The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 24, 1989
Filed:
Jan. 20, 1987
Kansei Izaki, Niigata, JP;
Takamasa Kawakami, Niigata, JP;
Kouichi Hakkei, Niigata, JP;
Kazuhiro Ando, Niigata, JP;
Abstract
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.