High-speed grinding fracture mechanism of Cf/SiC composite considering interfacial strength and anisotropy

Abstract

Cf/SiC composite is connected through the bonding interface to achieve the toughening effect, which makes the fiber direction and interface strength in the material directly affect the composite properties and grinding quality. Aiming at the high-quality processing of Cf/SiC composite, a single abrasive particle model is built to reveal the variation law of grinding force in the process and the surface damage phenomena such as interface debonding, fiber fracture and matrix fracture. Based on the constitutive relationship among matrix, reinforcement and interface phase, the constitutive model of composite was established. However, Cf/SiC composite is a typical hard brittle material. Low grinding speed cannot yield to good machining quality. Thus, to improve the output quality, high speed grinding is applied in this paper. Meanwhile, by considering the heterogeneous structure characteristics of composite materials, the two-dimensional simulation of grinding of single abrasive particle grinding, based on FEM (Finite Element Model) method, is realized. Finally, composite fracture behavior is analyzed by observing microstructure in the grinding process. The effects of fiber orientation, surface strength, grinding speed, and grinding depth on the surface properties and the quality of Cf/SiC composite are studied by grinding force and surface analysis. The mechanism of high-speed grinding of ceramic matrix composites, as well as the practical approach and theoretical underpinnings of grinding process optimization, are examined.