Abstract:
The sliding frictional behaviour of oxide films formed on low alloy steel by the combined plasma nitrocarburising and post oxidation
treatment has been investigated. Unlubricated sliding tests of the as-nitrocarburised and nitrocarburised-oxidised specimens showed that
the frictional behaviour depends not only on the oxidation treatment conditions, but also on the counterface material and the testing
conditions. When sliding against a steel counterface, all the tested specimens exhibited similar frictional behaviour, which is dominated
by the material transfer from the counterface to the sliding surface. On the other hand, when sliding against an alumina slider, all the
oxidised specimens exhibited a low friction regime. The duration of this low friction regime depends on the treatment and test conditions,
with the low temperature oxidised/nitrocarburised specimen being the most durable. The mechanisms associated with the observed
frictional characteristics are discussed in terms of material transfer and the structure and mechanical integrity of the films.
r 2006 Elsevier Ltd. All rights reserved.
