Wear Performance of Thermally Sprayed NiCrBSi and NiCrBSi - WC Coatings Under Two Different Wear Modes

NiCrBSi
is a Ni
-
based alloy universally recognized for its superior mechanical properties,
attributed to the presence of hard
-
dispersed carbides and borides, which is dependent on
the deposition technique. Moreover, Metal Matrix Composites (MMC) materials will ai
m
to combine the resilience of metals with high wear resistance specific of ceramics which
made them innovative for a large wide of wear resistance applications. In this paper, thick
NiCrBSi and NiCrBSi
-
WC coatings are made ontoS235JR mild steel substrates
using an
oxyacetylene flame
-
spraying torch (SuperJetEutalloy, Castolin Eutectic). Two different
wear tests: sand/wheel wear test in dry conditions and the pin
-
on
-
disc wear test in
continuous motion are used to investigate addition effects of WC reinforcin
g ceramic
phase on the microstructure and wear resistance of the coatings layers. The results show
that the presence of ceramic phase affects the wear resistance of the coating. For both
wear tests, the meta
llic alloy coating has an improv
ed wear resistanc
e than the reinforced
ones. WC reinforcement does not play the protective role of the matrix against wear but
improve the hardness. Wear mechanism is mainly controll
ed by the scratching and by the
pull out of WC particles because of their faceted shape.