Effect of various methods of pre-treatment of carbon fibers on the mechanical properties of PIP-based ceramics/carbon composites

The purpose of the work was to determine the conditions of CF preparation to obtain carbide composites with favorable mechanical response. The relationships between the interfacial properties of fiber/polymethylsiloxane composite, and mechanical properties of the resulting fiber/carbide composites were investigated. The CF/resin interfacial strength was modified by oxidation of CF surface with nitric acid, silanization, and depositing CNT or a pyrolytic carbon layer (PyC). The study of composite interphases (ILSS and SEM) and surface tests of the modified CF (XPS, FT-IR, wettability measurements) showed different nature of the bonding occurring at the fiber/resin and fiber/ceramics boundary. The CF silanization significantly improved the ILSS between CFs and resin by 38.5%, while reduced flexural properties of carbide composites. The most promising treatment method of CF for PIP-based ceramic composites was modification with PyC, which provided 2 times higher ILSS, 1.5 times higher flexural strength and improved work to fracture (WF) as compared to unmodified CF.

Automated summary

The purpose of the study was to determine the conditions for preparing CF to obtain carbide composites with favorable mechanical response. The study investigated the relationship between the interfacial properties of fiber/polymethylsiloxane composites and the mechanical properties of resulting fiber/carbide composites. The CF/resin interfacial strength was modified using different methods, and the study revealed different bonding characteristics at the fiber/resin and fiber/ceramics interfaces. Silanization of CF significantly improved the interfacial shear strength, while reducing the flexural properties of the carbide composites. The most promising treatment method for CF in PIP-based ceramic composites was modification with PyC, which resulted in enhanced interfacial shear strength, flexural strength, and work to fracture compared to unmodified CF.