二十面体Zn6Mg3Y1对AZ91D镁合金性能的影响
Effect of I-Zn6Mg3Y1 on Mechanical Properties of AZ91D Alloy
史 菲1,2, 郭学锋2, 张忠明2
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作者单位：1. 哈尔滨工业大学(威海) 材料科学与工程学院, 山东 威海 264209; 2.西安理工大学 材料科学与工程学院, 陕西 西安 710048
中文关键字：AZ91D镁合金； 二十面体准晶； Mg-Zn-Y合金； 维氏硬度； 热膨胀系数； 电化学腐蚀
英文关键字：AZ91D alloy; icosahedral quasicrystal; Mg-Zn-Y alloy; vickers hardness; thermal expansion coefficient; electrochemical corrosion
中文摘要：通过普通凝固技术获得5种含有二十面体准晶相Zn6Mg3Y1的Mg-Zn-Y合金，按质量比2 ∶ 5与AZ91D熔合制备实验合金。利用金相显微镜(OM)、扫描电镜(SEM)观察合金微观组织形貌；用扫描电镜附带的能谱分析仪(EDS)分析其微区化学成分；采用维氏硬度测试仪测试合金硬度；用热膨胀分析仪测定合金的热膨胀系数；模拟海洋环境下，测试合金的电化学腐蚀性能。结果表明：二十面体准晶相Zn6Mg3Y1的添加提高了AZ91D镁合金的硬度；降低了AZ91D镁合金的热膨胀系数，并表现出良好的高温热稳定性；AZ91D镁合金的抗腐蚀性能得到显著改善，腐蚀电流密度较AZ91D合金有1～2个数量级的提高。
英文摘要：Five species of Mg-Zn-Y alloys with I-Zn6Mg3Y1 phase were prepared by cast technology. The experimental alloys were cast, the mass ratio of Mg-Zn-Y alloys and AZ91D alloy is 2 ∶ 5. The microstructure of the samples was analyzed by OM and SEM. The composition and phases of the experiment alloys were analyzed by EDS, Vickers hardness and thermal expansion coefficient were tested, and the electrochemical corrosion was studied by potentiodynamic polarization measurements in 3.5wt%NaCl for 2 h. The results show that adding I-Zn6Mg3Y1 to AZ91D alloy, the hardness and corrosion resistance increase. After the immersion of the experimental alloy for 2 h, the corrosion current is increased by 1～2 order of magnitude compared with AZ91D alloy. In addition, the thermal expansion coefficient of the experimental alloy decreases, and thermal stability at high temperature greatly improves.