A SiC whisker reinforced high-temperature resistant phosphate adhesive for bonding carbon/carbon composites

•The spine-like SiCw were synthesized via carbothermic reaction.•The above SiCw have a good compatibility in phosphate adhesives containing B4C.•The new slender SiCw generated at 1300 °C play a role of secondary reinforcement.•The strengthening and toughening effect of SiCw was obvious.

A SiC whisker reinforced phosphate adhesive was developed for bonding carbon/carbon composites. A kind of spine-like SiCw with a large specific surface area was synthesized at first and then was chosen as the reinforcement phase. It was found that the mechanical performance of adhesive was promoted by the appropriate amount (1 wt.%) of SiCw within the whole heat-treatment temperature range, while the excessive whisker content caused a side effect. With the temperature increasing, the variation of composition and structure of adhesive was closely related to the reinforcing effect of whiskers at different temperatures. Moreover, the reinforcement effect from 900 °C to 1500 °C was better than that below 900 °C. At 1300 °C, the fracture displacement could be extended by 100%, which was attributed to the influence of both spine-like SiCw and the newly-formed slender SiCw.