Friction and wear behaviour of β -silicon nitride–steel couples under unlubricated conditions

Abstract

The friction and wear behaviour of colloidally processed and pressureless sintered β-silicon nitride (Si₃N₄) ceramics against steel DIN Ck45K under unlubricated condition were investigated using a pin on disk tribometer. β-silicon nitride (Si₃N₄) ceramics consolidated by slip casting from suspensions with different solid loading have been studied, aiming at increasing the use of β-Si₃N₄ as cutting tools in industrial applications. The morphology of the worn surfaces of β-silicon nitride ceramics was analysed by scanning electron microscopy (SEM) and energy dispersion spectroscopy (EDS). Under the conditions used, it was found that β-Si₃N₄ ceramics exhibited a low wear rate (10⁻⁶ mm³ N⁻¹ m⁻¹) and the frictional behaviour of β-Si₃N₄ ceramics–steel couples depended on a metallic layer transferred from the steel disk to the β-Si₃N₄ ceramic pin.