Other

Agency of Industrial Science and Technology

Tokyo Kokyu Rozai Co., Ltd.

Eiichi Sudoh

Tadahiko Watanabe

Kazuhisa Shobu

Hideki Yamamoto

Osamu Yagishita

Junshiro Hayakawa

Yuji Enomoto

Yuko Tsuya

Yukio Kai

A powder of at least one of TiB.sub.2, ZrB.sub.2 and HfB.sub.2 is mixed with at least one of Ti, Zr, Hf, TiB, ZrB and HfB, or with at least one of Ti, Zr, Hf, TiB, ZrB and HfB and a powder of boron, to prepare a mixed powder which can form a sintered product having a boron content of 65 to 67 atom %. Alternatively, a powder of at least one of Ti, Zr, Hf, TiB, ZrB and HfB is mixed with a powder of boron to prepare the mixed powder. The mixed powder may further contain up to a maximum of 30% by weight of a powder of AlN. Then, the mixed powder is sintered to make metal diboride ceramics. The lower-melting metal or compound which the mixed powder contains melts to form a liquid phase and enables the manufacture of a sintered product of high density by a customary sintering operation employing a low temperature. The sintered product having a boron content of 65 to 67 atom % consists solely of metal diboride crystals having a structure of the hexagonal system.

Method of manufacture metal diboride ceramics

The present invention is characterized by ceramic materials comprising ceramic sintered bodies consisting of (1) 1-90 wt % chromium carbide and the remainder carbonic titanium nitride; (2) 1-90 wt % chromium carbide, 0.1-5 wt % B.sub.4 C and the remainder titanium carbo-nitride; or (3) either of the above compositions plus less than 95 wt % of a metal boride such as Ti or Zr. Such ceramic sintered bodies are used for cutting tools or wear-resistant machine parts because of their high density, high hardness and high strength.

Sintered titanium carbo-nitride ceramics

Growing community of inventors

Ohmuta, Japan

Eiichi Sudoh