Ti75Al25合金微观结构演变的分子动力学模拟

本文利用分子动力学模拟方法, 研究了液态Ti75Al25合金在不同冷却条件下形成晶体及非晶的过程(Q1:1.0×1013 Ks-1, Q2: 1.0×1011 Ks-1). 利用平均原子体积、双体分布函数、键角分布函数、键对分析和Voronoi多面体方法研究了微观局域结构随温度的变化关系. 研究发现：在Q1冷却过程中，液态Ti75Al25合金在1000 K发生玻璃化转变，形成非晶结构; 而在Q2冷却过程中，液态Ti75Al25合金发生结晶，并最终形成hcp晶体结构。

Molecular dynamics simulation of microstructure evolution in Ti75Al25 alloys

The structural transitions of Ti75Al25 during two different quenching processes (Q1: 1.0×1013 Ks-1, Q2: 1.0×1011 Ks-1) were studied by using molecular dynamics simulations. This work gives the structural properties, including the average atomic volume, pair-correlation function, bond-angle distribution function, Honeycutt-Andersen (HA) and Voronoi indices, and temperature dependence. Our results indicated that the liquid was frozen into glass state at the temperature about 1000 K under the quenching condition Q1. While the liquid Ti75Al25 transformed to hcp phase at the temperature under the quenching condition Q2.