Titanium carbide powder and titanium carbide-ceramics composite powder and method for production thereof, and sintered compact from the titanium carbide powder and sintered compact from the titanium carbide/ceramics composite powders and method for production thereof

Abstract

Disclosed is a highly-pure fine titanium carbide powder having a maximum particle size of 100 nm or less and containing metals except titanium in an amount of 0.05 wt % or less and free carbon in an amount of 0.5 wt % or less. The powder has a NaCl-type crystal structure, and a composition represented by TiCxOyNz, wherein X, Y and Z satisfy the relations: 0.5≦X≦1.0; 0≦Y≦0.3; 0≦Z≦0.2; and 0.5≦X+Y+Z≦1.0.) The powder is produced by: dissolving an organic substance serving as a carbon source in a solvent to prepare a liquid, wherein the organic substance contains at least one OH or COOH group which is a functional group coordinatable to titanium of titanium alkoxide, and no element except C, H, N and O; mixing titanium alkoxide with the liquid to satisfy the following relation: 0.7≦α≦1.0 (wherein α is a molar ratio of the carbon source to the titanium alkoxide), so as to obtain a precursor solution; and subjecting a product in the precursor solution to a heat treatment in a non-oxidizing atmosphere or a vacuum atmosphere at a temperature of 1050 to 1500° C. The present invention can provide fine titanium carbide powders with nano-scale particle sizes, which are free of inorganic impurities, such as titanium oxide and metal, low in free carbon, and effective in enhancing characteristics of a titanium carbide-ceramics composite sintered body.