1991 Volume 32 Issue 10 Pages 957-960
The logarithmic decrement δ and the rigidity modulus G were investigated for heat-treated and cold-worked Al–Ge alloys containing 2 to 20 mass% Ge. The δ and G values were measured by an inverted torsion pendulum method.
The δ values upon furnace-cooling were somewhat higher than those upon water-quenching, which were as low as 0.007. By cold-working after heat treatment, the δ values of all alloys were increased considerably. With increasing Ge concentration, the δ upon cold-working increased abruptly to 5 mass% Ge and then gradually. Moreover, in the alloys cold-worked after furnace-cooling, the δ became higher than in those cold-worked after water-quenching.
With increasing Ge concentration, the G increased, and cold-working after heat treatment caused G to decrease. The ΔG effect increased abruptly up to 5 mass% Ge and then gradually, and higher δ values were obtained in the alloys with a larger ΔG effect.
