Compressive strength and damage mechanisms of 2D-C/SiC composites at high temperatures

Compressive strength of 2D-C/SiC composite was investigated from room temperature(RT) to 1600 degrees C at present work. Damage evolution was investigated by conducting loading/unloading tests at RT and the damage mechanisms were elucidated by observing the fracture morphology. It is found that compressive strength of 2D-C/SiC was retained until 1200 degrees C and then decreased with increasing temperature. The variation of compressive strength is closely related to the degradation in matrix modulus. The compressive damage of 2D-C/SiC starts at the buckling of 0 degrees fiber and is followed by opening and closing of original pores, initiation and growth of longitudinal interbundle cracks, separation of 90 degrees fiber bundles by longitudinal cracks, matrix cracking from intrabundle pores, propagation of matrix cracks into 0 degrees fiber bundles, connection of cracks in 0 degrees fiber bundles and longitudinal cracks in 90 degrees fiber bundles.