Transmission Electron Microscopy Study of Alumina Fiber-Reinforced Magnesium Composite

摘要

A detailed microstructral analysis of alumina (FP) fiber-reinforced ZE41A magnesium composite was performed by means of transmission electron microscopy (TEM). Fifty-five volume percent FP fiber-reinforced ZE41A magnesium composite thin foils were prepared by methods of mechanical polishing and ion thinning. Three major areas of interest in the composite microstructure were studied; the filaments, the interface (fiber/matrix reaction zone), and the matrix. In addition, the effects of heat treatments at 450 C on the composite microstructure were investigated. It was found that the alumina/magnesium interface consisted of a thin layer of magnesium aluminum oxide spinel and relatively large magnesium oxide (MgO) particles. A concentric layer of magnesium alloy grains encircling the alumina the magnesium matrix microstructures. Upon heat treatment at 450 C for 95 hours, polygonization of the magnesium matrix occurred while the spinel interfacial layer grew with decreasing magnesium oxide particle size.