Genesis and role of wear debris in sliding wear of ceramics

"Introduction Advanced Ceramics in Tribological Applications, Said Jahanmir Fundamental Mechanisms of Friction and Wear Wear Mechanisms of Aluminum Oxide Ceramics, Said Jahanmir and X. Dong Relation Between Surface Chemistry and Tribology of Ceramics, Traugott E. Fischer and William M. Mullins Friction and Wear of Silicon Nitride Exposed to Moisture at High Temperatures, Steven Danyluk, D. S. Park, and M. McNallan Surface Damage and Mechanics of Fretting Wear in Ceramics, P. J. Kennedy, A. A. Conte, Jr., E. P. Whitendon, L. K. Ives, and Marshall B. Peterson Abrasive Wear of Ceramics, Jorn Larsen-Basse Solid Lubrication and Composites A Review of the Lubrication of Ceramics with Thin Solid Films, Ali Erdemir Self-Lubricating Ceramic-Matrix Composites, Arup Gangopadhyay, Said Jahanmir, and Marshall B. Peterson Tribological Behavior of Whisker-Reinforced Ceramic Composite Materials, Charles S. Yust Tribological Characteristics of Silicon Carbide Whisker-Reinforced Alumina at Elevated Temperatures, Christopher DellaCorte Microstructure and Wear Resistance of Silicon Nitride Composites, Steven F. Wayne and S. T. Buljan Tribological Applications Ceramic Cutting Tools, Ranga Komanduri Ceramic Materials for Rolling Element Bearing Applications, R. Nathan Katz Tribological Performance of Ceramic Cam Roller Followers, Arup Gangopadhyay, H. S. Cheng, Joseph F. Braza, Stewart Harman, and John M. Corwin Ceramics in Mechanical Face Seal Applications, Ramesh Divakar Ceramics for Magnetic Recording Applications, S. Chandrasekar, T. N. Farris, and B. Bhushan "

Friction and Wear of Ceramics

The friction and wear behavior of materials are not intrinsic properties, but extrinsic properties; in other words, they can drastically vary depending on test and environmental conditions. In ambient air, humidity is one such extrinsic parameter. This paper reviews the effects of humidity on macro- and nano-scale friction and wear of various types of materials. The materials included in this review are graphite and graphene, diamond-like carbon (DLC) films, ultrananocrystalline diamond (UNCD), transition metal dichalcogenides (TMDs), hexagonal boron nitride (h-BN), boric acid, silicon, silicon oxide, silicates, advanced ceramics, and metals. Details of underlying mechanisms governing friction and wear behaviors vary depending on materials and humidity; nonetheless, a comparison of various material cases revealed an overarching trend. Tribochemical reactions between the tribo-materials and the adsorbed water molecules play significant roles; such reactions can occur at defect sites in the case of two-dimensionally layered materials and carbon-based materials, or even on low energy surfaces in the case of metals and oxide materials. It is extremely important to consider the effects of adsorbed water layer thickness and structure for a full understanding of tribological properties of materials in ambient air.

Effect of Humidity on Friction and Wear—A Critical Review

The combined effect of speed and humidity on the wear and friction of silicon nitride

The tribological behavior of self-mated ceramic composites, like SiC-TiC, Si3N4-TiN and (Ti, Mo) (C, N)+Ni, were characterized under dry-sliding friction. The coefficient of friction still remains unchanged on a level known from SiC and Si3N4 ceramics. The addition of titanium compounds to SiC and Si3N4 ceramics reduced the wear rate compared to titanium-free ceramics. Increasing sliding speed and temperature enhances this trend. The (Ti, Mo) (C, N) materials exhibited a wear behavior nearly independent from sliding speed and temperature with wear rates lower than 10−7 mm3/Nm up to 800°C. The present study utilized small-spot X-ray diffraction, laser raman spectroscopy (LRS) and transmission electron microscopy (TEM) TiO2 and TinO2n·1,-type crystalline Magneli-phases with a crystallographic shear structure as well as some double oxides like NiTiO3, Mo0.975Ti0.025O2 and β-NiMoO4, were detected on different ceramic substrates formed by tribo-oxidation during tests at 400°C and 800°C. The conditions during t...

The concept of lubrication by a tribochemically generated oxide layer on the surface of silicon nitride is further investigated. Previous work has shown that low friction coefficients (μ≈0.1) are obtained in a range of sliding velocities and loads when otherwise unlubricated silicon nitride slides in humid air at temperatures between 150 and 650oC. In order to verify the hypothesis that this behavior results from a competition between the growth of an oxide layer (with growth kinetics accelerated by friction) and its removal by wear, we have performed model experiments at room temperature, wherethe oxide layer is grown statically (i.e. without friction) and the friction coefficient and its evolution in time are subsequently measured. In order to avoid high friction by plowing, ultraflat surfaces were first prepared by sliding in water. The experiments showed that the oxide layer growing in humid air on silicon nitride produces a friction coefficient as low as μ≈0.05 that survives about 30 Newton meter of sliding, which corresponds to several hundred passes of the counterface. When sliding in water, the surface acquires a high friction coefficient (μ≈0.7) very rapidly. The difference in the lubricating properties of tribochemical surface layers on aluminum oxide and silicon nitride can be understood on the basis of the differing surface chemistries of these materials. We offer a tentative lubrication mechanism based on low adhesion between the oxide surface and the silicon nitride counterface and the structure of oxides grown inhumid ambients.

W. M. Mullins

Papers

Tribochemical Lubricious Oxides on Silicon Nitride