中文摘要：

运用Miedema模型研究了Al3X（Sc，Er，Zr，Li）金属间化合物的形成焓，并结合点缺陷形成理论计算了A13x空位和反位缺陷的形成焓。结果表明Al-Sc和Al-Er系形成焓较为接近，说明Sc和Er在Al中性质相近。A1-XSc，Er，Li）二元化合物中X原子的空位形成焓高于Al原子的空位形成焓，表明Al-X系二元化合物更易形成Al空位。Al3Er反位缺陷形成焓最大，A13Zr和Al3Sc居中，Al3Li最小。Al3Sc、Al3Er和Al3Zr易于出现空位和反位两类缺陷共存的情形，而Al3Li反位缺陷形成焓明显小于空位形成焓，因而更易形成反位缺陷。

英文摘要：

Based on the Miedema＇s model, the formation enthalpies of Al3X（Sc, Er, Zr, Li） intermetallics were investigated. Combining with the formation theories of point defects, the formation enthalpies of mono-vacancy and anti-site defect of Al3X intermetallics were also calculated. The results show that the formation enthalpies of A1-Sc system are similar to those of Al-Er system. It indicates that scandium has the similar metallurgical chemical behavior to erbium in aluminum alloys. The mono-vacancy formation enthalpies of X atoms are all higher than those of aluminum atoms in binary compounds for Al-X（Sc, Er, Li） system, and it pointes that aluminum vacancies are formed prior to X（Sc, Er, Li） vacancies in Al-X intermetallics. The formation enthalpies of anti-site defect of Alex intermetallics follow the sequence of Al3Er〉 Al3Sc 〉 Al3Zr 〉 Al3Li. Compared with the formation enthalpies of vacancy and anti-site defect of Al3X intermetallics, it is found that the major point defects in Al3Sc, Al3Er and Al3Zr intermetallics are the vacancy and anti-site defect while the major point defect in Al3Li intermetallic is the anti-site defect.