过冷Fe85Ni15熔体的结构及动力学研究

基于嵌入原子势(EAM)，采用分子动力学(MD)模拟的方法探讨了过冷液态Fe85Ni15合金的微观结构及动力学性质.对B-T结构因子(SF)与相对长度(Correlation length)的分析发现：Fe85Ni15熔体具有相分离的趋势，但不十分明显.配位数(CN)及F-Z结构因子的计算结果证实了体系的短程序对应着二十面体结构.均方位移(MSD)的计算结果表明：Fe85Ni15合金属于脆性液体.将获得的扩散激活能与其它合金系进行对比发现扩散激活能并不能反映熔体的玻璃形成能力，熔体中的二十面体结构不利于非晶的形成.

Structure and dynamics of undercooled Fe85Ni15 melts

Molecular dynamics simulation (MD) based upon the newly developed embedded atom method (EAM) has been performed to explore the microstructure and dynamic properties of liquid Fe85Ni15 alloy. The analyses of Bhatia-Thornton (B-T) structure factors (SF) and correlation length show that the Fe85Ni15 melt exhibits phase segregation tendency but it is rather weak. The calculated F-Z structure factor and coordination number (CN) indicate the existence of icosahedral short-rang order (ISRO) in the liquid. The results of mean square displacement (MSD) manifest that Fe85Ni15 melt is fragile and the glass formation ability is rather weak. Comparing our calculated diffusion activation energy with the experimental results in other alloys it is suggested that this energy is not a good parameter used to reflect the glass forming ability of melts and the ISRO in the melt is not favorable for the formation of glass.