On Anneal Hardening of Several Copper Alloys (I). Experiments on Thermal Dilatation

Abstract

Thermal dilatometric measurements have been carried out on cold-worked specimens of Cu-Zn and Cu-Al alloys. Several changes in thermal dilatation have been observed in the temperature ranges of anneal hardening. These changes are more pronounced with increase of cold working degree and still more so with higher concentration of the solute. They are considered as anisotropy of cold-worked structure, because their amount is conspicuously larger than may be expected from the changes in density. These changes are also presumed to be due to the release of internal stresses brought about by the preferential migration of solute atoms or lattice defects, which are anisotropically distributed in the cold-worked direction.