Published online by Cambridge University Press: 15 August 1999
Al-C at% Mg alloys (C = 0.82, 1.84, 3.76, 5.74 and 12.18) have been selected forthis study. From the electrical resistivity measurements it is concluded that theresistivity increment of Al–Mg alloys (in a solid solution state) is proportional tothe atomic fractional constituents (Mg and Al) as $\Delta\rho_{\rmall}=64.66\ c(1-c)~\mu\Omegarm$ cm. In addition, both the temperature coefficient ofresistivity, α all and the relaxation time of the free electronsτ all in the alloys diminish with increasing the solute Mg concentration.The increase of the scattering power, η, with increasing C is interpreted to bedue to the contribution of electron-impurity scattering. The percentage increase dueto electron-impurity scattering per one atomic percent Mg has been determined as12.99%. The Debye temperature θ decreases as the Mg concentration increases.The microhardness results showed that the solid solution hardening obeys the relationΔHV s = 135.5C 0.778 MPa which is comparable to the theory of solid solution hardening for all alloys; ΔHV s ≈ C 0.5−0.67 MPa.