Study On Graphite/Bakelite/BaTiO₃-based PTC Composites

Graphite/Bakelite/PTC Ceramics Composite was offered as a new composite system.And the size match between ceramic and graphite particle, graphite and bakelite content ,molding pressure and solidify time were argued as important factors which greatly affect the PTC intensity of this new composite. It was found that The resistance of BaTiO3-based composite ceramic material presented an inverse "v" with the graphite amount increase when the bakelite content was fixed. And it also accorded with bakelite when the graphite content was fixed. So the composite system could acquire maximum resistance jump only on the condition that graphite and bakelite be of proper content. The content ratio of graphite to bakelite range from 1.31 to 1.35 when the relevant composite system possessed the maximum resistance jump. And the maximum numerical value increased with the graphite content increase in the fixes range mentioned above.In this study, it also found that the molding pressure and solidify time highly affect the character of this new composite as technics factors, which is related to the ingredient of the composite.This new composite system is of distinct lower room-temperature resistivity and little lower resistance jump magnitude when compared with the original PTC ceramic materials.