| 摘要 |
PURPOSE:To enhance characteristics such as strength and toughness by specifying beta-phase content and the crystal effective strain of beta-Si3N4 by powder X-ray diffraction. CONSTITUTION:Metallic Si powder having 0.8-1.5 bulk density is compacted and the resulting compact is nitrided under heating by a method such as direct nitriding by which heating is carried out at 1,300-1,500 deg.C in an atmosphere contg. N2 and/or NH3 to produce the objective silicon nitride powder having >=20wt.% beta-phase content, >=4.0X10<-4> crystal effective strain of beta-Si3N4 by powder X-ray diffraction and >=2m<2>/g specific surface area. |
