Influence Of High Magnetic Field On Structure And Property Of In-situ Deformed Cu-25%Ag Composite

High-strength, high-conductivity Cu-based alloy has excellent physical and mechanical properties. With the development of modern science and technology, more excellent property is proposed for high-strength and high conductivity Cu-based alloy, people advanced Higher demands. Recently, there has been a considerable interest in in-situ deformed Cu-Ag composite with excellent property.In this paper, the influence of high magnetic field (HMF) on the solidification microstructure of Cu-25%Ag alloys and the action mechanism of high magnetic field the was investigated, and the alloy with and without HMF were fabricated in-situ deformed Cu-25%Ag composite by many passes drawing to study the evolution of the microstructure, mechanical propertis and conductivity under different deformation ratio and the effect of HMF. The research results as follow:1The nucleation supercooling degree of Cu-rich cellular dendrites in Cu-25%Ag alloy is increased as imposed12T HMF, so that the primary Cu-rich phase is refined in some degree, and the thickness of the Ag-rich eutectic structure and its content is also increased.2Under the12T HMF, the solubility of Ag elements in Cu-rich phase is reduced, so that the hardness of the alloy matrix is also reduced.3After many passes drawing, the Cu-rich phase and eutectic structure in Cu-25%Ag alloys solidified with and without HMF are both gradually elongated and refined with the increasement of deformation ratio. Moreover, as the deformation ratio is up to6.0and the final diameter is0.5mm, the eutectic structure in the in-situ deformed Cu-25%Ag composite also remained the net morphology as that in as-cast alloy. This result shows that the solidification microstructure of the alloy has important effect on the microstructure of drawn composite, that is the microstructure of Cu-25%Ag alloy has heredity. The reason is that the Ag fiber and Cu phase has the Cubic-Cubic coherent phase relation and their deformation is carried out in cubic synergism institution.4The tensile strength and hardness of in-situ deformed Cu-25%Ag composite fabricated with and without HMF all increased along with the deformation ratio. At the same deformation ratio, compared to the case without HMF, the ultimate tensile strength of the composite fabricated under12T HMF decreased about100MPa and its hardness decreased15HV. This is due to the coarseness of the eutectic structure in Cu-25%Ag alloy under12T HMF, and it results to thicker fiber in the composite.5The conductivity of in-situ deformed Cu-25%Ag composite fabricated with and without HMF reduced along with the deformation ratio. When the deformation ratio η<5.7, the conductivity of the composite fabricated under12T HMF is less than that of the composite fabricated without HMF. When the deformation ratio η>5.7, the conductivity of the composite fabricated under12T HMF is little higher than that of the composite fabricated without HMF.