Polymer-derived, graphene reinforced ceramic matrix composites and processes for producing graphene-ceramic ceramic matrix composites are provided. An example process mechanically delaminates graphite mixed in a thermosettable, liquid preceramic polymer through a mechanical, high shear process to generate a composition of a preceramic polymer in which graphene is homogeneously dispersed. This example process does not require high temperatures and pressures to produce the graphene. The resulting composition can be pyrolytically converted to a graphene-reinforced ceramic matrix composite. A polysilazane can be used as the preceramic polymer, in some cases providing ammonia or an amine in the process to facilitate delamination of the graphite to graphene. Ceramic, metal, mineral or carbon particulates, platelets, or fibers may be added to the composition to impart enhanced mechanical and/or electrical properties to the finished graphene-reinforced ceramic matrix composites.

In an electrolyte sheet for a solid oxide fuel cell according to the present invention, the number of flaws on at least one of surfaces of the sheet detected by a fluorescent penetrant inspection is 30 points or less in each of sections obtained by dividing the sheet into the sections each measuring 30 mm or less on a side. A unit cell for a solid oxide fuel cell according to the present invention comprises a fuel electrode, an air electrode, and the electrolyte sheet for a solid oxide fuel cell according to the present invention, which is disposed between the fuel electrode and the air electrode. A solid oxide fuel cell of the present invention includes the unit cell for a solid oxide fuel cell according to the present invention.

A ceramic tool material, in particular with piezoelectric effect and a preparation method thereof, and a cutting tool. The ceramic tool material includes the following raw materials by weight: 30-70 parts of matrix material, 30-70 parts of piezoelectric material, 5-10 parts of binder, and 10-20 parts of reinforcing phase and can be made into cutting tools. The cutting tool has a piezoelectric effect and excellent mechanical properties and can convert the cutting force signal into the charge signal during machining. By collecting charge signals, a cutting force can be measured and ceramic cutting tool condition can be monitored. Cutting force measurement function and high mechanical properties are integrated. A ceramic tool material with piezoelectric effect can measure the cutting force on the premise by meeting the cutting performance requirements.

A cutting tool (1) formed of a silicon nitride-based sintered body (2) including a matrix phase (3), a hard phase (4), and a grain boundary phase (10) in which a glass phase (11) and a crystal phase (12) exist. The sintered body (2) contains yttrium in an amount of 5.0 wt % to 15.0 wt % in terms of an oxide, and contains titanium nitride as the hard phase (4) in an amount of 5.0 wt % to 25.0 wt %. In an X-ray diffraction peak, a halo pattern appears at 2θ ranging from 25° to 35° in an internal region of the sintered body (2). A ratio B/A of a maximum peak intensity B to a maximum peak intensity A satisfies 0.11≤B/A≤0.40 . . . Expression (1) in a surface region of the sintered body (2), and satisfies 0.00≤B/A≤0.10 . . . Expression (2) in the internal region of the sintered body (2).

A cubic boron nitride sintered material tool contains a plurality of cBN grains. cBN grains located on a surface of the cutting edge contain a cubic boron nitride phase, and a hexagonal boron nitride phase. When a ratio I.sub.π*/I.sub.σ* between an intensity of a π* peak derived from a π bond of hBN in the hexagonal boron nitride phase and an intensity of a σ* peak derived from a σ bond of hBN in the hexagonal boron nitride phase and a σ bond of cBN in the cubic boron nitride phase is determined by measuring an energy loss associated with excitation of K-shell electrons of boron, the ratio I.sub.π*/I.sub.σ* of the cBN grain on the surface of the cutting edge is 0.1 to 2, and the ratio I.sub.π*/I.sub.σ* of the cBN grain at a depth position of 5 μm from the surface of the cutting edge is 0.001 to 0.1.

The present invention relates to the field of new materials technology, in particular to carbon nitride composite ceramic tool materials, preparation method and cutting tools thereof. The raw materials comprise carbon nitride, titanium carbonitride, molybdenum, nickel and cobalt, carbon nitride as the matrix phase, titanium carbonitride as the reinforcing phase are added to the carbon nitride based composite ceramic materials, with molybdenum, nickel and cobalt as a suitable sintering aid, dense composite tool material is obtained with vacuum hot press sintering method. The prepared carbon nitride based composite ceramic tool materials boast the advantages of low cost, high hardness, high bending strength and high fracture toughness, which is an important way to promote the innovation, development and popularization of carbon nitride materials.

A piezoelectric material composition, a method of manufacturing the same, a piezoelectric device, and apparatus including the piezoelectric device. The piezoelectric device may include a piezoelectric device layer including a first material and a second material surrounded by the first material, a first electrode portion disposed at a first surface of the piezoelectric device layer, and a second electrode portion disposed at a second surface of the piezoelectric device layer opposite to the first surface, wherein the piezoelectric device layer comprises a piezoelectric material composition represented by Chemical Formula 1: 0.96(Na.sub.aK.sub.1-a)(Nb.sub.b(T.sub.1-b))O.sub.3-(0.04-x)MZrO.sub.3-x(Bi.sub.cAg.sub.1-c)ZrO.sub.3+d mol % NaNbO.sub.3, wherein T is Sb or Ta, M is Sr, Ba or Ca, a is 0.4≤a≤0.6, b is 0.90≤b≤0.98, c is 0.4≤c≤0.6, d is 0≤d≤5.0, and x is 0≤x≤0.04 and wherein T is Sb or Ta and M is Sr, Ba, or Ca.

Disclosed is a method for manufacturing a ceramic susceptor, the method including: preparing ceramic sheets; preparing a lamination structure of a molded body, in which the ceramic sheets are laminated and a conductive metal layer for electrodes is disposed between the ceramic sheet laminated products; and sintering the lamination structure of the molded body, wherein the preparing of the ceramic sheets includes: obtaining a vitrified first additive powder by heat-treating a slurry containing MgO, SiO.sub.2, and CaO; preparing a slurry by mixing an Al.sub.2O.sub.3 powder with the first additive powder, a second additive powder containing a MgO powder, and a third additive powder containing a Y.sub.2O.sub.3 powder; and forming the ceramic sheets by tape casting the slurry.

In an embodiment a conversion element includes a first phase and a second phase, wherein the first phase comprises lutetium, aluminum, oxygen and a rare-earth element, wherein the second phase comprises Al.sub.2O.sub.3 single crystals, and wherein the conversion element comprises at least one groove.

The invention relates to a method for producing a non-oxide ceramic powder comprising a nitride, a carbide, a boride or at least one MAX phase with the general composition Mn+1AXn, where M=at least one element from the group of transition elements (Sc, Ti, V, Cr, Zr, Nb, Mo, Hf and Ta), A=at least one A group element from the group (Si, Al, Ga, Ge, As, Cd, In, Sn, Tl and Pb), X=carbon (C) and/or nitrogen (N) and/or boron (B), and n=1, 2 or 3. According to the invention, corresponding quantities of elementary starting materials or other precursors are mixed with at least one metal halide salt (NZ), compressed (pellet), and heated for synthesis with a metal halide salt (NZ). The compressed pellet is first enveloped with another metal halide salt, compressed again, arranged in a salt bath and heated therewith until the melting temperature of the salt is exceeded. Optionally, melted silicate can be added, which prevents the salt from evaporating at high temperatures. Advantageously, the method can be carried out in the presence of air.