Abstract
Mechanical properties and microstrutures were investigated of polycrystalline Cu and Cu-Ge alloys deformed at 4.2°K. Elastic limit, tensile strength and elongation of the Cu specimens annealed at 500°C for 2hr were 4.1kg/mm2, 44kg/mm2, and about 50%, respectively. The relation between grain diameter and elastic limit of Cu was given by the “Petch” formula. In stress-strain curves of the Cu specimens which were pre-strained at 290°K, a pseudo-easy glide was observed. Serrated stress-strain curves were observed in cold rolled Cu-Ge alloys.
The change in ρ of Cu (Δρ) deformed at 4.2°K was represented by an empirical formula Δρ∝ε1.2-1.6, where ε=stress. The microstructures of deformed Cu and Cu-Ge alloys were discussed.
