This paper introduces a new technology to fabricate a micro electromagnetic actuator with high energy density without an enclosed magnetic circuit. This technology includes fabricating multi-turns planar micro coils a...This paper introduces a new technology to fabricate a micro electromagnetic actuator with high energy density without an enclosed magnetic circuit. This technology includes fabricating multi-turns planar micro coils and fabricating the thick magnetic （NiFe） core on the silicon wafer. The multi-turns planar micro coils are fabricated by the electroplating method from the surface along the line and by dynamically controlling the current density of the copper electrolytes. In order to fabricate thick NiFe plating,the adhesion properties between the NiFe plating and the silicon substrates are improved by changing the surface roughness of the silicon substrates and increasing the thickness of the seed layer. Furthermore,the micro electromagnetic actuator is tested and the energy density of the actuator is evaluated by force testing. The experiments show that the microactuator is efficient in producing high magnetic energy density and high magnetic force.展开更多
High-energy micro-arc alloying (HEMAA) is a consumable electrode,micro-welding process which uses electrical pulses that are typically three orders of magnitude shorter than in other pulse welding processes.Pulse dura...High-energy micro-arc alloying (HEMAA) is a consumable electrode,micro-welding process which uses electrical pulses that are typically three orders of magnitude shorter than in other pulse welding processes.Pulse durations of a few microseconds combined with pulse frequencies in the 0.1 to 2-kilohertz range thus allow substrate heat dissipation over ～99% of the duty cycle while heating only about 1%.The cooling rates may approach 105 to 106 ℃/s,depending on material.This obtained coating can produce unique corrosion and tribological benefits.Substrates require no special surface preparation and nearly any metal,alloy or cermets can be applied to metal surfaces.This paper details experimental results when alloying Mg base alloy ZM5,using Mg-Y electrodes with a water-based dielectric fluid.The morphology and the composition of the alloying was analyzed by scanning electron microscope(SEM) and energy dispersive X-ray analysis(EDX).At the discharge energies employed,a thin recast layer thickness and rougher layers were formed on the surface.All layers were in general discontinuous.EDX analysis showed that the Y transferred from the solid electrodes to the workpiece surface.展开更多
文摘This paper introduces a new technology to fabricate a micro electromagnetic actuator with high energy density without an enclosed magnetic circuit. This technology includes fabricating multi-turns planar micro coils and fabricating the thick magnetic （NiFe） core on the silicon wafer. The multi-turns planar micro coils are fabricated by the electroplating method from the surface along the line and by dynamically controlling the current density of the copper electrolytes. In order to fabricate thick NiFe plating,the adhesion properties between the NiFe plating and the silicon substrates are improved by changing the surface roughness of the silicon substrates and increasing the thickness of the seed layer. Furthermore,the micro electromagnetic actuator is tested and the energy density of the actuator is evaluated by force testing. The experiments show that the microactuator is efficient in producing high magnetic energy density and high magnetic force.
基金Foundation item:National Nature Science Foundation of China(50801050)
文摘High-energy micro-arc alloying (HEMAA) is a consumable electrode,micro-welding process which uses electrical pulses that are typically three orders of magnitude shorter than in other pulse welding processes.Pulse durations of a few microseconds combined with pulse frequencies in the 0.1 to 2-kilohertz range thus allow substrate heat dissipation over ～99% of the duty cycle while heating only about 1%.The cooling rates may approach 105 to 106 ℃/s,depending on material.This obtained coating can produce unique corrosion and tribological benefits.Substrates require no special surface preparation and nearly any metal,alloy or cermets can be applied to metal surfaces.This paper details experimental results when alloying Mg base alloy ZM5,using Mg-Y electrodes with a water-based dielectric fluid.The morphology and the composition of the alloying was analyzed by scanning electron microscope(SEM) and energy dispersive X-ray analysis(EDX).At the discharge energies employed,a thin recast layer thickness and rougher layers were formed on the surface.All layers were in general discontinuous.EDX analysis showed that the Y transferred from the solid electrodes to the workpiece surface.
