MECHANICAL PROPERTIES OF Hi-NTCALON S AND SA3 FIBER REINFORCED SiC/SiC MINICOMPOSITES

摘要

The tensile behavior of CVI SiC/SiC reinforced with Hi-Nicalon S or SA3 fibers is investigated. Minicomposite test specimens were used. Minicomposites are reinforced by single tows. The mechanical behavior was correlated with microstructural features including tow failure strength and interface characteristics. The Hi-Nicalon S fiber reinforced minicomposites exhibited a conventional response, comparable to that one observed on composites reinforced with as-received Nicalon or Hi-Nicalon S fibers and possessing weak fiber/matrix interfaces. The SA3 fiber reinforced minicomposites exhibited stronger interfaces and premature failures. The behavior was improved after heat treatments.