A crystal plasticity finite element model was developed for the drawing deformation of pure copper micro wire,based on rate-dependent crystal plasticity theory.The impact of wire diameter compression ratio on the micr...A crystal plasticity finite element model was developed for the drawing deformation of pure copper micro wire,based on rate-dependent crystal plasticity theory.The impact of wire diameter compression ratio on the micro-mechanical deformation behavior during the wire drawing process was investigated.Results indicate that the internal deformation and slip of the drawn wire are unevenly distributed,forming distinct slip and non-slip zones.Additionally,horizontal strain concentration bands develop within the drawn wire.As the wire diameter compression ratio increases,the strength of the slip systems and the extent of slip zones inside the deformation zone also increase.However,the fluctuating stress state,induced by contact pressure and frictional stress,results in a rough and uneven wire surface and diminishes the stability of the drawing process.展开更多
To disclose the effect of contact force and electrode gap on the material transfer behavior of Ag-based contact material, arc-erosion tests of the Ag-4wt.%TiB2 contact material were performed for 5000 operations at 24...To disclose the effect of contact force and electrode gap on the material transfer behavior of Ag-based contact material, arc-erosion tests of the Ag-4wt.%TiB2 contact material were performed for 5000 operations at 24 V/16 A under resistive load on an electric contact material testing system. The arc energy and arc duration were investigated, the surface morphologies of eroded anode and cathode were characterized, the mass changes after arc-erosion tests were determined, and the material transfer behavior was discussed as well. The results show that contact force has a significant effect on the arc energy, arc duration and erosion morphology, but has no impact on the material transfer mode. However, electrode gap not only influences the arc energy, arc duration and surface morphology, but also changes the material transfer mode. At 1 mm, the material transfers from anode to cathode. Nevertheless, an opposite mode presents at 4 mm, which is from cathode to anode.展开更多
基金the National Natural Science Foundation of China(Nos.U21A2051,52173297,52071133)the R&D Projects of Henan Academy of Sciences of China(No.220910009)+2 种基金the Key R&D and Promotion Projects of Henan Province of China(No.212102210441)the Joint Fund of Henan Science and Technology R&D Plan of China(No.222103810037)the Zhongyuan Scholar Workstation Funded Project of China(No.214400510028).
文摘A crystal plasticity finite element model was developed for the drawing deformation of pure copper micro wire,based on rate-dependent crystal plasticity theory.The impact of wire diameter compression ratio on the micro-mechanical deformation behavior during the wire drawing process was investigated.Results indicate that the internal deformation and slip of the drawn wire are unevenly distributed,forming distinct slip and non-slip zones.Additionally,horizontal strain concentration bands develop within the drawn wire.As the wire diameter compression ratio increases,the strength of the slip systems and the extent of slip zones inside the deformation zone also increase.However,the fluctuating stress state,induced by contact pressure and frictional stress,results in a rough and uneven wire surface and diminishes the stability of the drawing process.
基金Projects(51274163,51605146) supported by the National Natural Science Foundation of ChinaProject(U1502274) supported by Key Program of the National Natural Science Foundation of China+2 种基金Project(2018M632769) supported by the China Postdoctoral Science FoundationProject(2017SKY-WK010) supported by the Research Fund of Shaanxi Key Laboratory of Comprehensive Utilization of Tailings Resources,ChinaProject(18JK0722) supported by Special Research Program of Shaanxi Provincial Department of Education,China
文摘To disclose the effect of contact force and electrode gap on the material transfer behavior of Ag-based contact material, arc-erosion tests of the Ag-4wt.%TiB2 contact material were performed for 5000 operations at 24 V/16 A under resistive load on an electric contact material testing system. The arc energy and arc duration were investigated, the surface morphologies of eroded anode and cathode were characterized, the mass changes after arc-erosion tests were determined, and the material transfer behavior was discussed as well. The results show that contact force has a significant effect on the arc energy, arc duration and erosion morphology, but has no impact on the material transfer mode. However, electrode gap not only influences the arc energy, arc duration and surface morphology, but also changes the material transfer mode. At 1 mm, the material transfers from anode to cathode. Nevertheless, an opposite mode presents at 4 mm, which is from cathode to anode.
