Friction and wear behaviour of SiAlON ceramics under fretting contacts

The goal of this paper is to understand the friction and wear mechanism of monolithic SiAlON ceramics against important engineering materials. Unlubricated fretting tests were performed on monolithic sialon ceramics against sialon, alumina, steel and hardmetal. The wear experiments were carried out in a gross slip fretting regime with identical testing parameters (8 N, 200 μm, 10 Hz and 100,000 cycles) under ambient conditions of temperature (23–25 °C) and humidity (50–52% RH). Microstructural characterization of the worn surfaces was performed, and the underlying wear mechanisms in the investigated fretting couples are elucidated. Tribochemical interaction, abrasion and spalling were observed to be the predominant wear mechanisms in most of the studied material combinations. Based on the friction and wear data, a relative ranking of the different wear couples was established. The lowest wear volume was measured for the sialon–hardmetal (WC–Co) combination, whereas the sialon–steel combination showed the highest wear volume.