This paper presents microstructural properties and damage behaviour of a
vacuum mixed poly(methyl metacrylate) (PMMA) bone cement, during the sliding
contact with AISI 316L stainless steel, under micro-loads. Influence of the
Ringer's solution on the wear was analysed in comparison to dry contact. The
variation of load did not produce any significant change of the wear factor
while the increase in the sliding speed induced significant increases in the
wear factor, more pronounced in the case of dry sliding. The obtained wear
factors were in average higher for the sliding in Ringer's solution than
those obtained under dry conditions. Significant fragmentation of the worn
tracks, of irregular shapes with broken edges, was observed, slightly more
pronounced for the dry contact. Many cavities and voids were formed on the
wear track surface, but they did not extend into the bulk material. Higher
loads produced more uniform and less fragmented wear tracks. Abrasive,
adhesive wear and plastic deformation grooves were observed, as well as
fatigue and erosive wear. Fatigue cracks developed in the direction normal
to sliding. Network of fine craze cracks was exhibited on the surface of
wear tracks, especially pronounced in the case of dry sliding. These results
are important since they contribute to understanding the sites of crack
initiation, and development mechanisms on the surface of PMMA bone cements,
also including synergistic effects of physiological environments pertaining
to the non-steady crack and craze behaviour and crack pattern development in
PMMA.
Influence of Duplex USSP/Nitriding Surface Treatments on the Dry Sliding Behavior of Ti6Al4V/AISI 316L Tribopairs
