| 摘要 |
<p>A method for producing alpha -form silicon nitride ( alpha -Si3N4) of high-grade and fine powder for its sintered body excellent in heat-stability and mechanical strength which comprises heat-treating, in an atmosphere containing nitrogen, a mixture prepared by adding at least one of additives: (a) a mixture of at least one of Be, Mg, Ca, Sr, Ge, Sn, Ti, Hf and compounds thereof with 0.01 - 1 part by weight of silicon nitride powder, and (b) a mixture of Zr and compounds thereof with 0 - 1 part by weight of silicon nitride powder, in a total amount of 0.001 - 0.1 part by weight calculated in terms of elemental weight(s) of Be, Mg, Ca, Sr, Ge, Sn, Ti, Hf and Zr and 1 part or less by weight of silicon nitride powder, to 1 part by weight of silicon oxide powder and 0.4 - 4 parts by weight of carbon powder.</p> |
