三元稀土钨电极材料的研制

【作者】 刘孙和；

【导师】 王孟君； 曾欣荣；

【作者基本信息】 中南大学 ， 材料加工工程， 2002， 硕士

【摘要】 本文采用传统的工业生产方法，按掺杂-→还原制粉-→压制-→预烧-→垂熔-→旋锻-→拉伸的工艺制备了Φ2.0mm的CeO₂+La₂O₃+Y₂O₃三元复合稀土钨电极。通过与铈钨、二元复合稀土钨等电极相比较，发现：三元复合稀土钨电极有更优越的热电子发射性能。 利用金相显微镜、扫描电镜、能谱仪，并结合电子探针通过对加工态下不同规格的杆料进行观察，分析结果表明：第二相含量一定时，材料的加工性能与第二相的大小和分布密切相关，细小而弥散均匀的第二相有利于加工，复合稀土氧化物改变了材料的变形特性。通过对退火料的分析表明：不同稀土配比的钨电极第二相的变化是不相同的。Y₂O₃比例较低时，第二相加工到最后呈纤维状，退火后会分裂、球化；而Y₂O₃比例较高时，第二相在退火后形成长颗粒串。这直接影响到材料的加工性能及热电子发射性能。更多还原

【Abstract】 W LCY(dopped with La2O3+CeO2+Y2O3) electrode of 2.0mm has been made by means of traditionally industrial metal-processing technology. Compared with Wce electrode and Wcv(dopped with CeO2+Y2O3) electrode, the former is of better electrode performance.Observing and analyzing of the worked WLCY material of different diameter by metallograph,SEM,EDS and electronprobe micro-analyzer ,the results show: While wt percent of dopant is certain,the material’s processing property is closely connected with the size and distribution of dopant. Fine and dispersive dopant is benefit to work processing. Oxide compounded with rare-earth elements changes the transfiguration character of material. Analysis of WLCY electrode annealed at high temperature shows: Different proportion of La2O3:CeO2:Y2O3,different changes of dopant in tungsten electrode. Little Y2O3 lead to seperating and spherizing of annealed dopant,while much Y2O3 makes annealed dopant become long particle-chains.That directly influence on processing property and transmit property of heated electrons.更多还原