Metal Coating Process
| is a
supplier of equipment, training,
& publications, for the electropolishing
process. At this site you will find comprehensive expertise
regarding the electropolish process, deburring of metals, how
to passivate contaminated metal surfaces and select chemicals
for the entire process of electropolishing.
|Our chemical and mechanical engineering capabilities
provide a solid foundation for the design of innovative process
equipment. More than twenty years of front line experience in
solving complex problems in materials, manufacturing, mechanical
preparation, fixturing, precleaning and post-treatment technologies
have aided in the development of a scientific approach to the
technology of electropolishing. We proudly represent the Hydrite®
line of electrolytes and auxiliary chemicals.
|We deliver and maintain a high level of commercial
and technical service to our current and future customers. Our
seminar and consulting services are the industry standard for
education and training.
Benefits of Electropolishing
|Electropolishing produces a number of favorable
changes in a metal part which are viewed as benefits to the buyer.
All of these attributes translate into selling advantages depending
upon the end use of the product. These include:
Oxide and tarnish removal
Reduction in surface profile
Removal of surface occlusions
Increased corrosion resistance
Increased ratio of chromium to iron
Improved adhesion in subsequent plating
Reduced buffing and grinding costs
Removal of directional lines
Radiusing of sharp edges
Reduced surface friction
Stress relieved surface
Removal of hydrogen
|Electropolishing produces the most spectacular
results on 300 series stainless steels. The resulting finish often
appears bright, shiny, and comparable to the mirror finishes of
"bright chrome" automotive parts. On 400 series stainless
steels, the cosmetic appearance of the parts is less spectacular,
but deburring, cleaning, and passivation are comparable.
Solutions are available to electropolish most common metals. Notable
exceptions include cast alloys of zinc, aluminum, brass, bronze,
and carbon steel. Investment cast stainless steels may also be
difficult to electropolish to a satisfactory finish unless parts
are solution annealed after heat treating. In general, only the
200 and 300 series stainless steels, certain tool steels, copper,
and some single phase brass alloys can be electropolished to mirror
finishes. The principal effects on other types of metal are deburring,
smoothing, improvement of surface finish, and increased adhesion
of plated coatings.
Electropolishing produces a combination of properties which can
be achieved by no other method of surface finishing. Mechanical
grinding, belting, and buffing can produce beautiful mirror-like
results on stainless steel, but the processes are labor intensive
and leave the surface layer distorted, highly stressed, and contaminated
with grinding media. The passivation methods commonly employed
produce clean, corrosion resistant surfaces, but do not achieve
the bright, lustrous appearance obtained by electropolishing.
The corrosion resistance of electropolished stainless steel exceeds
that of standard passivation processes.
Electroplating can produce extremely bright finishes, but the
finish is a coating which can chip or wear off. Electroplated
surfaces may also exhibit hydrogen embrittlement which must be
stress-relieved in a separate step. Neither passivation nor electroplating
can accomplish burr removal.
Processes are available for chemical deburring and brightening
of steel and stainless steel, but these methods cannot match the
surface improvement produced by electropolishing. The corrosion
resistance produced by such processes is decidedly inferior to
that produced by electropolishing.