Aluminum has long been used as an alternative to stainless steel:
It is cheaper than steel to cast and fabricate, and the cheapest of the metals we’re looking at pound for pound.
Its passive oxide layer gives it high corrosion resistance, which can be further improved through anodizing or PEO.
It is about a third of the density of steel, giving it a useful strength-to-weight ratio. Its that is easily further improved through alloys and coating techniques.
Aluminum has a high ductility and malleability. As a result, it can be precision machined with ease. This saves time in the process of fabrication, making it a greener and more economic option.
Despite these advantages, it is worth keeping in mind:
The low hardness of aluminum tends to give it poor abrasion and wear resistance. Hence, hard wearing coatings are required in many circumstances to enable its use where it otherwise provides suitable mechanical properties.
While aluminum does have a fairly low tensile strength, there are alloys that can raise it from 70 MPa to around 700 MPa, providing a very high strength-to-weight ratio. It should be noted that the price for such high strength tends to be a significant loss of corrosion resistance. Coatings are normally essential to prevent corrosion where high-strength alloys such as 7xxx and 2xxx series are employed.
Although it is widely used in food packaging and cooking utensils, there is some concern about aluminum’s biocompatibility and potential links to Alzheimer’s disease. Again, protective coatings can provide the answer in many cases, helping to ensure no reaction of the substrate occurs.
From aircraft fuselage to coke cans, aluminum, with its light weight, low cost, and ease of fabrication lends itself to a myriad of engineering applications:
Many cars have a lightweight aluminum hood and other body panels. Typically, major engine components such as engine blocks and pistons are now almost exclusively made from cast aluminum alloys. Other lightweight aluminum components such as brake calipers, electrical housings, interior trim parts all help to reduce vehicle weight and increase fuel efficiency.