Generalized large deformation behaviour for face-centred cubic solids: Nickel, aluminium, gold, silver and lead

The stage III deformation of 318 single crystal tests of 40 experimentalists in aluminium, nickel, gold, silver, lead and copper is quantitatively compared, through the Taylor aggregate theory, with the present writer's generalized linearly temperature-dependent stress–strain law for completely annealed polycrystals earlier determined by the writer from the measurement of dynamic plastic strain by means of diffraction gratings. From calculations dependent upon a knowledge of stage II parameters, and from independent direct stage III calculations, the single crystal deformation of these six f.c.c. metals is found to be in close agreement with prediction. This parabolic linearly temperature dependent stage III deformation of the single crystals of these six f.c.c. metals is found to be independent of purity, of strain rate, of type of test (i.e. tension or compression) and of initial orientation when the resolved shear strain is calculated for single slip. The universal constant, β 0=58·0 Kg/mm2, from the polycrystalline deformation is found to be determinable from the single crystal tests of all six metals at temperatures varying from 4·2°K to 1173°K, with single crystal parabolas grouped according to lattice spacing and atomic volume.