Influence Factors on Grinding Force in Surface Grinding of Unidirectional C/SiC Composites

Abstract

C/SiC has excellent mechanical properties and is extensively utilized in the aerospace field. Meanwhile, it is a typical intractable material in virtue of its special intrinsic structure. To investigate the grinding force and material removal mechanism of fiber reinforced CMC, a unidirectional C/SiC composite material was designed and prepared. A series of particular surface grinding experiments were carried out, and then the grinding force model was established based on multiple-exponential function method. Furthermore, the surface morphology and grinding mechanism of the composites were analyzed. The results show that the grinding parameters (wheel speed, grinding depth, feed speed) have a significant impact on the grinding force, and the order of grinding force is as follows: Normal>Longitudinal>Transverse. The R2 (Goodness of fit) values of the grinding force model are all above 0.9, which demonstrates the models can reliably predict the grinding force of the unidirectional C/SiC composite grinding. Besides, the dominant removal mechanism of C/SiC composites is the brittle fracture, and its failure modes are the combination of matrix cracking, fiber breakage and interface debonding. Then, the factors affecting the grinding force in surface grinding of the composite are revealed. The research results can provide theoretical support for improving grinding efficiency and precision machining of composites.