A composite ceramic including: a lithium garnet major phase; and a grain growth inhibitor minor phase, as defined herein. Also disclosed is a method of making composite ceramic, pellets and tapes thereof, a solid electrolyte, and an electrochemical device including the solid electrolyte, as defined herein.

A cemented carbide including a hard phase, a binding phase, and inevitable impurities. The hard phase satisfies a first hard phase composed mainly of tungsten carbide, and a second hard phase composed mainly of a compound. The compound contains multiple types of metallic elements including tungsten and at least one element selected from carbon, nitrogen, oxygen, and boron. The second hard phase satisfies D10/D90<0.4, wherein D10 denotes a cumulative 10% grain size in an area-based grain size distribution on a surface or cross section of the cemented carbide, and D90 denotes a cumulative 90% grain size in the area-based grain size distribution, and satisfies .sup.2<5.0, wherein .sup.2 denotes the variance of the distance between the centroids of the nearest two of the second hard phases. The average grain size D.sub.W of the first hard phase ranges from 0.8 to 4.0 m and satisfies D.sub.M/D.sub.W<1.0, wherein D.sub.M denotes the average grain size of the second hard phase.

Disclosed is a method for fabricating a solid article from a boron carbide powder comprising boron carbide particles that are coated with a titanium compound. Further disclosed herein are the unique advantages of the combined use of titanium and graphite additives in the form of water soluble species to improve intimacy of mixing in the green state. The carbon facilitates sintering, whose concentration is then attenuated in the process of forming very hard, finely dispersed TiB.sub.2 phases. The further recognition of the merits of a narrow particle size distribution B.sub.4C powder and the use of sintering soak temperatures at the threshold of close porosity which achieve post-HIPed microstructures with average grain sizes approaching the original median particle size. The combination of interdependent factors has led to B.sub.4C-based articles of higher hardness than previously reported.

Disclosed is a method for fabricating a solid article from a boron carbide powder comprising boron carbide particles that are coated with a titanium compound. Further disclosed herein are the unique advantages of the combined use of titanium and graphite additives in the form of water soluble species to improve intimacy of mixing in the green state. The carbon facilitates sintering, whose concentration is then attenuated in the process of forming very hard, finely dispersed Ti B2 phases. The further recognition of the merits of a narrow particle size distribution B4C powder and the use of sintering soak temperatures at the threshold of close porosity which achieve post-HIPed microstructures with average grain sizes approaching the original median particle size. The combination of interdependent factors has led to B4C-based articles of higher hardness than previously reported.

A method for producing a metal fluoride ceramic, comprising: providing a sedimented compound comprising metal fluoride particles having an average particle size lower than 30 nm and a solvent, partially drying the sedimented compound at a temperature lower than 65 C. until the partially dried compound comprises from 5 wt % to 45 wt % of the solvent, and sintering, for example in air, the partially dried and sedimented compound.

Synthetic ceramic proppants are described. Proppants having a monodispersity of 3-sigma distribution or lower are also described, including methods to make these proppants and methods of using these proppants.

A multi-layer ceramic capacitor has a structure where the dispersion, nd, of average grain size of the dielectric grains constituting the dielectric layer (a value (D90/D10) obtained by dividing D90 which is a grain size including 90% cumulative abundance of grains by D10 which is a grain size including 10% cumulative abundance of grains) is smaller than 4.

The disclosure relates to sintered ceramic grains comprising 3-55 wt. % alumina, 40-95 wt. % zirconia and 1-30 wt. % of one or more other inorganic components.

The invention further relates to a method for preparing ceramic grains according to the invention, comprising: making a slurry comprising alumina, zirconia; making droplets of the slurry; introducing the droplets in a liquid gelling-reaction medium wherein the droplets are gellified; drying the gellified deformed droplets.

Synthetic ceramic proppants are described. Proppants having a monodispersity of 3-sigma distribution or lower are also described, including methods to make these proppants and methods of using these proppants.

A method for manufacturing an alumina sintered body, according to the present invention, includes the steps of (a) obtaining a compact by putting a slurry containing an Al.sub.2O.sub.3 powder, a MgO powder, a MgF.sub.2 powder, a solvent, a dispersing agent, and a gelatinizer into a mold, gelatinizing the slurry by a chemical reaction of the gelatinizer in the mold, and causing mold release, (b) obtaining a calcined body by drying the compact, performing degreasing, and further performing calcination, and (c) obtaining a ceramic sintered body by subjecting the calcined body to hot-press firing at 1,150 C. to 1,350 C. In the step (a), the Al.sub.2O.sub.3 powder having a purity of 99.9 percent by mass or more is used and 0.1 to 0.2 parts by mass of MgO powder and 0.13 parts by mass or less of MgF.sub.2 powder relative to 100 parts by mass of Al.sub.2O.sub.3 powder are used.