Research And Resistance To High Pressure Low Density Ceramic Microspheres Preparation And Performance

Hollow ceramic spheres are provided with heat insulation, sound insulation, low density, Low thermal conductivity, low dielectric constant etc. they are widely being developed for electronic uses in piezoelectric sensor, low dielectric constant substrates, radiation burner, insulation materials, refractories and metal foam material.The foreign countries are holding the high-quality preparation technology of hollow ceramic spheres and the preparation technology is still lagging behind the international level, high quality hollow ceramic spheres are not being produce.In this dissertation, using sodium silicate,aluminnum oxide powder as raw material,urea as foaming agent,hollow ceramic microspheres containing mullite phase was fabricated by granulating,removal-sodium and high temperature sintering process.The as-synthesized hollow ceramic microspheres were investigated by scanning electron icroscopy(SEM),Energy Dispersive Spectrometer (EDS),X-ray diffraction(XRD)etc.The following conclusion can be drawn from the studies:(1) using sodium silicate,aluminnum oxide powder as raw material,urea as foaming agent,hollow ceramic microspheres with outer diameter of500μm～1000μm and wall-thickness of50μm～60μm was fabricated by granulating,removal-sodium and high temperature sintering process.(2) The content of sodium in hollow ceramic microspheres can be decreased by the process of acid pickling and removal-sodium.(3) Hollow ceramic microspheres containing mullite phase can be prepared at1500℃.(4) Hollow ceramic microspheres with density about1g/cm3can be prepared when the sodium silicate and alumina ratio is20/5.5.