Applying a finish to metal components can adjust their properties radically, giving manufacturers a vastly improved palette of solutions for manufacturing as well as improving a range of characteristics.
Let’s take a look at some of these treatments. For a more detailed look, check out this in-depth look at surface treatments: https://www.poeton.co.uk/standard-treatments/.
Before any surfaces can be properly treated, it is important that all products should be cleaned properly in order that treatments can adhere correctly.
Metals have been heated and rapidly cooled to make them harder for centuries. Heat treatments can also be used to help eliminate any internal stresses which are caused by shaping.
Painting and Powder Coating
A great way in which to change the appearance of a surface is to paint or powder coat. Anti-corrosion paint can help protect surfaces from humid or salty environments. Some of these treatments work by creating a barrier, and others are dependent on chemical inhibitors to protect the surfaces.
Dry Film Lubricants
A dry film lubricant can be applied to a surface to offer improved wear resistance. Using a liquid lubricant is no good if heat or electricity are going to be present close to the parts to be protected, so the dry film allows the parts to be lubricated adequately.
Anodising involves changing the surface of the metal by way of an electro-chemical process. Aluminium is the most commonly coated material by anodising, but titanium can also be anodised successfully. Varying properties when anodising can provide massive differences to the results.
A great coating in its own right, anodising can also be used as a base for other treatments as well as providing artistic finishes. Another benefit of anodising is to provide resistance against the extreme heat experienced by aerospace components.
Hard coating is a specific sort of anodising which takes place by using an acid bath at a lower temperature. The resulting coating is harder and more durable than that created by regular anodising.
Using substances like hexavalent chrome to protect aluminium was once very popular, but this is no longer recommended under many different chemical regulations. Alternative coatings such as Surtec 650 are now preferred.
High-energy equipment like plasma arcs are used to deposit a thin yet firm and tough surface layer. Thermal sprays are often applied via robots which have been programmed to complete the job in a very controlled manner. One of the most common materials which is used to coat metal via plasma spray is ceramic material. This provides exceptional resistance against heat and corrosion.
Surfaces are often treated by way of plating, which involves depositing a different metal surface layer over the first metal. This can be done electrochemically or autocatalytically. Generally speaking, the biggest benefits of plating include wear resistance and corrosion resistance. However, plating can also be carried out to improve the appearance of the metal, such as when things are gold or silver plated.