Patent ID: 11919824
Assignee: YANTAI ZHONGKE RESEARCH INSTITUTE OF ADVANCED MATERIALS AND GREEN CHEMICAL ENGINEERING
Field: Materials, metallurgy (Chemistry)
Classification: CPC C | IPC C

Claim 4:
5. A method for preparing the silicon nitride ceramic sintered body as claimed in claim 1, comprising steps of
burying a tungsten toughened silicon nitride ceramic sintered body in a burying powder; and
subjecting the tungsten toughened silicon nitride ceramic sintered body to a heat treatment for a carbonization reaction, to obtain the silicon nitride ceramic sintered body,
wherein the tungsten toughened silicon nitride ceramic sintered body comprises a third silicon nitride crystalline phase and a metal tungsten grain boundary phase, the metal tungsten grain boundary phase being tungsten elementary substance and/or a tungsten alloy; and
wherein the burying powder comprises a carbon source;, the heat treatment is performed at a temperature of 1100-1450° C. for 0.5-5 h;
wherein the tungsten toughened silicon nitride ceramic sintered body is prepared by a process comprising steps of
mixing and ball milling a silicon nitride source, a metal tungsten grain boundary phase precursor, and a sintering assistant, to obtain a mixed powder, the metal tungsten grain boundary phase precursor being at least one selected from the group consisting of tungsten elementary substance, and a tungsten alloy; and
forming the mixed powder into a preform, and sintering the preform in a nitrogen atmosphere, to obtain the tungsten toughened silicon nitride ceramic sintered body,

wherein the sintering is performed at a temperature of 1600-1900° C. and at a nitrogen pressure of not less than 0.3 MPa.