Ultra-high temperature transverse and longitudinal compressive properties and failure mechanism of fine woven pierced C/C composites up to 2000 °C

Abstract

Under ultra-high temperatures up to 2000 °C conditions, the effect of temperatures on the transverse and longitudinal compressive properties and failure mechanism of fine woven pierced C/C composites (FWPCCCs) was revealed. Results showed that the Y- and Z-direction compressive strengths and modulus increased dramatically with the increase of temperature. FWPCCCs had better compression properties at ultra-high temperatures. The Y-direction compressive strength and modulus at 2000 °C increased by 95.24 % and 62.40 %; the Z-direction compressive strength and modulus increased by 51.70 % and 61.94 %, respectively. As the temperature increased, the shear angle of the Y-direction compression failure fracture became larger but that of the Z-direction compression became smaller. Failure cracks emerged from the slits around the Z-direction yarns. The crack then continued to expand along the slits around the Z-direction yarn or between the layers of the two-dimensional woven fabric. But at high temperatures, these slits were smaller and the yarns and matrix were more tightly connected, which resulted in better compressive properties of FWPCCCs.