EFFECTS OF Y2O3 AND CeO2 ON PROCESSING AND CHARACTERISTICS OF TUNGSTEN ELECTRODES
(School of Materials Science and Engineering,BeijingPolytechnic University, Beijing100022, P. R. China)
Abstract: The effects of Y2O3and CeO2 in the rare earth tungsten electrodes of W-Y2O3, W-CeO2and W-Y2O3-CeO2 on the processing and operating characteristics were discussed. The results suggested that the growth of tungsten powders and sintered crystal granularity is greatly retarded by Y2O3, and hindrance of CeO2 is comparatively slighter. It was also indicated that tungstates or oxytungstates are the most phases of rare earth elements in the sintered rod, and its stability will affect the forming process. W-Y2O3-CeO2 electrode has superior properties of arc starting and consumption resistance. And it is shown that the distribution characteristics of rare earth elements in the surface layer of electrode tip as well as the thermal stability of rare earth compounds are the determinate factors of the characteristics of electrodes’arc starting and consumption resistance.
Key words: Y2O3 CeO2 tungsten electrode arc-starting consumption