喷射沉积法制备Al-Zn-Mg-Cu-Zr合金的显微组织与性能

摘要

Al-8.11Zn-2.01Mg-2.36Cu-0.12Zr (mass fraction, %) alloy was prepared by spray deposition method, and the microstructure and relevant properties were studied in detail. The results show that uniform and fine equiaxed grains with grain size of about 50μm appears in spray deposition casting ingot. After homogenization treatment at 470℃ for 24 h, hot extrusion at 420℃ with extrusion ratio 39, solution treatment at 470℃ for 1 h, and aging treatment at 140℃ for 8 h, the alloy achieves excellent properties: the tensile strength is 723 MPa, yield strength is 700 MPa, elongation is 11%. When the alloy is aged at 140℃, GP zones appear in the early state for 10 min, thenη'-MgZn2 phase and Al3Zr phase form as aged at 140℃ for 8 h and they are the main strengthening phases, as the aging time increases to 72 h, the meta-stable needle-shapeη'-MgZn2phase gradually grows into stable rod-shapeη-MgZn2phase. The studied alloy exhibits excellent strength and toughness, and the alloy can be widely used in aerospace, automotive, rail transportation, marine, electronic, electrical fields.%采用喷射沉积技术制备Al-8.11Zn-2.01Mg-2.36Cu-0.12Zr(质量分数，%)合金，并对其显微组织和性能进行研究。结果表明：喷射沉积的沉积态合金为近等轴状，且晶粒均匀细小，尺寸约为50μm；对合金进行(470℃，24 h)均匀化处理、420℃热挤压(挤压比为39)、(470℃，1 h)固溶处理、(140℃,8 h)时效处理后合金具有优良的性能，合金的抗拉强度为730 MPa，屈服强度为700 MPa，伸长率为11%。合金在140℃时效过程中，时效10 min即形成GP区；时效8 h后，主要强化相为针状的η'-MgZn2和球状的Al3Zr粒子；时效72 h后，针状的η'-MgZn2亚稳相呈现为棒状的η-MgZn 2稳定相。该喷射沉积法制备的合金表现出优异的强度和韧性，可广泛应用于航天航空工业、汽车工业、轨道交通、船舶、电子电工等领域。