Low Temperature Release of Stored Energy in Cold Worked Copper

Abstract

Pure polycrystalline copper and alpha-brass specimens were deformed in compression at temperatures near -185°C. The release of stored energy was observed during subsequent warmups to room temperature and above. The annealing spectrum of pure copper shows prominent peaks at -25°C and -90°C, and smaller resolvable peaks at lower temperatures. The total energy release was about 0.17 cal/g for a specimen strained to 0.65. In contrast to pure copper, the spectrum for brass shows only one clearly resolvable peak at -10°C and extends to higher temperatures. The energy release was almost three times that of pure copper for comparable strains.