Effect of Annealing on the Microstructure and Properties of In-situ Cu-Nb Microcomposite Wires

The effects of annealing on microstructure, magnetoresistance, and hardness of an in situ Cu-Nb microcomposite wire have been investigated. Neither changes in microstructure nor hardness were found until 500 degrees C. Particularly, microstructural change within the Nb films was observed in the annealed samples. The room-temperature magnetoresistivity was almost negligible, while magnetoresistivity at -196 degrees C increased with magnetic field. At temperature above 500 degrees C, recovery and recrystallization occurred, and both the resistance and hardness decreased.