热镀Al_3Ni耐蚀合金镀层液态冷凝过程的分子动力学模拟研究

Molecular dynamics simulations of corrosion resistant alloy Al_3Ni in its solidification

钢铁表面热镀Al3Ni耐蚀合金镀层工艺涉及Al3Ni合金由液态冷凝固化成镀层的过程。冷凝速度对微结构的影响是工艺中关键问题之一。本文采用F S多体势对液态合金Al3Ni在不同冷却速度下的微观结构及其转变机制进行了分子动力学模拟,得到了不同冷速下各温度的双体分布函数;采用HA键型指数法对其结构进行了分析,结果表明,Al3Ni在两种冷速下均以非晶的形式出现,只是慢冷时体系的有序度略有升高,这为最终确定工艺参数提供了理论依据。

During the hot-dip process of the corrosion resistant alloy Al3Ni on the surface of the steel, it involves the solidification from liquid to the coating. It is found that the cooling rate has a great influence on the microstructure. By means of molecular dynamics simulation technique, the solidification process of liquid alloy Al3Ni has been performed. The F-S N-body potentials have been adopted to describe the atomic interactions. The structural features have been revealed with the pair distribution. The energy variation with temperature and the relationship between energy and microstructure has also been studied. It has been concluded that non-crystal occurs at different cooling rates, but the degree of order rises slightly at the low cooling rate.