Research On The Solidiication Micro Structure And Properties Of The Cu-Fe Alloy In The Rapid Cooling Condition

Cu-Fe alloy is widely applied to the preparation of large-scale integrated circuit leadframe, overhead wires for high speed electric railway, switching bridge of electricalengineering, resistance welding electrode, etc, because of its high strength, excellent plasticity,good conductivity, giant magneto resistive effect and special physical properties. Rapidsolidification that can refine grain and increase the solubility is an effective way to inhibit orreduce the formation of segregation of Cu-Fe alloy in solidification process, so the study ofsolidification behavior and phase selection mechanism of the Cu-Fe alloy has become thefocus. In order to study the solidification behavior and mechanism of Cu-Fe alloy underdifferent cooling conditions, researches have been carried out as following:The microstructure of Cu-Fe alloy prepared by vacuum induction melting showed asmany primary α-Fe dendrites uniform distributed in the Cu matrix. With the increasing of thenominal composition of iron, the α-Fe dendrites became coarse and the micro-hardness ofCu-Fe alloy increased. CuFe10and CuFe15alloys prepared by vacuum induction meltingwere cold rolled with slow strain at room temperature without inter mediate heat treatments.As the deformation is increased, the uniform distribution of α-Fe dendrites gradually becameinto fiber alignment along the rolling direction. With the increasing of deformation, themicro-hardness of the Cu-Fe alloys gradually improved, and the electrical conductivity of theCu-Fe alloys first decreased and then increased after the strain rate greater than2.3.The microstructure of Cu-Fe alloys respectively prepared by vacuum non-consumed arcmelting, electronmagnetic levitation and single roller spin casting was composed of Cu matrix,α-Fe dendrites and rich-Fe partical. With the increasing of cooling rate, the size of the rich-Fepartical decreased and the number of rich-Fe partical was increased. The micro-hardness wasincreased with the increasing of content of Fe and cooling rate.CuFe10alloy was modified by high current pulsed electron beam （HCPEB） withdifferent process parameters. The typical surface morphology after electron beam irradiatedsuch as wavy texture, microscopic cracks and pores was appeared. High current pulsedelectron beam irradiated Cu-Fe alloy, and the surface was solidified rapidly, and generated ametastable liquid phase separation of rich-Fe partical. With the increasing of acceleratingvoltage and times of irradiation, grain was refined. After HCPEB modified, the micro-hardness, corrosion resistance and wear resistance of Cu-Fe alloy was improvedapparently.Coated Al films on the surface of CuFe10by magnetic sputter, then alloying with Al byusing high current pulsed electron beam. Generated a strengthening phase of CuAl₂phase,which was an intermetallic compound. The surface was also solidified rapidly, and generated ametastable liquid phase separation of rich-Fe partical, too. With the increasing of acceleratingvoltage and times of irradiation, grain was refined. After HCPEB modified, themicro-hardness, corrosion resistance and wear resistance of Cu-Fe alloy was improved clearly.