Improving mechanical strength and thermal shock resistance of SiC/zinc aluminum silicate joint by electrophoretic deposited multi-walled carbon nanotubes

Abstract

Improving the SiC/zinc aluminum silicate (SiC/ZAS) interface was essential for increasing the mechanical strength of SiC/ZAS joints that were used to join carbon/carbon (C/C) composites and lithium aluminum silicate (LAS) glass ceramics. In this work, well-dispersed multi-walled carbon nanotubes (MWCNTs) were introduced at the SiC/ZAS interface in the joints by electrophoretic deposition, which changed the fracture feature of the bonded C/C-LAS from SiC/ZAS interface fracture to C/C fracture, resulting in significant improvements of the shear strength. Results showed that the average shear strength of the joints was increased by 94.8% after introducing MWCNTs, which was attributed to the obviously decreased micro-defects at the SiC/ZAS interface in the joints. MWCNT-reinforced joints also exhibited better thermal shock resistance evidenced by higher residual shear strengths than those of neat joints after thermal shock tests from 800°C to room temperature and 1000°C to room temperature, respectively, which was primarily attributed to the positive role of MWCNTs in alleviating thermal stress.