High-density polycrystalline material was fabricated by spark plasma sintering of powder prepared by using the boron carbide reduction method. The effects of sintering temperature and pressure upon phase formation, microstructure and properties of the sintered bulks were studied systematically. The optimum technological parameters were a sintering temperature of 1650C, a sintering pressure of 50MPa and a holding time of 10mins. It was shown that the mechanical and emissive properties of the sintered LaB6 bulks were much better than that of those prepared using other methods. The relative density of material sintered by spark plasma sintering was up to 96.2%, and its Vickers hardness attained 1720kg/mm2. The highest bend strength was 203.2MPa. The electron emitting density of the polycrystalline LaB6 sintered by spark plasma sintering was 17.41A/cm2 at 1520C, and the work function was 2.40eV.

Properties of High Density LaB6 Cathode Prepared by Spark Plasma Solid Phase Sintering. Zhou, S., Zhang, J., Liu, D.: High Power Laser and Particle Beams, 2010, 22[1], 171-5