(中南大學(xué) 粉末冶金國家重點(diǎn)實(shí)驗(yàn)室，長沙 410083)
摘 要: 通過鑄錠冶金工藝，制備含微量Sc的AA7085鋁合金。采用金相觀察、力學(xué)性能測試、掃描電鏡及透射電鏡分析，研究添加0.3%Sc對基體合金的鑄態(tài)及鍛造態(tài)的顯微組織和力學(xué)性能的影響。結(jié)果表明，添加0.3%Sc能細(xì)化鑄態(tài)合金的晶粒，抑制鍛造態(tài)合金的再結(jié)晶，最終提高基體合金的強(qiáng)度和斷裂韌性；含0.3%Sc的合金抗拉強(qiáng)度達(dá)到562 MPa，斷裂韌性KIC(S-L)達(dá)到34 MPa·m1/2。含Sc的AA7085合金的強(qiáng)化機(jī)制主要是Al3(Sc, Zr)相引起的細(xì)晶強(qiáng)化、亞結(jié)構(gòu)強(qiáng)化和沉淀強(qiáng)化。
關(guān)鍵字: AA7085鋁合金；Sc；再結(jié)晶；顯微組織；力學(xué)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
