Joining of various engineering ceramics and composites by a modified preceramic polymer for high-temperature application

A modified heat-resistant polymer adhesive, which can be applied under both aerobic and anaerobic environments, was developed to bond various ceramics and composites. After curing process, as-received joints do not need subsequent processing and can keep appropriate strength within the whole heat-treatment processes. With increasing temperature, a series of reactions occurred at bonding area, thus influencing the adhesive's performance and successively dividing the bonding mechanism into four modes: resin physical bonding, glass physical bonding, ceramic physical bonding and chemical bonding. The maximum strength of mullite joints could reach 33 MPa after heating at 1300 °C in air, while those of SiC and C/C joints were just 26 MPa and 13 MPa at 1100 °C in Ar, respectively. The finite-element and fracture analysis of these joints indicated that the failure of mullite and SiC joints only occurred at bonding layer, while that of C/C joints occurred at both bonding layer and interface.