Properties of CeB_6 Cathode Fabricated by Spark Plasma Reactive Liquid Phase Sintering Method

CeHx nano-powders were prepared by hydrogen arc plasma method,and then the mixed powders of nano-CeHx and micron boron were sintered by Spark Plasma Reactive Liquid Phase Sintering (SPS) method to fabricate high-properties polycrystalline bulk CeB6 cathodes. The reaction equation of sintering CeB6 and reactive liquid phase sintering mechanism were studied. The optimum process parameters are listed as follows,pressure of 50MPa,temperature of 1500℃,and holding time of 5min. The experimental results show that the CeB6 sintered body with purity of 99.89% and relative density of 99.61% is single-phase of cerium hexaboride. The hardness and bend strength of the sintered CeB6 reach 2051kg/mm2 and 254.2MPa. The electron emitting density of the CeB6 sintered by SPS is 20.38A/cm2 at 1600℃,the work function is 2.42eV. In contrast to traditional preparation method,SPS method obviously reduces the sintering temperature and shortens the sintering time of CeB6,and improves the mechanics and emission properties.