Metal Surface Treatments: Understanding the Different Types

Views: 6     Author: Site Editor     Publish Time: 2022-07-28      Origin: Site

Most metal products end up corroding or rusting because of the elements they are exposed to. The only way to deal with this is to use surface treatments. Simply put, surface treatments are a process done after production to provide a protective layer that ensures the metallic piece does not rust. Sometimes, this treatment will add a decorative touch to the finished item. If you have no idea what surface treatment you should use. Here are the common types:

Metal Plating


Electroplating is the price of plating one metal on another using hydrolysis. The process is used as both protective as well as decorative. Hydrolysis dissolves metal cations to develop a material that coats the electrode. By electroplating, you can modify the surface features of the object in question. You can also use this process to improve the object's thickness or make objects through electroforming. Commonly used metals are chromium, gold, copper, nickel, tin, and silver.

Electroless plating

Electroless plating works the same way as electroplating but does not use an electric current but a chemical. The plated piece is immersed in the reducing agent, which is then catalyzed by certain materials. the process changes the metal ions to metal and deposits them on the plated piece. Electroless plating is commonly used in the area of plastics. The most common technique is nickel plating, although gold, silver, and copper are also used.

Chemical treatment

Chemical treatment is a process that creates a film of sulfide or oxide using a chemical reaction. It is commonly used during metal coloring, corrosion prevention, and priming the surface. The three common treatment processes are pickling, chemical polishing, and chromatin. The common treatment for steel parts is black oxide. It removes the free iron from steel parts for them to be corrosion-free.

Anodic oxidation

Anodic oxidation produces an oxide film or metallic substrate that acts as a protective layer. The process removes the electrons from the object and oxidizes the node. The process is common for light metals like titanium and aluminum.


The oxide films are developed through electrolysis. Since they are more porous, you need to use dyeing or coloring agents to improve the appearance of the surface. Other materials can create a thicker ceramic coating on the metal surface.

Hot dipping

With hot dipping, you need to dip your object into the dissolved metal to form the coating. The commonly melted metals are lead, zinc, tin, or aluminum. The molten metals need to have a relatively lower melting point for them to work effectively. The method has been commonly used in Japan and is known as tempura.

Even though this procedure itself is simple, it needs a certain skill set to successfully do it. Most industries that do it have gone the automation way as that is the surest way to ensure safety to whoever is doing it. Despite this, care still needs to be taken so no accidents are involved. The method is preferred because it is the surest way to prevent corrosion to the treated object. It has proven to be very effective over the years.

Vacuum plating

Vacuum plating uses a chamber with a high vacuum to deposit metal on a surface. The coating is applied through vaporization. Since there is no pressure in the chamber, the temperature goes really high, making the layer condensate and coat the substrate being treated. Various heating methods, like plasma beams, resistance heating, or electron beams, are also used to hasten the process.


The most inexpensive way to carry out surface treatment is painting. You can choose to go with pry painting or electroplating painting. There are also options to use brushing, dipping, or powered coating. All these work as well and are often inexpensive. The paint you use will determine how long it will take before you need another layer of paint done. Painting is common in the automotive industry and utilizes robotics to get the job done.

Wrap up

Metal surface treatment is necessary when you are working with metallic pieces. Most of these pieces tend to rust and corrode after a short while, so care needs to be taken when handling them. The procedures above will work for different metal indifferent situations. All you need to do is figure out which method works best for you.