"Coating bores of light metal engine blocks with
a nano-composite material using the plasma transferred wire are thermal
spray process".
by Bobzin, K.^Ernst, F.^Zwick, J.^Schlaefer, T.^Cook,
D.^Nassenstein, K.^Schwenk, A.^Schreiber, F.^Wenz, T.^Flores, G.^Hahn,
M.
Engine blocks of modem passenger car engines are generally made of
light metal alloys, mostly hypoeutectk Al-Si alloys. Due to their low
hardness, these alloys do not meet the tribological requirements of the
system consisting of cylinder running surface, piston rings, and
lubricating oil. Today, to provide a suitable cylinder running surface,
cylinder liners made of gray cast iron are pressed in or cast into the
engine block. A newer approach is to apply thermal spray coatings onto
the cylinder bore walls. Due to the geometric conditions, the coatings
are applied with specifically designed internal diameter thermal spray
systems. With these processes, a broad variety of feedstock can be
applied, but mostly low-alloy carbon steel feedstock is being used in
this application. In the context of this work, an iron-base wire
feedstock has been developed that leads to a nanocrystalline coating.
The application of this material was carried out with the plasma
transferred wire arc system. As substrates, AIMgSiO.5 liners were used.
The coating microstructure and the properties of the coatings were
analyzed.
[ILLUSTRATION OMITTED]
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