2Cu）從細(xì)小的網(wǎng)絡(luò)結(jié)構(gòu)轉(zhuǎn)變?yōu)閺浬⒓?xì)小顆粒結(jié)構(gòu)。當(dāng)Er含量達(dá)到0.4%（質(zhì)量分?jǐn)?shù)）時(shí)，晶粒細(xì)化效應(yīng)達(dá)到最大，合金的力學(xué)性能最佳；α-Al的平均晶粒尺寸為19 μm；抗拉伸強(qiáng)度和伸長(zhǎng)率分別為298.14 MPa和6.56%；斷裂模式從脆性斷裂轉(zhuǎn)變?yōu)轫g性-脆性斷裂，有利于鋁合金的實(shí)際應(yīng)用。當(dāng)Er含量超過0.4%（質(zhì)量分?jǐn)?shù)）時(shí)，合金的晶粒尺寸增大，力學(xué)性能下降。;The effects of Er addition on the microstructure and mechanical properties of ZL201A aluminum alloy were studied via metallographic microscope, scanning electron microscope, transmission electron microscope, energy dispersive spectrometer, and mechanical property tests. Results show that the Er addition can refine the α-Al matrix from columnar grains into fine equiaxed grains. Additionally, the θ phase (Al2Cu) is transformed from fine network structure into the dispersed fine particle structure. When the Er content reaches 0.4wt%, the grain refinement effect reaches the maximum state and the mechanical properties of the alloy are optimal. The average grain size of α-Al matrix is 19 μm; the tensile strength and the elongation are 298.14 MPa and 6.56%, respectively. The fracture mode also changes from brittle fracture to ductile-brittle fracture, which is beneficial to the practical application of aluminum alloys. When Er content exceeds 0.4wt%, the grain size increases and the mechanical properties of alloy decrease."/>