Preparation and tribological properties of hierarchical porous SiOC/BN composites from wood powder and polysiloxane precursor

Abstract

Hierarchical porous SiOC/BN composites were prepared through pyrolysis of polysiloxane and wood biomass, using hexagonal boron nitride (h-BN) as inert filler and solid lubricant. The effects of sintering temperature on the microstructure and tribological properties of the composites were observed, and the wear mechanisms of the composites were suggested by examining the morphologies of worn surfaces. With increasing sintering temperature, the composites display higher porosity, specific surface area and pore volume attributed to the formation of a large amount of nanocrystals. The composites prepared at 1200°C display excellent tribological properties in the condition of higher applied load or lower linear velocity from the protection of self-lubricating film. The abrasive wear and adhesion wear are identified as the dominant wear mechanisms for the composites.