An inert gas substituting method includes: a closing step of accommodating a honeycomb formed body in an indoor space of a gas substituting chamber and closing the same with airtightness from the outside being maintained; a pressure reducing step of reducing the pressure in the indoor space to a preset first vacuum pressure; a pressure increasing step of introducing argon gas into the pressure-reduced indoor space and increasing the pressure to a second vacuum pressure which is higher than the first vacuum pressure and lower than atmospheric pressure; a pressure re-reducing step of reducing the pressure to the first vacuum pressure again; and a pressure recovering step of repeating the pressure increasing step and the pressure re-reducing step at least twice, introducing argon gas into the indoor space in which the pressure has been reduced to the first vacuum pressure again, and recovering the pressure to atmospheric pressure.

A method for producing a metal-ceramic substrate includes attaching a metal layer to a surface side of a ceramic layer, the metal layer being structured into a plurality of metallization regions respectively separated from one another by at least one trench-shaped intermediate space to form conductive paths and/or connective surfaces and/or contact surfaces. The method further includes filling the at least one trench-shaped intermediate space with an electrically insulating filler material, and covering first edges of the metallization regions facing and adjoining the surface side of the ceramic layer in the at least one trench-shaped intermediate space, as well as at least one second edge of the metallization regions facing away from the surface side of the ceramic layer in the at least one trench-shaped intermediate space, by the electrically insulating filler material.

An oxide superconductor of an embodiment includes an oxide superconductor layer having a continuous Perovskite structure containing rare earth elements, barium (Ba), and copper (Cu). The rare earth elements contain a first element which is praseodymium (Pr), at least one second element selected from the group consisting of neodymium (Nd), samarium (Sm), europium (Eu), and gadolinium (Gd), at least one third element selected from the group consisting of yttrium (Y), terbium (Tb), dysprosium (Dy), and holmium (Ho), and at least one fourth element selected from the group consisting of erbium (Er), thulium (Tm), ytterbium (Yb), and lutetium (Lu).

The present invention provides a welding tool member for friction stir welding comprising a silicon nitride sintered body, wherein the silicon nitride sintered body includes an additive component other than silicon nitride in a content of 15% by mass or less, and the additive component includes three or more elements selected from Y, Al, Mg, Si, Ti, Hf, Mo and C. It is preferable that the content of the additive component is 3% by mass or more and 12.5% by mass or less. It is also preferable that the additive component includes four or more elements selected from Y, Al, Mg, Si, Ti, Hf, Mo and C. Due to above structure, there can be provided a welding tool member for friction stir welding having a high durability.

It is an object of the present disclosure to provide a thin-film carbon foam and a method of manufacture the same. It is another object of the present disclosure to provide a stack carbon foam having fewer through holes and a method of manufacturing the same. The carbon foam of the present disclosure is, for example, a stack carbon foam being a stack of at least two monolayer carbon foams stacked one another, each monolayer carbon foam comprising linear portions and node portions joining the linear portions, or a carbon foam comprising linear portions and node portions joining the linear portions, wherein the ratio of the number of large through holes having a diameter of 1 mm or more to the surface area of the carbon foam is 0.0003/mm.sup.2 or less.

Set forth herein are processes and materials for making ceramic thin films by casting ceramic source powders and precursor reactants, binders, and functional additives into unsintered thin films and subsequently sintering the thin films under controlled atmospheres and on specific substrates.

An oxide superconductor of an embodiment includes an oxide superconductor layer having a continuous Perovskite structure including rare earth elements, barium (Ba), and copper (Cu). The rare earth elements include a first element which is praseodymium, at least one second element selected from the group consisting of neodymium, samarium, europium, and gadolinium, at least one third element selected from the group consisting of yttrium, terbium, dysprosium, and holmium, and at least one fourth element selected from the group consisting of erbium, thulium, ytterbium, and lutetium. When the number of atoms of the first element is N(PA), the number of atoms of the second element is N(SA), and the number of atoms of the fourth element is N(CA), 1.5(N(PA)+N(SA))N(CA) or 2(N(CA)N(PA))N(SA) is satisfied.

A ceramic article includes a ceramic matrix composite that has a porous reinforcement structure and a ceramic matrix within pores of the porous reinforcement structure. The ceramic matrix composite includes a surface zone comprised of an exterior surface of the ceramic matrix composite and pores that extend from the exterior surface into the ceramic matrix composite. A glaze material seals the surface zone within the pores of the surface zone and on the exterior surface of the surface zone as an exterior glaze layer on the ceramic matrix composite. The glaze material is a glass or glass-ceramic material. The ceramic matrix composite includes an interior zone under the surface zone, and the interior zone is free of any of the glaze material and has a greater porosity than the surface zone.

An oxide superconductor of an embodiment includes an oxide superconductor layer having a continuous Perovskite structure containing rare earth elements, barium (Ba), and copper (Cu). The rare earth elements contain a first element which is praseodymium (Pr), at least one second element selected from the group consisting of neodymium (Nd), samarium (Sm), europium (Eu), and gadolinium (Gd), at least one third element selected from the group consisting of yttrium (Y), terbium (Tb), dysprosium (Dy), and holmium (Ho), and at least one fourth element selected from the group consisting of erbium (Er), thulium (Tm), ytterbium (Yb), and lutetium (Lu).

Provided are a method for producing a ceramic sintered body having improved light emission intensity, a ceramic sintered body, and a light emitting device. The method for producing a ceramic sintered body comprises preparing a molded body that contains a nitride fluorescent material having a composition containing: at least one alkaline earth metal element M.sup.1 selected from the group consisting of Ba, Sr, Ca, and Mg; at least one metal element M.sup.2 selected from the group consisting of Eu, Ce, Tb, and Mn; Si; and N, wherein a total molar ratio of the alkaline earth metal element M.sup.1 and the metal element M.sup.2 in 1 mol of the composition is 2, a molar ratio of the metal element M.sup.2 is a product of 2 and a parameter y and wherein y is in a range of 0.001 or more and less than 0.5, a molar ratio of Si is 5, and a molar ratio of N is 8, and wherein the nitride fluorescent material has a crystallite size, as calculated by X-ray diffraction measurement using the Halder-Wagner method, of 550 or less, and calcining the molded body at a temperature in a range of 1,600 C. or more and 2,200 C. or less to obtain a sintered body.