LAUSR

Abstract Two types of carbon fibers (CF-A, CF-B) with different mechanical properties as well as microstructure were used as the reinforcement to prepare carbon/carbon composites (C/C-A, C/C-B) for aircraft brakes. The deformation ability of carbon fiber determined the wear mode of itself and also influenced the wear resistance of the nearby pyrocarbon. In C/C-A, the fracture of CF-A at the wear surface was attributed to its hardness and indentation modulus being close to pyrocarbon as well as its weak interface bonding with pyrocarbon, which caused larger wear rate and thicker friction layer at the surface of C/C-A. Large deformation of the friction surface contributed to the larger contact area and higher friction coefficient of C/C-A but induced cracks between friction layer and the substrate, causing the unstable brake process under high energy brake. The enhanced interlaminar shear strength of the composites as well as better wear resistance of CF-B contributed to the lower wear loss of C/C-B. Brake discs reinforced by CF-B exhibited a lower friction coefficient but more stable curves under different braking conditions, which was mainly due to the higher hardness and indentation modulus of CF-B and steady friction surface of C/C-B during braking.