Abstract: A zirconia powder is provided comprising a yttria source and zirconia, wherein a content of the yttria source is 4.5 mol % or more and 6.5 mol % or less and the remainder is zirconia, a ratio of a total of tetragonal and cubic crystals to an entire crystal phase of zirconia is 90% or less, a BET specific surface area is 7.5 m2/g or more and 15 m2/g or less, and an average crystallite size is 325 ? or greater. The powders are useful in producing sintered bodies having the mechanical strength and the translucency desired for use in dental prosthetic materials, and precursors thereof.

Abstract: To provide a sintered body with improved impact resistance due to impact absorption through plastic deformation before brittle fracture for an impact exceeding the fracture resistance of the sintered body, and/or a method for producing the sintered body. A sintered body including: zirconia containing a stabilizer; and a region in which an impact mark is formed when an impact force is applied.

Abstract: A zirconia sintered body is provided and includes yttria and zirconia, containing yttria by a content ranging from 4.5 mol % or more to 6.5 mol % or less and zirconia as the remainder, the total light transmittance of a 1-mm thick sample measured in compliance with JIS K 7361-1 being 46.5% or higher, the three-point bending strength being 700 MPa or higher, and a ratio of an integrated value for the total light transmittance to an integrated value for the parallel light transmittance of a 1-mm thick sample measured at the measurement wavelength ranging from 400 to 700 nm being 1.3% or less.

Abstract: A sintered body that includes zirconia containing a stabilizing element; and a plastic deformation region, wherein the stabilizing element includes at least one rare-earth element other than yttrium, and the stabilizing element content is 1.5% or more by mole and less than 3.0% by mole.

Abstract: A complex sintered body includes a lamination of a layer composed of a zirconia sintered body containing 0.5% or more by mole and less than 4% by mole of an oxide of cerium in terms of CeO2, 2% or more by mole and less than 6% by mole of yttria and 0.1% or more by mass and less than 2% by mass of an oxide of aluminum; and at least one of a layer composed of a zirconia-based sintered body containing 2.0% or more by mass and 20.0% or less by mass of an oxide of aluminum, and a layer composed of a zirconia-based sintered body containing 2% or more by mole and less than 6% by mole of yttria and a coloring agent.

Abstract: A zirconia sintered body comprising 3.0 wt % or more and 30.0 wt % or less of aluminum in terms of Al2O3 and a remainder is zirconia containing 2 mol % or more and 4 mol % or less of erbia, in which the zirconia sintered body includes grains of aluminum oxide, and a total light transmittance with respect to a D65 light source at a sample thickness of 1.0 mm is 10% or less.

Abstract: A zirconia sintered body is provided and includes yttria and zirconia, containing yttria by a content ranging from 4.5 mol % or more to 6.5 mol % or less and zirconia as the remainder, the total light transmittance of a 1-mm thick sample measured in compliance with JIS K 7361-1 being 46.5% or higher, the three-point bending strength being 700 MPa or higher, and a ratio of an integrated value for the total light transmittance to an integrated value for the parallel light transmittance of a 1-mm thick sample measured at the measurement wavelength ranging from 400 to 700 nm being 1.3% or less.

Abstract: A zirconia sintered body contains aluminum, cobalt, and manganese and a remaining portion consisting of yttria-containing zirconia. In an oxide exchange, aluminum content is 5.0 wt % or more and 30.0 wt % or less, cobalt content is 0.1 wt % or more and 2.0 wt % or less, and manganese content is 0.5 wt % or more and 7.0 wt % or less.

Abstract: A zirconia sintered body comprising 3.0 wt % or more and 30.0 wt % or less of aluminum in terms of Al2O3 and a remainder is zirconia containing 2 mol % or more and 4 mol % or less of erbia, in which the zirconia sintered body includes grains of aluminum oxide, and a total light transmittance with respect to a D65 light source at a sample thickness of 1.0 mm is 10% or less.

Abstract: A zirconia sintered body contains aluminum, cobalt, and manganese and a remaining portion consisting of yttria-containing zirconia. In an oxide exchange, aluminum content is 5.0 wt % or more and 30.0 wt % or less, cobalt content is 0.1 wt % or more and 2.0 wt % or less, and manganese content is 0.5 wt % or more and 7.0 wt % or less.

Abstract: To provide a zirconia sintered body which has at least two different color tones such as white and black, and which has no color bleeding or no gap between sintered bodies. A zirconia sintered body comprising a first zirconia sintered body and a second zirconia sintered body, characterized in that the first zirconia sintered body is a zirconia sintered body containing aluminum oxide; the second zirconia sintered body is a zirconia sintered body containing a spinel oxide; a bonding plane is formed between the first zirconia sintered body and the second zirconia sintered body; and it has no gap or no color bleeding at the bonding plane.

Abstract: Provided is an apparatus that includes a molding die for producing a sintered body. The molding die is configured for cold isostatic pressing and includes a knockdown mold frame comprised of plural frame members and a bottom plate provided in contact with the knockdown mold frame. An upper punch is provided to be movable along the inner surface of the knockdown mold frame. The frame members configured to be movable relative to each other to accommodate an expansion of a green body which takes place at the time of reducing the pressure after the completion of pressing.

Abstract: To provide a zirconia sintered body which has at least two different color tones such as white and black, and which has no color bleeding or no gap between sintered bodies. A zirconia sintered body comprising a first zirconia sintered body and a second zirconia sintered body, characterized in that the first zirconia sintered body is a zirconia sintered body containing aluminum oxide; the second zirconia sintered body is a zirconia sintered body containing a spinel oxide; a bonding plane is formed between the first zirconia sintered body and the second zirconia sintered body; and it has no gap or no color bleeding at the bonding plane.

Abstract: Provided is an apparatus that includes a molding die for producing a sintered body. The molding die is configured for cold isostatic pressing and includes a knockdown mold frame comprised of plural frame members and a bottom plate provided in contact with the knockdown mold frame. An upper punch is provided to be movable along the inner surface of the knockdown mold frame. The frame members configured to be movable relative to each other to accommodate an expansion of a green body which takes place at the time of reducing the pressure after the completion of pressing.

Abstract: Provided is an apparatus that includes a molding die for producing a sintered body. The molding die is configured for cold isostatic pressing and includes a knockdown mold frame comprised of plural frame members and a bottom plate provided in contact with the knockdown mold frame. An upper punch is provided to be movable along the inner surface of the knockdown mold frame. The frame members configured to be movable relative to each other to accommodate an expansion of a green body which takes place at the time of reducing the pressure after the completion of pressing.

Abstract: Provided is an apparatus that includes a molding die for producing a sintered body. The molding die is configured for cold isostatic pressing and includes a knockdown mold frame comprised of plural frame members and a bottom plate provided in contact with the knockdown mold frame. An upper punch is provided to be movable along the inner surface of the knockdown mold frame. The frame members configured to be movable relative to each other to accommodate an expansion of a green body which takes place at the time of reducing the pressure after the completion of pressing.

Abstract: 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·m0.5 or 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 ?m or less is preferred.

Abstract: 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·m0.5 or 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 ?m or less is preferred.

Abstract: To provide a large sputtering target excellent in discharge characteristics during sputtering and in characteristics of a thin film thereby obtainable. Further, a process for producing a sintered body is provided, whereby a large green body excellent in shape accuracy can be obtained by means of cold isostatic pressing directly without preforming, and a sintered body capable of providing the above-mentioned excellent sputtering target, can be produced efficiently at a low cost. The sputtering target is produced by using a sintered body having the content of carbon contained as an impurity reduced to less than 0.005 wt %. Such a sintered body is obtainable by molding a raw material powder by cold isostatic pressing directly without adding a binder containing an organic substance or a molding aid, followed by firing.

Abstract: The object of the present invention is to provide a double side polisher capable of maintaining thickness control accuracy over a long period of time without being affected by a gradual change in thickness of a polishing pad, and a thickness control method. The first polishing operation is finished based on the polishing duration time, and the second and subsequent polishing operations are finished based on the measured distance values of a distance sensor, and after each polishing operation including the first polishing, the measured value of the distance sensor is calibrated based on the measured value and target value of finishing thickness of the work piece. Since the calibration is performed for each polishing operation, it is possible to maintain thickness control accuracy over a long period of time.