Owing to good formability, wrought Al alloys are used in a wide range of industries, including turbochargers in automobile engines. The development of Al alloys with increased high-temperature strength is necessary to improve the fuel efficiency of engines. In this study, a modified heat-resistant Al–Mg–Zn–Cu–Ni quinary alloy with superior high-temperature strength and creep rupture life at 200 °C (potential temperature in service for compressor radial impellers) was designed. The thermodynamic assessments provided a modified alloy composition of Al–5Mg–3.5Zn–2Cu–2Ni (at %) exhibiting α-Al phase in equilibrium with T-Al₆Mg₁₁Zn₁₁ and Al₃(Ni, Cu)₂ phases at elevated temperatures. The experimental alloy showed granular T and Al₃(Ni, Cu)₂ phases often located on grain boundaries in the α-Al matrix, although the undissolved Al₃Ni phase (formed in solidification) locally remained. Apart from the T phase, the η-Zn₂Mg phase containing Cu element preferentially precipitated on grain boundaries. A large number of fine precipitates were dispersed homogeneously in the grain interior after the aging at 200 °C or 300 °C. Compared to the base alloy with a ternary composition of Al–5Mg–3.5Zn (at %) and conventional Al alloys, the designed quinary alloy (pre-aged at 200 °C for 10 h) showed a high strength at elevated temperatures above 200 °C. The creep-rupture life at 200 °C/105 MPa was remarkably extended to 665 h by the addition of Cu and Ni elements into the base ternary alloy. The rupture life was more than ten times longer than one (57 h) of the ternary alloys. The alloy modification based on the thermodynamic calculations provides an effective approach for designing lightweight Al alloys with superior high-temperature strength and creep rupture life.

由于良好的成型性，锻造铝合金被广泛用于各种行业，包括汽车发动机的涡轮增压器。开发具有更高高温强度的铝合金是提高发动机燃油效率的必要条件。在这项研究中，设计了一种改进的耐热 Al-Mg-Zn-Cu-Ni 五元合金，在 200 °C（压缩机径向叶轮的潜在工作温度）下具有优异的高温强度和蠕变断裂寿命。热力学评估提供了 Al-5Mg-3.5Zn-2Cu-2Ni (at %) 的改进合金成分，显示出与 T-Al ₆ Mg ₁₁ Zn ₁₁和 Al ₃ (Ni, Cu) _{2平衡的 α-Al 相}在高温阶段。实验合金显示粒状 T 和 Al ₃ (Ni, Cu) ₂相通常位于 α-Al 基体的晶界上，尽管局部保留了未溶解的 Al ₃ Ni 相（在凝固中形成）。除了 T 相，η-Zn ₂含Cu元素的Mg相优先在晶界析出。200℃或300℃时效后，大量细小析出物均匀分散在晶粒内部。与具有三元成分 Al-5Mg-3.5Zn (at %) 的基础合金和传统铝合金相比，所设计的五元合金（在 200 °C 预时效 10 h）在高于 200 的高温下表现出高强度摄氏度。通过在基础三元合金中添加 Cu 和 Ni 元素，200 °C/105 MPa 下的蠕变断裂寿命显着延长至 665 h。断裂寿命比一种（57 小时）三元合金长十倍以上。基于热力学计算的合金改性为设计具有优异高温强度和蠕变断裂寿命的轻质铝合金提供了一种有效的方法。