A novel heat-resistant organic matrix adhesive for hydrophobic silica aerogels composites and 1Cr18Ni9Ti steel bonding

The novel organic matrix adhesive was used to join hydrophobic mullite fiber reinforced silica aerogels (HMF/SA) composites and 1Cr18Ni9Ti steel. It was prepared using silicone resin (SR) as a matrix, Al, low melting point glass (GP), ZnO and Fe2O3 powders as inorganic fillers, γ-aminopropyltriethoxysilane (γ-APS) as curing agent and dibutyltin dilaurate (DBTDL) as catalyst. The curing mechanism and character of the adhesive were studied, as well as the bonding mechanism of the adhesive. The tensile shear strength of the adhesive was investigated after heat-resistant experiment in atmosphere surroundings. Results showed that the adhesive could be cured at room temperature through polycondensation reaction using γ-APS. The adhesive had a good wettability with HMF/SA composites and 1Cr18Ni9Ti steel, and established strong adhesion between both of them. The adhesive could be resistant to 750 °C with satisfactory bonding strength (4.68 MPa). The optimized ratio of inorganic fillers had important influences on the bonding properties of the adhesive. Al took an important effect in giving a strong refractory ceramic bond to the adherends. Failure mode of joint was substrate failure due to the high chemical bonding force between the adherends.