10 facts about aluminium
Aluminium is one of the most abundant metals in the crust of the Earth. This great abundance of aluminium combined with its many excellent properties has made it a popular industrial material which you find in a wide range of solutions and constructions worldwide. Here, we give you 10 facts about the widespread metal.
- Aluminium is element number 13 and the third most common element in the crust of the Earth – in fact, aluminium makes up about 8 % of the total weight of the Earth’s crust.
- Compared to e.g. copper which has been used by man since 5000 BC, aluminium is a rather “young” metal – it has been used by man for barely 200 years.
Danish H C Ørsted was the first person to succeed in isolating pure aluminium. He succeeded in 1825, but it was not until the 1880s that other methods of extracting aluminium were developed that ensured the extraction of pure metal in larger quantities. Until these methods were developed, aluminium was therefore very difficult to isolate and, thus, also very expensive. By way of example, Napoleon had tableware made of aluminium which was only used when he was visited by the finest guests - others had to settle for tableware made from gold.
Today, aluminium is a widely used material and most of the world's aluminium resources are extracted from the reddish rock bauxite via electrolytic methods. By 2020, the total worldwide aluminium consumption is expected to reach 62.5 million tonnes.
- According to Statista.com, in 2019, approximately half of all extracted aluminium was used in construction and transport.
- Some of the most prominent properties of aluminium are:
- Low weight (By way of example, aluminium weighs one-third of steel
- High electrical conductivity
- High thermal conductivity
- Good corrosion resistance
- High mechanical strength in relation to weight
- When an alloy is made by combining pure aluminium with smaller quantities of other metals, new properties emerge which are characteristic of the individual alloys. By way of example, the 2xxx series, which has primarily had copper added to it, has very high strength but low corrosion resistance. The 6xxx series, which has basically had magnesium and silicon added to it, is very mouldable and some of the alloys are typically defined as being "seawater resistant". It is therefore very important to be aware that there are big differences between the individual alloys.
- Aluminium has excellent recycling properties and can be recycled indefinitely at a very low energy consumption. When aluminium is melted down again, an energy saving of 95 % is achieved, compared to the energy consumption of aluminium extraction. Since the properties of aluminium do not change during remelting, it is possible to recreate products on a 1:1 basis – e.g. window profiles.
Since approximately 75 % of all aluminium that has ever been produced is still in use (e.g. in connection with construction, offshore structures and the transport industry), however, there is a limit to the amount of recycled aluminium available.
- When raw aluminium comes into contact with oxygen, a thin oxide layer develops on the aluminium surface. The oxide layer is very strong and provides optimum protection of the aluminium in environments with a pH value of 4-8. Due to this oxide layer, aluminium is said to have a high corrosion resistance in non-acidic as well as non-basic environments.
- As a raw metal, aluminium has a silvery, grey colour that develops a matt surface finish which can be polished to a shine. Through surface treatment, the visual expression and/or properties of the surface can be changed: Some of the most commonly used surface treatments are anodising and painting. Both anodising and painting can change the aesthetics of the aluminium while also making the material more corrosion resistant. In some cases, it is not necessary to surface treat aluminium but, depending on the application, environment and the requirements for the aesthetic expression as well as corrosive conditions, it may be necessary to surface treat the material.
- It is possible to process and shape aluminium into a myriad of shapes: Aluminium is available in every shape from extruded profiles to rolled sheets and the material can be machined, bent, punched, turned, milled and welded depending on its final function. This provides great freedom of design which is a particular advantage in the development of customised profile designs where the profiles having a very high level of detail with low tolerances is often a requirement.
- Aluminium is used for everything from food packaging and electronic parts to buildings and vehicles - in modern society, aluminium is an inevitable building block which, with its many excellent properties, allows for the creation of both innovative, durable and recyclable solutions.