中文摘要：

微结构成分和在有在高锌以内的典型作文的 permanent-mould-cast Mg-Zn-Al 合金的主要金属间化合的阶段的结晶的形态学扔了有能力的领域被调查。有不同形态学的三种主要混合物作为 Mg_(32 ) 被识别(艾尔， Zn )_(49 )( 字形物) ， MgZn (epsilon ) ，和第三的 icosahedralquasi 水晶的混合物(与 Q 表示了) 。成分被发现随着 Zn 和 Alcontent 和他们的集中比率变化。有到艾尔和艾尔的 Zn 的中间的集体比率的合金满足，由 alpha-Mg 组成，当有高度的合金集中时，字形物分阶段执行到艾尔和低艾尔的 Zn 的比率一 alpha-Mg ， epsilon 和字形物的小数量改组了，那些与 Q 由 alpha-Mg 与到艾尔和 highAl 的 Zn 的低比率组成。团结特征和过程被建议。Thesolidification 范围和液体我们有增加 Zn 和艾尔的温度减少为字形物满足 -- 并且 Q 类型合金，而 epsilon 类型合金表演颠倒趋势。当艾尔满足 Zn 的增加和比率到 Aldecreases 时，到更高的温度的第二个阶段转变行动变化。

英文摘要：

The microstructuml constituents and the crystallographic morphology of the primary intermetallic phases in permanent-mould-cast Mg-Zn-Al alloys with typical compositions within high zinc castable domain were investigated. Three kinds of primary compounds with distinct morphology were identified as Mg32（Al,Zn）49（r）, MgZn（e）, and a ternary icosahedral quasi-crystalline compound （denoted with Q）. The constituent is found to change with Zn and Al content and their concentration ratio. Alloys with middle mass ratio of Zn to Al and Al content, consist of a-Mg and τ phase, while alloys with high mass ratio of Zn to Al and low Al are composed of a-Mg, ε and a small amount of τ, those with low ratio of Zn to Al and high Al consist of a-Mg with Q. Solidification characteristics and process were proposed. The solidification ranges and liquidus temperature decrease with increasing Zn and Al content for τ- and Q-type alloys, whereas ε-type alloy shows reverse tendency. The second phase transformation moves to higher temperature range when Al content increases and ratio of Zn to Al decreases.