Abstract:By using the high energy ball milling method, the nanosized ThO₂ powders were obtained. Through mixing powders, sintering and hot swaging processing, a nanocomposite thoriated tungsten cathode was fabricated. The relative density of the nanocomposite material is near 100%. The microstructure of nanocomposite cathode is quite different from that of conventional thoriated tungsten cathode. Most of thoria particles are less than 100nm in diameter, and distribute on t he boundaries of tungsten grains. The nanocomposite cathode shows a much lower arc starting field than that of conventional cathode, which will improve the performance of the cathode significantly.

Key words: W-ThO₂ cathode; nanosized powders; nanocomposite; swaging