Heat treatment can be used to strengthen or improve the properties of a metal, or as a form of stress relief after cold production processes have been carried out. During the heat treatment process, the material is heated (but not quite to the material's melting point) and held at this temperature for a period of time. It is then cooled either rapidly via quenching, or slowly depending on the material and the desired effect.
Heat treatment is a very common finishing process, favoured for its versatility and the fact it can be carried out on a wide range of materials. Metals such as aluminium, stainless steel, cast iron, titanium, alloy steels, brass and copper can all be heat treated, increasing the material's resistance to wear and increasing its lifespan.
However, heat treatment can sometimes be quite a costly and lengthy process. There is also a risk of surface oxidation occurring, which is when the metal reacts with oxygen when heated to certain temperatures. This results in discolouration and tarnishing of the material.