無酸素銅の冷間加工直後からの低温焼鈍効果について

抄録

In some cold-worked metals and alloys, extraordinary hardening occurs by annealing at lower temperature than their recrystallization temperature. The hardening phenomena of purest Ni, Al, Cu, Ag and Fe have been reported, but their mechanism has not been studied sufficiently. In the experiment of this report, anomalous phenomena of isothermal change in the region from 10 to 400°C were observed by electric resistivity method in vacuum. The experimental results may be summarized as follows: (1) In the specific resistance-time curve, OFHC copper showed anomalous changes of electric resistance at each annealing temperature, and the shape of curve of the change became sharp in proportion as the reduction was increased. (2) The extinction time of peak of this change became longer in proportion as the reduction was heightened. (3) There was no linear relation among the reciprocal of absolute temperature of annealing, extinction time of peak, and the beginning time of the 1st and 2nd peaks.