At NovaCast, a large proportion of our castings are produced using Aluminium alloy. The formation of Aluminium Oxide and the presence of non-metallic inclusions, collectively known as dross, is an inherent part of the casting process and one that must be managed to achieve the highest quality castings. For many years, part of the foundryman’s … Read more
Metal Finishing and Surface Treatments
NovaCast routinely provides a wide range of metal finishing and surface treatments to its cast products in order to enhance their mechanical or aesthetic properties.
Once the component surface preparation, usually in the form of fettling, linishing and shot blasting is complete, surface treatments and finishes are applied and these can include heat treatment, anodising, plating, Alocroming, painting, powder-coating or lacquering.
Fettling & Linishing
These are the first processes usually performed on raw sand and die-cast components. Fettling removes the risers and excess material while linishing is the process of grinding or sanding the surface to remove surface irregularities.
Shot Blasting & Peening
Shot blasting is used to create a uniform surface finish by removing surface burrs or debris remaining from the casting process. Shot peening is a similar but less aggressive process where finer particles are blasted at the surface thus avoiding the risk of surface cracking in some alloys. These processes provide an excellent key for further surface finishes.
Painting & Powder Coating
Castings can be finished according to customer specification, with wet painting and powder coating being the most common. The choice depending on whether aesthetics or durability and resistance to abrasion is the primary objective.
NovaCast can provide any form of surface treatment required including sulphuric or chromic anodising, for enhanced durability and corrosion resistance. Alocrom, which is a chromate conversion coating, can be used where a less durable surface finish is required.
Castings can be subjected to various heat treatment techniques that can be used to harden them, change the properties of the alloy or remove internal stresses. NovaCast is able to advise on the options and deliver castings that are optimised for their operating environment.