Disclosed is a coated ceramic fiber including a silicon carbide coating layer adjacent to the ceramic fiber and a silicon dioxide coating layer adjacent to the silicon carbide coating layer, wherein the silicon dioxide coating layer forms micro cracks after a crystal structure transformation. The coated ceramic fiber may be included in a composite material having a ceramic matrix.

Provided are a powder for laser manufacturing which can be stably manufactured and from which a three-dimensional manufactured object ensuring a manufacturing accuracy can be obtained and a using method thereof. A powder for ceramic manufacturing for obtaining a manufactured object by repeatedly sintering or fusing and solidifying in sequence a powder in an irradiation portion with laser light, in which the powder includes a plurality of compositions, at least one composition of the compositions is an absorber that relatively strongly absorbs the laser light compared to other compositions, and at least a part of the absorber changes to a different composition that relatively weakly absorbs the laser light by irradiation with the laser light and a using method of a powder in which the powder is used.

One aspect of the disclosure provides an optical wavelength conversion member including a polycrystalline ceramic sintered body containing, as main components, Al.sub.2O.sub.3 crystal grains and crystal grains represented by formula (Y,A).sub.3B.sub.5O.sub.12:Ce. In the optical wavelength conversion member, a (Y,A).sub.3B.sub.5O.sub.12:Ce crystal grain has a region wherein the A concentration of a peripheral portion of the (Y,A).sub.3B.sub.5O.sub.12:Ce crystal grain is higher than that of an interior portion of the (Y,A).sub.3B.sub.5O.sub.12:Ce crystal grain. Thus, the optical wavelength conversion member exhibits high fluorescence intensity (i.e., high emission intensity) and high heat resistance (i.e., low likelihood of temperature quenching). The optical wavelength conversion member has a structure wherein the element A concentration of a peripheral portion of a (Y,A).sub.3B.sub.5O.sub.12:Ce crystal grain differs from that in an interior portion of the crystal grain. This structure can achieve a ceramic fluorescent body exhibiting superior fluorescent characteristics and superior thermal characteristics with varied colors of emitted light.

One aspect of the disclosure provides an optical wavelength conversion member including a polycrystalline ceramic sintered body containing, as main components, Al.sub.2O.sub.3 crystal grains and crystal grains represented by formula (Y,A).sub.3B.sub.5O.sub.12:Ce. In the optical wavelength conversion member, a (Y,A).sub.3B.sub.5O.sub.12:Ce crystal grain has a region wherein the A concentration of a peripheral portion of the (Y,A).sub.3B.sub.5O.sub.12:Ce crystal grain is higher than that of an interior portion of the (Y,A).sub.3B.sub.5O.sub.12:Ce crystal grain. Thus, the optical wavelength conversion member exhibits high fluorescence intensity (i.e., high emission intensity) and high heat resistance (i.e., low likelihood of temperature quenching). The optical wavelength conversion member has a structure wherein the element A concentration of a peripheral portion of a (Y,A).sub.3B.sub.5O.sub.12:Ce crystal grain differs from that in an interior portion of the crystal grain. This structure can achieve a ceramic fluorescent body exhibiting superior fluorescent characteristics and superior thermal characteristics with varied colors of emitted light.

Provided is a ceramic composite material and a wavelength converter. The ceramic composite material includes: an alumina matrix, a fluorescent powder uniformly distributed in the alumina matrix, and scattering centers uniformly distributed in the alumina matrix, wherein the alumina matrix is an alumina ceramics, the scattering centers are alumina particles, the alumina particles each have a particle diameter of 1 μm to 10 μm, and the fluorescent powder has a particle diameter of 13 μm to 20 μm.

Provided is a ceramic composite material and a wavelength converter. The ceramic composite material includes: an alumina matrix, a fluorescent powder uniformly distributed in the alumina matrix, and scattering centers uniformly distributed in the alumina matrix, wherein the alumina matrix is an alumina ceramics, the scattering centers are alumina particles, the alumina particles each have a particle diameter of 1 μm to 10 μm, and the fluorescent powder has a particle diameter of 13 μm to 20 μm.

A ceramic substrate made of a dielectric material including silicon carbide particles, which is used as a forming material, in which the number of the silicon carbide particles per unit area on the surface of the substrate is smaller than the number of the silicon carbide particles per unit area in a cross section of the substrate.

A ceramic substrate made of a dielectric material including silicon carbide particles, which is used as a forming material, in which the number of the silicon carbide particles per unit area on the surface of the substrate is smaller than the number of the silicon carbide particles per unit area in a cross section of the substrate.

Disclosed is a method for manufacturing a ceramic susceptor, the method including: preparing ceramic sheets; preparing a lamination structure of a molded body, in which the ceramic sheets are laminated and a conductive metal layer for electrodes is disposed between the ceramic sheet laminated products; and sintering the lamination structure of the molded body, wherein the preparing of the ceramic sheets includes: obtaining a vitrified first additive powder by heat-treating a slurry containing MgO, SiO.sub.2, and CaO; preparing a slurry by mixing an Al.sub.2O.sub.3 powder with the first additive powder, a second additive powder containing a MgO powder, and a third additive powder containing a Y.sub.2O.sub.3 powder; and forming the ceramic sheets by tape casting the slurry.

Disclosed is a method for manufacturing a ceramic susceptor, the method including: preparing ceramic sheets; preparing a lamination structure of a molded body, in which the ceramic sheets are laminated and a conductive metal layer for electrodes is disposed between the ceramic sheet laminated products; and sintering the lamination structure of the molded body, wherein the preparing of the ceramic sheets includes: obtaining a vitrified first additive powder by heat-treating a slurry containing MgO, SiO.sub.2, and CaO; preparing a slurry by mixing an Al.sub.2O.sub.3 powder with the first additive powder, a second additive powder containing a MgO powder, and a third additive powder containing a Y.sub.2O.sub.3 powder; and forming the ceramic sheets by tape casting the slurry.