2O3-Y2O3-ZrO2;tungsten cathode;TIG;rare-earth oxides;nanometer-sized;micrometer-sized;COMSOL Multiphysics"/> 2O3, Y203) were separately mixed with tungsten powder by a mechanical alloying method. Afterwards, the W-1.5La2O3-0.1Y2O3-0.1ZrO2 (wt%) was prepared by cold isostatic pressing, medium-frequency induction sintering, rotary forging, and drawing. Then we performed tungsten argon arc welding (TIG) under the same welding current for 0.5, 1, and 2 h on the cathode samples containing, separately, nanometer- and micrometer-sized RE oxides. Results show that the sample with nanometer-sized RE oxides exhibits higher working stability during the welding process, and the burning loss is decreased by nearly 85.4%. Moreover, with prolonging the working time, the aggregation degree of RE oxides in different regions of the tip significantly increases. Combined with the temperature simulation by COMSOL Multiphysics, we found that the diffusion activation energy of the second phase is decreased by nearly 34%. This is because the finer second phase effectively controls the evolution of the tungsten matrix structure, thus preserving many grain boundaries as channels and promoting the diffusion of active substances."/>
1.College of Materials Science and Engineering, Beijing University of Technology, Beijing 100124, China;2.Jiangxi College of Applied Technology, Ganzhou 341000, China
National Natural Science Foundation for Innovative Research Groups Projects (51621003)
[Guo Yinchen, Yang Jiancan, Zhou Shaoxin, Yuan Delin, Nie Zuoren. Microstructure and Properties of Nanometer- and Micrometer-Sized Rare-Earth Oxide Doped W-La2O3-Y2O3-ZrO2 Cathode Tip[J]. Rare Metal Materials and Engineering,2023,52(2):416~425.]
DOI:10.12442/j. issn.1002-185X.20220691