The present invention provides a focus ring having favorable plasma resistance. In addition, the present invention provides a method for producing a focus ring which enables the easy production of focus rings having favorable plasma resistance. The focus ring of the present invention is a focus ring made of a sintered body of silicon carbide, in which the sintered body includes a plurality of first crystal grains having an -SiC-type crystal structure and a plurality of second crystal grains having a -SiC-type crystal structure, a content of the first crystal grains is 70% by volume or more of a total of the first crystal grains and the second crystal grains, and a volume-average crystallite diameter of the first crystal grains is 10 m or less.

A particulate composite ceramic material may include: particles of at least one first ultra-high-temperature ceramic UHTC, the outer surface of the particles being at least partially covered by a porous layer made of at least one second UHTC in amorphous form; and the particles defining a space therebetween; optionally, porous clusters of the at least one second ultra-high-temperature ceramic in amorphous form, distributed in said space; a dense matrix and at least one third UHTC in crystallized form at least partially filling the space; optionally, a dense coating made of at least the third UHTC in crystallized form, covering the outer surface of the matrix, the matrix and the coating representing 5% to 90% by mass with respect to the total mass of the material. A part may include such a particulate ceramic composite material.

Provided is a composite sintered body for an electrostatic chuck, which is not easily broken even if it is exposed to high-power plasma. Further, provided are an electrostatic chuck device using such a composite sintered body for an electrostatic chuck and a method of manufacturing a composite sintered body for an electrostatic chuck. The composite sintered body for an electrostatic chuck is a composite sintered body including an insulating ceramic and silicon carbide, in which crystal grains of the silicon carbide are dispersed in at least one selected from the group consisting of a crystal grain boundary and a crystal grain of a main phase formed by sintering crystal grains of the insulating ceramic.

An electrostatic chuck device includes: a base having one principal surface which is a placing surface on which a plate-shaped sample is placed, wherein the base is made from a sintered compact of ceramic particles, which include silicon carbide particles and aluminum oxide particles, as a forming material; and an electrostatic attraction electrode which is provided on a surface of the base on the side opposite to the placing surface of the base, or in the interior of the base, in which the volume resistivity value of the sintered compact is 0.510.sup.15 cm or more in the entire range from 24 C. to 300 C., a graph which shows the relationship of the volume resistivity value of the sintered compact to a temperature at which the volume resistivity value of the sintered compact is measured has a maximum value in the range from 24 C. to 300 C., and the amount of metal impurities in the sintered compact other than aluminum and silicon in the sintered compact is 100 ppm or less.

A ceramic aerogel includes a porous framework including interconnected double-paned wall structures of a ceramic material, wherein each double-paned wall structure includes a pair of walls spaced apart by a gap.

The present invention relates to a method of producing a SiCSi composite component. The method includes preparing a first molded body containing SiC particles by a 3D printing method, wherein the first molded body has a first average pore diameter M.sub.1; forming a second molded body, in which the first molded body and a dispersion containing carbon particles are brought into contact so that the pores are impregnated with the carbon particles, wherein the carbon particles have a secondary particle having an average particle diameter M.sub.2, and the carbon particles satisfy the following formula:

M.sub.2?M.sub.1/10; and forming a SiCSi composite component by carrying out that the second molded body is impregnated with a metallic si and is reactively sintered; wherein the content of Si is in the range of 5% by mass to 40% by mass in the SiCSi composite component.

The present invention relates to joined silicon carbide (SiC) ceramics and a method for processing the same. And, most particularly, the joined silicon carbide (SiC) ceramics and the method for processing the same provide a method for processing joined silicon carbide (SiC) ceramics including the steps of sintering silicon carbide substrates configuring the joined ceramics, processing a joined silicon carbide ceramics preparation by layering a non-sintered silicon carbide bond having a same composition as the silicon carbide substrate between at least two substrates selected from the sintered silicon carbide substrates, and processing the joined silicon carbide ceramics by performing heat treatment on the joined silicon carbide ceramics preparation. According to the above-described invention, by using a bond having the same composition as the silicon carbide substrate, since residual stress-free joined ceramics can be processed, joined silicon carbide ceramics having a high strength corresponding to 65 to 190% of a strength of the substrate may be processed.

A method of producing a component of a composite of diamond and a binder, wherein a Hot Isostatic gas Pressure process (HIP) is used, includes the step of enclosing a de-bound green body having compacted diamond particles in an infiltrant. The method includes the further steps of enclosing the de-bound green body and the infiltrant in a Zr-capsule that has Zirconium as a main constituent and sealing the Zr-capsule, and applying a predetermined pressure-temperature cycle on the unit formed by the de-bound green body, infiltrant and capsule in which the infiltrant infiltrates the de-bound green body and the de-bound green body is further densified in the sense that the volume thereof is decreased.

The present invention relates to a method for preparing a fully ceramic capsulated nuclear fuel material containing three-layer-structured isotropic nuclear fuel particles coated with a ceramic having a composition which has a higher shrinkage than a matrix in order to prevent cracking of ceramic nuclear fuel, wherein the three-layer-structured nuclear fuel particles before coating is included in the range of between 5 and 40 fractions by volume based on after sintering. More specifically, the present invention provides a composition for preparing a fully ceramic capsulated nuclear fuel containing three-layer-structured isotropic particles coated with the substance which includes, as a main ingredient, a silicon carbine derived from a precursor of the silicon carbide wherein a condition of L.sub.c>L.sub.m at normal pressure sintering is created, where the sintering shrinkage of the coating layer of the three-layer-structured isotropic nuclear fuel particles is L.sub.c and the sintering shrinkage of the silicon carbide matrix is L.sub.m; material produced therefrom; and a method for manufacturing the material. The residual porosity of the fully ceramic capsulated nuclear fuel material is 4% or less.

The present invention provides a focus ring having favorable plasma resistance. In addition, the present invention provides a method for producing a focus ring which enables the easy production of focus rings having favorable plasma resistance. The focus ring of the present invention is a focus ring made of a sintered body of silicon carbide, in which the sintered body includes a plurality of first crystal grains having an -SiC-type crystal structure and a plurality of second crystal grains having a -SiC-type crystal structure, a content of the first crystal grains is 70% by volume or more of a total of the first crystal grains and the second crystal grains, and a volume-average crystallite diameter of the first crystal grains is 10 m or less.