The effect of carbon fiber length on the microstructure, selected mechanical, wear, and thermal conductivity of Cf/SiC composite fabricated via spark plasma sintering (SPS) method

This research aims to fabricate and develop a composite brake disc made of carbon/silicon carbide. For this purpose, the first silicon carbide nanoparticles were ultrasonicated with alumina sintering aid and carbon fiber (between 10 and 20%) with different lengths of 3 mm, 10 mm, and 15 mm. Next, the final C-f/SiC composite bulk was made-up via the spark plasma sintering (SPS) method. After that, the effect of different lengths of carbon fiber was explored on the porosity, coefficient of friction, fracture toughness, thermal conductivity, and microhardness of samples. The results showed that the density of sintered samples with a carbon fiber length of 10 mm was higher than that of samples with fiber lengths of 3 and 15 mm. Also, the hardness (25.79 GPa) and fracture toughness (5.72 MPa.m(1/2)) of this sample were higher than those of the samples sintered with carbon fiber lengths of 3 and 15 mm. Further, this sample with the maximum density showed a coefficient of friction (COF) of 0.43. Since for aeroplane brake discs, the COF should be between 0.3 and 0.4, and the porosity of samples should range within 3-5%, the samples sintered with the carbon fiber length of 10 mm had the nearby features to the preferred air brake disc indices.