Effects of interface area density and solid solution on the microhardness of Cu-Nb microcomposite wires

Cu-Nb microcomposite wires drawn to different strain values were studied by means of scanning electron microscopy and transmission electron microscopy. The Cu and Nb near the interfaces show a typical Kurdjumov-Sachs relationship with a deviation angle of 12 degrees. This deviation accommodates internal stresses and slip discontinuity between Cu and Nb. The dislocations are mainly stored around the interface near the Cu matrix. Lattice distortion occurred near the interfaces, where Nb is believed to mix into Cu matrix. Microhardness is affected by interface area density as well as by strain-induced lattice distortion, which can produce a supersaturated solid solution.