Aluminium
Discovery date: 1825
Discovered by: Hans Oersted
Name origin: Derived from Latin, the name for aluminium was originally alum, after ‘alumen’ meaning bitter salt.
- Aluminium is believed to be the third most abundant element on the Earth’s crust
- Aluminium has an atomic number of 13 and an atomic symbol of Al
- Aluminium melts at 1220.576 Fahrenheit and boils at 4472.33
- The atomic weight of aluminium is 26.98154 and has an atomic radius of 143.1pm.
- Aluminium is largely known as one of the most ductile and malleable metals and it is also non-magnetic.
Uses of aluminium
The chemical and physical properties of aluminium make in an ideal metal for a variety of purposes and uses. Aluminium is silvery in colour, and it is non-tarnishing. It is a good conductor of electricity and heat, making it ideal for electrical wiring and appliances. Aluminium is also malleable, making it ideal for foil, tubing, and other objects that need to be bendable. The metal is also resistant to corrosion, making it ideal for food packaging.
Aluminium products are especially versatile and can be used for a variety of uses for large scale manufacturing and engineering and smaller scale DIY projects.
Aluminium flat bar is measured by width and depth and used for machinery parts, transportation, construction and fabrication work, and shelving and storage.
Additionally, aluminium square bar is used for a variety of structural purposes, including road signage, frames and structural fabrications. Other uses include the manufacturing of machine and equipment parts, as well as architecture and engineering projects.
Aluminium round tube, on the other hand, is used by the outdoor leisure industry to construct tent poles, camp chair frames, outdoor tables, as well as wheelchair frames and much more.
Manufacturing
During manufacturing, aluminium is combined with a number of different elements to enhance.
Pure aluminium
Pure aluminium is unable to occur naturally due to its reactivity and instead occurs in an ore, known as Bauxite. Pure aluminium is soft and not suitable for many industrial applications, so it is often combined with other metals to create alloys.
In order to yield aluminium for industrial uses, the bauxite must undergo a purification process called the Bayer process.
The Bayer process is a multi-step process that begins with mining the bauxite ore from the earth. The ore is then transported to a refinery where it is crushed and mixed with caustic soda and water. The mixture is then filtered to remove impurities and the aluminium oxide is precipitated out of the solution.
The aluminium oxide is then placed in a smelter where it is heated to extreme temperatures and the aluminium is extracted.
Aluminium alloys
An aluminium alloy is a combination of aluminium and one or more other metals, such as copper, magnesium, manganese, or silicon. The addition of these other metals gives the alloy different properties from pure aluminium.
They are widely used in the aerospace industry and in the construction of buildings and bridges. Aluminium alloys are also used in the food and beverage industry, as well as in the production of medical equipment and in the automotive industry.
The most common aluminium alloys are:
Aluminium Oxide
Aluminium oxide has a chemical formula of Al203 and is a very hard crystalline compound with a melting point at over 2,000 degrees Celsius. Pure aluminium atoms will react with oxygen atoms to form a layer of aluminium oxide on the surface of a pure aluminium sample piece.
The aluminium oxide layer will protect the aluminium from further oxidation and it is this property that makes aluminium oxide an important material in the production of many products, including:
Corrosion
Aluminium is a reactive metal, and it will corrode in the presence of water and oxygen. The aluminium oxide layer that forms on the surface of the metal protects it from further corrosion. This is done through electrolysis.
However, if the aluminium oxide layer is damaged, then the metal will start to corrode.
There are a number of ways to protect aluminium from corrosion, including:
Changing the Aluminium Oxide
Aluminium oxide is not impervious to other chemical changes and reacts with OH-ions to create aluminium hydroxide. For this reason, it is not recommended to expose any aluminium pots or pans to alkaline or foods or chemicals. As the aluminium oxide breaks down, it can leach into the food or drink, which is then consumed.
The aluminium hydroxide will then precipitate out of solution and will be deposited on the surface of the metal, where it will act as a barrier to further corrosion.
You can see the aluminium extraction process here.
Properties of aluminium
Density
The density of aluminium is 2.7 g/cm3, which is about one-third the density of steel.
Strength
Aluminium is a strong metal, but it is not as strong as steel.
Corrosion resistance
Aluminium is highly resistant to corrosion.
Electrical conductivity
Aluminium is an excellent conductor of electricity.
Thermal conductivity
Aluminium has a high thermal conductivity, which means that it can conduct heat away from a hot surface very effectively. It makes it ideal for cookware.
Reflectivity
Aluminium has a high reflectivity, which makes it ideal for use in mirrors and other reflective surfaces.
Recyclability
Aluminium is 100% recyclable and infinitely recyclable, making it a valuable resource. Today, around 75% of all aluminium that has been produced is still in use.
Interesting facts about aluminium:
Aluminium is the most abundant metal in the Earth's crust, but it is never found in its pure form.
The first aluminium products were made in 1825 by Hans Christian Orsted.
Aluminium foil is widely used in food packaging, and it can be recycled over and over again without losing any of its properties.
Aluminium is non-magnetic.
Because it is so easily recyclable, nearly 75% of all aluminium that has been produced, ever, is still in use today.
Aluminium can be used to create a more energy-efficient roof. A roof made from aluminium can reflect up to 95% of the solar energy it takes in.
History of aluminium
Aluminium is the third most abundant element in the Earth’s crust and is heavily relied upon for a variety of uses in modern society. The first written record of aluminium was then known as alum. Alum was first used in the 5th century BCE by the Greek historian Herodotus. The ancient Greeks used it as a dyeing mordant in medicine, in chemical milling, and as a fire-resistant coating for wood to protect fortresses from enemy arson. Aluminium metal was unknown at this time.
Aluminium metal was not discovered until 1808 by Sir Humphrey Davy. Following this, Berthier of France discovered bauxite (the most common aluminium ore) in the form of a hard, reddish clay-like substance. You can read a more in depth account of the origins of aluminium here.
The first aluminium products were not made until 1825 by Hans Oersted. He produced small quantities of aluminium using dilute potassium amalgam as a reaction to aluminium chloride.
Later, France’s Emperor Napoleon III was a driving factor in aluminium production. He had hoped the metal could be used to produce weapons and armour and provide his soldiers with an edge in battle. As such, he funded research into aluminium to support his ideas. The process took a long time and Napoleon became irritated and had all of France’s stock melted down and turned into cutlery for his most honourable guests to use.
Aluminium industry
The aluminium industry can largely be attributed to the Bayer and Hall-Heroult processes which helped generate a viable production method that led to aluminium being used in a variety of ways at the turn of the XIX and XX centuries.
1891: first passenger boat to use an aluminium hull was created in Switzerland.
1894: Yarrow & Co created a 58-metre torpedo boat made of aluminium (Sokol).
1894: Aluminium was later used for passenger railroad cars.
1899: Karl Benz presented the first aluminium body used for a sports car at a Berlin exhibition.
Following this, aluminium became widely used in shipbuilding, aviation, and automotive industries, gradually progressing into civil engineering, and has been considered a truly revolutionary material. The Empire State Building was built in 1931 and it was the first building to use aluminium in construction.
The revolutionary aluminium can emerged in 1958 in the USA and began an environmentally friendly campaign where Coors began selling their beer in aluminium cans, as well as organised a collection of empty cans for a recycling system. Later in 1967, Coca-cola and Pepsi began selling their drinks in aluminium cans also. You can read more about the production of aluminium here.
Uses of aluminium
Aluminium has a wide variety of uses across a breadth of industries, including the below.
- Road
- Rail
- Aerospace
- Military
- Electrical
Aluminium is used for a wealth of uses, from conventional at-home uses to larger industrial uses that benefit entire industries. Below are some of the most common uses for aluminium.
Power lines
Aluminium is used for wiring power grids and the construction of power lines. Aluminium is used because it provides a better conductivity-to-weight ratio than copper and is also one of the most common materials used for electrical applications.
Using aluminium cables has a significant economic as it is cheaper than copper and has a higher conductance which allows transmitting more electricity while using the same infrastructure.
Uses of aluminium
Window frames
Aluminium frames are typically durable and cost-effective, which makes them a perfect option for homes and offices. Aluminium window frames are lightweight and can be made to withstand impact which is especially useful for places that experience high winds, powerful storms and other weather conditions. Although they are not as energy efficient as wood, they are a popular use of aluminium.
Household appliances
Aluminium can be found in almost any home in small and large-scale appliances. Every household should be familiar with aluminium foil, but many consumer washers, dryers, dishwashers, and other home appliances also utilise aluminium frames in their design. Refrigeration and freezing appliances in particular are great practical applications of aluminium. This is because aluminium has a lot of characteristics that facilitate the cooling process, which creates highly efficient refrigeration and has led to a lot of modern advancements.
Aside from the body of kitchen appliances, aluminium can also be found in modern utensils, including pots, baking moulds, frying pans, and more. Aluminium utensils are easier to wash and allow heat to spread evenly. Additionally, they do not scratch easily, and the corrosion resistance quality makes for a great, long-lasting utensil.
Consumer electronics
Basically every smartphone, tablet, laptop and flat screen TV has aluminium as part of its production. Aluminium is used in consumer electronics because it combines aesthetics and practicality to create a refined but reliable product, which is fundamental to the electronics industry.
Electronic manufacturers have also been attempting to replace steel and plastic parts with more reliable aluminium. Newer models of electronics feature aluminium bodies and casing components due to its ability to absorb and dissipate heat, which has led to an increase in aluminium usage amongst a variety of market-leading names.
Packaging
Perhaps one of the most iconic uses of aluminium is the recyclable aluminium can. Aluminium has been used for a huge variety of packaging goods, including versatile aluminium foil. Aluminium foil is eight times thinner than a banknote but still provides effective protection from light, liquid, and bacteria.
Aluminium cans are the most environmentally friendly and the most recyclable type of container in the world. Aluminium cans allow the liquid inside to retain its taste whilst also protecting them from anything outside the can.
Packaging made from aluminium foil is used widely across the food industry. This is because groceries are affected by sunlight, which can damage their appearance and worsen their taste. Aluminium helps to combat this and maintain the life of the product.
Aluminium capsules have been adopted by companies such as Nespresso. The idea was conceived by Eric Favre, a Nestle employee, in 1976. Traditional coffee bags lose their aroma once opened, while a single-use aluminium pod helps to maintain flavour, and they are also recyclable.
Aluminium containers can be recycled an indefinite number of times without damaging the quality of the can.
Aircraft components
There are some properties that aluminium has that make it useful for the aviation industry:
- High strength-to-weight ratio
- Excellent ductility
- High corrosion resistance
Parts such as the fuselage, the wings, doors, floors, and seats of an aircraft are made from aluminium. In fact, aluminium makes up 75-80% of modern aircraft and it was first used in aviation before aeroplanes were invented. Count Ferdinand Zeppelin made the frames for his airships from aluminium.
Spacecraft components
The advancement of spacecraft technology is directly tied to the advancement of aluminium alloys. Aluminium has been a part of the space program since its inception; from the first prototype engines to the use of aluminium-lithium alloy.
Aluminium is incredibly useful for the aerospace industry for the same reasons highlighted above for aircraft components. A list of some spacecraft components that use aluminium are listed below:
- Control arms
- Aluminium wheels
- Steering knuckles
- Brake callipers
- Model rockets
- Solid rocket boosters
Aluminium has proven to be an indispensable material for the aviation and aerospace industry where its low weight and maximum strength are sought after. All modern spacecraft contain between 50% and 90% of aluminium alloys in their parts.
Public and private transport
Public and private transport, such as trains, cars, and larger transport such as ships all utilise aluminium as part of their structure, largely due to the above benefits of a high strength-to-weight ratio.
Ships, in particular, are increasingly being built from ‘marine aluminium’ which refers to a broad range of aluminium-magnesium alloys
Aluminium became an essential component of cars after 1994 when it debuted in the Audi A8. Other brands such as BMW, Mercedes-Benz, Porsche, Land Rover and Jaguar. More recently, in 2014, the iconic Ford-150 truck released a new model with an all-aluminium body which made the vehicle 315kg lighter, allowing it to boast much better fuel economy and lower CO2 emissions.
Other uses include rail transport where aluminium freight cars are used to transport coal, minerals, rocks, grain, and much more. Additionally, aluminium freight cars are a third lighter than a steel car and have a longer service life due to corrosion resistance. On average, an aluminium freight car will lose only 10% of its value over 40 years of operation, making them valuable tools for the transport industry.
Aluminium is also used in high-speed rail systems, which began to be introduced in the 1980’s. This is made possible because aluminium reduces the weight of trains and thus reduces bends in the rails, helping the trains to reach higher speeds.
Uses of aluminium angles
Aluminium is a great DIY material that is easy to work with and requires very little maintenance once installed. Aluminium angles are L shaped and were designed mainly for architectural utilisation. Aluminium angle is a versatile material that is used for structural and decorative application purposes.
Aluminium angles have a variety of uses:
- Hiding gaps
- Covering rough edges
- Disguising screw holes
- Safety cages
- Scaffolding
- Building equipment
- Transmission towers
Uses of aluminium bars
Aluminium bars are used widely in DIY projects because they offer a cost-effective solution for a variety of applications. Aluminium bars come in various shapes and sizes and are used for construction uses such as the below:
- Siding
- Structural frames
- Window frames
- Infrastructure construction
- Roofing
- Door frames
Aluminium bars come in a variety of shapes, including square bars, round bars, and flat bars.
Uses of aluminium tubes
Aluminium tubing is used across a variety of industries, predominantly for building and industrial uses. Outdoor recreation manufacturers, for example, utilise aluminium tubing for camp chairs, outdoor tables, tent poles, and much more. Additionally, wheelchair frames, stretchers, crutches, and some bed frames are made using aluminium tubing in the medical industry.
The aerospace, automobile, and transport industry also use aluminium tubing for the fuselage, hydraulic systems, and fuel lines. Aluminium tubing is incredibly versatile, being an integral piece of refrigerator systems, engines, and HVAC systems.