Abstract
In order to apply Carbon/Carbon composites (C/Cs) to various hot structures, a secondary bonding technique effective at elevated temperatures is frequently required. In the present study, carbon and SiC bondings between C/Cs were formed, and strengths of the bondings were evaluated at elevated temperatures up to 2273K in vacuum using the double-notched shear method. The results revealed that bonding strengths became higher than the inter-laminar shear strength of the substrate C/C when the bonding layer was thin, and bonding strengths increased with increasing temperature. The enhancement of carbon bonding with temperature were shown to be caused mainly by the evaporation of absorbed water up to a temperature of 1800 K with a slight additional effect of residual thermal stress. It was also shown that heat treatment at higher temperature than the processing temperature made the bonding stronger.
