Characteristics of Hypoeutectic Cu-Zr Alloy Rods Manufactured by Vertically Upwards Continuous Casting

摘要

This study applied a vertically upwards continuous casting (VUCC) mass-production method to the pilot-scale production of hypoeutectic Cu-xZr (x = 0.25-5 at%) alloy rods. The microstructures of these VUCC rods were investigated and compared with those of rods produced by copper mold casting (CMC). In addition, the wire-drawing ability of the VUCC rods was examined, and the adaptability of the VUCC method to the mass production of hypoeutectic Cu-Zr alloys was fully investigated. The results show that VUCC provides a higher rate of cooling than CMC, with the resulting dendritic microstructure expected to contribute to its arm-spacing refinement. Furthermore, the VUCC rods exhibit good wire-drawing ability. The ultimate tensile strength, total strain to fracture, and electrical conductivity of Cu-2.5Zr (at%) alloy wires with diameter of 13.8 mu m drawn from a VUCC rod are 1882 +/- 28 MPa, 2.2 +/- 0.2%, and 21% IACS (i.e. 21% of the International Annealed Copper Standard conductivity of annealed copper), respectively. The results suggest that VUCC has good potential to be adapted for mass production of hypoeutectic Cu-Zr alloy rods.