Oxidation effects on failure mechanism of plain-woven SiC/SiC Z-pinned joints subjected to push-out loading

Plain-woven SiC/SiC Z-pinned joints were prepared using chemical vapour infiltration. The oxidation behaviours and failure mechanism were investigated using push-out tests before and after oxidation. Microstructural analysis indicated that the degree of oxidation of the pin near the surface was more severe than that in the middle region. Internal damage was monitored using an acoustic emission (AE) system. Pattern recognition was introduced to study the evolution of failure during the test. Combined with the failure morphology, all AE signals were labelled as matrix cracking, fibre-matrix debonding, matrix peeling, and fibre break. The results suggest that the failure mechanism of the Z-pinned joints under axial loading is dominated by fibre-matrix debonding and matrix cracking.

Automated summary

Plain-woven SiC/SiC Z-pinned joints were prepared using chemical vapour infiltration. The oxidation behaviors and failure mechanism of the joints were investigated through push-out tests before and after oxidation. Microstructural analysis showed that the pin near the surface had a more severe oxidation degree than the middle region. An acoustic emission (AE) system was used to monitor internal damage and pattern recognition was employed to study the evolution of failure during the test. Combined with the failure morphology, all AE signals were identified as matrix cracking, fiber-matrix debonding, matrix peeling, and fiber breakage. The results indicate that the failure mechanism of the Z-pinned joints under axial loading is predominantly governed by fiber-matrix debonding and matrix cracking.