Characterization of Cold-Rolled Cu-Nb Composite

Copper (Cu)-18wt.% niobium (Nb) composite was studied as one of the high strength conductors with various applications. The high strength is related to the nanostructure achieved by heavy deformation of the composite, in which both Cu matrix and Nb second phase are deformable. This paper reports both the hardness test and texture examination results of this composite after cold drawing and rolling to 71% with intermediate annealing. The cold-rolled conductors produced hardness of 270 #+ 4.5 HV with strain-hardening rate of 17 HV. The deformation mechanism and texture evolution in this system are complex because two phases have different crystal structures. X-ray diffraction crystallographic macrotexture analysis showed that deformation results in a production of texture with the maxima at {325} < 111 > Cu and {116} < 110 > Nb orientations in cold-drawn rectangular Cu18wt.%Nb. Further cold rolling rotates the texture of Cu and Nb to {113} < 665 > Cu and {001} < 011 > Nb, respectively. In addition to those maxima, brass {110} < 112 > Cu and Goss {110} < 001 > Cu components with a considerable intensity were found in rolled Cu. The mechanism for the formation of such complicated texture components is related to the nanostructure and discussed in this paper.