ALUMINUM and magnesium, being the lightest commercial metals and therefore the most suitable for aircraft construction, are discussed in their pure and alloyed states. Physical properties of the pure metals and their alloys are given and the effects of adding small quantities of alloying elements are shown. Heat-treating as a means of increasing the strength per unit weight of the alloys is discussed at length, together with the effects of natural aging and artificial aging at elevated temperatures and of quenching in hot and in cold water after heat-treating.
The several types of corrosion are considered and resistance to corrosion of the metals and their various alloys are discussed. Protection afforded to aluminum alloy by a surface coating of pure aluminum is described, and other methods are mentioned.
