THE EFFECTIVENESS OF SURFACE MODIFICATION ON THE TRIBOLOGICAL PROPERTIES OF SIC AND SI_3N_4 CERAMICS

摘要

It is well known that it is a challenge to produce a nanostructured surface layer in ceramics by plastic deformation. This study reports the change in microstructural, mechanical and tribological characteristics of sintered silicon carbide (SiC) and silicon nitride (Si_3N_4) ceramics subjected to ultrasonic nanocrystalline surface modification (UNSM) technique. The tribological properties of the specimens were assessed using a ball-on-disk tribometer. The tribological results showed that the UNSM-treated specimens exhibited a lower friction coefficient and higher wear resistance compared to those of the untreated specimens. In addition, it was found that the UNSM technique was able to decrease the quantity of pores. The results of this study are expected to make sintered SiC and Si_3N_4 ceramics more attractive for numerous applications in various industries.