Studies on influence of graphite inclusion size on properties of SiC-graphite composites
Agnieszka Gubernat, Kamil Kornaus, Marian Rączka, Wojciech Piekarczyk, Sławomir Zimowski, Bartłomiej Muś
Quarterly No. 3, 2018 pages 180-187
DOI:
keywords: pressureless sintering, silicon carbide, solid lubricant-graphite, face seal
abstract The study presents research on the influence of the size of solid lubricant inclusions-graphite on the properties of pressureless sintered SiC-graphite composites. The purpose of these composites is to achieve a self-lubricating effect between the working elements of a friction seal. For this purpose, studies were carried out, on the basis of which the composite with the inclusion size that provides the optimal mechanical andtribological properties was selected. The apparent density, hardness, bending strength, abrasive wear resistance, friction coefficient and linear wear in contact of the same kind of material pairs were determined. Mechanical and tribological tests were correlated with qualitative and quantitative microstructure analyses, on the basis of which it was found that SiC-graphite composites with inclusions not larger than 0.056 mm meet the requirements for the materials used to produce self-lubricanting elements of face seals. It was then observed that small inclusions of graphite are more uniformly distributed in the SiC matrix.