纳He原子的区域是晶界,其次是空位和位错.在fcc-铝的两种间隙位中,He原子优先充填四面体间隙位.间隙He原子的迁移能很小,易于通过迁移在晶内聚集,或被空位、晶界、位错等缺陷束缚.更多还原

【Abstract】 The energies of helium atoms in the interstitial,vacancy,grain boundary,and dislocation sites in aluminum lattice in the presence of large quantity of helium atoms,have been calculated with density functional theory(DFT),and the helium atom behavior has also been predicted theoretically.The results show that vacancies are the preferential sites for helium atoms inside the unit cell.But in the view of the whole lattice,grain boundaries are the most favorable sites for containing helium atoms than vacancies and dislocations.In the two interstitial sites in aluminum unit cell,helium atoms prefer to occupying the tetrahedron sites.The migration energy of interstitial helium atoms is so small that it is easy to accumulate or be trapped by vacancies,grain boundaries and dislocations through the migration for interstitial helium atoms.更多还原