La-W、Ce-w、Y-W电极材料热发射性能研究

    Thermal-Emission Properties of La-W、Ce-W、Y-W Electrode Materials

    • 摘要: 研究了稀土元素La、Ce、Y对钨极材料热电子发射能力和稳定性的影响.利用粉末冶金和压力加工方法,制备了系列稀土钨电极材料,并对它们分别进行了引弧、静特性等焊接性能研究,借助于扫描电镜和X-ray能谱仪对镧钨、钇钨、铈钨等燃弧后的4种电极(含用于参照的钍钨电极)进行显微观察,分析了稀土元素在钨电极热发射过程中的行为和作用机制.研究表明:在中小电流时w(La2O3)=2.2%的La2O3-W电极具有较好的电子发射能力和稳定性,钇钨和铈钨次之,在大电流工作时,钇钨电极热电子发射能力和稳定性最好.

       

      Abstract: The influence of rare-earth oxide La2O3, Ceo2 and Y2O3 on the emission ability and stability of tungsten electrode materials were investigated. Three new kinds of RE-W electrode materials were produced by powder metallurgy and metal processing technology. They were compared with one another in respect of the arc starting characterstics and the arc voltage-current characteristics. The La-W, Ce-W, Y-W, and Th-W cathode tip microstructure after arc burning were observed through SEM and EDAX. The action of rare-earth elements and their acting mechanism in the emission process of tungsten electrode. As it turned out that the La2O3-W electrode. of which w(La2O3)=2.2% exhibited the best properties when the current is of little or middle volume, and when the cathodes are used in large current, the Y2O3-W electrode is the best.

       

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