Aluminum is an excellent conductor of heat and electricity. It is also lightweight, resistant to corrosion and ductile. It is used to make a variety of products including foils, utensils, frames and airplane parts.
Iron is an essential element in many alloys and can be added to make the alloy more durable. It is also a good insulator and can be used to improve the strength of an alloy.
Lead (Pb) and Bismuth – Additions of lead or bismuth to aluminum assist in chip formation and improve machinability. However, these additives can cause low melting constituents and poor mechanical properties in the resulting alloys.
Manganese (Mn) 3xxx – The addition of manganese to aluminum increases strength somewhat by solution strengthening and strain hardening, while not appreciably reducing ductility or corrosion resistance. These moderate strength, nonheat-treatable alloys are used in applications requiring moderate corrosion resistance and aqueous strength at elevated temperatures such as cooking utensils, radiators, air conditioning condensers, evaporators, and heat exchangers.
Zinc – A zinc content of approximately 0.03 to 0.05 percent by weight has been found to be required to produce the desired strength in these alloys. Zinc, when combined with the basic alloying elements of aluminum and manganese, is known to bind iron impurity to form intermetallic phases which can improve corrosion resistance.
Phosphorus – Phosphorus concentrations in these alloys will be greater than those in the base metals due to a high level of phosphorus content in the raw materials. The maximum phosphorus levels in the base alloys range from 0.2 to 0.03 percent by weight, typical levels being 0.045 to 0.055 percent.