| 摘要 |
PROBLEM TO BE SOLVED: To produce a ceramic resistor comprising a silicon nitride-bound silicon carbide/ silicon nitride sintered compact and used as a resistor for protection of an inverter for controlling an electric power, the protection, etc., of a superconductive coil for a nuclear fusion reactor in a circuit having a great electric power load capacity under a high voltage and to provide a method for producing the ceramic resistor. SOLUTION: This ceramic resistor contains a silicon carbide powder comprising a mixed powder of a coarse grain SiC powder A containing >=0.1% of Al converted into a solid solution with a fine grain SiC powder B having the β type crystal form and a metal silicide powder of a mixed powder of Si with FeSi2 in a silicon nitride-bound silicon carbide/silicon nitride sintered compact obtained by heat-treating a formed compact of the mixed powder of the silicon carbide powder with the silicon nitride powder and the metal silicide powder in a nitrogen gas atmosphere. The method for producing the ceramic resistor comprises adding water and a binder to the mixed powder comprising 40-50 wt.% of the coarse grain SiC powder A containing >=0.1% of Al converted into the solid solution and having 100-1 000 μm grain diameter, 3-27 wt.% of the fine grain SiC powder B having the μ type crystal form and 0.1-10 μm grain diameter, 3-27 wt.% of the Si3N4 powder having 0.1-10 μm grain diameter and 20-30 wt.% of the mixed powder of the Si with FeSi2 having 10-100 μm grain diameter, kneading the resultant mixture, forming the kneaded mixture and then heat-treating the formed mixture at 1,300-1,500 temperature in a nitrogen gas atmosphere. |
