Friction Reduction and Wear Resistance Enhancement of SiC and Si₃N₄ Ceramics under Dry Conditions

ABSTRACT

In this study, an effort was made to control the friction and wear behavior of silicon carbide (SiC) and silicon nitride (Si₃N₄) ceramics using an ultrasonic nanocrystalline surface modification (UNSM) technique. The friction and wear behavior of the ceramic specimens was investigated using a ball-on-disk tribotester under dry conditions against two different Si₃N₄ and bearing steel (SUJ2) balls. The experimental test results revealed the possibility of controlling the friction and wear behavior of ceramics, where the friction coefficient and wear resistance of the specimens were improved by the UNSM technique. The hardness of the specimens also increased after UNSM treatment, but it decreased abruptly with increasing depth from the very top surface. Microscratch tests showed that the critical load of the specimens was improved by the UNSM technique. In addition, Raman spectra results revealed that no additional phase was detected after UNSM treatment, but the intensity decreased after UNSM treatment. Hence, the UNSM technique ensures stronger ceramics and enables better friction and wear behavior than available conventional sintered ceramics.

KEYWORDS:

• Ceramics
• surface modification
• friction
• wear

Funding

This work was supported by the Sun Moon University Research Grant of 2014.