92%冷間圧延したAl-0-8%Mg固溶体の焼なましによる比抵抗と強度の変化 Change in resistivity and strength of 92% cold rolled Al-0 to 8%Mg solid solutions by annealing
Al–0 to 8.1 mass (0 to 8.9 at) %Mg solid solution alloys were annealed at 623 K for 3.6 ks (FA) after 92% final cold rolling and holding at room temperature for 60 Ms (CR–60 Ms). Resistivity was measured at 77 and 300 K(ρ<sub>77</sub> and ρ<sub>300</sub>) before and after the annealing. Tensile test was carried out at room temperature with strain rate of 6.7 × 10<sup>−4</sup>s<sup>−1</sup>. Work hardening by the cold rolling was estimated from the difference in proof stress δσ<sub>0.2</sub> = σ<sub>0.2</sub><sup>CR-60Ms</sup>–σ<sub>0.2</sub><sup>FA</sup> between the CR-60 Ms state and the FA state. For the solid solution alloys with Mg contents up to 5%Mg, the δσ<sub>0.2</sub> due to the increase in dislocation density, N<sup>DISL</sup>, is related to the resistivity increment by the CR, δρ<sub>77</sub>=ρ<sub>77</sub><sup>CR-6OMs</sup>− ρ<sub>77</sub><sup>FA</sup>, as δρ<sub>0.2</sub>/MPa= 263 (δρ<sub>77</sub>/nΩm) <sup>1/2</sup> = 0.57 <i>G</i>b (N<sup>DISL</sup>/m<sup>−2</sup>)<sup>1/2</sup>, where <i>G</i> is the rigidity modulus, 26 GPa, b is the magnitude of the Burgers vector, 0.29 nm, and the contribution to resistivity by the unit density of dislocation is 2.7 × 10<sup>−25</sup>Ωm<sup>3</sup>. For the alloys with Mg contents higher than 6%, the δσ<sub>0.2</sub> is lower than expected from the above relation, perhaps because the ρ<sub>77</sub><sup>CR</sup>, and therefore the δρ<sub>77</sub>, was increased by the contribution of G.P. zones formed during a prolonged holding at room temperature after the CR.
軽金属 48(7), 335-339, 1998-07
The Japan Institute of Light Metals