Tribological Properties of Silicon Nitride Ceramics Modified by Titanium and subsequent Oxygen Implantation

A silicon nitride based ceramic was implanted with 150
keV titanium to a fluence of 1017 ions/cm2. Subsequently the samples were
implanted with oxygen using plasma immersion ion implantation (PIII) and
conventional beam-line implantation to stimulate the formation of lubricating
oxides in the surface. The wear is reduced for all implanted samples. The
friction coefficient is slightly higher than in the non-implanted case
for all implantation conditions investigated although oxide formation in
the wear track is suggested by detection of a relatively high amount of
oxygen in the wear track as indicated by energy-dispersive X-ray spectroscopy
(EDX). We discuss the possible mechanisms that lead to the observed tribological
behaviour.