Tosoh Corporation

Isao Yamashita

Koji Tsukuma

Shoichi Yamauchi

Takeshi Ito

Kohei Imai

Masayuki Kudou

Hitoshi Nagayama

Toru Tsuyoshi

Yuji Matsumura

Yuya Machida

Yushi Nawata

Provided is at least one of a zirconia sintered body and a method for producing the same. The zirconia sintered body can be used in a wide range of applications compared with ceramic joined bodies of the related art that include transparent zirconia. A zirconia sintered body includes a transparent zirconia portion and an opaque zirconia portion, wherein the zirconia sintered body has a biaxial flexural strength of greater than or equal to 300 MPa.

Zirconia sintered body and method for producing same

Disclosed is a coating layer-bonded continuous ceramic fiber formed from a continuous ceramic fiber having a coating layer of a metal compound with a thickness of 50 nm or less on the surface. Also disclosed is a ceramic matrix composite material having the above-described coating layer-bonded continuous ceramic fiber.

Coating layer-attached continuous ceramic fiber and method for producing same, and ceramic matrix composite material and method for producing same

A zirconia sintered body that includes a transparent zirconia portion and an opaque zirconia portion has a biaxial bending strength of 300 MPa or more. In addition, the opaque zirconia portion is configured by an opaque zirconia sintered body that is any one of a dark-colored zirconia sintered body, a medium-light-colored zirconia sintered body, and a light-colored zirconia sintered body.

Zirconia sintered body and manufacturing method of the same

A sintered body includes a solid solution containing cobalt and iron, with the balance being zirconia. The total content of cobalt in terms of CoO and iron in terms of FeOis more than 0.1 wt % and less than 3.0 wt %, and the proportion of cobalt regions larger than 5.5 &#x3bc;min an elemental map obtained using an electron probe microanalyzer is 25% or less.

Black sintered body and method for producing the same

A composite plate having a thickness of no more than 2 mm, and having laminated therein a zirconia sintered body, an adhesive layer, and a base material, the elasticity of the base material being no more than 100 GPa, and the apparent density of the composite plate being no more than 4.3 g/cm.

Composite plate and production method therefor

A composite plate has a thickness of 2 mm or less, which is obtained by laminating and closely fixing a zirconia sintered body and a fiber-reinforced plastic with each other, and the thickness ratio of the zirconia sintered body to the fiber-reinforced plastic is 0.01 to 1, and the apparent density of the composite plate is 4.3 g/cmor less. A composite plate has a thickness of 2 mm or less, which is obtained by laminating and closely fixing a zirconia sintered body and a fiber-reinforced plastic with each other, and the maximum roughness depth of the surface of the zirconia sintered body is 50 &#x3bc;m or less per 1 cm.

Composite plate and method for producing same

Provided is a zirconia sintered body having both high translucency and high strength. The zirconia sintered body includes crystal grains that include a cubic domain and a tetragonal domain, wherein a stabilizer and lanthanum is dissolved as a solid solution therein. The sintered body can be obtained by a manufacturing method including: a mixing step of obtaining a mixed powder by mixing a zirconia source, a stabilizer source, and a lanthanum source; a molding step of obtaining a green body by molding the obtained mixed powder; a sintering step of obtaining a sintered body by sintering the obtained green body at a sintering temperature of 1650&#xb0; C. or higher; and a temperature lowering step of lowering the temperature from the sintering temperature to 1000&#xb0; C. at a temperature lowering rate exceeding 1&#xb0; C./min.

Translucent zirconia sintered body, method for manufacturing same, and use thereof

Translucent zirconia sintered bodies have had a problem that incorporation of titania improves translucency but lowers mechanical strength. The invention provides: a zirconia sintered body containing titanium oxide, the sintered body containing 6-15 mol % yttria and 3-20 mol % titania and having an in-line transmission of 50% or higher when examined at a sample thickness of 1 mm and a measuring wavelength of 600 nm; and a zirconia sintered body having especially high translucency which is a high-quality transparent zirconia sintered body that contains 3-20 mol % titania and 6-15 mol % yttria and has an in-line transmission, as measured at a wavelength of 600 nm, of 73% or higher and a haze value of 2.0% or less and that is highly translucent and is undimmed (cloudless). The invention further relates to a production process in which a powder having the composition is molded and thereafter subjected to ordinary-pressure primary sintering and hot isostatic pressing (HIP) under specific conditions.

High-strength transparent zirconia sintered body, process for producing the same, and uses thereof

A colored translucent zirconia sintered body contains a transition metal element as a coloring agent, having a clear color tone and high transparency, and being excellent in both design properties and esthetic properties, and its production process. A colored translucent zirconia sintered body includes yttria in an amount of at least 6 mol % and at most 15 mol % and at least one member selected from the group consisting of iron, nickel, manganese, cobalt, chromium, copper and vanadium in an amount of at least 0.02 mol % and at most 0.5 mol % as calculated as oxides, and having a porosity of at most 1,000 ppm. The average crystal grain size is preferably at most 60 &#x3bc;m.

Colored translucent zirconia sintered body, its production process and its use

The invention relates to the use of a sintered body obtained by subjecting a primary sintered body having a relative density of 95% or higher produced from a fine yttria-containing zirconia powder to HIP sintering at a temperature of 1,200-1,600&#xb0; C. and a pressure of 50 MPa or higher. This sintered body is either a sintered body which has a total light transmittance, as measured at a thickness of 0.5 mm, of 43% or higher and a three-point bending strength of 1,700 MPa or higher or a zirconia sintered body which has a total light transmittance, as measured at a thickness of 1 mm, of 40% or higher and a three-point bending strength of 500 MPa or higher and which combines high strength and total light transmission.

Zirconia sintered bodies with high total light transmission and high strength, uses of the same, and process for producing the same

Because fracture toughness and translucency of translucent colored alumina sintered body of the past were low, the alumina sintered body was not suitable for uses such as dental materials, which require high toughness. The present invention relates to providing a translucent colored alumina sintered body that contains transition metal oxides, and with which the fracture toughness is 4.5 MPa&#xb7;mor more and the maximum value of total forward transmittance (sample thickness 1 mm) to a wavelength of 300-800 nm is 60% or more. The present invention relates to obtaining a sintered body, at least 20% of which contains anisotropic grains with a long axis length of 10 &#x3bc;m or greater and an aspect ratio of 1.5 or more by subjecting an alumina sintered body containing transition metal oxides having a eutectic point with alumina or an alumina sintered body containing transitional metal oxides and at least one selected from the group consisting of Group 1A alkali metal oxides, Group 2A alkaline earth metal oxides, and SiO, BO, POand GeOto pressureless sintering and HIP treatment.

Colored alumina sintered body of high toughness and high translucency, and its production method and its uses

In the conventional alumina sintered bodies, a sintered body having high flexural strength, high toughness and high translucency in combination is not obtained, and a translucent alumina sintered body suitable for a dental material requiring both strength and sensuousness was not obtained. A translucent alumina sintered body having fracture toughness of 4.5 MPa&#xb7;mor more, flexural strength of 350 MPa or more, and all light transmittance (sample thickness: 1 mm) to a visible light having a wavelength of 600 nm, of 60% or more is provided. The sintered body wherein sintered crystal grains are slender plate-like and/or columnar shape having an average aspect ratio of 1.5 or more and an average long axis length of 15 &#x3bc;m or less is preferred.

High toughness translucent alumina sintered body, method for producing the same, and its uses

A primary sintered body having a density of 95 % or more obtained by sintering a zirconia powder comprising an yttria main component as a stabilizer under ordinary pressure is set in a vessel of a semi-sealed state and subjected to HIP treatment (secondary sintering) at a temperature of from 1,600 to 1,900&#xb0; C. under a pressure of 50 MPa or higher, and according to need, heated treated in an oxidizing atmosphere, thereby producing a polycrystalline sintered body of zirconia having high transparency of an in-line transmission of 50% or higher.

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Kanagawa, Japan

Isao Yamashita