Structural adhesive bonding of sintered silicon carbide (SSiC) subjected to thermal treatment in air atmosphere

Abstract

The adhesive bonding of sintered silicon carbide (SSiC) has been studied. Two structural epoxy-amine adhesives were used to perform bonded assemblies with SSiC substrates thermally treated in air atmosphere to 800°C, with a view to improving the adhesion properties of the substrates. The mechanical strength of such compressive-shear and tensile loaded assemblies was found to be closely linked to the modification of the chemical composition of the SSiC surface, while its roughness remained unchanged at the micrometer scale. The main reason for the sudden increase of strength of the bonded assemblies is the sharp decrease in concentration of hydrocarbon contaminants together with formation of silica at the SSiC surface. These chemical modifications probably involve acid-base interactions, which contribute to the increase of the work of adhesion.