Anodize Type III

The knowledgeable team at Elite Metal Finishing provides quality recommendations and solutions to meet your complicated metal finishing needs.
PROPERTIES

Anodizing is an electrochemical conversion process that forms an oxide film, usually on aluminum, in an electrolyte (chemical solution). The aluminum parts are the anode (thus the term “anodizing”) and current is passed between them and a cathode, usually flat aluminum bars, through the above mentioned electrolyte (sulfuric acid is most commonly used). There are different types of anodize, most commonly referred to as *Type I-Chromic Acid Anodize, Type II-Sulfuric Acid Anodize, and Type III Hard Anodize or Hardcoat from the Mil-A-8625 designation. Other less common types are phosphoric acid and titanium anodize. The anodize is a porous structure that grows out of the base aluminum and absorbs colored dye very well. This is done through a secondary operation with either an organic or inorganic coloring. Elite Metal Finishing processes black, blue, red, gold, grey, blue grey, yellow, green, desert sand and purple colored anodize.  Custom colors on request.

The sulfuric acid process is the most common method for anodizing. The sulfuric acid anodize process films range from .0001″-.001″ thick. The overall thickness of the coating formed is 67 percent penetration in the substrate and 33 percent growth over the original dimension of the part.

How is Sulfuric Acid Anodize different from other types of anodize?

It is particularly suited for applications where hardness and resistance to abrasion is required. However, where parts are subjected to considerable stress, (such as aircraft parts), the possible presence of the corrosive acid residue is undesirable. The porous nature of sulfuric acid films prior to sealing is used to particular advantage in the production of colored surface finishes on aluminum and its alloys. The porous aluminum oxide absorbs dyes well, and subsequent sealing helps to prevent color loss in service. Although dyed anodized films are reasonably colorfast, they have a tendency to bleach under prolonged direct sunlight. Some of the colors are: Black, Red, Blue, Green, Urban Grey, Coyote Brown, and Gold. Parts can be treated chemically or mechanically prior to anodizing to achieve a matte (non-reflective) finish.

What are the attributes / characteristics of Sulfuric Acid Anodize?
  •  Less expensive than other types of Anodize with respect to chemicals used, heating, power consumption, and length of time to obtain required thickness.
  • More alloys can be finished.
  • Harder than chromic anodize.
  • Clearer finish permits dying with a greater variety of colors.
  • Waste Treatment is easier than chromic anodize, which also helps to reduce cost.

What are the applications of Sulfuric Acid Anodize?

  • Optical components
  • Hydraulic valve bodies
  • Military weapons
  • Computer and electronic enclosures
  • Mechanical hardware

* Elite Metal Finishing does not offer Type I  Chromic Acid Anodize

FAQs about Metal Finishing

Anodizing is an electrochemical conversion process that forms an oxide film, usually on aluminum, in an electrolyte (chemical solution). Compared to Type II anodizing, the coating applied via Type III anodizing is usually thicker, done at a lower temperature, and more expensive. However, there are benefits to Type III anodizing, such as a thicker coating (typically between 0.001 and 0.002 inches) that tends to be more durable and abrasion resistant.

Anodizing is an electrochemical conversion process that forms an oxide film, usually on aluminum, in an electrolyte (chemical solution).

Yes, we can.

Please submit your inquiry with details or call us at (760) 597-8725

  • Anti-static / ESD control – coatings used to minimize static electricity in sensitive environments.
  • Chemical resistant – coatings which resist acids, alkalis, oils, and general chemicals.
  • Conductive – coatings used to form an electrically-conductive layer.
  • Dielectric – coatings made from nonconducting materials used in optical applications. High-reflection coatings consist of a stack of alternating layers of high-and-low refractive-index materials. Each layer in the stack has an optical thickness of a quarter-wave at the design wavelength.
  • Corrosion inhibiting – coatings which prevent moisture from reaching the metal or underlying substrate, or provide a sacrificial layer.
  • EMI / RFI shielding – coatings provide shielding from electromagnetic interference (EMI) or radio frequency interference (RFI).
  • Flame retardant – coatings are flame-retardant in accordance to Underwriters Laboratories, Inc. (UL) Flame Class 94V-0, or other equivalent ISO standards. These materials reduce the spread of flame or resist ignition when exposed to high temperatures. They also insulate the substrate and delay damage to the substrate.
  • Heat resistant – coatings resist damage from heat, or are formulated for use in high-temperature environments.
  • Protective – coatings are designed to protect substrates and surfaces.
  • Touch-up – coatings are used to repair and match the original coating where it has been damaged by scratching, corrosion, abrasion, erosion, scuffing, denting, chipping, delaminating, or other processes.
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