(中南大学 粉末冶金国家重点实验室，长沙 410083)
摘 要: 通过铸锭冶金工艺，制备含微量Sc的AA7085铝合金。采用金相观察、力学性能测试、扫描电镜及透射电镜分析，研究添加0.3%Sc对基体合金的铸态及锻造态的显微组织和力学性能的影响。结果表明，添加0.3%Sc能细化铸态合金的晶粒，抑制锻造态合金的再结晶，最终提高基体合金的强度和断裂韧性；含0.3%Sc的合金抗拉强度达到562 MPa，断裂韧性KIC(S-L)达到34 MPa·m1/2。含Sc的AA7085合金的强化机制主要是Al3(Sc, Zr)相引起的细晶强化、亚结构强化和沉淀强化。
关键字: AA7085铝合金；Sc；再结晶；显微组织；力学性能
（State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China）
Abstract:AA7085 alloys with minor Sc content were prepared by ingot metallurgy method. The effect of Sc addition on the microstructure and mechanical properties of the based alloys was investigated using optical microscope, mechanical properties testing, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results show that 0.3%Sc addition refines the grains of the casting alloys, and inhibits the recrystallization of the forged alloy. AA7085 alloy with 0.3%Sc content has higher strength and fracture toughness, and σb and KIC(S-L) are 562 MPa and 34 MPa·m1/2, respectively. The strengthening mechanisms of AA7085 alloy with Sc element are mainly the sub-structure strengthening, precipitation strengthening and refiner grain strengthening of Al3(Sc, Zr) phase.
Key words: AA7085 alloy; scandium; recystallization; microstructure; mechanical property
