Fretting wear of SiAlON ceramic

Abstract

Friction andwear properties of Si6- Z Al zO zN8- Z ( z = 0.5) were studied in case of fretting. SiAlON samples were prepared by hot pressing without any externally added liquid. The effect of running time, slip amplitude, and normal load on friction and wear were investigated. A constant coefficient of 0.45 was observed during running time; however, friction coefficient increased from 0.445 to 0.475 for normal load variation of 20N to 60N. Wear increased linearly with the increase in sliding time and normal load for both SiAlON and steel; however, it decreased with the increase in slip amplitude. Higher wear was observed at low amplitudes as compared with wear at higher amplitudes. Transition from higher wear to lower wear occurred at fretting amplitude of 100–150μm. Wear coefficient of 7.0 × 10−4 and 18 × 10−4 was observed for SiAlON and steel, respectively. Micrographs proved useful for understanding wear mechanism. The wear in SiAlON/steel tribopair was caused by a combination of third body abrasion, tribofilm formation, and minor scoring.