Patent classifications
C04B2235/449
Moldable silicon nitride green-body composite and reduced density silicon nitride ceramic process
A moldable green-body composite includes milling silicon nitride powder with a solvent and adding a surface modifier to the milled slurry to modify a surface of the silicon nitride particles. A polysiloxane in a solvent and a binder are also added to create a green body slurry. The solvents may be polar or non-polar solvents. A sintering aid, such as yttria-alumina, may be added to the slurry as well. A reduced density silicon nitride ceramic is made from the moldable green-body composite by molding the moldable green-body composite in a mold and curing at a curing temperature to convert the moldable green-body composite to a converted composite. The converted composite can then be sintered to form a reduced density silicon nitride ceramic that has a smooth surface finish and requires no post machining or polishing. The reduced density silicon nitride ceramic may also have very good dielectric properties.
COLD-SETTING DRY VIBRATABLE MIX
The invention relates to a refractory dry vibratable mix which sets at room temperature when water is added, for use in metallurgical vessels and comprising a refractory main component, a binder and a retarder.
INSULATING PRODUCT FOR THE REFRACTORY INDUSTRY, CORRESPONDING INSULATING MATERIALS AND PRODUCTS, AND USES
An insulating product for the refractory industry or an insulating material as intermediate for production of such a product, and a corresponding insulating material/insulating product are provided. Likewise the use of a matrix encapsulation process in the production of an insulating product for the refractory industry and a corresponding insulating product and/or an insulating material as intermediate for production of such a product are provided.
Titanium nitride-reinforced zirconia toughened alumina ceramic powder and preparation method thereof
The present invention provides titanium nitride-reinforced zirconia toughened alumina (ZTA) ceramic powder and a preparation method thereof, and belongs to the technical field of ceramic materials. The preparation method provided in the present invention includes the following steps: mixing an aluminum salt, a zirconium salt, a yttrium salt, and a titanium salt with water to obtain a mixed aqueous solution, where the aluminum salt, the zirconium salt, the yttrium salt, and the titanium salt are water-soluble inorganic salts; mixing the obtained mixed aqueous solution and an alkaline precipitant for precipitation, to obtain hydroxide precipitate powder; successively conducting first calcination and second calcination on the obtained hydroxide precipitate powder, to obtain oxide solid solution powder; and subjecting the obtained oxide solid solution powder to selective nitridation reaction, to obtain titanium nitride-reinforced ZTA ceramic powder.
GAS DETECTION COMPLEX AND METHOD FOR PRODUCING SAME, GAS SENSOR COMPRISING GAS DETECTION COMPLEX AND METHOD FOR MANUFACTURING SAME
The inventive concept relates to a complex for detecting gas responsive to gas to be tested. The complex for the detecting the gas contains a nanostructure made of an oxide semiconductor, and a Terbium (Tb) additive supported on the nanostructure.
Oxide superconductor and method for manufacturing the same
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).
Oxide superconductor and method for manufacturing the same
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.
MULTIPHASE CERAMIC MATERIAL WITH GIANT DIELECTRIC CONSTANT, AND PREPARATION METHOD THEREOF
The present invention discloses a multiphase ceramic material with a giant dielectric constant, wherein the multiphase ceramic material has a general formula of A.sub.xB.sub.nxTi.sub.1−(n+1)xO.sub.2; wherein A is at least one selected from the group consisting of Nb, Ta, V, Mo, and Sb, B is at least one selected from the group consisting of In, Ga, Al, Co, Cr, Sc, Fe (III), and a trivalent rare-earth cation; n is a molar ratio of B to A, 1<n≤5 , 0<x≤0.1. The multiphase ceramic material possesses outstanding properties including a giant dielectric constant, a low dielectric loss, and excellent frequency- and temperature-stability. In particular, it exhibits a high insulation resistivity of higher than 10.sup.11 Ω.Math.cm and a high breakdown voltage, which implies it can be applied in high-energy storage devices and supercapacitors. This invention also provides a method to synthesize the multiphase ceramic material.
Zirconia article with high alumina content, process of production and use thereof
The invention relates to a porous zirconia article in particular for use in the dental or orthodontic field, the porous zirconia article comprising ZrO.sub.2: 80 to 87 wt. %, Y.sub.2O.sub.3: 3 to 5 wt. %, Al.sub.2O.sub.3: 10 to 14 wt. %, wt. % with respect to the weight of the porous zirconia article, the porous zirconia article being characterized by a BET surface from 15 to 100 m.sup.2/g. The invention also relates to a sintered zirconia article in particular for use in the dental or orthodontic field, the sintered zirconia article comprising ZrO.sub.2: 80 to 87 wt. %, Y.sub.2O.sub.3: 3 to 5 wt. %, Al.sub.2O.sub.3: 10 to 14 wt. %, wt. % with respect to the weight of the porous zirconia article, the sintered zirconia article being characterized by a corundum crystal phase content of 7 to 12 wt. % and a flexural strength of at least 2,000 MPa.
Sintered platelet-like randomly shaped abrasive particles and method of making same
The present invention relates to sintered platelet-like randomly shaped abrasive particles based on alpha alumina having a hardness H.sub.V of at least 20 GPa and a crystal structure with an average crystal size between 100 nm and 300 nm, whereby the abrasive particles comprise a body having a first surface and a second surface opposite to the first surface, both surfaces are separated from each other by a randomly shaped sidewall having a thickness (T) between 20 μm and 500 μm.