Abstract:
The present invention relates to a powder comprising solid ceramic particles, characterized that said particles have an inner porosity of at least 30 %, preferably of at least 45 % and preferably at most 65%, wherein said powder has a particle size with a d10 of at least 100 µm.
Abstract:
Metal ion conducting ceramic materials are disclosed having characteristics of high ion conductivity for certain alkali and monovalent metal ions at low temperatures, high selectivity for the metal ions, good current efficiency and stability in water and corrosive media under static and electrochemical conditions. The metal ion conducting ceramic materials are fabricated to be deficient in the metal ion. One general formulation of the metal ion conducting ceramic materials is Me 1+x+y-z M III y M IV 2-y Si x P 3-x O 12-z/2 , wherein Me is Na + , Li + , K + , Rb + , Cs + , Ag + , or mixtures thereof, 2.0 ≤ x ≤ 2.4, 0.0 ≤ y ≤ 1.0, and 0.05 ≤ z ≤ 0.9, where M III is Al 3+ , Ga 3+ , Cr 3+ , Sc 3+ , Fe 3+ , In 3+ , Yb 3+ , Y 3+ , or mixtures thereof and M IV is Ti 4+ , Zr 4+ , Hf 4+ , or mixtures thereof.
Abstract:
The invention relates to ceramics and glass ceramics exhibiting low and/or negative coefficients of thermal expansion. The invention therefore addresses the problem of indicating a possible method which, at minimized cost and with low melting temperature, can produce ceramics and/or glass ceramics exhibiting low or else negative thermal expansion. According to the invention, the problem is solved via crystalline phases of the type AM 2 Si 2-y Ge y O 7 (A = Sr and Ba, and M = Zn, Mg, Ni, Co, Fe, Cu, Mn, where Sr, Ba and Zn must be present) which can be produced by conventional ceramic processes or by crystallization from glasses. The stated compositions form solid solutions where the elements mentioned as component M can replace one another at almost any desired concentration but the concentration of Zn must always be at least 50 % of the entirety of components listed as M. The stoichiometry of these silicates, and their structure, can differ to a variable extent.
Abstract:
Provided is a coated member which is provided with a heat shielding coating layer that exhibits excellent characteristics in a high temperature environment in which water vapor is present. A coated member (100) which is provided with a heat shielding coating layer (102) that is composed of a zirconia-dispersed silicate wherein ZrO 2 stabilized by Yb 2 O 3 is precipitated as dispersed phases in a matrix that is a rare earth disilicate, a rare earth monosilicate or a mixed phase of a rare earth disilicate and a rare earth monosilicate. The rare earth disilicate is a (Y 1-a [Ln 1a ) 2 Si 2 O 7 solid solution (wherein Ln 1 is Sc, Yb or Lu) or a (Y 1-c [Ln 2 ] c ) 2 Si 2 O 7 solid solution (wherein Ln 2 is Nd, Sm, Eu or Gd); and the rare earth monosilicate is Y 2 SiO 5 , [Ln 1 '] 2 SiO 5 , a (Y 1-b [Ln 1 '] b ) 2 SiO 5 solid solution (wherein Ln 1 ' is Sc, Yb or Lu) or a (Y 1-d [Ln 2 '] d ) 2 SiO 5 solid solution (wherein Ln 2 ' is Nd, Sm, Eu or Gd).
Abstract:
L'invention concerne un procédé comportant les étapes suivantes : a) préparation d'une charge de départ à partir d'un mélange particulaire, b) mise en forme d'une préforme à partir de ladite charge de départ, c) frittage de ladite préforme de manière à obtenir une pièce frittée, le mélange particulaire comportant, en pourcentage massique et pour un total de 100% : - entre 40% et 88% d'une première fraction particulaire constituée de particules de zircone ZrO 2 et contenant un composé apte à stabiliser la zircone, - entre 10% et 50% d'une deuxième fraction particulaire constituée en particulier de particules en un composé de formule XAl m O n , avec X choisi parmi Mg, Ca, Sr, Y, les oxydes de lanthanides et leurs mélanges, m étant un nombre entier tel que 10 ≤ m ≤ 12, n étant un nombre entier tel que 16 ≤ n ≤ 20, et/ou de particules en un composé de formule X x Al a Si b O c (OH) y (H 2 O) z avec X choisi parmi Mg, Ca, Sr, Sc, Y, les oxydes de lanthanides, Ti, Fe, Mn, Co, Cr et leurs mélanges, x, a, b, c, y, z étant des nombres entiers tels que x+a >0, c > 0, b > 0, a/b ≤ 2, x/b ≤ 1, y ≤ 3 (a+x), et z ≤ b, et/ou de particules de SiAlON et/ou constituée de particules en un orthosilicate et/ou de particules en un sorosilicate et/ou de particules en un cyclosilicate et/ou de particules en un inosilicate et/ou de particules en un phyllosilicate et/ou de particules en un tectosilicate et/ou de particules en une argile et/ou de particules en un mélange de ces composés, - moins de 10% d'une troisième fraction particulaire constituée de particules en un oxyde de structure pérovskite, et/ou de particules en un oxyde de structure spinelle et/ou de particules en un oxyde de structure rutile et/ou de particules en un oxyde de structure hématite E 2 O 3 , et/ou de particules en un composé choisi dans le groupe des orthosilicates de zirconium et de praséodyme (Zr,Pr)SiO 4 , des orthosilicates de zirconium et de vanadium (Zr,V)SiO 4 , des orthosilicates de zirconium dans lesquels se trouve de l'oxyde de fer en inclusion et leurs mélanges, et/ou de particules en un mélange de ces composés, - moins de 2% d'une quatrième fraction particulaire constituée d'autres particules.
Abstract:
LTCC devices are produced from dielectric compositions comprising a mixture of precursor materials that, upon firing, forms a dielectric material comprising a matrix of titanates of alkaline earth metals, the matrix doped with at least one selected from rare-earth element, aluminum oxide, silicon oxide and bismuth oxide.
Abstract:
The present invention provides a refractory composition containing expandable powder that consists of an alkali metal oxide and silicon oxide and is coated onto a steel frame structure of a building or a structure requiring fire prevention or fireproofing in order to prevent the strength or resistance force of the structure from being deteriorated by high-temperature heat in case of fire. The refractory composition of the present invention specifically consists of 1wt% to 50wt% of expandable powder composed of silicate, 20wt% to 80wt% of silicate binder, 0.05wt% to 5wt% of stabilizer, and 0.01wt% to 10wt% of fiber.
Abstract:
A coating including a bond layer deposited on a substrate. The bond layer includes a rare earth silicate and a second phase, the second phase including at least one of silicon, silicides, alkali metal oxides, alkali earth metal oxides, glass ceramics, Al2O3, TiO2, Ta2O5, HfO2, ZrO2, HfSiO4, ZrSiO4, HfTiO4, ZrTiO4, or mullite. The coating may provide thermal and/or environmental protection for the substrate, especially when the substrate is a component of a high-temperature mechanical system.