To explore the influence of trace addition of rare earth element Ce on the microstructure and property of 7020 aluminum alloy,the three-stage homogenization treatment,solid solution strengthening,and double-stage aging were per-formed on 7020 aluminum alloy containing Ce. The state of alloy as-cast and the change of microstructure after homogeni-zation treatment were observed by using a metallographic microscope. The alloy microscopic images were analyzed by using an electron probe micro-analyzer. The element composition of each alloy phase was analyzed by using a wavelength dispersive spectrometer. The hardness of the alloy after aging treatment was measured by using a microthickness meter. The mechanical performance indexes,such as tensile strength,yield strength,elongation,and so on were tested by using an electronic universal testing machine. The results show that with the addition of Ce with mass fraction of 0.12%,the crystal grains of aluminum alloy are refined markedly. The alloy can obtain high alloy strength and good hardening effect at the aging treatment of 23 h,and gain an ideal comprehensive aluminum alloy performance including strength,hard-ness,and elongation at 15 h.%为了研究微量稀土元素Ce对7020铝合金微观组织与性能的影响,对含Ce的7020铝合金进行三级均匀化热处理、固溶强化与双级时效处理;采用金相显微镜观察合金铸态与均匀化后的显微组织变化,采用电子显微探针分析合金显微图像,采用波谱仪分析合金各相的元素组成,采用显微硬度计测试时效处理后的合金硬度,采用电子万能试验机测试抗拉强度、屈服强度与延伸率等力学性能指标.结果表明,添加质量分数为0.12%的Ce后,铝合金晶粒显著细化,合金可以在时效处理时间为23 h时获得较大的合金强度与较好的硬化效果,在15 h时可获得强度、硬度与延伸率等综合性能均较理想的铝合金.
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