Galling
wear occurs when 2
contact surfaces are in
sliding friction
under
relatively high
pressure. Often this is
exacerbated by either a
lack or failure of
lubrication, and occurs principally in
materials with
a high
coefficient of friction.
Galling wear or failure can be recognized by deep scoring in the contact
surfaces. Galling occurs when a surface (or both surfaces) undergoes plastic
deformation, developing gouges in the contact area.
Galling commonly occurs in stainless steel, aluminum and other relatively
ductile materials which also exhibit high friction in sliding contact. This
type of wear can include or be exacerbated by bits of one surface becoming
embedded in the other. This is most likely to occur when the surfaces in
contact are of the same or similar materials. Severe galling is likely to
result in seizing (in the event that the surface deformations result in
the mechanisms degrees of freedom becoming fully constrained, creating
an interference fit).
Galling wear can be avoided by material selection and choice of
lubrication. Parts which cannot or should not be lubricated can often be
prevented with anti seize compound.