| 摘要 |
PURPOSE:To control PTC characteristics easily by calcining (V1-xCrx)2O3 and mixing Fe and baking a mixture. CONSTITUTION:The oxide of V, preferably, V2O3 is used as a main component, and a proper quantity of the oxide of Cr such as Cr2O3 is compounded with the oxide of V and mixed and ground through wet grinding, etc., in alcohol so as to obtain (V1-xCrx)2O3 (where 0<=x<=0.015). Mixed powder is calcined for one to five hr at 1100 deg.C or higher in a hydrogen air flow and reduced. Fe, preferably Fe powder having grain size of 8mum is added to a reduced substance acquired at 1.5-20wt.% to final sintered-body weight in the form of metal and wet-ground and mixed for approximately twelve hr, and an organic binder, etc., are added and pressure-molded, and baked at 1535 deg.C or higher in the hydrogen flow. |
