钨铼锇三元混合基扩散阴极的制备及发射性能研究

Study of Preparation and Emission Properties of Tungsten-Rhenium-Osmium Ternary Mixed Matrix Diffusion Cathode

摘要:

本文采用固液混合法制备出了铼钨核壳粉体,然后加入锇粉经预处理后制备出具有特殊包覆结构的三元混合粉体。粉体经过压制、烧结、浸渍、洗盐和退火等工艺制备出钨铼锇三元混合基阴极,经过浸渍411盐后,脉冲发射测试发现三元混合基阴极中成分为W2Re1Os1阴极的电子发射性能最好,在1050℃电流发射密度能够达到35 A/cm2,电流发射密度略高于同类型的二元混合基阴极,达到覆钨铼锇三元膜阴极的水平。通过实验验证在钨铼锇三元混合基阴极浸渍过程中,Re和Os与活性盐均不发生反应,活性物质是由W和活性盐反应产生的。

Abstract:

In this paper, rhenium-tungsten core-shell powder was prepared by solid-liquid mixing method and then osmium powder was added to prepare ternary mixed powder with special coating structure after pretreatment. After the powder was pressed, sintered, impregnated with salt, washed and annealed, a ternary mixed-base cathode of tungsten-rhenium osmium was prepared. After impregnation with 411 salt, the pulse emission test found that W2Re1Os1 cathode which is a ternary mixed-base cathode has the best electron emission performance and the current emission density can reach 35 A/cm² at 1050℃, which is slightly higher than that of the same type of binary mixed-base cathode, reaching the level of the ternary film cathode covered with tungsten, rhenium and osmium. It is verified by experiments that neither Re nor Os reacts with the active salt during the impregnation process of the ternary tungsten-rhenium-osmium mixed-base cathode, and the active substance is produced by the reaction of W and the active salt.