BORIDE COMPLEX CERAMIC AND ITS PRODUCTION

摘要

PROBLEM TO BE SOLVED: To provide a high performance boride ceramic material. SOLUTION: This boride complex ceramic disperses 3-30vol.% one or two or more kinds of SiC, TiC or B4 C having <=500nm particle diameter and 0.01-3vol.% Ni-Zr particles in crystal grains and/or grain boundary of a matrix of TiB2 or ZrB2 . The ceramic is produced by mixing and forming boride with dispersed fine particles and Ni-Zr particles and sintering the resultant compact at >=1,700 deg.C in a vacuum or inert atmosphere. The ceramic has a specific structure containing dispersed fine particles having nanometer size in crystal particles and/or grain boundary and enable densification even in sintering under ordinary pressure by addition of a small amount of Ni-Zr particles and can control crystal particles of boride in columnar or needle-like shape and is remarkably high in mechanical characteristics such as fracture toughness and hardness.