以准晶成分Ti40Zr40Ni20为基准, 在Ti-Zr-Ni-Cu系中设计出 电子浓度为1.200和原子尺寸为0.1474 nm的系列合金, 并用铜模吸铸法制备直径为 3 mm的合金棒试样. 结果表明, Ti12Zr55Ni13Cu20成分附近 可形成块体非晶合金, 而Ti3Zr60Ni12Cu25和 Zr60Ni10Cu30成分点上形成了单一的四方Zr2Cu型非晶相 关相. 准晶、块体非晶合金和Zr2Cu相是具有相同电子浓度的电子化合物, 它们在成分图上表现出鲜明的等电子浓度特征, 表明块体非晶合金的等电子浓度判据 适用于Ti-Zr-Ni-Cu非晶系. 二十面体与截角八面体间的结构关联可作为准晶或 非晶合金多型性转变成Zr2Cu相的结构模型.
An e/a-constant rule shows that the composition of the bulk metallic glass formers is always located in an e/a constant line or plane defined by the glass-related phases. Following this criteria, a series of alloys, with e/a (i.e. valence electron per atom) value of 1.2 and Ra (average atomic size) of 0.1474 nm, are designed in Ti-Zr-Ni-Cu system basing on an optimized quasicrystals-forming composition Ti40Zr40Ni20, then the alloy rods with diameter of 3mm are fabricated by the conventional suction casting method, the experimental results showed that a bulk glassy can be obtained in the vicinity of Ti12Zr55Ni13Cu20, and at the composition of Ti3Zr60Ni12Cu25 and Zr60Ni10Cu30, the another glass-related phase, tetragonal tI-Zr2Cu phase, is formed as the exclusive phase in the alloys. Electronic and atomic structural analysis revealed that the above quacrystals, bulk metallic glass and the tI-Zr2Cu phase are a group of electronic compounds sharing the nearly same e/a value, meanwhile, the local atomic structure of these phases are also correlative with each other, And a clearly e/a-constant phenomenon can be found in the compositional diagram, indicating that the e/a-constant criteria is valid for Ti-Zr-Ni-Cu glass forming system. Meanwhile, the structural correlations between the icosahedron and truncated octahedron clusters, which can be considered as an structural model to describe the polymorphous transformation from quacrystals or metallic glass to Zr2Cu-type phase，have been revealed in the present work.
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