(中南大学 粉末冶金国家重点实验室，长沙 410083)
摘 要: Al-Cu-Mg-Ag合金展示了比传统Al-Cu及Al-Cu-Mg合金更加优异的室温与高温力学性能，源于其主要强化相(Ω相)有较好的热稳定性。然而该合金的使用温度仍然低于200 ℃，当温度超过200 ℃时，Ω相的粗化速率急剧增加，容易发生共格失稳而转变为θ相，从而降低合金的高温力学性能。研究表明通过添加合适的稀土或过渡族元素可以有效地抑制Ω相的生长速率，提高Ω相的形核密度和热稳定性，从而提高合金的高温力学性能。综述了Ce、Yb及Sc元素对Al-Cu-Mg-Ag合金显微组织与力学性能的影响，并探讨了Ce、Yb及Sc元素提高Ω相热稳定性的机理。
关键字: Al-Cu-Mg-Ag合金；稀土；显微组织；力学性能
（State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China）
Abstract:Al-Cu-Mg-Ag alloys exhibit much better mechanical properties than traditional Al-Cu and Al-Cu-Mg alloys at both room- and elevated temperatures because of the good thermal stability of the main strengthening phase (Ω phase). However, this type of alloys can only be used under 200 ℃. When the temperature is above 200 ℃, the coarsening speed of Ω phase increases dramatically, and Ω phase is very easy to lose coherent with the matrix and changes to θ phase, which substantially decreases the mechanical properties of the alloys at elevated temperature. It is shown that adding proper rare earth or transient elements can substantially inhibit the growth speed of Ω phase, increase the nucleation density and thermal stability of Ω phase, and thus improve the mechanical properties of Al-Cu-Mg-Ag alloys. The effects of Ce, Yb and Sc on the microstructures and mechanical properties of Al-Cu-Mg-Ag alloys were reviewed, and the mechanisms of the effects of Ce, Yb and Sc on the thermal stability of Ω phase were discussed.
Key words: Al-Cu-Mg-Ag alloy; rare earth; microstructures; mechanical properties
