A generalized large deformation behaviour for face-centred cubic solids—high purity copper

Abstract

Abstract The stage III deformation of high purity copper single crystals of initially single slip orientations is found, through the Taylor aggregate theory, to be in close qualitative and quantitative agreement with Bell's generalized, temperature-dependent, dead annealed face-centred cubic polycrystalline stress–strain law. Parabolic stage III deformation is shown to be determinable from stage II measurement for all orientations. Thus, in dead annealed face-centred cubic polycrystals the wave speeds and strain of large amplitude plastic compression waves (which had been obtained from diffraction grating measurements) are governed by a constitutive relation whose origin is in the stage III deformation of face-centred cubic single crystals. The 49 high purity copper single crystal tension tests examined are found to have the same stage III parabola in the data of the several investigators. The stage III deformation, whose parabola coefficient is dependent upon the temperature of the test and the melting point of the metal is shown to be independent of the length of stage I and stage II deformation.