Synthesis and characterisation of Cf/SiC composites with modified silicon carbide matrix

Abstract

Cf/SiC composites with multilayer [(PyC/SiC)n; n = 4] interface and modified silicon carbide matrix were prepared through isothermal isobaric chemical vapor infiltration (ICVI) technique and characterised room temperature mechanical properties. The monotonic tensile properties were studied at elevated temperature (i.e. 1250 °C, and 1350 °C) and compared with room temperature tensile properties. The tensile strength at RT, 1250 °C, and 1350 °C of the composite was found to be 193 ± 10 MPa, 238 ± 14 MPa, and 189 ± 20 MPa respectively. This paper also focusses the effect of thermal exposure of composites on residual tensile strength. The enhanced strength and toughness behaviour observed for the prepared composites because of the presence of multi-layer interface and modified matrix (SiC/Si-B-C/SiC). SEM microstructural studies carried out on tested specimens and cross section of prepared composites revealed the evidence for the self-healing behaviour from the modified matrix.