Abstract
The change of internal friction accompanied by the recovery of cold-work in aluminum was measured and compared with the changes in other physical properties, namely, hardness and thermoelectric power. The results show that (1) internal friction increases monotonously with the increase of cold-work, (2) the values of internal friction and other properties decrease exponentially by annealing, the relaxation times and saturation values of the exponential curves are functions of annealing temperatures, and (3) the internal friction changes remarkably by low temperature annealing but other physical properties do not change. These results were explained by considering that the internal friction is caused by the viscous behavior of grain boundary which consists of many kinds of lattice defects.
