Heterogeneous structures are an effective way to give materials excellent combined strength-ductility properties. In this study, Cu–Zn–Al–Fe alloys were prepared by homogenizing and hot rolling-annealing, and an α+β diphase brass with harmonic structure was obtained by adjusting the content of Zn. The microstructure and mechanical properties of Cu-Zn-4Al-2.8Fe ( = 14, 20, 22.5, 24, wt.%) were systematically investigated. The Cu–Zn–Al–Fe alloy has an α single-phase matrix at 14 wt% Zn and an α+β diphasic matrix at 20, 22.5, and 24 wt% Zn, all uniformly distributed with nano β(FeAl). A large amounts of twins are produced after rolling in α phase that has a low stacking fault energy. The Cu–20Zn–4Al-2.8Fe alloy exhibits a unique harmonic structure of the α-phase soft cores embedded in α+β biphasic hard shells. This alloy exhibits an excellent strength-ductility combination at room temperature, possessing an ultimate tensile strength of 473.7 MPa while maintaining a total elongation of 50.7%. Increases total elongation by 30.3% while maintaining high strength compared to homogeneous alloys (22.5 wt% Zn). While α single-phase alloy (14 wt% Zn) exhibits excellent plasticity (total elongation of 58.0%), their strength is not satisfactory (ultimate tensile strength of 419.7 MPa). In contrast, too much Zn (24 wt% Zn) produces a high proportion of β phase, which exhibits high strength (ultimate tensile strength of 507.9 MPa) and relatively poor plasticity (total elongation of 22.8%). Overall, the Cu–20Zn–4Al-2.8Fe alloy with a harmonic structure achieves excellent overall mechanical properties due to twinning, precipitation strengthening, and hetero-deformation induced (HDI) strengthening. This study provides an essential reference for designing heterogeneous structures of brass alloys.

中文翻译：

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调和结构的 α+β 双相黄铜实现强度和延展性的卓越组合

异质结构是赋予材料优异的强度-延展性综合性能的有效方法。本研究通过均匀化、热轧-退火制备Cu-Zn-Al-Fe合金，并通过调节Zn含量获得调和结构的α+β双相黄铜。对Cu-Zn-4Al-2.8Fe (= 14, 20, 22.5, 24, wt.%)的显微组织和力学性能进行了系统研究。Cu-Zn-Al-Fe 合金具有 14 wt% Zn 的 α 单相基体和 20、22.5 和 24 wt% Zn 的 α+β 双相基体，均均匀分布有纳米 β(FeAl)。轧制后在层错能低的α相中产生大量孪晶。Cu-20Zn-4Al-2.8Fe合金表现出独特的调和结构，即α相软核嵌入α+β双相硬壳中。该合金在室温下表现出优异的强度-延展性组合，具有 473.7 MPa 的极限拉伸强度，同时保持 50.7% 的总伸长率。与均质合金（22.5 wt% Zn）相比，总伸长率提高了 30.3%，同时保持高强度。虽然α单相合金（14 wt% Zn）表现出优异的塑性（总伸长率为58.0%），但其强度并不令人满意（极限拉伸强度为419.7 MPa）。相反，过多的Zn（24 wt% Zn）会产生高比例的β相，表现出较高的强度（极限拉伸强度为507.9 MPa）和相对较差的塑性（总伸长率为22.8%）。总体而言，具有调和结构的Cu-20Zn-4Al-2.8Fe合金由于孪晶、沉淀强化和异质变形诱导（HDI）强化而实现了优异的综合机械性能。该研究为黄铜合金异质结构的设计提供了重要的参考。