The application of pulse magnetic field to metal solidification is an advanced technique which can remarkably refine solidification structure. In this paper, the effect of pulse magnetic field on solidification struct...The application of pulse magnetic field to metal solidification is an advanced technique which can remarkably refine solidification structure. In this paper, the effect of pulse magnetic field on solidification structure, mechanical properties and conductivity of pure copper was experimentally investigated. The results showed that the solidification structure transformed from coarse columnar crystal to fine globular crystal with increasing pulse voltage. Increasing pulse voltage also improved the tensile strength. However, with the increase of pulse voltage, the elongation and electrical resistivity firstly decreased, then increased when the pulse voltage beyond a critical value. Moreover, in some conditions, pulse magnetic field can simultaneously improve the conductivity and mechanical property of pure copper.展开更多
Single crystal copper with large diameter is prepared in vacuum induction furnace under the protection of argon using downward continuous unidirectional solidification method. The process parameters are determined thr...Single crystal copper with large diameter is prepared in vacuum induction furnace under the protection of argon using downward continuous unidirectional solidification method. The process parameters are determined through the experiments. The effects of the process parameters on solidification structure and surface quality of the single crystal copper with large diameter are investigated. The results show that single crystal copper of Φ16 mm with bright surface can be obtained continuously and stably under the following conditions: melting temperature is 1150 ℃, outlet temperature of mold is 750 ℃, cooling water volume is 0.9 m3·h-1, cooling distance is 50 mm, and drawing speed is 0.1 to 0.15 mm·s-1. By X-ray diffraction, the orientation and competition growth of single crystal copper have been analyzed, and the crystallization surfaces of (311), (220) and (111) are eliminated sequentially during evolutionarily processing. The final growth face of single crystal copper is (200). its direction of crystallization is [100]. Effect of solid-liquid interface on crystal growth has been investigated, the micro-convex interface to liquid is the key to getting single crystal copper.展开更多
基金The projects was supported by the Pre-research Foundation of the National Basic Research Program (973 Program, grant No. 2004CCA07000)the Science and Technology Committee of Shanghai Municipality (Grant No. 04XD14008).
文摘The application of pulse magnetic field to metal solidification is an advanced technique which can remarkably refine solidification structure. In this paper, the effect of pulse magnetic field on solidification structure, mechanical properties and conductivity of pure copper was experimentally investigated. The results showed that the solidification structure transformed from coarse columnar crystal to fine globular crystal with increasing pulse voltage. Increasing pulse voltage also improved the tensile strength. However, with the increase of pulse voltage, the elongation and electrical resistivity firstly decreased, then increased when the pulse voltage beyond a critical value. Moreover, in some conditions, pulse magnetic field can simultaneously improve the conductivity and mechanical property of pure copper.
文摘Single crystal copper with large diameter is prepared in vacuum induction furnace under the protection of argon using downward continuous unidirectional solidification method. The process parameters are determined through the experiments. The effects of the process parameters on solidification structure and surface quality of the single crystal copper with large diameter are investigated. The results show that single crystal copper of Φ16 mm with bright surface can be obtained continuously and stably under the following conditions: melting temperature is 1150 ℃, outlet temperature of mold is 750 ℃, cooling water volume is 0.9 m3·h-1, cooling distance is 50 mm, and drawing speed is 0.1 to 0.15 mm·s-1. By X-ray diffraction, the orientation and competition growth of single crystal copper have been analyzed, and the crystallization surfaces of (311), (220) and (111) are eliminated sequentially during evolutionarily processing. The final growth face of single crystal copper is (200). its direction of crystallization is [100]. Effect of solid-liquid interface on crystal growth has been investigated, the micro-convex interface to liquid is the key to getting single crystal copper.
