MECHANICAL AND RESISTOMETRY STUDIES ON AL-ZN ALLOYS

Al+1.3, Al+3.2, Al+5.2 and Al+11.5 at % Zn alloys were studied by means of micro-hardness and the electrical resistivity measurements. The results showed that the additive hardness contribution of the solute zinc and the zinc precipitates to the microhardness of pure aluminium can be given by ΔHVs=22.2 CZn1.36 and ΔHVp=164 CZn1.05, respectively. On the other hand, the contributions of electron-phonon scattering and electron-impurity scattering to the resistivity increase at T>θ has been obtained. In addition, the characteristic temperatures of Guinier-Preston zone formation, the dissolution of the zones, the precipitation of the solute zinc atoms and the dissolution of the precipitates have been determined. © 1990 Chapman and Hall Ltd.