公开(公告)号：US4800182A

公开(公告)日：1989-01-24

申请号：US4476

申请日：1987-01-20

申请人： Kansei Izaki ,  Takamasa Kawakami ,  Kouichi Hakkei ,  Kazuhiro Ando

发明人： Kansei Izaki ,  Takamasa Kawakami ,  Kouichi Hakkei ,  Kazuhiro Ando

IPC分类号： C01B21/068 ,  C01B31/36 ,  C04B35/589 ,  C04B35/593 ,  C04B35/56 ,  C04B35/58

CPC分类号： C04B35/589 ,  C01B21/068 ,  C01B31/36 ,  C04B35/593 ,  C04B35/5935 ,  C01P2002/02 ,  C01P2004/03 ,  C01P2004/32 ,  C01P2004/61 ,  C01P2004/62 ,  C01P2006/10 ,  C01P2006/80 ,  C01P2006/90

摘要： The invention relates to a sintered silicon nitride-silicon carbide composite material excellent in toughness and strength and to a process for producing the same. The present sintered composite material is substantially formed of silicon nitride predominantly in .beta.-phase and about 5 to 35% by weight of silicon carbide predominantly in .beta.-phase, which is characterized by the microstructure such that the silicon nitride is in the form of fine grains comprising elongated grains, 0.2 to 1.0 .mu.m in length of minor axis and 1 to 10 .mu.m in length of major axis, and equiaxed grains, 1 .mu.m or below in average size, and the silicon carbide is in the form of equiaxed grains, 1 .mu.m or below in average size, said silicon carbide grains being uniformly dispersed. Having a three-point flexural strength of at least 95 kg/mm.sup.2 and a fracture toughness (K.sub.IC) of at least 54 MN/m.sup.3/2, the present sintered material is excellent in toughness and strength. The process for producing such a material is disclosed in detail.