| 摘要 |
PROBLEM TO BE SOLVED: To provide the porous silicon nitride showing large resistance to destruction and having high porosity and high strength. SOLUTION: The porous silicon nitride consists only of oriented columnar particles of the silicon nitride and pores, has strength at least 1000 MPa and large resistance to destruction against fructure progress. The silicon nitride having high porosity and strength is characterised by orienting the columnar particles of the silicon nitride which has the minor axis of 0.5-10 μm and aspect ratio of 10-100, in one direction to combine, and by having a structure consisting only of pores of 5-30% except the columnar particles. The porous silicon nitride uses only the columnar particles of the silicon nitride, having the minor axis of 0.5-10 μm and aspect ratio of 10-100, as the silicon nitride and is mixed with an auxiliary agent for combining with the columnar particles to form moldings orienting the columnar particles of the silicon nitride in one direction by using a forming method such as sheet forming and extrusion, after dewaxing, and sintered in a sintering condition becoming the porosity to be 5-30% to produce. |
