Effect of the fibre volume content on the machinability and surface integrity in grinding C/C-SiC composites

Machining of carbon fibre reinforced silicon carbide composites (C/SiC, C/C–SiC) is a challenging task owing to their anisotropic, heterogeneous, and brittle nature. Effort is made in optimizing the process, yet the material microstructure is essential. In this regard, majority of studies evaluate the influence of fibre orientation. This paper investigates the effect of the fibre volume content of 2D fabric and short fibre reinforced C/C-SiC on the machinability and surface integrity by different grinding conditions. The effect on the grinding forces is discussed. The characterization of physical/mechanical properties, as well as the microstructure and phase composition are presented. Results reveal that the surface integrity is more influenced by the microstructure than by the grinding process. Little influence on the three-point-flexural strength was observed after machining. Samples with lower fibre content exhibit inferior mechanical properties, and higher grinding forces and surface roughness due to higher silicon, porosity and microcracks content.