When we have refined the alumina into aluminium, we get a liquid metal that is cast into extrusion ingots, sheet ingots or foundry alloys, all depending on the product. The aluminium is mixed with other materials to give it its desired property, typically copper, magnesium, manganese, silicon, tin or zinc. Depending on the use, we make the aluminium easily malleable or strong and energy absorbing. The metal is then shipped to production facilities, where it’s pressed into sheets or extruded into all shapes and sizes – materializing the ideas of the engineers and designers.
The world of aluminium is full of technical expressions. But don’t worry, we’ve translated them for you:
Anodizing is an electrochemical process that converts the surface of aluminium into a long-lasting, high performance aluminium oxide finish. Because it is integrated into the metal rather than just applied to the surface, it cannot peel or chip. This protective finish is very hard and durable and enhances the product’s resistance to corrosion, so it can withstand extreme wear and tear. In fact, the anodized finish is the second hardest substance known to man, exceeded only by the diamond. The metal is also porous, so it can be coloured and sealed, or undergo additional processing, if desired.
A billet is an aluminium log that is used when extruding the aluminium into parts and products.
Cast-house products are all the products we make in the cast-house like extrusion ingots, sheet ingots, foundry alloys and high-purity aluminium.
Aluminium reacts with the oxygen in the air to form an extremely thin layer of oxide. This layer is dense and provides excellent corrosion protection. It’s even self-repairing if damaged.
The extrusion process starts by heating a billet of aluminium alloy and then forcing it under high pressure through a special steel die using a hydraulic press or ram. Sort of like squeezing toothpaste out of a tube. The result is a piece of aluminium – an extrusion or profile – that will maintain the specific shape of the die and hence has almost unlimited possibilities for design.
After the profile has been extruded it can be fabricated into different shapes and fitted with various features, like holes for screws etc.
There are a variety of techniques to join aluminum such as fusion welding, friction stir welding, bonding and taping. Features that facilitate easy joining are often incorporated into the design of the extrusions.
Milling, drilling, cutting, punching and bending are all common methods for shaping aluminium. The energy input during machining is low, meaning a more sustainable final product.
Aluminium is 100 % recyclable and does not lose any of its original properties in the process. As it is recycled aluminium only uses 5 % of the energy that is used to make primary aluminium. Hydro’s goal is to enable a more circular economy through our re-melt facilities. Here we sort and recycle used and scrapped aluminium, so the metal can be used again and again.