| 摘要 |
PURPOSE:To obtain fine powder as starting material for a silicon nitride sintered compact smaller in size than conventional fine powder, uniform in particle size distribution and having a large specific surface area. CONSTITUTION:This fine silicon nitride powder is fine crystalline silicon nitride powder having 0.1-0.35mum average particle diameter measured by a laser beam scattering method, contg. <=15vol.% particle each having >=0.5mum particle diameter and <=3vol.% particles each having >=1.0mum particle diameter and having 15-50m<2>/g specific surface area. It is desirable that the beta- or alpha-phase content of the powder be >=80wt.%. Silicon nitride powder is dispersed in a solvent under wet pulverization with a ball mill to prepare a slurry of silicon nitride powder, coarse particles are removed by wet sedimentation classification and fine particles having a narrow particle size distribution are produced. |
