Agency of Industrial Science and Technology

Ministry of International Trade & Industry

Nissan Chemical Industries Limited

Agency of Industrial Science and Technology Ministry of International

Michihide Machida

Shoichi Kume

Kazutaka Suzuki

Haruo Yoshida

Yoshio Tasaki

Masamitu Ishikawa

Shiro Ikuta

Masanobu Awano

Masamichi Obitsu

Yuzi Hoshi

Hiroyoshi Takagi

Hideyo Tabata

Takeo Iga

Kazuo Saitoh

Shyoichi Kume

Shinji Tomura

Haruo Yoshido

Yoshitaka Kuwahara

A light transmitting sintered body of cordierite has a composition equal or close to the stoichiometric composition of cordierite which is represented as 2MgO.2Al.sub.2 O.sub.3.5SiO.sub.2, consists mainly of a phase of cordierite crystals, and has a total transmittance of at least 20%. A method of preparing it is also disclosed.

Sintered body of light transmitting cordierite and a method of preparing

A cubic boron nitride-containing high-density inorganic composite is prepared by mixing cubic boron nitride with a powdered inorganic compound capable of forming a rigid sintered article having a density of at least 85% and a Vickers hardness of at least 800, which does not promote the conversion of cubic boron nitride into graphite-type phase boron nitride (hBN). The powder mixture is compressed into a mold, and fired at low pressure of between 1,000-2,000 MPa, at a temperature of not more than 1,500.degree. C., under which conditions the cubic boron nitride does not convert to hBN, but is sufficiently metastable to permit the formation of the high-density inorganic composite.

Method for production of cubic boron nitride-containing high-density

A cubic boron nitride-containing high-density inorganic composite sintered article is produced by a method which essentially consists of preparing a mixture of a cubic boron nitride powder with an inorganic compound powder capable of forming a high-rigidity sintered article under the conditions permitting the cubic boron nitride to remain in a substantially metastable, though not thermodynamically stable, state, a mixture of an inorganic compound-coated cubic boron nitride powder with an inorganic compound powder, or an inorganic compound-coated cubic boron nitride powder, and sintering the mixture of the cubic boron nitride powder with an inorganic compound powder, the mixture of the inorganic compound-coated cubic boron nitride powder with an inorganic compound powder or an inorganic compound-coated cubic boron nitrides powder, under the conditions of not more than 2,000 MPa of pressure and not more than 1,500.degree. C. of temperature for permitting the cubic boron nitride to remain in a substantially metastable, though not thermodynamically stable, state for a period incapable of causing conversion of the cBN into a graphite-type phase.

Method of production of cubic boron nitride-containing high-density

A sintered article of diamond is obtained by coating the surface of diamond particles with 30 to 0.1% by volume, based on the total volume of the diamond particles and aids, of at least one member selected from the group consisting of the transition metals of Groups 4a, 5a, and 6a in the Periodic Table of Elements and boron and silicon, and sintering the coated diamond particles under conditions of high pressure and high temperature, which sintered article consists of 70 to 99.8% by volume of diamond and 30 to 0.2% by volume of the carbide of the coating substance. A method for the production of the sintered article of diamond is also disclosed.

Sintered article of diamond and method for production thereof

Method for production of a sintered article of diamond

A high-strength sintered article of chemical substances having the .beta.-silicon nitride type crystal structure is produced by blending 50 to 99.9 weight percent of a .beta.-silicon nitride and/or .beta.'-Sialon and 50 to 0.1 weight percent of a mixture, as a sintering aid, consisting of BeO, Ga.sub.2 O.sub.3, and Al.sub.2 O.sub.3 in respective amounts such as to have a Ga.sub.2 O.sub.3 /BeO ratio in the range of from 2.8 to 9.4, an Al.sub.2 O.sub.3 /BeO ratio in the range of from 0.0 to 2.6, and an Al.sub.2 O.sub.3 /Ga.sub.2 O.sub.3 ratio in the range of from 0.0 to 1.1, all ratios being ratios by weight and sintering the resultant blend.

Method for manufacture of high-strength sintered article of substances

Growing community of inventors

Nagoya, Japan

Michihide Machida