Metal finishing makes components look better and last longer. Understanding the different finishing options can help manufacturers choose the right process for their needs, so let’s take a look.
Understanding metal finishing
Metal finishing is a treatment that improves the surface of metal. Finishes can be something simple such as polishing to complex processes that change the structure of metal. It can also make cheaper metals work like expensive ones by improving properties such as electrical conductivity, durability, and resistance to chemicals. It also prevents corrosion and creates a uniform appearance, which is important for consumer products.
Common metal finishing methods
- Plating
Plating covers metal with thin layers of nickel, chromium, cadmium, or zinc nickel plating. Available from surface treatments specialists such as swmf.co.uk/surface-coatings/zinc-nickel-alloy-plating/, electroplating uses electricity to apply metal ions onto the surface, while electroless plating uses chemical reactions without electricity.
- Hot dip galvanizing
This process dips clean steel in molten zinc. The zinc reacts with the iron to form protective layers that become part of the steel.
- Anodising
Anodising makes a hardwearing oxide finish by placing metal in an acid bath and running electricity through it. This controlled oxidation works well on aluminium, magnesium, and titanium.
- Metal grinding
Grinding machines use abrasives to smooth metal surfaces. Usually one of the final steps in machining, it reduces roughness from earlier processes.
- Polishing and buffing
These techniques use abrasives with felt or leather wheels to smooth surfaces to improve appearance. In some industries, polishing can make the hygienic surfaces needed for food or medical equipment.
- Electropolishing
Unlike electroplating, electropolishing removes metal from the surface. The metal is placed in a special bath and electricity pulls away ions. This removes any flaws and makes a smooth finish.
- Painting
Paint is an affordable finishing option that adds colour and prevents corrosion. Different types of paint can serve different purposes, from basic protection to specialised coatings for extreme conditions.
Each finishing method has unique benefits for different uses and can help manufacturers balance quality, performance, and cost.