Zinc Coatings Promote Speed and Performance
More zinc in wire electrode would enhance the
performance of WEDM but it is problematic to increase the
percentage of zinc in the wire to more than 40 percent, due to
wire drawing problems. Changes in the wire grain structure
make the wire too brittle for further processing into the fine
diameters necessary for wire EDM [4].To circumvent this,
the zinc is added to the surface of the wire. Zinc-coated wire
can go through a secondary heat treatment process in an
oxygen atmosphere. This produces a very thin layer of oxide
on the zinc surface which in turn helps the wire slide through
the wire guide and protects the softer zinc from flaking.
These coated wires offer highest level of productivity with
faster cutting speed.