A Novel B2o3/B4c-Modified Composite Adhesive With Wide Operative Temperature Range For Alumina Fiber Fabric Bonding

A heat resistance adhesive with wide operative temperature range for bonding alumina fiber fabric was developed by organic-inorganic modification. The polyvinyl alcohol modified by B2O3 generated a complex cross-linked network connected by B-O-C bonds, which can enhance the bonding strength of adhesive after heat-treatment from RT to 400 degrees C. Moreover, the addition of B4C can enhance the bonding strength of adhesive after heat-treatment from 400 degrees C to 800 degrees C due to the formation of molten B2O3 and borosilicate glass. Significantly, the appropriate addition of B4C can make the adhesive form a denser structure without transforming the fracture mode of the bonding joints, which is conducive to enhance the strength performance of bonding joints after sintered at 800 degrees C. On the contrary, the excessive addition of B4C will transform the fracture mode of the bonding joints into brittle fracture, which will degrade the strength performance of bonding joints.