A dielectric ceramic composition includes a first crystal grain that has a perovskite structure expressed by a general formula of BaCaTiO.sub.3, and has a core portion and a shell portion surrounding the core portion and including a rare earth element and manganese, and a second crystal grain in which an elemental ratio of total of barium and calcium to titanium is 0.70 or less and a main component is barium calcium titanate.

In a silicon nitride sintered body including silicon nitride crystal grains and a grain boundary phase, dislocation defect portions exists inside at least some of the silicon nitride crystal grains. A percentage of a number of the at least some of the silicon nitride crystal grains among any 50 of the silicon nitride crystal grains having completely visible contours in any cross section or surface of the silicon nitride sintered body is not less than 50% and not more than 100%. It is favorable that a plate thickness of the silicon nitride substrate, in which the silicon nitride sintered body is used, is within the range not less than 0.1 mm and not more than 0.4 mm. The TCT characteristics can be improved by using the silicon nitride substrate in the silicon nitride circuit board.

The disclosure relates to cubic boron nitride inserts for machining iron-based workpieces, as well as related methods and apparatuses. The insert includes a cutting element containing cubic boron nitride (cBN) in an amount in a range of 50 wt. % to 95 wt. % based on the cutting element, and a binder containing at least one of (i) alumina (Al.sub.2O.sub.3) and a manganese material (e.g., an oxide such as MnO.sub.x) and (ii) zirconia (ZrO.sub.2). The insert can be used for various machining processes, for example turning or boring. Suitable workpieces include iron-based materials or ferrous alloys, for example a cast iron such as compacted graphite iron (CGI).

The invention relates to a method of manufacturing a ceramic molding, comprising the following steps: a) providing three or more ceramic powder layers that are arranged in layers, one on top of the other, to form a compression-molded element and sintering the compression-molded element obtained in step b) to form a ceramic molding, characterized in that the ceramic powder layers have different compositions, each ceramic powder layer comprising a mixture of at least two different base powders and each base powder containing at least 80 wt. % ZrO.sub.2 and at least 0.02 wt. % Al.sub.2O.sub.3, each weight amount being relative to the total weight of the constituents of the base powder.

One aspect relates to a process for producing a sintered workpiece, which includes sintering of a ceramic material at a temperature of at least 1000 C. and in an atmosphere, in the case of which the partial pressure of atmospheric air is reduced to less than 10.sup.6-times, based on the ambient air at the same temperature under equilibrium conditions.

A cubic boron nitride sintered material includes cubic boron nitride and a binder. The binder includes a first material and a second material. The first material is one or two or more first chemical species each including at least one first metallic element selected from the group consisting of tungsten, cobalt, and aluminum. Each of the first chemical species is a metal, an alloy, an intermetallic compound, a compound, or a solid solution. The second material is one or two or more second chemical species each including at least one second metallic element selected from the group consisting of titanium, zirconium, hafnium, vanadium, niobium, tantalum, and chromium. Each of the second chemical species is a solid solution derived from at least one selected from the group consisting of nitride, carbide, and carbonitride. In each of the second chemical species, 0.1 atom % to 10 atom % of aluminum is dissolved.

A cutting element for a cutting tool. The cutting element may be at least partially made from a composite material including a carbide material, a binder material, and a plurality of diamond particles. The carbide material may be from 55 wt % to 97 wt % of a total weight of the composite material. The binder material may be from 3 wt % to 20 wt % of the total weight of the composite material. The plurality of diamond particles may be from 0.1% to 25% of the total weight of the composite material. The carbide material and the binder material may be combined and sintered together prior to being combined with the plurality of diamond particles, such that the carbide material and the binder material form a plurality of pellets having an average cross-sectional length from 10 m to 250 m.

A piezoelectric ceramic speaker includes a piezoelectric element using a vibration sheet formed with piezoelectric ceramic having a primary phase constituted by ceramic grains of perovskite crystal structure containing Pb, Nb, Zn, Ti, and Zr, and a secondary phase constituted by ZnO grains, wherein the primary phase is constituted by ceramic grains expressed by a composition formula Pb {(Zr.sub.(1-a)Ti.sub.a).sub.x.(Ni.sub.1/3Nb.sub.2/3).sub.y.(Zn.sub.1/3Nb.sub.2/3).sub.z}O.sub.3 (where 0<x0.85, 0y<1, 0<z<1, x+y+z=1, and 0.45a0.60); and an enclosure which encloses the piezoelectric element.

In one aspect, sintered ceramic bodies are described herein which, in some embodiments, demonstrate improved resistance to wear and enhanced cutting lifetimes. For example, a sintered ceramic body comprises tungsten carbide (WC) in an amount of 40-95 weight percent, alumina in an amount of 5-30 weight percent and ditungsten carbide (W.sub.2C) in an amount of at least 1 weight percent.

Set forth herein are garnet material compositions, e.g., lithium-stuffed garnets and lithium-stuffed garnets doped with alumina, which are suitable for use as electrolytes and catholytes in solid state battery applications. Also set forth herein are lithium-stuffed garnet thin films having fine grains therein. Disclosed herein are novel and inventive methods of making and using lithium-stuffed garnets as catholytes, electrolytes and/or anolytes for all solid state lithium rechargeable batteries. Also disclosed herein are novel electrochemical devices which incorporate these garnet catholytes, electrolytes and/or anolytes. Also set forth herein are methods for preparing novel structures, including dense thin (<50 um) free standing membranes of an ionically conducting material for use as a catholyte, electrolyte, and, or, anolyte, in an electrochemical device, a battery component (positive or negative electrode materials), or a complete solid state electrochemical energy storage device. Also, the methods set forth herein disclose novel sintering techniques, e.g., for heating and/or field assisted (FAST) sintering, for solid state energy storage devices and the components thereof.