Enhanced dry friction performance of MCMB@SiC-SiC composites via in-situ reaction-formed SiC shell layer structure

Mesocarbon microbeads (MCMB) have significant potential for enhancing the dry friction performance of SiC. However, the weak bonding between MCMB and SiC leads to a high wear rate in MCMB-SiC composites. This study addressed this issue by in situ formation of a SiC shell on the MCMB surface using the molten salt templating (MSS) method, followed by preparing MCMB@SiC-SiC composites through hot-pressing sintering. The in-situ SiC shell created a strong chemical bond between the MCMB and SiC, improving the interaction between the phases. Comprehensive investigations into the effects of the MCMB@SiC content on the microstructure, mechanical properties, dry friction, and wear performance revealed that the MCMB@SiC-SiC composites exhibited excellent dry friction performance, with a coefficient of 0.24 and a wear rate of 6.6 × 10 −7  mm 3  N −1  m −1 . Compared with the MCMB-SiC composites without the shell structure, the MCMB@SiC-SiC composites exhibited a 36 % reduction in the dry friction coefficient (μ) and an 81 % reduction in the wear rate (WR). The SiC shell structure effectively prevented MCMB extraction and SiC spalling, making this innovative design a promising solution for enhancing the performance of SiC as a sealing material under severe conditions.