Ngk Spark Plug Company, Limited

Kenji Sakurai

Hiroshi Tanaka

Yoshihiro Yamamoto

Ceramic materials for cutting tools are described, comprising molding a powder mixture comprising (a) Al.sub.2 O.sub.3, (b) TiN, and (c) at least one of ZrC, Zr, and ZrN, wherein component (a) constitutes between 25 and 80% of the total volume of the powder mixture and the volume ratio of component (c) to component (b) is 1/2 or less, and sintering the molded powder in vacuum or in an inert atmosphere. A process for production thereof is also described.

Ceramic material for cutting tools and process for the production thereof

A process for producing an alumina sintered product is disclosed wherein the starting alumina mixture contains about 0.01 to 0.55% by weight of MgO and 0.5 to 5.5% by weight of Y.sub.2 O.sub.3. The process yields a sintered product having a porosity on the order of less than 0.1% by volume and an average crystal grain size of about 2 microns or less and is particularly suitable for use in high speed microfinish cutting.

Alumina sintered products and process for their production

A sintered ceramic body for use in cutting tools which has an average crystal grain size of not more than about 2.mu. and comprises about 60 to 95% by volume of (a) Al.sub.2 O.sub.3 and the remainder being composed of (b) WC, provided that it may contain W.sub.2 C in which case the intensity ratio I.sub.W.sbsb.2.sub.C (101)/I.sub.WC (111) in X-ray diffraction using CuK.alpha. rays is not more than about 0.5, and (c) TiN, the volume ratio of components (b) to (c) being about 5:95 to 95:5.

Sintered ceramic body for cutting tools

A ceramic cutting tip which is applicable to a cutting tool of a lathe, a milling machine and the like is disclosed. The ceramic cutting tip comprises a ceramic sintered body including at least a cutting blade portion covered with a metal coating having a thickness of 1-10 .mu.,wherein the metal employed in the metal coating is selected from the group consisting of nickel, cobalt, aluminum and copper.

Growing community of inventors

Komaki, Japan

Kenji Sakurai