(西安理工大学 材料科学与工程学院, 西安 710048)
摘 要: 采用普通凝固技术制备了镁合金稳定态准晶相。 通过光学显微镜、 X射线衍射、 扫描和透射电子显微分析, 确定了准晶的组织、 相成分及结构。 实验结果发现: Mg-Zn-Y三元合金在室温冷却过程中, 准晶相直接从液相形核、 长大; 当合金成分为Mg74Zn25Y1时, 凝固组织为MgZn基体相、 析出相为α-Mg固溶体及二十面体Mg30Zn60Y10准晶相; 当x(Y)为2%、 3%时, 合金中出现共析组织。
关键字: 准晶; 二十面体; 镁合金; 凝固
(School of Materials Science and Engineering,
Xi′an University of Technology, Xi′an 710048, China)
Abstract: Stable icosahedral Zn60Mg30Y10 quasicrystals was prepared by as-cast method. The microstructure, composition and phases of the as-cast Mg-Zn-Y alloy are analyzed by optical microscope, SEM and EDS. The constituent phases are identified by XRD, and the quasicrystal structure is identified by TEM. Analyzing results show that the i-phases directly nucleate and grow from melt of cooling Mg-Zn-Y ternary alloys; the microstructures of the Mg74Zn25Y1 alloy consist of α-Mg, MgZn and i-phase. When the mole fraction of yttrium reach 2% and 3%, the eutectoid microstructures are found in the Mg-Zn-Y alloys.
Key words: quasicrystal; icosahedral; magnesium alloy; solidification