Finishing treatments for metal are not only important to improve surface appearances but also to protect from corrosion and, in some cases, even to enhance a surface’s properties, such as improving its electrical conductivity. A variety of treatments are available, each serving its own important purpose.
Anodising
First of the standard surface treatments offered by providers such as www.poeton.co.uk/standard-treatments is anodic oxidation. This form of corrosion protection is generally aimed at lighter metals, such as aluminium, and uses electrolysis to create an oxide film.
Plating
Plating includes electroplating, which uses an electrical current and dissolved metal ions to create a thin metal layer; electroless plating, where the electrical current is replaced with a reducing agent; and vacuum plating, where ionised metals and nitrates are transferred through a vacuum. Electroplating can enhance a metal’s conductivity. Titanium nitrate from vacuum plating is applied to steel and carbide to make tools last longer.
Thermal sprays
Open flame, plasma or an electrical arc are used to heat or melt the feedstock, which is a precursor to the coating material. The treatment could use ceramic, metal, or another substance. This process adds increased heat resistance to surfaces, such as those used in an exhaust.
Painting
Painting, as used on cars, can simultaneously protect against corrosion and improve the aesthetic appearance. Different formulations of paint are available depending on the purpose. Paint can be applied by brushing, dipping, spraying, or electrostatic or powder coating.
Chemical treatment
Chemical reactions are used to create thin oxide or sulphide films. Black oxide is particularly common when treating iron and steel. Chemical treatments can be used for priming in addition to corrosion resistance and aesthetics.
Hot dipping
The coating substance, which may be lead, tin, aluminium, solder or zinc, is melted and the surface to be protected is dipped into the liquid. This is another form of corrosion protection and is capable of withstanding more extreme environments.
These are six of the most common ways to treat metal surfaces. Understanding the differences between each is vital if you want to choose the most appropriate method to achieve your preferred results.
