Grinding quality analysis and removal mechanism for 2.5D Cf/SiC composites

2.5D C f /SiC composites are widely utilized in engineering applications, rocket nozzles, space vehicles, etc., for their excellent mechanical properties. However, the inherent anisotropy of carbon fibers and the intrinsic hardness and brittleness of the ceramic matrix present significant challenges for the efficient precision grinding of ceramic matrix composites. This study is devoted to investigating the grinding quality, wheel surface topography, oxidation mechanism and removal mechanism of 2.5D C f /SiC composites under varying process parameters, considering the effects of PIP and RMI preparation methods on material machinability. Using grinding force and surface roughness as the evaluation metrics of grinding quality, the effects of rotational speed, grinding depth and feed rate on the grinding quality and material mechanism were investigated through single-factor tests. Oxidation mechanisms were characterized by Energy Dispersive Spectrometer (EDS) method, and the fracture mechanisms, including fiber breakage, pull-out and delamination, were analyzed by using Scanning Electron Microscopy (SEM). The results indicate that increasing rotational speed effectively reduces grinding force and surface roughness, whereas increases in the feed rate and grinding depth elevate grinding force and surface defects. The results also show that the RMI C f /SiC composites exhibit greater density and are more challenging to remove compared to PIP composites, which require higher grinding forces. Consequently, the grinding wheel wear is more severe, yet its surface quality surpasses that of the C f /SiC composites prepared by the PIP method.