Al-2Ti变质处理对Zn-6Al-3Mg合金组织与力学性能的影响

摘要

The microstructures of Zn-6Al-3Mg alloy modified with Al-2Ti were observed using scanning electron microscopy and its mechanical properties were measured using electron universal testing machine and HVS-5Z/LCD Vickers hardness tester. The effect of adding amount of Al-2Ti and modification temperature on microstructures and mechanical properties of Zn-6Al-3Mg alloy was investigated. The results show that primary Al-fcc exists in the form of fine particles and its volume fraction is the least when Zn-6Al-3Mg alloy is modified with 0.5%Al-2Ti at 500℃. At the same time, the primary MgZn2phase disappears and the volume fraction of binary Zn/Al and ternary Zn/Al/MgZn2 is the most. When the adding amount of Al-2Ti is 0.5%, the Zn-6Al-3Mg alloy modified at 500℃ possesses the highest tensile strength and elongation. At this condition, the comprehensive mechanical properties of the alloy are the best.%采用扫描电镜、万能电子试验机和HVS-5Z/LCD维氏硬度计观察与测试变质处理Zn-6Al-3Mg合金的凝固组织与力学性能,研究Al-2Ti变质剂加入量和变质温度对合金组织和力学性能的影响.研究结果表明:当变质温度为500℃,Al-2Ti变质剂加入量为0.5%(质量分数)时,Zn-6Al-3Mg合金组织中初晶Al-fcc相呈细小颗粒状,其体积分数最小,初晶MgZn2相消失,Zn/Al二元和Zn/Al/MgZn2三元共晶体的体积分数最多;当变质剂加入量为0.5%,变质温度为500℃时,Zn-6Al-3Mg合金的抗拉强度和伸长率最高,合金的综合力学性能最好.