耐蚀合金Al3Ni和Ni3Al液态冷凝过程的比较研究

采用F S多体势对液态合金Al3Ni和Ni3Al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 ;而Ni3Al的结构及能量转变受冷速影响较大 ,快冷时形成非晶 ,而慢冷时出现明显结晶 ;同样冷速下Al含量较少的Ni3Al体系的有序度高 ,更易形成晶体 ,晶体的形成过程中有能量突变 .

The Comparison of the Solidification of Liquid Al3Ni and Ni3Al

By means of the molecular dynamics simulation technique, the solidification process of liquid alloyAl3Ni and Ni3Al has been performed. The F-SN-body potentials have been adopted to describe the atomic interactions. The structural features have been revealed with the pair distribution function and bonded pairs analysis method. The variation of energy with the temperature and the relationship between the energy and the micro structure have also been studied. It has been concluded that the cooling rates have different influence on the final structure of Al3Ni and Ni3Al. The Al3Ni becomes the glass state at both of the cooling rates, but the short-order of the system has been strengthened at the relatively low cooling rate (4×1011K/s). The Ni3Al also becomes the glass state at the relatively high cooling rate (4×1013K/s), but crystallizes out at the relatively low cooling rate (4×1011K/s). At the same cooling rate (4×1011K/s), the Ni3Al melts of which Al is more than Ni crystallize out much easier than the Al3Ni melts.