Modelling and grinding characteristics of unidirectional C-SiCs

At present, many scholars are experimentally investigating the grinding performance of ceramic matrix composites (C-SiCs). However, accurately reflecting the microscopic mechanisms of crack initiation and extension and the material removal mechanism (MRM) is difficult. To research the micro-MRM of C-SiCs, a theoretical model (TTM) and a numerical simulation model (NSM) were established in this study and were proven to be reliable by experiments. The TTM was established according to the kinematics and dynamics of a single abrasive particle. In the procedure of establishing the NSM, the SiC matrix (SiCM) and carbon fibre reinforcement (CFRT) were each modelled based on the internal structure characteristics of C-SiCs and then combined by an interface layer. The TTM, NSM and verification experiments all showed that fibre pull-out, fibre outcrop, matrix cracking and interfacial debonding were the basic defects in the C-SiCs. As the grinding depth (ap) increased, the grinding performance of the C-SiCs gradually deteriorated. The material removal characteristics of C-SiCs can be directly modelled at the microlevel by the NSM. The NSM showed that the grinding force fluctuated periodically because the CFRT and SiCM have different properties. High stresses occurred mainly in the SiCM. This research can supply a scientific basis for understanding the micro-MRM of C-SiCs and provide important guidance for the high-quality grinding of C-SiCs.

Automated summary

This study establishes a theoretical model and a numerical simulation model to research the micro-MRM of C-SiCs, and proves their reliability through experiments. The results show that fiber pull-out, fiber outcrop, matrix cracking, and interfacial debonding are the basic defects in C-SiCs. As the grinding depth increases, the grinding performance of C-SiCs gradually deteriorates.