【摘要】 采用吸铸法制备(Zr₅₅Cu₃₀Al₁₀Ni₅)_97.2La_2.8非晶合金，将其作为孕育剂添加至Al-Cu合金熔体中并进行浇铸，对合金进行811 K×10 h固溶+438 K×10 h时效热处理，研究了孕育处理Al-Cu合金的显微组织以及在试验温度433～493 K和应变速率10^-3～10^-1 s^-1下的高温拉伸性能。结果表明：ZrCuAlNiLa非晶合金孕育处理可显著细化Al-Cu合金的晶粒，使α-Al枝晶的平均晶粒尺寸由处理前的185μm减小至38μm。随着应变速率增加或试验温度降低，孕育处理合金的抗拉强度增大，且相同条件下的抗拉强度和断后伸长率均明显高于未孕育处理合金；孕育处理合金在温度433 K、应变速率10^-1 s^-1下的抗拉强度最高，为418 MPa，断后伸长率为14.7%，比未孕育处理合金分别提高了36%和25%。孕育处理Al-Cu合金高温拉伸性能提高的主要机制是细晶强化和第二相强化。高温下孕育处理合金表现出穿晶断裂为主、沿晶断裂为辅的混合拉伸断裂模式；与未孕育处理合金相比，孕育处理合金拉伸断口的韧窝尺寸更小，分布更均匀。更多还原

【Abstract】 (Zr₅₅Cu₃₀Al₁₀Ni₅)_97.2La_2.8 amorphous alloy was prepared by suction casting method, and was added as an inoculant to the Al-Cu alloy melt followed by casting. The alloy was subjected to heat treatment under solution at 811 K for 10 h and aging at 438 K for 10 h. The microstructure of the inoculated Al-Cu alloy and its elevated temperature tensile properties at test temperatures of 433–493 K and strain rates o.f 10^-3–10^-1 s^-1 were studied. The results show that inoculation treatment of ZrCuAlNiLa amorphous alloy could significantly refine the grains of Al-Cu alloy,reducing the average grain size of α-Al dendrites from 185 mm before treatment to 38 mm. With the increase of strain rate or the decrease of test temperature, the tensile strength of the inoculated alloy increased. The tensile strength and percentage elongation after fracture of the inoculated alloy under the same condition were significantly higher than those of the uninoculated alloy. The tensile strength of the inoculated alloy was the highest at a temperatur of 433 K and a strain rate of 10^-1 s^-1,which was418 MPa,and the percentage elongation after fracture was 14.7%;both of them increased by 36% and 25%,respectively,compared with those of the uninoculated alloy. The main mechanism for improving the elevated temperature tensile performance of Al-Cu alloy inoculated with ZrCuAlNiLa amorphous alloy was fine-grained strengthening and secondphase strengthening. At elevated temperatures,the tensile fracture mechanism of the inoculated alloy exhibited a mixed fracture mode dominated by transgranular fracture and supplemented by intergranular fracture. Compared with that of the uninoculated alloy, the dimples on the tensile fracture surface of the inoculated alloy were smaller and more evenly distributed.更多还原