Frictional Characteristics of Carbide Ceramics in Water

Frictional characteristics of carbide ceramics (SiC, B4C-SiC, and B4C) sliding against SiC balls in water were measured over a wide range of test conditions. Carbide ceramics can obtain hydrodynamic lubrication with low friction coefficients at 20 and 40 N; however, carbide ceramics cannot obtain hydrodynamic lubrication with low friction coefficients at 5 N. Carbide ceramics exhibit lower friction coefficients at 20 and 40 N than those at 5 N in each lubrication regime. Carbide ceramics can exhibit a wider application range with low friction at high loads (20 and 40 N). The low friction of carbide ceramics is achieved by the combination of hydrodynamic lubrication and tribochemical reactions. The products of tribochemical reactions of carbide ceramics improve the viscosity of water at or near the worn surfaces of carbide ceramics, promoting the hydrodynamic lubrication for carbide ceramics. B4C ceramic shows lower friction coefficients than those of SiC and B4C-SiC ceramics in boundary lubrication and mixed lubrication at 20 and 40 N.

Automated summary

Frictional characteristics of carbide ceramics sliding against SiC balls in water were measured under various test conditions. The results showed that carbide ceramics can achieve low friction coefficients at 20 and 40 N due to hydrodynamic lubrication and tribochemical reactions. Additionally, B4C ceramic exhibited lower friction coefficients compared to SiC and B4C-SiC ceramics at higher loads of 20 and 40 N in boundary and mixed lubrication regimes.