Some properties of silicon carbide composites fabricated with chopped Si-Al-C fibres

Silicon carbide (SiC) ceramics reinforced with 10∼50 mass% of chopped Si-Al-C fibre (average length; 394µm) and 5 mol% of A14C3 as a sintering aid were fabricated by hot pressing at 1800°C for 30 min under a pressure of 31 MPa. The hot-pressed SiC compact with 40 mass% of chopped Si-Al-C fibre addition showed a maximum relative density (96.8%) among the specimens examined and a Vickers hardness (Hv) of 28.3 GPa. The highest fracture toughness (KIC) (3.9 MPa • m1/2) was achieved at 30 mass% of Si-Al-C fibre addition. These Hv and KIC values were higher than those (Hv ;17.0 GPa and KIC 2.1 MPa • m1/2