Surface topography and roughness of silicon carbide ceramic matrix composites

摘要

The silicon carbide ceramic matrix composite (C-f/SiC) plays an important role in aeronautic and space applications due to its excellent performance. C-f/SiC consists of silicon carbide and carbon fibers. The effects of the grinding parameters on the 3D parameters of surface roughness and surface topography when grinding 2.5D needled C-f/SiC materials have rarely been investigated. The primary purpose of this paper is to fill this knowledge gap. C-f/SiC material was ground in the direction of the orthogonal surface, and the surface topography, grinding parameters and grinding mechanism were analysed through a series of experiments. The results indicated that matrix cracks, fiber fractures, fiber wear and interfacial debonding were the primary removal methods of the material. The grinding parameters exert a substantial influence on the quality of the machined surface, primarily because of the undeformed chip thickness and the length of the contact arc. In the grinding process of the 2.5D C-f/SiC material, the quality of the surface roughness and its parameters gradually improved with increasing grinding speed, whereas the feed speed and grinding depth produced the opposite effect. Based on the conclusions, the surface topography and roughness parameters of 2.5D C-f/SiC material can be predicted, which thus provides useful technical support for increasing the machining quality of 2.5D C-f/SiC material and all its composites.