Chromate Conversion Coating


Chromate conversion coating for aluminum and other types of metal is a chemical immersion process that is used to passivate and convert the surface properties of the substrate. The trivalent chromate conversion coating process provides outstanding corrosion resistance and conductivity, without any measurable buildup. This low-cost process is primarily used as a corrosion inhibitor and as a primer for paint, lacquer, or rubber bonding. Chromate conversion coatings also maintain exceptional electrical conductivity retention. Chromate conversion coating is a chemical immersion process that is used to passivate the following types of metals:

  • Aluminum
  • Steel
  • Zinc
  • Cadmium
  • Copper
  • Silver
  • Magnesium
  • Tin

Arrow Cryogenics offers Trivalent Chromate Conversion coating for aluminum parts and components. Our chromate conversion coating meets mil spec MIL-DLT-5541 Type II Class 1A and Class 3. The coating materials we use are licensed from the U.S. Navy under U.S. patents.

Contact us for more information regarding our chromate conversion process and chromate conversion coating for aluminum and other metal parts. Or call us at 800-813-0383 with any questions that you may have. We are your trivalent chromate conversion coating specialists.

The Trivalent Chromate Conversion Coating Process

Chromate conversion coatings are created through a passivation process. This method renders the coated surface structure chemically inactive. A complex metal-chrome molecule film then forms around the metal, which eventually forms into a continuous gelatinous coating. This type of gelatinous coating effectively eliminates the chemical reaction process, which is what causes corrosion. Chromate conversion coatings provide continuous corrosion protection to the metal on which it is applied.

Trivalent Chromate Conversion Coating Replaces Hexavalent Chromium

Chromate conversion coatings have been in use since at least the 1960s; however, the hexavalent chromium chemicals used have been found to be highly toxic. Arrow Cryogenics uses a unique chemical solution for our chromate conversion coatings that does NOT contain hexavalent chromium. This process allows for a clear, iridescent film to develop on treated parts, without the added toxicity of hexavalent chromium.

As a result, governmental regulations restricting the amount of hexavalent chromium in coatings have been enacted. RoHS is a common reference point for the elimination of hexavalent chromium. Trivalent chromate conversion coatings, using non-toxic, non-hexavalent chromium, are now used almost universally as a replacement.

Contact Arrow Cryogenics today for more information about our trivalent chromate conversion coatings for aluminum.

Chromate Conversion Coating Application Process

At Arrow Cryogenics we use a unique chemical solution for our chromate conversion coatings. Our conversion coatings are hexavalent free and are compliant with RoHS and WEEE directives. Arrow Cryogenics is also ISO 9001:2015 certified. Our chromate conversion coating for aluminum involves the following steps:

  1. Degreasing and rinsing to remove oil, grease, oxides, and heavy metallic impurities
  2. Deoxidize and desmut
  3. Chromate treatment by immersion
  4. Rinse
  5. Dry

Immediately following this process care must be taken so that overheating does not occur, since this would reduce the corrosion resistance of the film. Additionally, careful handling of the freshly coated parts is critical due to the films relatively soft and gelatinous nature, and since it may be easily marred until completely dried.

Industries That Benefit from the Chromate Conversion Coatings Process

Due to its broad range of capabilities, chromate conversion coatings are utilized throughout a wide range of industries. Some of which include:

Chromate Conversion Coating NADCAP Certified

 Arrow Cryogenics is Nadcap certified for chemical processing and is in compliance with the AC7004 Aerospace Quality System for the Aircraft, Space and Defense Industry. As part of Nadcap accreditation, our processes were audited based on stringent industry guidelines and are regularly reviewed to maintain compliance.

Contact Arrow Cryogenics for Chromate Conversion Coatings Today

Contact us to learn more about our chromate conversion coating for aluminum processes or to discuss finishing services for your aerospace application.