| 摘要 |
PURPOSE: To obtain composite ceramics having a structure contg. titanium nitride and silicon carbide dispersed in silicon nitride as a matrix and having improved strength and toughness by heating and nitriding a compact consisting of metallic silicon powder, titanium carbide and titanium oxide and further carrying out heat treatment. CONSTITUTION: A powdery mixture of metallic silicon powder with titanium oxide powder, titanium carbide powder and a sintering aid is compacted and heated at <=1,400 deg.C in a nitrogen atmosphere to obtain a sintered compact having a structure contg. dispersed particles and/or whiskers of titanium nitride and silicon carbide as well as to form silicon nitride from the metallic silicon. The sintered compact is heated to 1,600-2,000 deg.C in a nitrogen atmosphere optionally under pressure. By this heating, the densification of the silicon nitride is allowed to proceed and the objective composite ceramics contg. fine titanium nitride and silicon carbide uniformly dispersed in a matrix phase of silicon nitride is obtd. The titanium nitride in this composite ceramics preferably has 1-500nm average particle diameter and the pref. content is 5-30vol.%. |
