Microstructure, mechanical and ablation behaviour of C/SiC–Si with different preforms

In this paper, carbon fibre reinforced SiC–Si dual matrix composites (C/SiC–Si) with two-dimensional (2D) and three-dimensional needled (3DN) preforms were prepared. Compared with the 3DN preform, there was a higher effective volume fraction of carbon fibre (20 vol%) in the loading direction for the 2D preform, leading to higher flexural strength (348 ± 29 MPa) and fracture toughness (15.0 ± 1.7 MPa·m^1/2) of the 2D C/SiC–Si. The silicon agglomerated in the inter-bundle area to form a silicon pool in the 2D preform, and thus the silicon melt can easily be scoured by the heat flux. The silicon uniformly dispersed in the SiC matrix of the 3DN preform, which can allow them to protect each other in the ablation process, and thus the 3DN C/SiC–Si had a lower mass ablation rate (6.2 mg∙s^-1) than the 2D C/SiC–Si (12.3 mg∙s^-1).