Al_2O_3／Zn合金复合材料凝固组织的扫描电镜观察

SEM Observation of Solidifying Structures of Al_2O_3 /Zn Alloy Composites

利用扫描电子显微镜（ＳＥＭ）观察了铸造Ａｌ２Ｏ３／Ｚｎ合金复合材料的凝固组织，研究了复合材料凝固组织的一般特征．研究结果表明，复合材料的组织致密，纤维分布均匀，基体晶粒细小；在复合材料的凝固过程中，氧化铝纤维可作为Ｚｎ合金共晶体非自发形核的衬底，纤维／基体界面上的硅在共晶体的共生生长过程中起了领先相作用，导致了复合材料的共晶转变是由铝硅共晶转变和锌铝共晶转变两部分组成．

Observe the solidifying structures of casting Al2 O3 /Zn alloy composites with scanning electronic microscope (SEM) and study the general features of the solidifying structures of the composites.The results indicate that the structures are fine and close,the fibers distribute uniformly and the matrix grains are verysmall;the alumina fibers can serve as the lining of heterogenous nucleation of eutectic in m alloy during the solidi-fication of the composites,and the silicon on the interface between the fiber and the matrix plays a leading role during the coupled growth of the eutectic so that the eutectic transformation of the composites consists of Al -si eutetic transformation and Zn -Al eutetic transformation.