A polymer-derived composition and method for providing a ceramic-based precursor coating on a metal surface are disclosed. The composition comprises one or more preceramic polymers admixed with one or more metal particulates. The composition is integrally disposed on and within the metal surface of a metal part through pressure-assisted pyrolysis of a metal particulate-filled preceramic polymer under appropriate conditions, thereby providing a corrosion-resistant and oxidation-resistant metal surface. The precursor coating composition is applied and dried onto the metal surface. The coated steel material is then hot stamped at a pre-defined temperature under a time and pressure conditions sufficient to pyrolyze precursor coating composition to form a protective coating on the surface of the steel. The coated steel material is then cooled. Further, the hot stamping is performed in a period of no more than 1 minute and at a temperature controlled at 400-800? C.

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.

A sintered material includes a first material and a second material, wherein the first material is partially stabilized ZrO.sub.2 in which 1 to 90 volume % of Al.sub.2O.sub.3 is dispersed in crystal grain boundaries or crystal grains, the Al.sub.2O.sub.3 is a grain having a grain size of less than or equal to 1 m, and the second material is at least one compound selected from a group consisting of a carbide, a nitride, and a carbonitride, and 5 to 95 volume % of the second material is included in the sintered material.

A method is disclosed for forming a blended phosphor composition. The method includes the steps of firing precursor compositions that include europium and nitrides of at least calcium, strontium and aluminum, in a refractory metal crucible and in the presence of a gas that precludes the formation of nitride compositions between the nitride starting materials and the refractory metal that forms the crucible. The resulting compositions can include phosphors that convert frequencies in the blue portion of the visible spectrum into frequencies in the red portion of the visible spectrum.

A silicon nitride substrate including silicon nitride crystal grains and a grain boundary phase and having a thermal conductivity of 50 W/m.Math.K or more, wherein, in a sectional structure of the silicon nitride substrate, a ratio (T2/T1) of a total length T2 of the grain boundary phase in a thickness direction with respect to a thickness T1 of the silicon nitride substrate is 0.01 to 0.30, and a variation from a dielectric strength mean value when measured by a four-terminal method in which electrodes are brought into contact with a front and a rear surfaces of the substrate is 20% or less. The dielectric strength mean value of the silicon nitride substrate can be 15 kV/mm or more. According to above structure, there can be obtained a silicon nitride substrate and a silicon nitride circuit board using the substrate in which variation in the dielectric strength is decreased.

A silicon nitride substrate including silicon nitride crystal grains and a grain boundary phase and having a thermal conductivity of 50 W/m.Math.K or more, wherein, in a sectional structure of the silicon nitride substrate, a ratio (T2/T1) of a total length T2 of the grain boundary phase in a thickness direction with respect to a thickness T1 of the silicon nitride substrate is 0.01 to 0.30, and a variation from a dielectric strength mean value when measured by a four-terminal method in which electrodes are brought into contact with a front and a rear surfaces of the substrate is 20% or less. The dielectric strength mean value of the silicon nitride substrate can be 15 kV/mm or more. According to above structure, there can be obtained a silicon nitride substrate and a silicon nitride circuit board using the substrate in which variation in the dielectric strength is decreased.

A production process for a crystal oriented ceramics includes: a first step of preparing composite particles formed of particles having magnetic anisotropy having magnetic susceptibility anisotropy and seed particles having magnetic susceptibility anisotropy less than or equal to 1/10 of the magnetic susceptibility anisotropy of the particles having magnetic anisotropy and are formed of an inorganic compound having an anisotropic shape in which a crystal axis intended to be corresponds to a minor axis or a major axis; a second step of adding raw material powder including the composite particles to a solvent to prepare a slurry a third step of preparing a green compact by disposing the slurry in a static magnetic field of 0.1 tesla and drying the slurry in a state in which crystal axes of the seed particles in a major axis direction are in one direction; and a fourth step of sintering the green compact.

A method is disclosed for forming a blended phosphor composition. The method includes the steps of firing precursor compositions that include europium and nitrides of at least calcium, strontium and aluminum, in a refractory metal crucible and in the presence of a gas that precludes the formation of nitride compositions between the nitride starting materials and the refractory metal that forms the crucible. The resulting compositions can include phosphors that convert frequencies in the blue portion of the visible spectrum into frequencies in the red portion of the visible spectrum.

A method for improving thermal efficiency of a heating device that reduces an amount of heat flowing out from a heating device 11 to the outside by installing a heat-resistant inorganic conjugated molded product 16 in and along a pathway 15 for heated gas generated from the heating device 11 without interrupting the flow of heated gas passing the pathway 15, heating the inorganic conjugated molded product 16 with the heated gas, and putting radiation heat from the heated inorganic conjugated molded product 16 back into the heating device 11, the inorganic conjugated molded product 16 being provided with an interior layer and an exterior layer, the exterior layer consisting of a coverture for inorganic materials that protects the interior layer from heated gas.

A method for improving thermal efficiency of a heating device that reduces an amount of heat flowing out from a heating device 11 to the outside by installing a heat-resistant inorganic conjugated molded product 16 in and along a pathway 15 for heated gas generated from the heating device 11 without interrupting the flow of heated gas passing the pathway 15, heating the inorganic conjugated molded product 16 with the heated gas, and putting radiation heat from the heated inorganic conjugated molded product 16 back into the heating device 11, the inorganic conjugated molded product 16 being provided with an interior layer and an exterior layer, the exterior layer consisting of a coverture for inorganic materials that protects the interior layer from heated gas.