Type 1: Plating (or conversion) coatings
Metal plating is the process of changing the surface of a substrate by covering it with thin layers of another metal such as zinc, nickel, chromium or cadmium.
Metal plating can improve the durability, surface friction, corrosion resistance and aesthetic look of a component. However, plating equipment may not be ideal for eradicating metal surface imperfections. There are two major types of plating:
Type 2: Electroplating
This plating process involves immersing the component in a bath containing metal ions for coating. A direct current is then delivered to the metal, depositing ions on the metal and forming a new layer over the surfaces.
Type 3: Electroless plating
This process uses no electricity because it is an autocatalytic plating that requires no external power. Instead, the metal component is immersed in copper or nickel solutions to initiate a process that breaks up the metal ions and forms a chemical bond.
Type 4: Anodizing
An electrochemical procedure that contributes to the creation of a long-lasting, attractive, and corrosion-resistant anodic oxide finish. This finish is applied by soaking the metal in an acid electrolyte bath before passing an electric current through the medium. The aluminum serves as the anode, with a cathode housed within the anodizing tank.
The oxygen ions released by the electrolyte mix with the aluminum atoms to form an anodic oxide on the workpiece’s surface. Anodizing, therefore, is a highly controlled oxidation of the metal substrate. It is most often used to finish aluminum parts, but it is also effective on nonferrous metals such as magnesium and titanium.
Type 5: Metal grinding
Grinding machines are used by manufacturers to smooth out metal surfaces with the use of abrasives. It is one of the final phases in the machining process, and it helps to decrease the surface roughness left on the metal from previous processes.
There are many grinding machines available, each providing varying degrees of smoothness. Surface grinders are the most commonly used machines, but there are many more specialty grinders available too such as Blanchard grinders and centerless grinders.