石墨纤维增强Al基复合材料界面反应机制研究

本文利用透射电子显微镜（ＴＥＭ）对不同条件下形成的石墨长纤维增强Ａｌ—Ｔｉ（０．３５ａｔ—％）基复合材料的界面微观结构进行了比较研究，用高分辨透时电子显微术研究了Ａｌ＿４Ｃ＿３的生长规律，结果表明Ａｌ＿４Ｃ＿３顶端与Ａｌ基体间的界面粗糙，其生长机制为连续生长，Ａｌ＿４Ｃ＿３的（０００１）面与Ａｌ基体的界面光滑，其生长机制为沿面生长．两种生长机制在不同的生长驱动力作用下，具有不同的相对生长速率。因此在不同的材料制备工艺条下，Ａｌ＿４Ｃ＿３的形态也表现出不同的特点。讨论了纤维分布情况对界面微观结构的影响，认为适当降低纤维体积含量对进一步改善复合材料性能有利。

INTERFACIAL REACTION IN GRAPHITE FIBRES REINFORCED Al ALLOY COMPOSITES

Comparative study under TEM was carried out of the interfacial microstructure in the long graphite fibres reinforced Al-0.35at.-%Ti alloy composites prepared under various conditions. The growth of interfacial reaction product,i.e., Al_4.C_3, was observed under high resolution electron microscope. Results show that the interfaces between the top of Al_4 C_3 and Al alloy matrix are rough and Al_4C_3 grows up continuously, while between the (000l) plane of Al_4C_3 and Al alloy matrix are smooth and Al_4C3 grows up along surfaces. These interfaces have different relative growth rates under differnt growth driving forces.Thus,the morphologies of Al_4C_3 in the composites differ upon the manufacturing parameters were changed. It seems that a proper reduction of volume fraction of graphite fibres will be available to improve further the properties of compsite.