Tribological Properties of Si3N4-hBN Composite Ceramics Bearing on GCr15 under Seawater Lubrication

Abstract

This paper concerns a comparative study on the tribological properties of Si3N4-10 vol% hBN bearing on GCr15 steel under seawater lubrication and dry friction and fresh-water lubrication by using a pin-on-disc tribometer. The results showed that the lower friction coefficient (around 0.03) and wear rate (10−6 mm/Nm) of SN10/GCr15 tribopair were obtained under seawater condition. This might be caused by the comprehensive effects of hydrodynamics and boundary lubrication of surface films formed after the tribo-chemical reaction. Despite SN10/GCr15 tribopair having 0.07 friction coefficient in the pure-water environment, the wear mechanismsits were dominated by the adhesive wear and abrasive wear under the dry friction conditions, and delamination, plowing, and plastic deformation occured on the worn surface. The X-ray photoelectron spectroscopy analysis indicated that the products formed after tribo-chemaical reaction were Fe2O3, SiO2, and B2O3 and small amounts of salts from the seawater, and it was these deposits on the worn surface under seawater lubrication conditions that, served to lubricate and protect the wear surface.

Characterization and Microstructural Evolution of Continuous BN Ceramic Fibers Containing Amorphous Silicon Nitride

“…Its amorphous state at 1600 °C would guarantee reliable performance for the composite ceramics or ceramic fibers in high-temperature environments. However, unlike the results of Tan et al [ 14 ], who used PSZ as the raw materials rather than PCS, no h-BN crystals were found in this system. After analyzing the oxygen contents of PSZ and PCS, which were 3% and 0.6%, respectively, it was concluded that the introduction of oxygen could promote the crystallization process of h-BN by formulating the oxides with low melting points.…”

“…Generally, Si 3 N 4 fibers possess higher mechanical strength than BN fibers, while the thermal resistance and the dielectric properties of Si 3 N 4 fibers are inferior to BN fibers [ 12 ]. Therefore, it is urgent to develop new types of ceramic fibers containing B, N, and Si to combine the merits of both BN and Si 3 N 4 fibers in order to ensure excellent dielectric properties, high mechanical properties and good thermal resistance [ 13 , 14 , 15 , 16 ].…”

Friction Properties and Distribution Rule of Lubricant Film of Full Ceramic Ball Bearing Under Different Service Condition

“…Huang and Liu [18] established a thermal elastohydrodynamic lubrication mathematical model applicable to ceramic ball bearings, and found through comparative tests that, under the same working parameters, the lubricant film pressure of ceramic ball bearings was lower than that of steel bearings, and the lubricant film thickness was higher than that of steel bearings. Han et al [19] analysed the formation process of a lubricant film on the surface of a bearing raceway during operation based on the comprehensive effect of fluid dynamics and boundary lubrication. Galiev et al [20] proposed a distribution analysis model of a lubricant film considering the Erying characteristic stress, ultimate shear stress and shear elastic modulus under high shear rate elastohydrodynamic lubrication.…”

The Influence of Thermal Properties Anisotropy on Subtractive Laser Processing of B4C/h-BN Composites

“…The hexagonal boron nitride, also called white graphite, was very often investigated by researchers due to the possibilities to decrease the friction coefficient for cutting tools and bearing sliding applications [ 10 , 11 ]. This phase has been inserted into various oxides, nitrides, and carbides of advanced ceramic materials, for example: Si 3 N 4 , SiC, Al 2 O 3 , B 4 C, SiAlON.…”