Oxidation Behavior of a Si-C-O-Fiber-Reinforced Magnesium Aluminosilicate

The oxidation behavior of a Si-C-O-fiber-reinforced magnesium aluminosilicate has been investigated in the temperature range 1000°-1200°C. Parabolic weight gain, together with other experimental observations, has suggested that the oxidation process was controlled by the outward diffusion of carbon monoxide gas. The matrix and fibers reacted to form enstatite and forsterite. During the initial stages of oxidation, an interlayer containing a mixture of silica and turbostratic carbon was formed. This interlayer was modified progressively over time to create interface morphologies near the surface and near the center of the oxidized samples that were different from one another. A mechanism explaining the morphological evolution of the fiber-matrix interfaces has been proposed.