The first and the second wear round robin tests within the framework o
f the Versailles Project on Advanced Materials and Standards (VAMAS) h
ave been performed with materials combinations of alpha-Al2O3, Si3N4 a
nd AISI 52100 steel under given sliding conditions of the ball-on-disk
test system. The results, as reported elsewhere, showed a characteris
tic wear behavior depending on the material pairing. To obtain a deepe
r understanding of the wear behaviors of these materials, some additio
nal observations and analyses of the worn surfaces were conducted by m
eans of various observations and analytical tools, such as topographic
scanning electron microscopy, micro-Fourier transform IR and so on. I
t was shown that the wear of the steel and Si3N4 was not a simple proc
ess, but had a complex manner in that both tribo-oxidation action and
abrasive action of the steel and Si3N4 wear particles contributed to t
he higher wear of these materials.