Effect of hBN content on the friction and wear characteristics of B4C-hBN ceramic composites under dry sliding condition

In order to clarify the effect of hBN on the tribological properties of B4C ceramic, dry sliding friction and wear characteristics of hot pressed B4C-hBN composites containing different hBN amounts have been investigated in air environment using a pin-on-disc tribometer. Experimental results showed that the friction and wear behaviors of the composites were strongly dependent on the hBN content. An optimum content of hBN for the best tribological behaviors was obtained. The addition of hBN into B4C resulted in a significant decrease of the friction coefficient, from 0.586 for B4C against B4C to 0.179 for B4C-20 wt%hBN composite against B4C, which could be attributed to the formation of an H3BO3 lubricating film on the worn surface of the B4C-hBN specimen. The formation mechanism of the lubricating film is discussed.