Transportation, building and packaging account for a large portion of aluminium applications but the light metal’s usage isn’t restricted into only the three aforementioned categories. There are more aluminium applications and some of them are presented below.
Electrical Conductors
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.
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.
Machined Components
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.
Sporting Goods
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.
Lithographic Plates
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.
Cooking
Aluminium cookware is light and strong, so even a large sturdy pan is easy to handle. With proper care, it can last a lifetime. It imparts no taste or odour to food, is durable and, best of all, has excellent cooking characteristics. More than half the cookware sold each year is made of aluminium.
Water Treatment
Aluminium performs a valuable role in the treatment of water. Aluminium sulphate (alum) is widely used in the purification of waste water as well as water from rivers, lakes and reservoirs. It is a flocculating agent with the capacity to coagulate and trap solid matter that may be floating in the water, such as algae and other organic and non-organic matter. During the process a fine precipitate is formed which removes many contaminants, including the spores of dangerous pathogens. Before leaving the treatment plant the water is filtered to remove the flocculate and the vast majority of the aluminium.
Medical Uses
Aluminium hydroxide is widely used as an antacid to relieve gastric irritation and assist in the healing of peptic ulcers. It has good acid neutralising capacity and also has the ability to absorb and reduce the activity of pepsin.
Aluminium chloride was the first compound used as an antiperspirant although currently aluminium chlorohydrate which is much less acidic, is the major antiperspirant compound. The action mechanism is still under investigation but it appears to act by forming a plug of aluminium hydroxide within the sweat duct.
In 1926 alum-precipitation diphtheria toxoid was discovered to have greater antigenic properties (for stimulating the production of antibodies) than the toxoid alone. The enhancement of diphtheria toxoid by the adjuvant (beneficial additive) aluminium hydroxide is typical of the use of an aluminium salt to increase the level and duration of immunity afforded by a vaccine. Aluminium salts are the most widely used type of adjuvant due to its reputation for safety in humans.
Sources
Text: AZoM, International Aluminium Institute
Photos: Composite Technology Corporation, Aluminium Ladders, Subhash Metal Industries