| [1]
De-stressing |
| Springs and small stampings
subjected to thousands or millions of cycles fail pre-maturely due to
metal fatigue. By removing surface metal, electro-polishing helps to
solve metal fatigue problems caused by surface cracks, nicks, scratches,
and fabrication stresses. Electro-polishing completely removed the
surface skin and stresses. As well, it reduces or eliminates stress
risers (imperfections) caused by heat treating, decarburization,
microscopic scratches, tool marks and grinding checks. The end result is
a part with increased cycle life, along with a smooth, bright, deburred
surface. There is no other process that provides such successful
results. |
| [2]
Purification |
| Traditionally, bacterial
contamination has plagued surgical, medical, pharmaceutical, and food
services industries. However, anaerobic bacteria, such as
staphylococcus, is unable to grow in an environment absent of hydrogen,
Electro-polishing severely restricts bacteria growth by removing
hydrogen. The hydrogen is not only removed at the surface, but
throughout the metal as well.
After electro-polishing, parts are
chemically clean and the resulting finish is more resistant to
tarnishing or corrosion. Unlike paints, plating or other coatings, an
electro-polished surface cannot flake off or chip. This is especially
important for food or pharmaceutical processing, high vacuum assemblies,
and pure gas/water systems. |
| [3]
Sizing |
| Electro-polishing can control
the removal of surface metal to within .0001". This control over
stock removal together with the ability of the process to work on
complex and fragile components has opened new applications in part
sizing. Oversize and overweight parts can be brought back to original
specifications, within close tolerances, eliminating costly secondary
machining operations. For instance, parts made oversize by operator or
machine error, growth from heating, or other causes can be brought to
finish size with electro-polishing.
Often, secondary machining processes on
oversized parts are not practical once the part is in finished form or
has been hardened. Electro-polishing can be performed regardless of
hardness and the process will preserve most part geometries. This
enables industry to cut costs in production as well as salvaging scrap
parts. |
| [4]
Adhesion Improvement |
| Adhesion of coatings such as
paint, adhesives, or plasma onto metals improved substantially by the
Electro-polishing process. Coatings adhere better and more easily to
metals that have been electro-polished. The greatest obstacle in the
application of coatings if the impure condition of the surface. Oxides,
oil, corrosion, and organic debris on the surface of the metal make
adhesion difficult. When welding or soldering, the bonding ability is
improved greatly as outgassing is restricted once impurities are
removed. Welding is faster and can be accomplished with lower
temperatures.
The surface is made ultra-clean
electrochemically. No impure residue remains at the surface afterwards.
The bonding ability of any supplemental coating is increased
exponentially. |
| [5]
Deburring |
| Electro-polishing is an
excellent method for deburring, especially for large, complex or fragile
parts which do not lend themselves to conventional tumbling or vibratory
techniques.
During electro-polishing, concentration
of electro-chemical power is greatest at high points, which as a
leveling effect on sharp edges, ridges and burrs. Because it is a
controlled process, there is minimal change in overall part dimensions.
The process works equally well on finished parts that have been annealed
or hardened. For example, a life of cutting tools is increased
substantially once microscopic burrs are removed from the "cutting
edges". In addition, the surface is stress-relieved which reduces
the possibility of the cutting surface developing chips. |
| [6]
Surface Finishing |
| A poor micro-finish can cause
problems such as frictional resistance, leaking in critical assemblies,
and premature wear on related components. Electro-polishing can correct
these problems while leaving part dimensions within tolerance.
The high spots or "peaks" are
attacked more rapidly than the low spots or "valleys" to
create a smoother, bright surface. At the same time, all impurities such
as scale, rust, foreign debris, oils, grinding compounds and other
materials are removed as the surface material is dissolved.
Electro-polishing improves sealing
surfaces for valves, fittings, gaskets, and bearings. Cosmetic parts for
decorative purposes such as automotive and appliance accessories also
benefit from electro-polishing. Stainless steel will have a mirror
finish and appear to be chrome plated. |
| [7]
Mirror Finish |
| Electro-polishing removes
metal from the surface producing a unidirectional pattern that is
stress-free, microscopically smooth and often highly reflective. This
produces an often a mirror finish if desired. |
| [8]
Passivates |
| Improved corrosion resistance
and passivity are achieved on many ferrous and some non-ferrous alloys.
This process is used for micro- and macro-deburring, as the reverse
plating process (electropolishing) removes metal ions from the high
points on the surface without etching. Burrs are removed up to 20-times
faster than stock on parts proper. |
