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采用分子动力学方法对液态Zn_xAl_(100-x)(x=25,50,75)合金的快速凝固过程进行了模拟,并通过键型指数与原子团类型指数表征和分析了凝固过程中熔体微观结构的演变特性.结果表明,在冷速1×10~(12)K/s下,3种成分的Zn-A1合金都形成了以1551键对和二十面体(12 0 12 0 0 0)基本原子团为主体的非晶结构,并且在玻璃转变温度T_g附近熔体中1551键对和二十面体基本原子团的数目最多;随Zn含量增加,合金玻璃转变温度T_g、非晶形成能力和化学短程序参数降低.对应不同成分的合金,Zn和A1呈现不同程度的偏聚与团簇化趋势.
The rapid solidification process of liquid Zn_xAl_ (100-x) (x = 25,50,75) alloy was simulated by molecular dynamics method. The microstructure of melt was characterized and characterized by the bond index and atomic group index The results show that the three kinds of Zn-Al alloys with 1551 bond pairs and the icosahedron (12 0 12 0 0 0) are formed at a cooling rate of 1 × 10 ~ (12) K / s, Basic atomic group as the main amorphous structure, and the number of 1551 and icosahedral elementary groups in the melt near the glass transition temperature T_g is the largest. With the increase of Zn content, the glass transition temperature T_g, amorphous formation ability and chemical short The parameters of the process are reduced, and for the alloys with different compositions, Zn and Al show segregation and clustering to some extent.