| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for treating a high melting point material by sintering and/or densifying the high melting point substance having a melting point of >2,700 deg.K silicon nitride powder and a porous substance such as a sponge-like substance in the presence of a solid material as a pressure medium under a high pressure and a high temperature without adding an additive for binding the materials. SOLUTION: This method for sintering and/or densifying a high melting point material comprises sealing the high melting point substance having a melting point of >2,700 deg.K, the powder of silicon nitride and a porous substance 1 such as a sponge-like substance in a high pressure high temperature device using a solid material as a pressure medium and subsequently sintering and/or densifying the sealed materials under a high pressure of >=100 MPa. Therein, the sintering and/or the densification are carried out within a temperature below the melting point-pressure range under a condition: T>=0.7Tm -0.2P in a range of the equation: 2GPa>=P>=100<=MPa or a condition: T>=0.7Tm -400 in a range of the equation: P>=2GPa, wherein P is a pressure; Tm is the melting point, vaporization point or decomposition point of the material; T is a treating temperature; P is expressed by a unit of MPa; Tm and T are expressed by units of deg.K, respectively. |
