What Is Chem Film Coating?

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What Is Chem Film Coating?

Chem-film is a type of chemical conversion coating that protects metal surfaces from corrosion. There are many other names for chem film, including chromate conversion, Alodine®, and Iridite®. This chemical process not only provides a thin protective layer, but also offers many unique advantages. Here’s everything you need to know about the chem film coating process.

Chem Film Has Many Applications

The chem film process creates a thin, protective outer layer that tightly adheres to the metal surface. It acts as a barrier against environmental elements like air, water, and soil. The coating can help enhance corrosion resistance, conductivity, and adhesion.

Some of the most common applications for chem film coatings include:

  • Aerospace components: Chem film coatings are often applied to aerospace parts to enhance corrosion resistance and ensure the longevity of critical components.
  • Electrical equipment: The coating’s ability to maintain electrical conductivity makes it ideal for electrical connectors, enclosures, and other equipment. 
  • Automotive parts: Chem film is also used on automotive parts to safeguard against corrosion and improve durability. 

How the Chem Film Process Works

As with all surface treatments, applying chem film begins with a thorough cleaning of the metal surface. All dirt, oil, grease, and other residue must be removed before coating to ensure the protective layer adheres evenly. Coating the substrate involves dipping, brushing, or spraying the metal part with the chemical solution. 

Unlike traditional coatings, chem film does not deposit a solid layer onto the surface. Instead, it chemically alters the outermost layer of the metal, enhancing its natural properties. The chemical coating often contains chromates or other compounds that facilitate a specific desired reaction. 

Four Benefits of Chem Film Coating

1: Corrosion Resistance

Chem film offers exceptional corrosion resistance. The conversion layer acts as a durable barrier and shields the metal part from moisture, chemicals, and other corrosive agents. This helps extend the lifespan of metal components, reducing maintenance costs and enhancing the reliability of the final product.

2: Enhanced Adhesion

Chem film coating also makes an excellent base for an additional coating. It improves the adhesion of paint, adhesives, and other secondary coatings, making it an ideal pre-treatment. Additional coatings are less likely to peel or chip when pretreated with chem film. 

3: Electrical Conductivity

Some types of protective coatings can insulate metal surfaces and impede electrical conductivity. However, chem film maintains the natural conductivity of the metal. This property is especially important in the electronics and aerospace industries, where a consistent flow of electricity is crucial.  

4: Versatility 

Chem film coatings are not limited to one type of metal. They can coat aluminum, magnesium, copper, and even certain types of steel. However, they are most commonly used on aluminum substrates. For instance, a chem film coating can be used to repair minor damage to anodized aluminum surfaces.  

Professional Chem Film Coating Services in Phoenix, Arizona

Applying an even and precise chem film coating takes the expertise of a professional. At CRC Surface Technologies, we specialize in several categories of chem film coating that fall under the MIL-DTL-5541 specification, including Type I, Type II, Class 1A, and Class 3. 

We also offer 33 other types of surface treatments, as well as non-destructive testing services. If you’re looking for a metal coating expert, give us a call at 602-253-4175 or send an email to rfq@chemresearchco.com to request a quote. 


Images used under creative commons license – commercial use (8/25/2023). Photo by Philip Myrtorp on Unsplash