溶胶凝胶涂覆制备金刚石/陶瓷复合材料及其物理性能特点

Research on preparation of diamond/ceramic composite and its physical properties by sol-gel method

制备陶瓷前体溶胶,溶胶混合金刚石微粉中形成凝胶,通过烧结得到金刚石/陶瓷块状复合材料。利用SEM、DSC、FTIR和XRD对样品进行表征,表明溶胶凝胶法可以使复合材料中碱金属的添加量得到控制。利用共振电路测量了片状复合材料在高频范围内的电阻和介电性能,发现当锂离子的摩尔含量在0.04时,10MHz下金刚石块状复合材料的介电损耗小于0.002。

The Diamond/ceramic composite was obtained from composite precursor by sintering.The composite precursor is prepared from gelatin by mixing the synthesized collosol,which will generate the ceramic phase,into diamond powder.The gelatin powder was characterized by DSC,FTIR,SEM,EDS and XRD after thermal treatment,which proves that the amount of the alkali metal added into composite material can be controllable by sol-gel method,and the dielectric loss can be ultimately reduced.The resistivity and dielectric property of the sheet-shaped composite is calculated within high frequency region by resonance circuit.It shows that the resistivity of diamond massive composite is slightly larger than that of diamond thin-film,with the dielectric loss less than 0.002,which is lower than that diamond thin-film of nanometer.The softening temperature is reduced greatly in sol-gel method and the addition of the alkaline metal can be controlled.The diamond composites with dielectric properties superior to that of diamond films are eventually obtained.The simple composite preparation method provides a great potential for mass manufacturing.