A method of producing polycrystalline Y.sub.3Ba.sub.5Cu.sub.8O.sub.y (Y-358) whereby powders of yttrium (III) oxide, a barium (II) salt, and copper (II) oxide are pelletized, calcined at 850 to 950° C. for 8 to 16 hours, ball milled under controlled conditions, pelletized again and sintered in an oxygen atmosphere at 900 to 1000° C. for up to 72 hours. The polycrystalline Y.sub.3Ba.sub.5Cu.sub.8O.sub.y thus produced is in the form of elongated crystals having an average length of 2 to 10 μm and an average width of 1 to 2 μm, and embedded with spherical nanoparticles of yttrium deficient Y.sub.3Ba.sub.5Cu.sub.8O.sub.y having an average diameter of 5 to 20 nm. The spherical nanoparticles are present as agglomerates having flower-like morphology with an average particles size of 30 to 60 nm. The ball milled polycrystalline Y.sub.3Ba.sub.5Cu.sub.8O.sub.y prepared under controlled conditions shows significant enhancement of superconducting and flux pinning properties.

A polycrystalline cubic boron nitride comprising 96% by volume or more of cubic boron nitride, wherein the cubic boron nitride has a dislocation density of more than 8×10.sup.15/m.sup.2, the polycrystalline cubic boron nitride comprises a plurality of crystal grains, and the plurality of crystal grains have a median diameter d50 of an equivalent circle diameter of less than 100 nm.

The present invention provides a silicon nitride sintered substrate capable of reducing contamination caused by a boron nitride powder or the like used as a releasing agent and problems in bonding strength and dielectric strength at the time of laminating metal layers or the like, where the contamination is caused by a network structure provided by a silicon nitride crystal formed on the surface of the substrate in an unpolished state after sintering a silicon nitride powder. The silicon nitride substrate in an unpolished state after sintering is a silicon nitride sintered substrate where a cumulative volume of pores having a diameter in a range of 1 to 10 μm is not more than 7.0'10.sup.−5 mL/cm.sup.2 in a measurement by a mercury porosimetry. Preferably, Ra of the surface is not more than 0.6 μm and arithmetic mean peak curvature (Spc) of a peak is not more than 4.5 [l/mm].

A cubic boron nitride sintered material comprises cubic boron nitride particles and a binding phase. The binding phase includes a first region and a second region. The first region accounts for 1.0 vol % or more in the binding phase. The first region includes a plurality of needle crystals. Each of the plurality of needle crystals includes a boride. Each of the plurality of needle crystals has an aspect ratio of 1.5 or more in a cross-section image of the cubic boron nitride sintered material.

A corrosion-resistant component configured for use with a semiconductor processing reactor, the corrosion-resistant component comprising: a) a ceramic insulating substrate; and, b) a white corrosion-resistant non-porous outer layer associated with the ceramic insulating substrate, the white corrosion-resistant non-porous outer layer having a thickness of at least 50 μm, a porosity of at most 1%, and a composition comprising at least 15% by weight of a rare earth compound based on total weight of the corrosion-resistant non-porous layer; and, c) an L* value of at least 90 as measured on a planar surface of the white corrosion-resistant non-porous outer layer. Methods of making are also disclosed.

A corrosion-resistant component configured for use with a semiconductor processing reactor, the corrosion-resistant component comprising: a) a ceramic insulating substrate; and, b) a white corrosion-resistant non-porous outer layer associated with the ceramic insulating substrate, the white corrosion-resistant non-porous outer layer having a thickness of at least 50 μm, a porosity of at most 1%, and a composition comprising at least 15% by weight of a rare earth compound based on total weight of the corrosion-resistant non-porous layer; and, c) an L* value of at least 90 as measured on a planar surface of the white corrosion-resistant non-porous outer layer. Methods of making are also disclosed.

The present invention relates to the field of MAX-phase ceramic-based composites, specifically to a short-fiber-reinforced oriented MAX-phase ceramic-based composite and a preparation method therefor. By using a new process with a fiber, a nano lamellar MAX-phase ceramic powder, other additives, etc., for preparing a fiber-reinforced MAX-phase ceramic-based composite, a novel ternary composite is prepared, wherein a matrix is composed of a highly oriented lamellar MAX-phase ceramic, the fiber is distributed parallel to the lamellar MAX-phase ceramic in an axial direction, and a granulate ceramic phase enhancement phase is dispersed in the matrix. Thus, the problems of a MAX-phase ceramic-based composite matrix material prepared by an existing method, such as coarse grains, multiple internal defects and a low strength, and a poor fracture toughness; and a reaction sintering temperature being too high such that fibers are chemically and physically damaged in a substrate, resulting in performance degradation, are solved. Fibers prepared by the method are suitable for large-scale industrial preparation and have properties that are far superior to those of any existing known fiber MAX-phase composite.

A highly oriented nanometer MAX phase ceramic and a preparation method for a MAX phase in-situ autogenous oxide nanocomposite ceramic. The raw materials comprise a MAX phase ceramic nano-lamellar powder body or a blank body formed by the nano-lamellar powder body, wherein MAX phase ceramic nano-lamellar particles in the powder body or the blank meet the particle size being between 20-400 nm, and the oxygen content is between 0.0001%-20% by mass; MAX phase grains in the ceramic obtained after the raw materials are sintered are lamellar or spindle-shaped, the lamellar structure having a high degree of orientation. Utilizing special properties of the nano-lamellar MAX powder body, orientation occurs during compression and deformation to obtain a lamellar structure similar to that in a natural pearl shell, and such a structure has a high bearing capacity and resistance to external loads and crack propagation, just like a brick used in a building.

A method of producing polycrystalline Y.sub.3Ba.sub.5Cu.sub.8O.sub.y (Y-358) whereby powders of yttrium (III) oxide, a barium (II) salt, and copper (II) oxide are pelletized, calcined at 850 to 950° C. for 8 to 16 hours, ball milled under controlled conditions, pelletized again and sintered in an oxygen atmosphere at 900 to 1000° C. for up to 72 hours. The polycrystalline Y.sub.3Ba.sub.5Cu.sub.8O.sub.y thus produced is in the form of elongated crystals having an average length of 2 to 10 μm and an average width of 1 to 2 μm, and embedded with spherical nanoparticles of yttrium deficient Y.sub.3Ba.sub.5Cu.sub.8O.sub.y having an average diameter of 5 to 20 nm. The spherical nanoparticles are present as agglomerates having flower-like morphology with an average particles size of 30 to 60 nm. The ball milled polycrystalline Y.sub.3Ba.sub.5Cu.sub.8O.sub.y prepared under controlled conditions shows significant enhancement of superconducting and flux pinning properties.

The present invention relates to a bismuth-based solid solution ceramic material, as well as a process for preparing the ceramic material and uses thereof, particularly in an actuator component employed, for example, in a droplet deposition apparatus. In particular, the present invention relates to a ceramic material having a general chemical formula (I): (I): x(Bi.sub.0.5Na.sub.0.5)TiO.sub.3-y(Bi.sub.0.5K.sub.0.5)TiO.sub.3-z.sub.1SrHfO.sub.3-z.sub.2SrZrO.sub.3, wherein x+y+Z.sub.1+Z.sub.2=1; y, (z.sub.1+z.sub.2)≠0; x≥0. In embodiments, the present invention also relates to a ceramic material having a general chemical formula (II): x(Bi0.5Na0.5)TiO3-y(Bi0.5K0.5)TiO3-y(Bi0.5K0.5)TiO3-ZiSrHfO3-z2SrZrO3, wherein x+y+z−i+z2=1; x, y, fa+z2)≠0; as well as a ceramic material of general formula (III): y(Bi.sub.0.5K.sub.0.5)TiO.sub.3-z.sub.1SrHfO.sub.3-z.sub.2SrZrO.sub.3, wherein y+z.sub.1,+z.sub.2=1; y, (z.sub.1+z.sub.2)≠0.