The preparation of functional ceramics from mixtures of preceramic polymers and metal composites and its properties

We prepared functional SiC/MoSi2, BN composite phases as pellets and/or-films by using an uniaxial press and a spin-coater from two preceramic polymers; polymethylsilane(PMS) and polyborazine as SiC and BN precursor, respectively. PMS mixed with various ratio of Mo metal filler was pelletized, and also PMS with 5 wt.% of MoCls and polyborazine were spin-coated on Si wafer to form films. Then the samples were annealed upto 1400 degreesC to transform into various ceramics. The precursors and ceramics were analyzed by TGA, powder X-ray diffraction, SEM, TEM and dilatometer. Mo metal mixed precursor was started to form SiC/Mo2Si composites by diffusion of excess Si into Mo over 1000 degreesC. And it appeared that Al metal mixed precursor was transformed into BN/AlN/AlBX phases starting at 800 degreesC. We also determined electrical conductivity of the SiC/Mo2Si phase to be useful as a heating element in high temperature uses.