The Experimental Study On High Performance Cathode Materials In Plasma Ignition Equipment Of Power Plants

Plasma ignition equipments make the oil-free start-up come ture,which is animportant step on saving oil for power plants. But the short life of cathode influences theapplication and development of this technique.The paper ,based on analyzing theprinciple of thermionic emission,manufactured a series of Ag-TiC,Ag-Y₂O₃ thermalcathode materials by SPS,and measured the heat conduction performance of thesematerials.In order to further explain the correlative performance of materials,themicrostructures were studied by means of SEM and EDS.Finally the failure mechanismof pure silver cathode applied in plasma ignition equipments was analyzed,and thecharacteristics of Ag-Y₂O₃ cathode materials after arc burning were investigated.Theresults show the electron emission ability of Ag-Y₂O₃ cathode materials is better thanpure silver cathode.Under premise of guaranteeing heat conductionperformance,reducing work function and operating temperature,finally gaining the actualemission current density,this is a design thought that high performance cathodes shouldfollow.