(西安交通大学 金属材料强度国家重点实验室, 西安 710049)
摘 要: 采用高能球磨和真空热压烧结工艺制备出块体纳米晶W-La2O3电极材料, 研究了不同La2O3含量对纳米晶钨电极材料电性能的影响,同时用扫描电镜和能谱仪测定了燃弧后电极尖端La的分布及显微组织。 结果表明: 纳米晶W-La2O3电极的电性能优于传统的粉末冶金粗晶电极。 当La2O3含量在6%~8%时, 其热电子发射能力和稳定性最好。
关键字: 钨电极; La2O3; 电弧特性; 纳米材料
(State Key Laboratory of Metal Material Strength,
Xi′an Jiaotong University, Xi′an 710049, China)
Abstract:The nanostructured W-La2O3 electrode materials were fabricated by high energy ball milling and hot pressed sintering in vacuum atmosphere. The influence of content of rare-earth oxide La2O3 on the electric properties of nanocrystalline tungsten electrode materials was investigated. The microstructure of cathode tip and La distribution after arc burning were observed through SEM and EDX. The results show that, the properties of nanocrystalline W-La2O3 electrode materials are better than those of traditional coarse -gained W-La electrode. The nanocrystalline electrode materials exhibit the best thermionic electron-emission and stability when the content of La2O3 is 6%~8%.
Key words: tungsten electrode; La2O3; electrical arc characteristic; nanostructured materials