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利用团簇+连接原子模型设计Ni-Nb基三元块体非晶成分.首先,解析出二元共晶点Ni_(59.5)Nb_(40.5)的团簇式[(Ni_(0.5)Nb_(0.5))-Ni_6Nb_6]Ni_3,其中,(Ni_(0.5)Nb_(0.5))Ni_6Nb_6为源自Ni_6Nb_7(Fe_7W_6型)共晶相的以(Ni_(0.5)Nb_(0.5))为心的二十面体团簇.相应的,具有最大非晶形成能力的Ni-Nb二元成分Ni_(62)Nb_(38)可描述成团簇式[Ni-Ni_6Nb_6]Ni_3,此时,二十面体团簇的中心位置完全由Ni占据.以[Ni-Ni_6Nb_6]Ni_3二元非晶团簇式为基础,通过引入第3组元Zr,Ta或Ag,设计出具有更高非晶形成能力的Ni-Nb-(Zr,Ta,Ag)三元合金,利用水冷铜模吸铸方法获得临界直径为3 mm的块体非晶.热分析和力学测试表明这些三元块体非晶具有较高的热稳定性,其中[Ni-Ni_6Nb_5Ta]Ni_3具有最高的玻璃转变温度T_g(935 K)和晶化温度T_x(952 K);这些三元块体非晶具有一定的塑性变形能力(延伸率约为0.3%),[Ni-Ni_6Nb_5Zr]Ni_3和[Ni-Ni_6Nb_5Ta]Ni_3块体非晶的压缩断裂强度分别达到3.2和3.4 GPa.
Ni-Nb-based ternary bulk amorphous components were designed by using the cluster + connected atom model.Firstly, the cluster Ni_ (59.5) Nb_ (40.5) binary ([Ni 0.5 Nb 0.5 )) - Ni_6Nb_6] Ni_3, (Ni_ (0.5) Nb_ (0.5)) Ni_6Nb_6 is an icosahedron centered on (Ni_ (0.5) Nb_ (0.5)) originating from the Ni_6Nb_7 (Fe_7W_6) Correspondingly, the Ni-Nb binary composition Ni_ (62) Nb_ (38) with the maximum amorphous formation capacity can be described as a cluster [Ni-Ni_6Nb_6] Ni_3, in which case the center of the icosahedral cluster Which is entirely occupied by Ni. Based on [Ni-Ni_6Nb_6] Ni_3 binary amorphous clusters, the third component Zr, Ta or Ag was introduced into Ni-Nb- (Zr , Ta, Ag) ternary alloys, and the bulk crystallites with a critical diameter of 3 mm were obtained by a water-cooled copper die-casting method.The thermal analysis and mechanical tests showed that these ternary bulk amorphous alloys had high thermal stability, among them The Ni_3 [Ni-Ni_6Nb_5Ta] Ni_3 has the highest glass transition temperature T_g (935 K) and the crystallization temperature T_x (952 K). These ternary block have certain plastic deformation capacity (0.3% elongation) Ni-Ni_6Nb_5Zr] Ni_3 and [Ni-Ni_6Nb_5Ta] Ni_3 bulk amorphous Breaking strength reached 3.2 and 3.4 GPa.