Enhancement Of Tribological Properties In Siliconized Graphite Via Hierarchically Hybrid Sic/C Composite

This study aims to investigate tribological properties in a siliconized graphite (C?-11-0.5) and hierarchically hybrid SiC/C composites at the load ranging from 10-40 N under dry air/water lubrication conditions. A feasible liquid silicon infiltration (LSI) was used to fabricate the SiC/C composites. Morphology and phase identification of two materials were characterized and analyzed by scanning electron microscope (SEM) and energy dispersive spectrometer (EDS). An image feature extraction was used to post-process the data of wear test, further to gain the wear properties of the samples. The results demonstrated that a lower coefficient of friction (COF) and wear rate can be achieved in the LSI SiC composites than that in the sample of C?-11-0.5. Both COF decreased under waterlubricated conditions, compared with that under the dry air lubrication. The excellent tribological properties in two materials can be due mainly to the microstructure of the C?-11-0.5 sample, showing much more graphite and Si dispersed on the matrix. The C?-11-0.5 sample indicated the typical oxidative wear mechanism, whereas, the sample of LSI SiC demonstrated the combined oxidative and fatigue wear. This finding can provide a promising new siliconized graphite materials for ceramic rolling bearings.