In this study, high-performance Al-Cu-Mg alloys are developed through powder high-energy ball milling, press-forming and rolling deformation. During the high-energy ball milling, mixed pure metal powders undergo mechanical alloying and grain refinement due to high-energy collision between particles and balls. Concurrently, a high-density of dislocations and stacking faults is introduced into the powders after high-energy ball milling. Following powder press-forming under high temperatures and pressures, Al₂Cu and Al₂CuMg precipitates form from the supersaturated solid solution of the prepared alloys. Moreover, even after high-temperature press-forming and deformation, the matrix of the Al-Cu-Mg alloys retains high densities of dislocations, stacking faults, and ultra-fine grain structures. Although the ultra-fine grain structure, high-density dislocations, stacking faults, and precipitated phases confer high strength (approximately 562 MPa) to the press-formed Al–4.5Cu–1.5Mg alloy, the presence of internal pores and weak bonding between powder particles results in relatively low ductility (approximately 1.38%). However, after 70% rolling deformation at 400°C, significant improvements in both microstructure and mechanical properties of the prepared alloy are observed, even in the absence of artificial ageing treatment, which exhibits high strength (about 586 MPa) and good elongation at break (about 8.16%). Importantly, the strengthening mechanisms are systematically discussed and evaluated based on the microstructure evolution. This study presents a rational approach to the development of novel high-performance 2000-series Al alloys that do not require artificial ageing treatment, offering insights into advanced processing techniques for improved mechanical properties.

中文翻译：

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粉末压制成型和变形法制备的新型 Al-Cu-Mg 合金的显微组织和性能调控

本研究通过粉末高能球磨、压制成型和轧制变形开发高性能 Al-Cu-Mg 合金。在高能球磨过程中，由于颗粒与球之间的高能碰撞，混合的纯金属粉末发生机械合金化和晶粒细化。同时，在高能球磨后，高密度的位错和堆垛故障被引入粉末中。在高温和高压下粉末压制成后，Al₂Cu 和 Al₂CuMg 从制备合金的过饱和固溶体中形成沉淀。此外，即使在高温压制成型和变形后，Al-Cu-Mg 合金的基体仍保持高密度的位错、堆叠缺陷和超细晶粒结构。尽管超细晶粒结构、高密度位错、堆积缺陷和沉淀相赋予了压制成 Al-4.5Cu-1.5Mg 合金的高强度（约 562 MPa），但内部孔隙的存在和粉末颗粒之间的弱结合导致延展性相对较低（约 1.38%）。然而，在 400°C 下滚动变形 70% 后，即使没有人工时效处理，所制备合金的微观组织和机械性能也得到了显着改善，表现出高强度（约 586 MPa）和良好的断裂伸长率（约 8.16%）。重要的是，根据微观结构的演变对强化机制进行了系统的讨论和评估。 本研究为开发不需要人工时效处理的新型高性能 2000 系列铝合金提供了一种合理的方法，为改善机械性能的先进加工技术提供了见解。