A self-healing strategy for inorganic fillers: Toward practical applications of silicone resin treated at high temperatures for bonding ceramic joints

Abstract A high-temperature adhesive composed of a silicone resin (SR) matrix was prepared for bonding ceramic joints. The adhesive primarily consists of boehmite sol as the modifier and B 4 C, Al and fumed SiO 2 powders as inorganic fillers. In this study, the ceramic yield of the adhesive was determined to reach 138% after heat treatment at 1100 °C. The bonding strength of ceramic joints heated at 200 °C was measured as 6.25 MPa and increased to 41.67 MPa after heat treatment at 1000 °C. According to mechanistic analysis, the volume shrinkage induced by the pyrolysis of SR was effectively restrained, and the micro-pores and cracks resulting from the oxidation process of the inorganic fillers can be self-healed by introducing borate. In addition, chemical bonds were introduced at the interfaces, thereby further improving the adhesive strength at elevated temperatures.