Abstract:
Superconductor, comprisingmaterial comprising material comprising stacked first and second layers, each of the layers comprising a network of cations surrounded by oxygen anions. According to the present invention, the material has an ilmenite crystal structureandabasiccomposition of type ABX 3 , where A and B are elementsdominantly occupying the cation sites of the first and the second layers, correspondingly, at least one of the elements A and B being a transition metal, and Xis an anion element dominantly occupying the anion sites.
Abstract:
Disclosed is a method for producing an oxynitride powder (such as a Ca-containing alpha sialon powder) wherein a precursor compound containing at least M, Si Al and O elements (with M being one element or a mixture of two or more elements selected from the group consisting of Li, Mg, Ca, Sr, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu) is heated in a reducing-nitriding atmosphere, thereby reducing the oxygen content of the precursor compound while increasing nitrogen content thereof. Also disclosed is an oxynitride powder obtained by such a method. By this method, there can be obtained an oxynitride powder mainly containing a fine alpha sialon powder which is preferably used for phosphors and free from coloring caused by inclusion of impurities.
Abstract:
A continuous process for the manufacture of a ceramic sintered comopact wherein the process comprises the steps of: forming a green compact from a powder mixture comprising a first component comprising compounds which contain elements of silicon, aluminum, oxygen and nitrogen; and the powder mixture further comprising a second component comprising a compound of at least one element selected from the group consisting of yttrium, scandium, cerium, lanthanum and the metals of the lanthanide series, and the second component comprising between 0.1 and 10 weight percent of the powder mixture; heat treating the green compact wherein the heat treatment comprises continously passing the green compact through at least one heating zone so as to produce a sintered compact.
Abstract:
A sinterable material for forming SiAlON ceramic material. The sinterable material is a powder mixture containing six elements: (a) silicon nitride, (b) aluminum nitride, (c) an oxide or nitride of a rare earth element, (d) an oxide or nitride of strontium, (e) an oxide or nitride of calcium, magnesium, lithium, or sodium, and (f) a non-alloying additive which is an oxide or nitride of zirconium, tantalum, gallium, hafnium, or indium, the non-alloying additive being present in an amount of at least about 0.3 weight percent based on the weight of the powder mixture. The sinterable material can be made into a ceramic body using a method of the present invention. The method includes three steps: making the powder mixture, forming the powder mixture into a greenware body, and sintering the greenware body at an elevated temperature to form the SiAlON ceramic body. The SiAlON ceramic body of the present invention contains a ceramic material which incorporates the non-alloying additive within the material at a level of at least about 0.3 weight percent. The ceramic body has at least an alpha-SiAlON phase and a beta-SiAlON phase which define an alpha-to-beta weight ratio. The alpha-to-beta weight ratio is in the range of from about 10:90 to about 90:10. Silicon carbide particulates can be incorporated into the powder mixture. Low-pressure or pressureless sintering can be used.
Abstract:
The present invention proposes a blade for a cutting tool, wherein the blade is at least partly formed from a ceramic material with optical transparency. The present invention further proposes a method for production thereof.
Abstract:
A SiAlON composite according to an embodiment of the present disclosure comprises a SiAlON phase including α-SiAlON phase, β-SiAlON phase and grain boundary phase. The SiAlON composite is prepared from a starting powder mixture including a silicon nitride powder and at least one powder providing aluminum, oxygen, nitrogen, yttrium (Y) and erbium (Er) to the SiAlON composite. The SiAlON composite contains the SiAlON phase of at least 90 vol%, z-value of the β-SiAlON phase ranges between 0.27 and 0.36 and thermal diffusivity of the SiAlON composite is equal to or greater than 2.4 (mm 2 /sec) and equal to or less than 5.2 (mm 2 /sec).