【摘要】 采用普通凝固技术在高镁、低锌和低钇合金中制备出镁合金稳定态准晶相,为制备准晶增强自生复合材料的可行性开辟途径。通过光学显微镜、X-ray衍射、扫描和透射电镜显微分析技术,确定了准晶的组织、相成分及结构。分析了由于合金成分不同,特别是稀土元素Y摩尔分数的不同导致准晶的分布、数量等差异。结果表明: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;伴随Y摩尔分数的增加,准晶相的晶粒度、圆整度和分布均匀化程度均有提高。更多还原

【Abstract】 Stable icosahedral Zn60Mg30Y10 quasicrystals were prepared by as-cast method. On this base, the feasibility to prepare quasi crystalline reinforced low-density magnesium alloy was also discussed. The microstructure, the composition and the phases of the as-cast Mg-Zn-Y alloy were analyzed by optical microscope, SEM and EDS. The constituent phases were identified by XRD and quasi crystal structure was identified by TEM. Analyzing the different component of alloys, especially the mole fraction of yttrium, can lead quasi crystals that have different micro morphologies, amounts and distributing. Results show that the I-phases directly nucleate and grow from melt of cooling Mg-Zn-Y ternary alloys; the granularity, the circular-degree and the distributing-leveling of the quasi crystalline were improved with the increasing of yttrium’s contents.更多还原