Monte Carlo模拟
(中南大学材料科学与工程学院， 长沙 410083)
摘 要: 采用基于Multi-States Ising Model的Monte Carlo算法， 模拟研究了Al-Cu-Li-xMg合金时效初期微观结构的演变过程， 结果表明： 时效早期， 在Al-1.2Cu-5.7Li合金中微结构的主要形态是Li原子团簇、 Li-Cu原子对和空位团簇， 且空位团簇的出现多出现在Li原子团簇附近， 形成共生形态； 而Al-1.2Cu-5.7Li-xMg合金中， 出现明显的Cu-Clusters， 而Li原子的偏聚过程则受到抑制， 且空位团簇的形态也发生了变化， 多与Cu-Mg原子团簇形成共生形态； 微量Mg的作用是通过Mg／Li原子间存在强烈的相互作用调整Li原子团簇的偏聚形态， 导致大量被Li原子Clustering过程锁定的Cu原子和空位被置换出来， 进而影响Li、 Cu原子团簇的形态和空位的分布形态， 并影响随后的析出相分布形态。
关键字: Al-Cu-Li合金; Monte Carlo Method; 时效初期
initial ageing stage
（School of Materials Science and Engineering,
Central South University, Changsha 410083, China）
Abstract: The Monte Carlo Method, which based on the Multi-States Ising Model, was applied to simulate the microstructural evolution of Al-Cu- Li-xMg alloys during the initial ageing stage. The simulation results show that: there are Li-clusters, Li-Cu co-clusters and vacancy-clusters in Al-Cu-Li alloy during the initial ageing stage, and Li clusters exhibit a tendency to co-existed with vacancy clusters; with small addition of Mg, Cu clusters are provoked, while the clustering of Li atoms is restrained, the vacancy clusters have a tendency to co-existed with Cu-Mg co-clusters. Small addition of Mg has strongly effect on the morphology of Li clusters, which can release Cu atoms and vacancies from the locking-state by Li clusters. Therefore, the morphology of precipitates can be affected by the addition of Mg subsequently.
Key words: Al-Cu-Li alloys; Monte Carlo Method; initial ageing stage
