PLASTIC BEHAVIOR OF ANNEALED OFHC COPPER

The effect of progressive deformation in the plug-drawing process on the initial yield and subsequent plastic flow behavior of oxygen-free high-conductivity (OFHC) copper has been investigated. This paper relates to the behavior of the annealed material under combinations of tension, torsion and internal pressure, prior to cold-drawing. All loads were applied under constant stress ratio, and the initial yield points were obtained by utilizing the backward extrapolation of curves of stress versus strain and creep coefficient versus stress. The Maxwell-Mises criterion described the experimental yield locus obtained under biaxial tension but not the two tension-torsion loci. The difference is attributed to a small initial anisotropy.