Al–TiおよびAl–Zr合金固溶体の比抵抗の溶質濃度および測定温度依存性

Trace amounts of titanium and zirconium are often added to commercial aluminium alloys. Using the high purity Al–Ti and Al–Zr dilute binary alloys with 5 to 6 different compositions, the contributions per unit concentration of the solutes to resistivity, Δρ, are determined at 77 K and 300 K. The Δρ of solute Ti at 77 K and 300 K, ΔρTi77 and ΔρTi300, are 31.5 and 31.8 nΩm·mass%−1 respectively, showing small deviation from Matthiessen's rule (DMR). The solute Zr gives ΔρZr77 and ΔρZr300 as 19.7 and 18.2 nΩ·mass%−1 respectively, showing a negative DMR. The difference between ΔρTi and ΔρZr expressed per at% is less than 15% of the absolute values, which is roughly consistent with the Linde's law. Temperature of heat treatments (TH) vs resistivity diagrams (TH–ρ diagrams), calculated from present Δρ values and the temperature dependence of equilibrium solid solubilities, show the effect of Ti on the resistivity increase is extremely larger than that of Zr especially when heat treated at higher temperatures.