High Strength Aluminium Alloys with Emphasis on Scandium Addition

Aluminium is perhaps the youngest among the large group of metallic elements. It was first commercially produced in the year 1886 and rose in prominence meteorically to occupy today the second position in the total weight pro-duced, next only to steel. Aluminium is a silvery white ductile metal with a FCC structure. It has excellent electrical and thermal conductivity (next only to copper and silver). It has low density (2.7 g/cc) which gives it a very high specific modulus and strength. Pure aluminium is the soft metal with the modulus value of 70 GPa and the yield strength of about 40 MPa. One of the most important properties of aluminium is to form a thin protective oxide layer on the surface. This layer is tenacious, adherent, deformable and impervious to most corroding elements