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Metallic friction materials currently used in industry may adversely impact the environment. Substitutions for metals in friction materials, on the other hand, can introduce operational safety issues and other unforeseeable problems such as thermal-mechanical instabilities. In this work, a molecular dynamics model has been developed for investigating the effects of material composition, density, and surface asperities on the tribological properties of inorganic 3C-SiC under various contact conditions at the atomic level. Predictions on the following results have been made: (1) elastic modulus, (2) tensile strength, (3) thermal conductivity, and (4) friction coefficient. The research findings can help improve the design of metal-free friction materials against thermal-mechanical failures. Parametric studies were performed by varying a number of conditions including (1) ambient temperature, (2) sliding speed, (3) crystal orientation, (4) asperity size, (5) degree of asperity intersection, (6) types of loading, and (7) surface contact. Plastic deformation and material transfer were successfully modeled between two sliding pairs. Some of the computational results were validated against existing experimental data found in the literature. The evaluation of wear rate was also incorporated. The model can easily be extended to deal with other nonmetallic friction composites. 

Abstract Wear is an inevitable phenomenon in the working process of clutch and brake system. With the increase of transmission speed and power density, the thermoelastic instability (TEI) of clutch and brake system is becoming more serious over time. It is difficult to obtain the practical solution for conventional materials of clutches and brakes and their actual geometry with finite thickness using the existing analytical method. To study the comprehensive effects of wear and friction pair thickness on TEI, Archard Wear Law is combined with the Fourier Reduction Method to develop a finite element model, the accuracy of which is validated using the existing analytical method. Within the usual ranges of thickness and wear coefficient of friction pair, the increase of friction material thickness or the decrease of steel material thickness will suppress the TEI. Nonetheless, if the wear-rate is increased significantly, the effect of friction material thickness will be reversed. The worst thickness, which must be avoided in the design, and the local optimum thickness exist for the steel material.