The Effect of Deformation on the Resistivity Anomaly in Al-Cu-Cd Alloys

AbstractA study has been made of the influence of deformation on the resistivity increase that occurs during the artificial ageing of an aluminium-5.12% copper-0.14% cadmium alloy (E. Holmes and B. Noble, J. Inst. Metals, 1967, 95, 106). Small amounts of deformation between solution-treatment and ageing reduced the rise in resistivity. The effect of deformation on the increase was less marked when the material was subsequently annealed at 530°C, or when the deformation followed a short ageing treatment at 180°C. Strain applied simultaneously with ageing also lessened the resistivity rise. The results have been interpreted in terms of copper/cadmium/vacancy clusters. Deformation before ageing limited the number of clusters formed; deformation applied simultaneously with ageing prevented their growth.