Fabrication and Evaluation of 3-Dimensional Tyranno Fiber Reinforced SiC Composites by Repeated Infiltration of Polycarbosilane

Abstract

3-Dimensional Tyranno fiber reinforced SiC composites were fabricated by infiltration of molten polycarbosilane into a 3-dimensional textile preform (volume fraction: 39%) in an autoclave followed by pyrolysis in an argon atmosphere up to 1200°C. An attempt was made to improve the density of the composite by repeating the infiltration and pyrolysis process. Ten times repetition increased the density of the composite to 2.4×103kg·m-3 (relative density: 83%, open porosity: 5%). The bending strength and fracture toughness of the composite were 420 MPa and 11.5 MPa·m1/2, respectively. The composite showed semistable fracture behavior because of bridging of fibers parallel to the tensile direction.