SiO_2-TiC陶瓷复合材料的制备与特性

FABRICATION AND PROPERTY OF SiO 2 TiC CERAMIC COMPOSITES

以ＳｉＯ２（方石英和石英）作为绝缘的高膨胀性基体材料，并以ＴｉＣ作为导电性粒子，经１１５０～１３５０℃烧结３ｈ制得ＳｉＯ２ＴｉＣ陶瓷复合材料。研究结果表明，当ＴｉＣ的质量百分数在２０％～３２％之间时，其室温电阻率发生急剧变化，变化程度达１０５～１０６Ω·ｃｍ。其中当ＳｉＯ２为方石英相时，陶瓷复合材料在２４０℃左右具有ＰＴＣ效应，其ＰＴＣ效应的突跃达１０２～１０３Ω·ｃｍ；当ＳｉＯ２为石英相时，陶瓷复合材料在５８０℃左右具有ＰＴＣ效应，其ＰＴＣ效应的突跃达１０～１０２Ω·ｃｍ。

SiO 2 TiC ceramic composite was sintered in the temperature range of 1150 ～1350 ℃ for 3 hours ,using SiO 2( cristobalite and quartz) as high expansive matrix and titanium carbide (TiC) as conducting particles which was dispersed in SiO 2 matrix evenly.Results showed that the resistivity changed abruptly up to the extent of 10 5～10 6 Ω·cm of magnitude when TiC was between 20%～ 32%.In addition ,cristobalite TiC and quartz TiC ceramic composite materials showed an effect of positive temperature coefficient (PTC) in about 240℃ and 580℃. Its sudden change was up to the extent of 10 2～10 3 Ω·cm and 10～10 2 Ω·cm of magnitude.