High strength and high conductivity(HSHC) Cu alloys are widely used in many fields,such as high-speed electric railway contact wires and integrated circuit lead frames. Pure Cu is well known to have excellent electric...High strength and high conductivity(HSHC) Cu alloys are widely used in many fields,such as high-speed electric railway contact wires and integrated circuit lead frames. Pure Cu is well known to have excellent electrical conductivity but rather low strength. The main concern of HSHC Cu alloys is how to strengthen the alloy efficiently. However,when the Cu alloys are strengthened by a certain method,their electrical conductivity will inevitably decrease to a certain extent. This review introduces the strengthening methods of HSHC Cu alloys. Then the research progress of some typical HSHC Cu alloys such as Cu-Cr-Zr,Cu-Ni-Si,Cu-Ag,Cu-Mg is reviewed according to different alloy systems. Finally,the development trend of HSHC Cu alloys is forecasted. It is pointed out that precipitation and micro-alloying are effective ways to improve the performance of HSHC Cu alloys. At the same time,the production of HSHC Cu alloys also needs to comply with the large-scale,low-cost development trend of industrialization in the future.展开更多
The copper cathode ablation limits the maximum power and operating time of arc heaters significantly.In this work,copper cathodes were tested in an ablation testing system to investigate the ablation behaviors and mec...The copper cathode ablation limits the maximum power and operating time of arc heaters significantly.In this work,copper cathodes were tested in an ablation testing system to investigate the ablation behaviors and mechanism of copper cathode in air.The microstructure of the ablated cathodes was analyzed,and the ablation rate was measured.The maximum depth and ablation rate increased with the electronic discharge.The mean ablation rate was compared with the prediction by a thermophysical theoretical model.Many ablation pits formed in the ablated surface and evolved into crater-like structures with unexpected depth as the ablation time was prolonged.The presence of ablation pits and crater-like structures suggested an inhomogeneous ablation behavior of the copper cathode in air.The underlying mechanism is proposed to explain the ablation failure of copper cathode in the high-power arc heater.Future attention to improving the service life of copper cathode could be focused on the surface modification to reduce the ablation inhomogeneity.展开更多
基金This work was supported by the National Key R&D Program of China(Grant No.2017YFB1200800)the National Natural Science Foundation of China(Grant Nos.11725210,51827810 and 51637009)+1 种基金the Fundamental Research Funds for the Central Universities(Grant No.2018XZZX001-05)the Zhejiang Xinmiao Talent Projects。
文摘High strength and high conductivity(HSHC) Cu alloys are widely used in many fields,such as high-speed electric railway contact wires and integrated circuit lead frames. Pure Cu is well known to have excellent electrical conductivity but rather low strength. The main concern of HSHC Cu alloys is how to strengthen the alloy efficiently. However,when the Cu alloys are strengthened by a certain method,their electrical conductivity will inevitably decrease to a certain extent. This review introduces the strengthening methods of HSHC Cu alloys. Then the research progress of some typical HSHC Cu alloys such as Cu-Cr-Zr,Cu-Ni-Si,Cu-Ag,Cu-Mg is reviewed according to different alloy systems. Finally,the development trend of HSHC Cu alloys is forecasted. It is pointed out that precipitation and micro-alloying are effective ways to improve the performance of HSHC Cu alloys. At the same time,the production of HSHC Cu alloys also needs to comply with the large-scale,low-cost development trend of industrialization in the future.
基金This work was supported by the National Key R&D Program of China(Grant No.2017YFB1200800)the National Natural Science Foundation of China(Grant Nos.11725210,51827810,51637009 and 11572281)+1 种基金the Fundamental Research Funds for the Central Universities(Grant No.2018XZZX001-05)the National Student′s Platform for Innovation and Entrepreneurship Training Program(Grant No.201910335115).
文摘The copper cathode ablation limits the maximum power and operating time of arc heaters significantly.In this work,copper cathodes were tested in an ablation testing system to investigate the ablation behaviors and mechanism of copper cathode in air.The microstructure of the ablated cathodes was analyzed,and the ablation rate was measured.The maximum depth and ablation rate increased with the electronic discharge.The mean ablation rate was compared with the prediction by a thermophysical theoretical model.Many ablation pits formed in the ablated surface and evolved into crater-like structures with unexpected depth as the ablation time was prolonged.The presence of ablation pits and crater-like structures suggested an inhomogeneous ablation behavior of the copper cathode in air.The underlying mechanism is proposed to explain the ablation failure of copper cathode in the high-power arc heater.Future attention to improving the service life of copper cathode could be focused on the surface modification to reduce the ablation inhomogeneity.
