Physical Metallurgy of Aluminium Alloys

Abstract

Aluminium is a soft and weak and is strengthened by alloying with suitable elements. The elements which are added to aluminium in appreciable quantities to increase its strength are limited to only four elements namely magnesium, silicon, copper and zinc. These may be, added singly or in combination. It will be Seen that the alloying elements magnesium and silicon belong to aluminium period itself while the copper and zinc metals belong to the copper period in the periodic table. Out of these foux elements magnesium has biggAr atomic diameter (3. 1906 A) than aluminium (d = 2.857 A), while silicon, gopper and zinc have smaller diameters, 2.345 A, 2.551 A and 2.659° respectively. These values are within 15% of the aluminium diameter values. Therefore these alloying elements are favourably placed fer- forming. Substitutional solid solutions with aluminium.