Research On The Ageing Behavior Of Cu-0.3Cr-0.1Zr Alloy Under The Influence Of Current And Magnetic Field

With the rapid development of modern industry, the higher requirements for the performance of the copper alloy are proposed. Cu-Cr-Zr alloy is a kind of high-strength and high-conductivity copper alloy which has a high development prospects. Studying on the solution and ageing behavior of the alloy, together with further searching new preparation and processing techniques, have great significance on the improvement of the properties of strength and electrical conductivity of the alloy.Current and magnetic field are used in the ageing process of Cu-0.3Cr-0.1Zr alloy in the paper. As-cast structure and the influence of current, magnetic field on aged microstructure of Cu-0.3Cr-0.1Zr alloy were investigated by optical microscopy, SEM, XRD and TEM. Meanwhile, explore the performance of current and magnetic field on improving the properties of Cu-0.3Cr-0.1Zr alloy through the conductivity and tensile strength testing. The main results achieved are as follows:1. As-cast microstructure of Cu-0.3Cr-0.1Zr alloy is made up of a-Cu, Cr phase, Cu51Zr14phase. Cr phase and Cu51Zr14phase mainly distributed in the interdendritic.2. AC current has little effect on the microstructure and mechanical properties during the ageing process of Cu-0.3Cr-0.1Zr alloy.3. DC current can accelerate the ageing process of Cu-0.3Cr-0.1Zr alloy. The effect becomes more obvious with the increases of the current density. When current intensity is400A/cm2and ageing parameter is450℃×4h, the tensile strength of the alloy reaches the peak value535MPa, the corresponding conductivity is81%IACS. Compared to the regualar ageing, the peak of the tensile strength and the corresponding conductivity increase75MPa and6%IACS respectively.4. An appropriate parameters of pulsed current can accelerate the ageing process of Cu-0.3Cr-0.1Zr alloy. When frequency of pulsed current is500Hz, current intensity is300A/cm2,the duration of one impulse is400us and ageing parameter is450℃×3h, the tensile strength of the alloy reaches the peak value487MPa, the corresponding conductivity is77.3%IACS. Compared to the regualar ageing, the peak of the tensile strength and the corresponding conductivity increase27MPa and2.3%IACS respectively.5. High magnetic field can accelerate the ageing process of Cu-0.3Cr-0.1Zr alloy. When high magnetic field is12T and ageing parameter is450℃×4h, the tensile strength of the alloy reaches the peak value517MPa, the corresponding conductivity is79.4%IACS. Compared to the regualar ageing, the peak of the tensile strength and the corresponding conductivity increase57MPa and4.4%IACS respectively.6. The conductivity and tensile strength of Cu-0.3Cr-0.1Zr alloy can be further increased when aged under the role of both cold deformation and DC current. When cold deformation is60%, current intensity is400A/cm2and ageing parameter is450℃×4h, the tensile strength of the alloy reaches the peak value602MPa, the corresponding conductivity is83.7%IACS.7. The precipitates of Cu-0.3Cr-0.1Zr alloy during regular ageing are Cr phase and Cu51Zr14phase.When Cu-0.3Cr-0.1Zr alloy is aged under DC current, pulsed current or magnetic field, the size of precipitates decreases, the number increases,but the kinds of the precipitates have no change.