Damage behavior and removal mechanism of different yarn orientations 2.5D SiCf/SiC composites under single-abrasive scratch test

Abstract

This study aims to comprehensively investigate the effects of yarn orientation and grinding depth on the damage behavior and removal mechanism of 2.5D SiCf/SiC composites via single-abrasive scratch tests. Results show that brittle matrix damage and fiber fracture are the primary removal modes of the composites. As the scratching depth increases, the fiber fracture removal modes of warp yarns are cutting fracture, cutting and shear fracture, and shear fracture, whereas those of weft yarns are cutting fracture, shear fracture, and bending fracture. The matrix is primarily removed via cracking, damage, and peeling. The resulting debris is composed of fiber segments, fiber microsegments, interface fragments, matrix fragments, and microdebris. The scratching force and cross-sectional area gradually increase with increasing scratching depth; however, the specific scratching energy decrease. This study clarifies the damage behavior and removal mechanism of 2.5D SiCf/SiC composites and provides meaningful guidance for improving processing quality.