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用金相方法考察了微量添加元素对Al-Ge和Al-Si-Ge共晶合金显微结构的影响。ⅡB,ⅢA,ⅣA和ⅤA族元素对Al-Ge共晶结构并无影响;ⅣB,ⅤB和ⅥB族难熔金属影响较大,共晶Ge聚集为大块的结晶;碱金属,碱土金属和一些VⅢ族金属的加入,使Al-Ge共晶点向富Al方向移动。Al-Ge共晶不出现类似Al-Si共晶的那种变质现象.Al-Si-Ge系变质时,Si以变质的共晶团存在。根据Al-Ge和Al-Si结晶过程的对比,认为Al-Si共晶的变质,主要取决于变质剂原子对(100)_(Al)∥(110)_(Si)外延关系的影响。

The effect of micro-amount element additions on the microstructures of Al-Ge and Al-Si-Ge eutectic alloys has been studied by means of metallographic method. For Al-Ge eutectics, no evidence was found of occurring any modification something like that exists in the Al-Si system. Some elements which belong to the ⅣB, ⅤB and ⅥB groups in the periodic table of elements seriously influence their microstructures and change the feather-like Al-Ge euteetic into block Ge crystals. In the other case, it appears to move the eutectic point to the Al-rich side when some alkaline, alkaline earth and rare earth elements were added in this eutectic. The modifiers Na, Sr, La effective in the Al-Si system were scanned about their effects on the Al-Si-Ge system. In this ease, eutectic Si exists in modified clusters form and gradually dwindle their size with increasing the Ge content, finally they disappeared at the Al-Ge side. According to comparison of the modification between the Al-Ge and Al-Si systems, it was considered that the modification of Al-Si eutectic was mainly decided by the effects of modifier atoms on the epitaxial orientation relationship or decreasing the disregistry between {110}_(Si) and {100}_(Al).