Burnishing is a cold forming
process, without actual removal of metal,
where a tool is rubbed on the metal surface
of the part with sufficient force to cause
plastic flowing of the metal. This allows
the high spots to be flattened out and the
valleys filled in. It is a new concept in
finishing Components.This process eliminates
Grinding and honing which are costlier processes
while improving the surface finish, surface
hardness, wear-resistance, fatigue resistance
and corrosion resistance of a part.
The surface of metal parts
worked through turning, reaming or boring
operations is a succession of peaks and
valleys when microscopically examined. The
Roller burnishing operation compresses the
Projections (Peaks) into the Indentation
(Valleys) thus forming a smooth mirror finished
surface. Any material not exceeding 40 Rockwell
Hardness "C" can be roller burnished.
One or several rollers are
pressed against the workpiece with the nearly
perpendicular force (burnishing force).
This generates a high compressive stress
in the piece of the surface profile, which
plastically forms the top layer. The material
volume of the peaks is displaced into the
zones of lower compressive stress (the valleys).