Effect of selected microadditives on the mechanical properties of aluminium alloys

iron in the process of solutioning and ageing of these alloys was described. Basing on the results of investigations, a comparative analysis was made to disclose the effect of low content (microadditives) of the elements, like Mn, Ti, Zr, B, Cr, Ni, Zn, Sn, Cd, In, Mg, Sb, and Ag on the primary structure of castings, mainly on the morphology of iron-bonding intermetallic phases. The studies also allowed for an effect of these elements on dispersion hardening of the examined alloys, reflected in an improvement of the principal mechanical properties (Rm, A5, HV), and on the kinetics of ageing. Tin, cadmium and indium, added in an amount of 0,1 – 0,15 %, were reported to have the strong-est effect on the process of dispersion hardening. Beneficial effect on the morphology of iron phases have manganese, chromium and nickel.