放电等离子烧结原位制备LaB_6多晶纳米块体阴极材料

Nanostructured Bulk Polycrystal LaB_6 Cathode Prepared by in-Situ Spark Plasma Sintering

用氢直流电弧法制备La-LaH2纳米粉末,再采用放电等离子烧结技术,在原位、"无氧"条件下成功制备高纯LaB6多晶纳米块体热阴极材料,并系统研究放电等离子烧结温度、压强对材料物相、结构和性能的影响。结果表明,材料中形成单相的LaB6,纯度达到99.867%,平均晶粒尺寸为120nm,LaB6纳米块体相对密度达到99.2%,维氏硬度达到17.4GPa,抗弯强度高达245.6MPa,已达单晶材料的理论抗弯强度值。

In order to obtain LaBs cathode with high-purity and excellent properties, La and LaH2 nanopowders were prepared by hydrogen arc plasma method, and then La-LaH2 and B nanopowders were sintered to fabricate the high-purity LaBs polycrystal nano-bulk cathode by in situ SPS （Spark Plasma Sintering） in a oxygen free system. The effects of sintering temperature and pres＇sure on the phases, microstructure and properties of the nano-bulk were systematically studied. The results show that the single-phase LaBs was formed in the nano bulk with a high purity of 99.867 % and an average crystal size of about 120 nm. The relative densities of nano-bulk LaBs is up to 99.2%, and its hardness is up to 17.4 GPa, the bend strength of the polycrystal LaBs is as high as around 245.6 MPa, the theoretical bend strength value of single crystal.