What Are the Best Plating Metals for Corrosion Resistance?

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What Are the Best Plating Metals for Corrosion Resistance?

Corrosion slowly eats away at the integrity of metal parts, jeopardizing aircraft, vehicles, and equipment in various industries. Electroplating can significantly enhance a substrate’s ability to withstand corrosion. However, not all metals are created equal. Choosing the right plating metals for your project helps increase the lifespan of critical parts by improving their corrosion resistance. We put together this guide on the best plating solutions for corrosion resistance to help you decide which type fits your needs. 

The Five Best Metal Plating Solutions for Corrosion Resistance

1: Hard Chrome

This electroplating process involves depositing a layer of chromium onto a metal surface. Its excellent corrosion resistance is one of the main benefits of hard chrome plating, because it helps extend the life of metal parts that frequently get exposed to air and moisture. Although hard chrome plating looks duller than decorative chrome plating, it is thicker and much more durable, offering better protection against wear. 

Hard chrome plating can be used on a variety of metals, including stainless steel, aluminum, titanium, and more. The versatility of hard chrome plating makes it a popular choice for protecting metal parts in the aerospace, automotive, and defense industries. 

2: Electroless Nickel 

Because it does not need an electric current, electroless nickel plating takes less time than electroplating processes like hard chrome. This type of metal plating improves corrosion resistance by creating a thick, even coating of nickel onto a metal surface. It can even protect plastic parts like printed circuit boards. 

The protective nickel coating has a high hardness and is able to fill any flaws, making it the best metal plating solution for worn or degraded metal parts. Another advantage of electroless nickel plating is that after the plating process is complete, the metal part is ready to go—there’s no need for further surface finishing, grinding, or machining, unlike with other metal finishes. 

3: Manganese Phosphate

Manganese phosphate is the hardest type of phosphate coating, and it provides superior corrosion resistance for steel parts. Unlike other phosphate coatings, manganese phosphate can protect steel parts even after they are broken in. Manganese phosphate coatings absorb lubricants on steel surfaces to enhance corrosion resistance and prevent the galling of parts like bearings, bushings, and fasteners that are subject to wear. 

4: Cadmium

Also known as “cad plating,” cadmium plating is an electroplating process that gives steel and aluminum parts high resistance to saltwater corrosion. Cadmium coatings are also naturally resistant to mold and bacteria, which is crucial in the wet environments commonly encountered in the aerospace and defense industries. Cad plating can be used as a final finish on metal parts, or as a way to prepare a metal surface for painting. 

There are three types of cadmium coating:

  • Type I, which is silver in color and does not involve further treatment.
  • Type II, which receives a chromate treatment that results in a yellow color and prevents galvanic corrosion.
  • And Type III, which receives a phosphate pre-treatment that improves adhesion and electric isolation. 

All types of cad platings are sacrificial, meaning the coating breaks down while protecting the metal surface underneath. 

5: Zinc Nickel 

Zinc platings alone have high corrosion resistance, but provide even better protection when alloyed with nickel. Zinc nickel plating protects steel, copper, and brass against high temperatures. It can also minimize galvanic corrosion caused by dissimilar metals. 

This type of metal plating is commonly used in the aerospace industry for landing gears, flap tracks, and other metal parts. It’s also used widely in the defense, automotive, heavy equipment, and agricultural machinery industries. 

Like cadmium, zinc nickel is a sacrificial coating. However, zinc nickel is an environmentally safe alternative to cadmium that offers equivalent and, in some cases, better corrosion resistance. 

Corrosion Resistant Metal Plating Services in Arizona

If you’re looking for the best metal plating solutions for corrosion resistance, contact ChemResearch Corporation in Phoenix. We offer over 33 different metal plating services, including hard chrome, electroless nickel, manganese phosphate, cadmium, and zinc nickel. 

As a NADCAP-Certified and ITAR-registered company, we’re dedicated to providing reliable and durable surface treatments. We serve regional and national machine shops across a wide range of industries. If you would like to receive a quote for our services, please feel free to email our Estimator Team at rfq@chemresearchco.com, or give us a call at 602-253-4175 to learn more.

Images used under creative commons license – commercial use (9/21/2022). Photo by Tengyart on Unsplash