铝硅二元合金的共生生长机制  

Growth Mechanism of Al-Si Eutectic Alloy

作　　者：孙伟成[1] 张淑荣[1] 张桂芳[1] 李恒武 

机构地区：[1]沈阳工业学院 [2]辽宁省分析测试研究中心

出　　处：《特种铸造及有色合金》1996年第5期9-11,共3页Special Casting & Nonferrous Alloys

摘　　要：观察分析了铝硅二元共晶合金的显微结构。发现在不同凝固条件下凝固的共晶硅形貌虽然有极显著的差别，但它们的基本结构是相同的——铝硅二元合金共生生长成共晶团；共晶团的核心部分基本上相同；共晶团的尺寸与冷却速度和变质处理有关。稀土元素主要富集在共晶团的周界处，促使晶体缺陷增多，导致分枝急剧增加，从而使共晶硅由各向异性生长特性转变为各向同性生长特性。The microstructure of a Al Si eutectic alloy has been investigated by TEM,SEM and EPMA.It is found that basic structures of eutectic cluster cores in different solidification conditions are identical although their outside morphelogies are different.The size of the eutectic cluster is related to cooling rate and modification of the alloy. The analysis result reveals that RE elements are mainly enriched in the circumambiency of the eutectic clusters.Which increase both crystal defect and dendrite,thus leading to a transition of the eutectic Si from anisotropy to isotropy.

关 键 词：共生生长 显微结构 变质 铝硅合金 二元合金 

分 类 号：TG146.21[一般工业技术—材料科学与工程]