One of the most important routes for obtaining Al-Bi-x monotectic alloys is directional solidification. The control of the thermal solidification parameters under transient heat flow conditions can provide an optimized distribution of the Bismuth (Bi) soft minority phase embedded into an Al-rich matrix. In the present contribution, Al-Bi, Al-Bi-Zn, and Al-Bi-Cu alloys were manufactured through this route with their microstructures characterized and dimensioned based on the solidification cooling rates. The main purpose is to evaluate the influence of typical hardening elements in Al alloys (zinc and copper) in the microstructure, tensile properties, and wear of the monotectic Al-Bi alloy. These additions are welcome in the development of light and more resistant alloys due to the growing demands in new sliding bearing designs. It is demonstrated that the addition of 3.0 wt.% Cu promotes microstructural refining, doubles the wear resistance, and triples the tensile strength with some minor decrease in ductility in relation to the binary Al-3.2 wt.% Bi alloy. With the addition of 3.0 wt.% Zn, although there is some microstructural refining, little contribution can be seen in the application properties.

中文翻译：

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轻质滑动轴承用Al-Bi（-Cu，-Zn）合金的组织，耐磨性和拉伸性能的评估

获得Al-Bi-x单晶合金的最重要途径之一是定向凝固。在瞬态热流条件下对热固化参数的控制可以提供嵌入富铝基体中的铋（Bi）软少数相的最佳分布。在本发明中，Al-Bi，Al-Bi-Zn和Al-Bi-Cu合金是通过这种途径制造的，其微观结构的特征和尺寸基于凝固冷却速率而定。主要目的是评估铝合金（锌和铜）中典型的硬化元素对单晶Al-Bi合金的组织，拉伸性能和磨损的影响。由于对新的滑动轴承设计的需求不断增长，这些添加物在开发轻便，更耐久的合金时受到欢迎。已经证明，相对于二元Al-3.2重量％的Bi合金，添加3.0重量％的Cu促进了组织细化，使耐磨性增加了两倍，并且使拉伸强度增加了三倍，并且延展性略有降低。通过添加3.0重量％的Zn，尽管存在一些微结构的细化，但是在应用性能方面几乎看不到任何贡献。