Effect of electrode insulation on the electric field and the flow field of the machining gap during electrochemical drilling（ECD） is numerically studied. Electric field simulation shows that the current density alon...Effect of electrode insulation on the electric field and the flow field of the machining gap during electrochemical drilling（ECD） is numerically studied. Electric field simulation shows that the current density along the side gap decreases with increasing the thickness of electrode insulation. And the analysis of the electrolyte flow in the frontal gap shows that the insulation thickness has a remarkable influence on the pressure distributions. Ex- periments investigate the influence of the insulation thickness on the main characteristics of the machined hole, i.e. , radial overcut, entrance conicity, and current stability. The poor hole is observed and identified as most likely to occur with a combination of the low tool feed rate and the low insulation thickness. The appropriate thickness of the insulating layer leads to an improvement on hole accuracy and machining stability.展开更多
Spherical carbonyl iron(Fe)powders were coated with magnesioferrite(MgFe2O4)insulating coating layer and then mixed with epoxy-modified silicone resin(ESR).Soft magnetic composites(SMCs)were fabricated by compaction o...Spherical carbonyl iron(Fe)powders were coated with magnesioferrite(MgFe2O4)insulating coating layer and then mixed with epoxy-modified silicone resin(ESR).Soft magnetic composites(SMCs)were fabricated by compaction of the coated powders and annealing treatment.Transmission electron microscopy(TEM),scanning electron microscopy(SEM),energy dispersive spectroscopy(EDS),X-ray diffractometry(XRD)and X-ray photoelectron spectroscopy(XPS)revealed that the MgFe2O4 layer was coated on the surface of the iron powders.The magnetic properties of SMCs were determined using a vibrating sample magnetometer and an auto testing system for magnetic materials.The results showed that the SMCs prepared at 800 MPa and 550℃ exhibited a significant core loss of 167.5 W/kg at 100 kHz and 50 mT.展开更多
基金Supported by the National Natural Science Foundation of China(50635040)the National High Technology Research and Development Program of China("863"Program)(2006AA04Z321)the Natural Science Foundation of Jiangsu Province(BK2008043)~~
文摘Effect of electrode insulation on the electric field and the flow field of the machining gap during electrochemical drilling（ECD） is numerically studied. Electric field simulation shows that the current density along the side gap decreases with increasing the thickness of electrode insulation. And the analysis of the electrolyte flow in the frontal gap shows that the insulation thickness has a remarkable influence on the pressure distributions. Ex- periments investigate the influence of the insulation thickness on the main characteristics of the machined hole, i.e. , radial overcut, entrance conicity, and current stability. The poor hole is observed and identified as most likely to occur with a combination of the low tool feed rate and the low insulation thickness. The appropriate thickness of the insulating layer leads to an improvement on hole accuracy and machining stability.
基金Project(2016YFB0700302)supported by the National Key Research and Development Program of ChinaProjects(51862030,51563020)supported by the National Natural Science Foundation of China。
文摘Spherical carbonyl iron(Fe)powders were coated with magnesioferrite(MgFe2O4)insulating coating layer and then mixed with epoxy-modified silicone resin(ESR).Soft magnetic composites(SMCs)were fabricated by compaction of the coated powders and annealing treatment.Transmission electron microscopy(TEM),scanning electron microscopy(SEM),energy dispersive spectroscopy(EDS),X-ray diffractometry(XRD)and X-ray photoelectron spectroscopy(XPS)revealed that the MgFe2O4 layer was coated on the surface of the iron powders.The magnetic properties of SMCs were determined using a vibrating sample magnetometer and an auto testing system for magnetic materials.The results showed that the SMCs prepared at 800 MPa and 550℃ exhibited a significant core loss of 167.5 W/kg at 100 kHz and 50 mT.
