Abstract: Short carbon fiber reinforced SiC (C_sf/SiC) composite was prepared by hotpressing method. XRD, SEM and isothermal oxidation test were used to study the isothermal oxidation property of C_sf/SiC composite. The results show that the oxidation weight loss of the composite is the most at 900℃. The weight loss decreases with the oxidation temperatures rising. Below 900℃, the oxidation weight loss of the composites is caused by the carbon fibers oxidation. Above 1450℃, the composites gain weight. Between 900-1450℃, short carbon fibers on the composite surface are oxidized and the SiC matrix forms a protecting film. The inner short carbon fibers still have the strengthen effect for the oxidation layer and matrix protecting them from oxidation, and the composites have good self-resistance oxidation property. When the composites oxide at 1600℃, the composite surface is destroyed badly and lose the resistance oxidation capacity.

Key words: C_sf/SiC composite, isothermal oxidation, resistance oxidation property