STUDY ON THE MICROSTRUCTURE EVOLUTION OF Cu-Nb COMPOSITE WIRES DURING DEFORMATION AND ANNEALING
DENG Liping1,2, YANG Xiaofang1, HAN Ke2, SUN Zeyuan1, LIU Qing1()
1 School of Materials Science and Engineering, Chongqing University, Chongqing 400044 2 National High Magnetic Field Laboratory, Tallahassee, Florida, USA, 32310
Cite this article:
DENG Liping, YANG Xiaofang, HAN Ke, SUN Zeyuan, LIU Qing. STUDY ON THE MICROSTRUCTURE EVOLUTION OF Cu-Nb COMPOSITE WIRES DURING DEFORMATION AND ANNEALING. Acta Metall Sin, 2014, 50(2): 231-237.
Microstructure of as-deformed and annealed Cu-Nb composite wires were investigated by SEM and TEM. Hardness of the as-deformed and annealed samples were measured. The results showed that both the interface density and the rate of interface-increasing increased with increasing strain. When the microstructure reached nano-scale (strain=24.8), the interface density showed a sharp increase which induced a rapid increase in hardness, accompanied by formation of stacking faults and rotation grain boundaries in Cu. During the annealing, the size effect impacted the evolution of microstructure of the multi-scale Cu matrix. The evolution can be classified in to three stages with respect to annealing temperatures: recovery and recrystallization of large Cu, while that of the nano Cu were restrained; recovery and recrystallization of nano Cu; spheroidization and coarsening of Nb.
Fund: Supported by National Natural Science Foundation of China (Nos.51031002 and 51201188), Danish National Research Foundation and National Natural Science Foundation of China (No. NSFC-DNRF 51261130091), Natural Science Foundation Project of Chongqing Science and Technology Commission (No.2010BB4074), State Key Laboratory For Advanced Metals and Materials (No.2010ZD-02) and National Science Foundation of United States (No.DMR-0084173)