Metal Coatings: Reasons And Methods Of Application
Metal coatings are a means through which manufacturers improve the look and functionality of their components and, therefore, the final products. The desire to enhance appearance and properties of metal products is not new. In the form of plating or gilding, this has been going on for centuries. The industrial revolution and subsequent technological advances have worked together to provide the basis for improving the techniques. Today, while gold and silver plating are still common, other forms of metal and methods are employed to achieve the results that industries desire in their search to make their products and, therefore their company, successful in the marketplace.
Basic Reasons for Metal Coatings
It is possible to apply metal coatings to a variety of ferrous or non-ferrous substrates. The reasons for doing so vary. The most common is as a protective measure. In particular, the right type of metal coating is the means of inhibiting or preventing corrosion. Manufacturers utilize this form of metal finishing to help increase the functionality and longevity of a component exposed to a variety of external (or even internal) environmental forces that may reduce the ability of the part to withstand them.
Another less common reason for the application of metal coatings is to improve the overall appearance of a part or product. By selecting the right metal coating material, the product will gain an enhanced and more pleasing look. Gold, silver and nickel are several metals that can provide a base metal substrate with an improved and esthetically pleasing exterior. While plating is a common method, it is not the only way to achieve a striking appearance as well as a protective coating.
Common Methods for Applying Metal Coatings
In the finishing business, there are four basic methods used to apply metal coatings. These are:
1. Electroplating: This is the better known of the various methods. In this method, a metal coating is deposited onto the substrate metal. The method used is electrical deposition.
2. Mechanical Plating: This form of metal coating involves the cold welding of a metal powder onto the substrate part using a tumbler, an aqueous solution and suitable tumbling media.
3. Electroless Plating: This uses a chemical reaction to deposit the coating metal on the substrate.
4. Hot Dipping: As the name suggests this form of applying metal coatings involves immersing (dipping) the substrate in a bath containing the molten coating metal.
The employment of any technique is left to the discretion of the metal finishing company. It is based on several factors including the rationale behind the application and the specifics of the metal substrate, environment and intended usage.
Today, the protective measures manufacturers take involve the application of a metal finish or coat. While aesthetics may play a significant role in the decision to coat a component, the major reason is to provide a defense against such things as corrosion. Whatever type or techniques of metal coatings a company may consider, it needs to be the best possible solution if the product is to serve its intended purpose in a cost-effective and suitable manner.