Study on Improvement of Mechanical Property, Oxidation and Erosion Resistance of SiC Matrix Ceramic Composites Reinforced by Hybrid Fabric Composed of SiC and Carbon Fiber

In this study, C-f/SiC, SiCf/SiC and C-f-SiCf/SiC ceramic composites reinforcing carbon fiber, SiC fiber and hybrid fiber were fabricated by hybrid TGCVI and PIP process. After the thermal shock cycle, 3-point bending and Oxy-Acetylene torch test, their mechanical behavior, oxidation and erosion resistance were evaluated. The C-f/SiC composite showed a decrease in mechanical property along with increasing temperature, a pseudo-ductile fracture mode and a large quantity of erosion. The SiCf/SiC composite exhibited stronger mechanical property and lower erosion rate compared to the C-f/SiC, but brittle fracture mode. On the other hand, hybrid type of C-f-SiCf/SiC composite gave the best mechanical property, more ductile failure mode than the SiCf/SiC, and lower erosion rate than the C-f/SiC. During the Oxy-Acetylene torch test, the SiO2 formed by reaction of the SiC matrix with oxygen prevented further oxidation or erosion of the fibers for C-f-SiCf/SiC and SiCf/SiC composites particularly. In conclusion, if a hybrid composite with low porosity is prepared, this material is expected to have high applicability as a high temperature thermo-structural composite under high temperature oxidation atmosphere by improving low mechanical property due to the oxidation of C-f/SiC and brittle fracture mode of SiCf/SiC composite.