The invention relates to a lead-free piezoceramic material based on bismuth sodium titanate (BST) having the following parent composition: x(Bi.sub.0.5Na.sub.0.5)TiO.sub.3-yBaTiO.sub.3-zSrTiO.sub.3 where x+y+z=1 and 0<x<1, 0<y<1, 0≤z≤0.07 or x(Bi.sub.0.5Na.sub.0.5)TiO.sub.3-yBaTiO.sub.3-zCaTiO.sub.3 where x+y+z=1 and 0<x<1, 0<y<1, 0<z≤0.05 or x(Bi.sub.0.5Na.sub.0.5)TiO.sub.3-y(Bi.sub.0.5K.sub.0.5)TiO.sub.3-zBaTiO.sub.3 where x+y+z=1 and 0<x<1, 0<y<1, 0≤z<1, characterized by addition of a phosphorus-containing material in a quantity that gives a phosphorus concentration of from 100 to 2000 ppm in the piezoceramic material.

This document describes processes for preparing ceramics, especially lithium-based ceramics. The ceramics produced by this process and their use in electrochemical applications are also described as well as electrode materials, electrodes, electrolyte compositions, and electrochemical cells comprising them.

A process for making a thermal insulation material based on carbon and which includes carbon fibers, suitable for use at temperatures above 1,500° C. The process includes providing carbon fibers with embedded carbon black particles; cutting or milling said carbon fibers to obtain short carbon filaments; preparing a slurry by introducing the short carbon filaments in a liquid phase that includes a binder capable of forming a carbon residue upon pyrolysis under non-oxidizing conditions; casting the slurry into a mold capable of separating the slurry into a wet green body and a liquid phase; and drying and heat treating the wet green body to obtain a thermal insulation material.

A method of selectively removing at least part of a first phase from a surface of a nanocomposite includes at least a first phase and a second phase, each phase having a respective threshold fluence under a given number of applied laser pulses for removal of the phase by laser ablation. The threshold fluence of the first phase is less than the threshold fluence of the second phase. The method includes irradiating the surface of the nanocomposite with a laser beam having a laser beam diameter, a laser pulse duration, and a laser pulse energy during the irradiation. The laser fluence during the irradiation is less than the threshold fluence of the second phase and greater than the threshold fluence of the first phase. The laser beam diameter is greater than an average grain size of the first phase at the surface of the nanocomposite.

The invention belongs to the field of electronic ceramics and its manufacturing, in particular to the modified NiO-Ta.sub.2O.sub.5-based microwave dielectric ceramic material sintered at low temperature and its preparation method. It is guided by ion doping modification, not only considering the substitution of ions with similar radius, such as Zn.sup.2+ replacing Ni.sup.2+ ions, V.sup.5+ replacing Ta.sup.5+ ions; Meanwhile, the selected doped oxide still has the property of low melting point. Therefore, the microwave dielectric properties of NiO-Ta.sub.2O.sub.5-based ceramic material can be improved and the appropriate sintering temperature can be reduced. In the invention, by adjusting the molar content of each raw material, the NiO-Ta.sub.2O.sub.5-based ceramic material with low-temperature sintering, stable temperature and excellent microwave dielectric property is directly synthesized at one time, which can be widely applied to the technical field of LTCC.

The present invention relates to a ceramic ball having a detergent function and a method for manufacturing a ceramic ball, which can improve washing capacity since the ceramic ball is molded such that the surface area coming into contact with water gets wider, and can improve production efficiency and reduce the manufacturing cost since it is possible to manufacture ceramic balls continuously and automatically.

The present disclosure relates to a magnesium-based raw material and a preparation method thereof. According to the technical solution, 40-60 wt % fused magnesia particles, 30-40 wt % fine monoclinic zirconia powder, 5-20 wt % fine zirconium oxychloride powder, 0.5-1.5 wt % calcium hydroxide nanopowder, 0.2-0.5 wt % calcium hydroxide nanopowder, and 0.1-0.3 wt % maleic acid are stirred for 15 min to mix well in a high-speed mixing mill at a constant temperature of 25° C. to obtain a mixed powder; and the mixed powder is mixed through a ball mill at a constant temperature of 25° C. for 3 min, roasted in a high temperature furnace at 250-400° C. for 0.5-3 h, and finally cooled to room temperature.

A thermoelectric conversion material formed of a sintered body containing magnesium silicide as a main component contains 0.5 mass % or more and 10 mass % or less of aluminum oxide. The aluminum oxide is distributed at a crystal grain boundary of the magnesium silicide.

Provided is a piezoelectric ceramics including crystal grains each including: a first region that is formed of a perovskite-type metal oxide having a crystal structure in which a central element of a unit cell is located at an asymmetrical position; and a second region that is formed of a perovskite-type metal oxide having a crystal structure in which a central element of a unit cell is located at a symmetrical position, and that is present inside the first region, wherein a ratio of a cross-sectional area of the second region to a cross-sectional area of the piezoelectric ceramics is 0.1% or less.

A silicon nitride powder for sintering which, despite of its fine powdery form, shows a very small increase in the oxygen concentration with time and features excellent storage stability. The silicon nitride powder for sintering has a specific surface area of 5 to 30 m.sup.2/g, and is characterized by having a hydrophobicity (M value) of 30 or more and an increase in the oxygen concentration of 0.30% by mass or less after left to stand in the air of a humidity of 90% and 20° C. for 48 hours. The silicon nitride powder for sintering can be obtained by dry-pulverizing aggregated masses of the silicon nitride in an inert atmosphere in the presence of a silane coupling agent.