Despite Au, Al and Cu being individually very well-known elements, their ternary phase diagram has not been studied in as much detail as those of many other Au-containing ternaries. Here we review what is known, and consider the prospects for technological exploitation of some of the ternary compositions. The components of greatest interest in Al-Au-Cu may be the β-phases, at least two of which have shape memory properties. Of these, ‘Spangold’, which has the nominal stoichiometry Au7Cu5Al4, has received some attention for jewellery applications, while the edge compound Cu3Al is a well-known shape memory composition with corresponding specialised industrial uses. The properties of other β-phase compositions in the system have been scarcely investigated. The system also contains an extensive γ-phase, Al4AuxCu9−x, where x ranges from 0 to ∼6.5, and the purple gold phase AuAl2.

中文翻译：

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铝铜金三元体系

尽管 Au、Al 和 Cu 是单独非常知名的元素，但它们的三元相图并没有像许多其他含 Au 的三元相图那样详细地研究。在这里，我们回顾了已知的内容，并考虑了一些三元组合物的技术开发前景。Al-Au-Cu 中最受关注的成分可能是 β 相，其中至少有两种具有形状记忆特性。其中，标称化学计量为 Au7Cu5Al4 的“Spangold”在珠宝应用中受到了一些关注，而边缘化合物 Cu3Al 是一种众所周知的形状记忆成分，具有相应的专业工业用途。系统中其他 β 相组合物的性质几乎没有被研究过。该系统还包含一个广泛的 γ 相 Al4AuxCu9-x，其中 x 的范围从 0 到 ∼6.5，