Name plate made with Anodizing process
For any industrial environment name plates manufactured
with the Anodizing process are a perfect balance of
quality,
durability and a price.
{some recognize this
process as Metal Photoä}
We
will send samples
&
brochure per your
request!
ANODIZING
A process of coating aluminum by anodic treatment resulting in a thin film of aluminum
oxide of extreme hardness. A wide variety of dye colored coatings
are possible by impregnation in process.
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The following
are answers to the most commonly asked questions about Anodizing. Please contact us with any further questions or specific
problems you are experiencing.
1. WHAT IS ANODIZING?
Anodizing is a means of building an aluminum oxide film on the
surface of aluminum. The process consists of making the aluminum part
electrically positive, or the anode, in a suitable electrolyte. The most common
electrolyte is sulfuric acid. In sulfuric acid bath through hydrolysis, oxygen
is released in
an accelerated and uniform manner which reacts with the aluminum to
form an oxide film.
2. WHAT DOES ANODIZING
ACCOMPLISH?
Anodizing changes the
physical and chemical characteristics of the aluminum. The anodic film which is formed on the surface:
a) Renders the surface harder and more abrasion resistant
b) Insulates the aluminum surface against passage of electricity
c) Improves the natural corrosion resistance of aluminum
d) Ability to color aluminum by absorbing dye into the anodic film
3. WHAT IS HARD COATING
OR HARD ANODIZING?
Hard coating is a modification of the sulfuric acid anodizing
process, which produces a more dense and abrasion resistant oxide film. The process
consists of sulfuric acid anodizing performed at high current
densities and at low temperatures with additives sometimes added to the electrolyte.
The oxide film formed by hard coating is opaque and will vary in color
from gold to bronze or gray to black depending on the alloying elements and film
thickness.
4. HARD COAT OR
ANODIZE-WHICH SHOULD I CHOOSE?
Regular or color anodizing
is used mainly for corrosion resistance or decorative purposes. Coating thickness ranges from 0.0002" to
0.0007" and can be dyed in a variety of colors.
Hard coat anodizing is used when wear resistance or higher dielectric
strength is the main objective. Coating thickness ranges from
0.0005" to 0.0020" in production processing.
5. WHAT SHOULD I
CONSIDER WHEN DESIGNING A PART FOR HARD COAT?
a) Growth and penetration-On the whole, all alloys show a uniform
growth equal to that penetrated below the surface of the base metal.
Hard coating a shaft 0.002" thick will increase the diameter by only
0.002".
b) Corners-The aluminum oxide film grows perpendicular to the
surface of the metal. Sharp corners either concave or convex are left void and
becomes more pronounced as thickness increases.
c) Surface micro finish-Surface roughness is increased by hard coating.
Normally a 10 micro-inch surface on a wrought aluminum alloy will
read 16 micro-inch and a 60 micro-inch finish on a sand cast will read 100
micro-inch after hard coating.
d) Threads-The pitch diameter of a threaded diameter can increase up
to four times that of the surface coating thickness dependant upon the
pitch angle.
6. WHAT IS CHEMICAL
(CHROMATE) CONVERSION COATING?
Chemical conversion coating is an oxide film applied to aluminum. It
is considerably thinner than the oxide coating produced by anodizing.
Its main function is to act as a base for organic finishes, provide mild
corrosion resistance or provide an electrically conductive surface on
aluminum. It is
sometimes referred to as Alodine or Iridite.
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TM 
