Conductors in either the 1000 or 6000 series alloys are sensible technical alternatives to copper for all electrical conductors, even in domestic wiring.
A very large proportion of overhead, high voltage, power lines utilise aluminium rather than copper as the conductor on weight grounds. The relatively low strength of these grades requires that they be reinforced by including a galvanised or aluminium coated high tensile steel wire in each strand.
Aluminium alloys have a conductivity averaging 62% of the International Annealed Copper Standard (IACS) but, because of its density, it can carry more than twice as much electricity as an equivalent weight of copper.
Aluminium and its alloys have been the prime material of construction for the aircraft industry throughout most of its history. Even today, when titanium and composites are growing in use, 70% of commercial civil aircraft airframes are made from aluminium alloys, and without aluminium civil aviation would not be economically viable.
The combination of acceptable cost, low component mass (derived from its low density), appropriate mechanical properties, structural integrity and ease of fabrication are also attractive in other areas of transport. There are now very many examples of its use in commercial vehicles, rail cars both passenger and freight, marine hulls and superstructures and military vehicles.
Volume car production now includes aluminium as engine castings, wheels, radiators and increasingly as body parts. For general production the 5000 and 6000 series alloys provide adequate strength combined with good corrosion resistance, high toughness and ease of welding. In aircraft the very strong 2000, 7000 and 8000 series alloys are preferred, and in military vehicles the weldable 7000 series alloys can provide ballistic properties to match steel armour.
The successful use of the 1000 series alloys as foil for food wrapping and for containers utilises their good corrosion resistance and barrier properties against UV light, moisture and odour. Foil can be readily formed, attractively decorated and can be usefully combined with paper and plastic if required.
The most significant use of aluminium in packaging has been in the production of beverage cans which incorporate the `easy open ring pull' in the lid. This has rapidly grown to some 15% of all aluminium consumption, one hundred thousand million cans a year!
Cans for some food products, particularly fish, which also employ the easy opening facilities of aluminium, have been used for over sixty years. From a technical point of view there is no reason why more use should not be made of aluminium as a can material, to date costs seem to be the restraining factor. This may become less important in the future, see the section on recycling.
Building and Architecture
Aluminium is used in buildings for a wide spectrum of applications. These include roofing for factories which incorporate foil vapour barriers, windows and pre formed sheet cladding features, doors, canopies and fronts for shops and prestigious buildings, architectural hardware and fittings, rainwater goods and replacement windows.
Aluminium structures and cladding are also used to refurbish many of the concrete structures built in the 1950-60's which are now showing signs of deterioration and spoiling.
In building applications the durability of aluminium is of paramount importance. There are a number of good examples of the durability of aluminium which may be familiar to the reader including the statue of Eros in Picadilly Circus, London erected in 1893 and the clad dome of the church of San Gioacchino in Rome installed in 1887. More recently the oil and gas industry has employed aluminium widely in offshore structures.
The 1000, 3000, 5000 and 6000 wrought series alloys will perform, with no reduction of strength, without protection even in industrial and marine environments. They may however suffer some deterioration in their appearance and protection by painting or anodising can be advisable.
Anodised films may be clear, to preserve the `aluminium' finish or in a limited range of colours. Painting offers a wider range of colours and an appearance similar to other painted metals.
These finishing operations may also, of course, be used for purely decorative effects.
The applications outlined above account for some 85% of consumption. The remaining 15% are consist mainly of the following applications.
High Pressure Gas Cylinders
Compressed gas cylinders with capacities up to fifty litre capacity for storage and transportation of CO2, air, oxygen and special gases. The 6000 series alloys combine light weight, good corrosion resistance, compatibility with the product to be contained and mechanical toughness.
High tolerance components can be machined from the 2000 and 6000 series alloys. These alloys have additions of lead and bismuth which gives them machineability that approaches that of the free machining brasses.
Ladders and Access Equipment
Aluminium alloys are highly suited to ladders and access equipment due to their lightweight, corrosion resistance and toughness. The 6000 series extrusions in particular are used both industrially and domestically.
The 2000 and 7000 series alloys are used for golf clubs and trolleys, racquets for many sports, snooker and pool cues, ski poles, often employing spin off from aerospace technology.
Road Barriers and Signs
Extrusions and roll formed sheet in the 6000 and 5000 series alloys provide good corrosion resistance and decorative ability.
Domestic and Office Furniture
The complexity and surface finish of extrusions in the 6000 series alloys coupled with the range of shapes from castings and the use of superplastically formed sheet allows designers almost unlimited scope.
This is a high purity 1000 series sheet product which has its surface electrochemically grained then anodised to generate the base to receive the coatings used by printers.