Microstructure and mechanical properties evolution of 65Cu–35Zn brass tube during cyclic rotating-bending process
(1. School of Mechanical Engineering and Automation, Northeastern University, Shenyang 110819, China;
2. Department of Mechanical and Biofunctional Systems, Institute of Industrial Science, The University of Tokyo, Komaba 4-6-1, Meguro, Tokyo 153-8505, Japan;
3. Department of Mechanical Engineering, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji-shi, Tokyo 192-0397, Japan)
2. Department of Mechanical and Biofunctional Systems, Institute of Industrial Science, The University of Tokyo, Komaba 4-6-1, Meguro, Tokyo 153-8505, Japan;
3. Department of Mechanical Engineering, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji-shi, Tokyo 192-0397, Japan)
Abstract: The cyclic rotating-bending (CRB) processes under different deformation conditions were carried out to refine the microstructure and improve the mechanical properties of the 65Cu-35Zn brass tubes. The microstructure and the mechanical properties in the axial direction of the tubes after the CRB process were studied with the OM, EBSD and conventional tensile test. To obtain the accumulated effective plastic strain of the tube during the CRB process, the FEM simulation was also executed. The results show that the average grain size decreases with the increase of rotation time at RT, and with the decrease of bending angle at 200 °C. With the increase of accumulated effective plastic strain during the CRB process, the reduction rate of average grain size of the brass tube increases, the tensile strength of the brass tube increases in wave shape and the elongation increases first and then sharply decreases.
Key words: brass tube; cyclic rotating-bending process; severe plastic deformation; microstructure; mechanical properties