Patent classifications
C04B2235/608
Salt ceramic composites and manufacture thereof
Highly dense lithium based ceramics can be prepared by a low temperature process including combining a lithium based ceramic with a polar solvent having a lithium based salt dissolved therein and applying pressure and heat to the combination to form a salt-ceramic composite. Advantageously, the lithium salt is one that dissolves in the polar solvent and the heat applied to the combination is no greater than about 250° C. Such composites can also have high ionic conductivity.
Multilayer substrate
A multilayer substrate that includes a first ceramic layer that is a dense body, a second ceramic layer that has open pores, and a resin layer adjacent the second ceramic layer, wherein a material of the resin layer is present in the open pores of the second ceramic layer.
Indirect additive manufacturing process for producing SiC—B4C—Si composites
A method for indirect additive manufacturing of an object constructed of boron carbide, silicon carbide, and free silicon, comprising: (i) producing a porous preform constructed of boron carbide and silicon carbide by an indirect ceramic additive manufacturing (ICAM) process in which particles of a powder mixture become bonded together with an organic binder, wherein the powder mixture comprises: a) boron carbide particles, and b) silicon carbide particles, wherein at least 80 vol % of the silicon carbide particles are larger than the boron carbide particles; and wherein the boron carbide and silicon carbide particles are each included in an amount of 40-60 wt. % of the powder mixture, provided that the foregoing amounts sum to at least 95 wt. %; (ii) subjecting the porous preform to a temperature of 500-900° C. to volatilize the organic binder; and (iii) infiltrating molten silicon into pores of the porous preform to produce the object.
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.
METHOD FOR MANUFACTURING HIGH-DENSITY ARTIFICIAL GRAPHITE ELECTRODE
Provided is a method for manufacturing a high-density artificial graphite electrode without substantially changing a particle size or a proportion of needle coke used, increasing an amount of binder pitch, or performing extrusion molding at a high molding pressure. The method for manufacturing a high-density artificial graphite electrode is kneading binder pitch into needle coke, performing extrusion molding thereof, and then calcining and graphitizing thereof, wherein needle coke obtained by performing coke shape changing treatment for at least some of pulverized needle coke to be used, thereby increasing a ratio of an enveloping perimeter/a perimeter by 1% or more as compared with a value before the changing is used. Here, the enveloping perimeter is a length of a perimeter when apexes of convex portions of the pulverized needle coke are connected to each other via the shortest distance, and the perimeter is a length of a perimeter of a particle.
METHOD TO FABRICATE A MACHINABLE CERAMIC MATRIX COMPOSITE
A method to form a machinable ceramic matrix composite comprises forming a porous ceramic multilayer on a surface of a fiber preform. In one example, the porous ceramic multilayer comprises a gradient in porosity in a direction normal to the surface. In another example, the porous ceramic multilayer includes low-wettability particles having a high contact angle with molten silicon, where an amount of the low-wettability particles in the porous ceramic multilayer varies in a direction normal to the surface. After forming the porous ceramic multilayer, the fiber preform is infiltrated with a melt, and the melt is cooled to form a ceramic matrix composite with a surface coating thereon. An outer portion of the surface coating is more readily machinable than an inner portion of the surface coating. The outer portion of the surface coating is machined to form a ceramic matrix composite having a machined surface with a predetermined surface finish and/or dimensional tolerance.
Process and slip for the production of ceramic shaped bodies made of zirconium oxide by 3D inkjet printing
Process and slip for the production of ceramic shaped parts made of zirconium oxide ceramic by a 3D inkjet printing process. The slip contains zirconium oxide which is suspended in a liquid medium, wherein the slip has a zirconium oxide content of from 68 to 88 wt.-% and contains not more than 5 wt.-% organic components. The process for the production of ceramic components comprises the layered shaping and subsequent sintering of the desired component from the slip.
ZINC OXIDE VARISTOR CERAMICS
Provided according to embodiments of the invention are varistor ceramic formulations that include zinc oxide (ZnO). In particular, varistor ceramic formulations of the invention may include dopants including an alkali metal compound, an alkaline earth compound, an oxide of boron, an oxide of aluminum, or a combination thereof. Varistor ceramic formulations may also include other metal oxides. Also provided according to embodiments of the invention are varistor ceramic materials formed by sintering a varistor ceramic formulation according to an embodiment of the invention. Further provided are varistors formed from such ceramic materials and methods of making such materials.
ZIRCONIA MOLDED BODY SUITABLE FOR DENTAL USE
A zirconia molded body and a dental mill blank may decrease of the translucency of a zirconia sintered body upon firing even when the cooling solvent used for wet processing of the zirconia molded body or dental mill blank by a dental CAD/CAM system is contaminated. This can allow more convenient fabrication of a zirconia sintered body. A zirconia molded body may include zirconia; a stabilizer capable of inhibiting a phase transformation of zirconia; and a binder, and having an open porosity of 25% or less.
Diamond composites by lithography-based manufacturing
A lithography based method for the manufacture of diamond composite materials in which green bodies are prepared by a layer-by-layer construction with resulting green bodies de-bound and sintered to achieve a dense high hardness material.