Toyo Soda Manufacturing Co., Ltd.

Tosoh Corporation

Kuniyoshi Ueda

Takaaki Tsukidate

Koji Tsukuma

Toshihiko Arakawa

Naomichi Sakai

Koji Matsui

Michiharu Ogawa

A novel optical fiber connector part is provided which comprises a ferrule having a capillary hole for holding an optical fiber, the ferrule being formed from a zirconia-alumina composite oxide containing yttria at a content ranging from 2 to 4 mol % in zirconia. In the optical fiber connector part, a sleeve for connecting and holding the ferrule may be formed from zirconia and/or a zirconia-alumina composite oxide. A process for producing the optical fiber connector part is provided wherein the granular zirconia-alumina composed of a particulate zirconia-alumina mixture having an average particle diameter of not more than 1 .mu.m is used as raw material. The granular zirconia-alumina preferably contains alumina at a content ranging from 0.1% to 50% by weight. The process comprises spray-drying a slurry containing a particulate zirconia-alumina mixture having an average particle diameter of not more than 1 .mu.m. The ferrule has a stable spherical face at the tip, and will not deform during long-term connection. The granular zirconia-alumina has excellent sintering characteristics.

Optical fiber connector part and process for producing the same

A zirconia type sintered body consisting essentially of 50 to 98% by weight of zirconia (ZrO.sub.2) containing 1.5 to 5 mole % of yttria (Y.sub.2 O.sub.3) and 50 to 2% by weight of alumina (Al.sub.2 O.sub.3), spinal (MgAl.sub.2 O.sub.4) or mullite (3Al.sub.2 O.sub.3.2SiO.sub.2), and having a three-point bending strength of at least 1700 MPa is provided. This sintered body is prepared by a process wherein a powdery composition consisting essentially of 50 to 98% by weight of (a1) a powder of zirconia containing 1.5 to 5 mole % of yttria or (a2) a mixture comprising 1.5 to 5 mole % of yttria powder and 95 to 98.5 mole % of a zirconia powder and 2 to 50% by weight of (b) a powder of an alumina type oxide selected from alumina, and alumina-magnesia type oxide, an alumina-silica type oxide, a mixture of alumina and magnesia and a mixture of alumina and silica is subjected to a hot isotactic pressing treatment under a pressure of at least 50 MPa at temperature of 1300.degree. C. to 1700.degree. C. or a monoaxially compression-sintering treatment under a pressure of at least 20 MPa at a temperature of 1400.degree. C. to 1700.degree. C.

High-strength zirconia type sintered body and process for preparation

Disclosed is a process for the preparation of high .alpha.-type silicon nitride powder, wherein a nitrogen-containing silane compound and/or amorphous silicon nitride is crystallized to form crystalline silicon nitride. In this process, crystalline silicon nitride having a particle size not larger than 0.05 .mu.m is incorporated in an amount of at least 0.1% by weight into the nitrogen-containing silane compound and/or amorphous silicon nitride, the mixture is formed into a power or molded body having a powder bulk density of at least 0.1 g/cm.sup.3 as silicon, and the powder or molded body is heated to 1,350.degree. to 1,700.degree. C. while controlling the temperature-elevating rate to at least 15.degree. C./min throughout the temperature range of from 1,200.degree. to 1,350.degree. C. The resulting high .alpha.-type silicon nitride is composed of a fine granular crystal and the does not contain a needle crystal or columnar crystal.

Process for preparation of high .alpha.-type silicon nitride powder

A zirconia type sintered body consisting essentially of 50 to 98% by weight of zirconia (ZrO.sub.2) containing 1.5 to 5 mole % of yttria (Y.sub.2 O.sub.3) and 50 to 2% by weight of alumina (Al.sub.2 O.sub.3), spinal (MgAl.sub.2 O.sub.4) or mullite (3Al.sub.2 O.sub.3.2SiO.sub.2), and having a three-point bending strength of at least 1700 MPa is provided. This sintered body is prepared by a process wherein a powdery composition consisting essentially of 50 to 98% by weight of (a1) a powder of zirconia containing 1.5 to 5 mole % of yttria or (a2) a mixture comprising 1.5 to 5 mole % of a yttria powder and 95 to 98.5 mole % of a zirconia powder and 2 to 50% by weight of (b) a powder of an alumina type oxide selected from alumina, an alumina-magnesia type oxide, an alumina-silica type oxide, a mixture of alumina and magnesia and a mixture of alumina and silica is subjected to a hot isotactic pressing treatment under a pressure of at lesast 50 MPa at temperature of 1300.degree. C. to 1700.degree. C. or a monoazially compression-sintering treatment under a pressure of at least 20 MPa at a temperature of 1400.degree. C. to 1700.degree. C.

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Yamaguchi, Japan

Kuniyoshi Ueda