A preparation method of a SiC porous ceramic material and porous ceramic material manufactured by using the method, comprising: mixing a SiC aggregate, a sintering aid (zirconium oxide), a pore-forming agent (activated carbon) and a polymer binder with a reinforcing agent (SiC whiskers) according to a certain proportion, and obtaining a porous ceramic material via forming, drying and high-temperature sintering. The porous ceramic material has a high strength, a high porosity, a good thermal shock resistance and a low sintering temperature, and can server as a filter material of high-temperature flue gas and a carrier material in vehicle exhaust purification.

A cubic boron nitride sintered body has between 50% and 75% cubic boron nitride by volume and between 25% and 50% binder phase by volume, and inevitable impurities. The binder phase contains an Al compound and a Zr compound. The Al compound contains Al and one or more of N, O and B; and the Zr compound contains Zr and one or more of C, N, O and B. At a polished surface of the cubic boron nitride sintered body, 40% or more of the Zr compounds satisfy the ratio 0.25≦n/N≦0.8, where: N represents the number of line segments drawn radially at equal intervals from a center of gravity of a given Zr compound to a boundary with a non-Zr compound; and n represents the number among those N line segments which intersect a boundary between the given Zr compound and cubic boron nitride.

A method for preparing a boron carbide material includes: providing raw materials of a boron material, a carbon material and a rare earth oxide, wherein an element molar ratio B:C of the boron material to the carbon material is in a range of 4:1 to 4:7, and the rare earth oxide is in an amount of 5 wt % or less based on a total weight of the raw materials, mixing and milling the raw materials to obtain a mixture, compressing the mixture into a tablet form by a tablet press, and sintering the compressed mixture by a laser, wherein the laser has a laser wavelength of 980 nm, a laser power in a range of 100 to 3000 W, and a laser irradiation time of 3 to 60 s.

A semiconductor ceramic composition represented by formula (1),

(Ba.sub.vBi.sub.xA.sub.yRE.sub.w).sub.m(Ti.sub.uTM.sub.z)O.sub.3  (1),

wherein, A represents at least one element selected from Na and K, RE represents at least one element selected from Y, La, Ce, Pr, Nd, Sm, Gd, Dy and Er;

0.750y≦x≦1.50y  (2),

0.007≦y≦0.125  (3),

0≦(w+z)≦0.010  (4),

v+x+y+w=1  (5),

u+z=1  (6),

0.950≦m≦1.050  (7),

0.001 to 0.055 mol of Ca is contained, and 0.0005 to 0.005 mol of at least one selected from Mg, Al, Fe, Co, Cu and Zn is contained.

The present invention discloses a method for uniformly coating metal nanoparticles without a carbon impurity on an oxide ceramic powder surface, which includes the steps of putting grinded and mixed a metal organic material and oxide ceramic powder into a rotational reaction chamber, then bubbling oxidizing gas under a rotational and heating condition to oxidize the metal organic material into a metal oxide, and finally bubbling reducing gas to reduce the metal oxide into nanoparticles in a metallic state, so as to implement the uniform coating of the nanoparticles in the metallic state, and avoid coarsening and growing problems of nanoparticles led by a long-term coating reaction under a high temperature. The present invention has a simple method and a short preparation period, and the metal nanoparticles prepared are uniformly dispersed and have wide application prospects in multiple fields like catalytic materials and conductive ceramics.

A ceramic substrate and a method for production thereof are provided, in which the ceramic substrate includes a composite of : a first ceramic layer including Sr anorthite and Al.sub.2O.sub.3 or an oxide dielectric with a dielectric constant higher than that of Al.sub.2O.sub.3; and a second ceramic layer including Sr anorthite and cordierite and having a dielectric constant lower than that of the first ceramic layer.

The present disclosure is directed to a low cost sintering process for the preparation of gadolinium oxysulfide having a general formula of Gd.sub.2O.sub.2S, referred to as GOS, scintillation ceramics, comprising uniaxial hot pressing primary sintering and hot isostatic pressing secondary sintering.

Disclosed are a composite sintered body for a cutting tool and a cutting tool using the same. The composite sintered body for a cutting tool has enhanced heat conductivity and electrical conductivity to be strong against abrasion by heat and impact and to be capable of minimizing an influence on an edge during an Electrical Discharge Machine (EDM) operation.

A method for making a thin ceramic part involves making a casting slurry including a ceramic powder, a solvent, a binder, a plasticizer, and a dispersant. The casting slurry is tape casted to achieve a single layer green tape. At least two single layer green tapes are laminated to form a green tape lamination. The green tape lamination is dry pressed, dried, shaped, degreased, and fired to achieve the exterior component required.

A method of making a polycrystalline cubic boron nitride (PCBN), material is provided. The matrix precursor powder comprises an aluminium compound. The method comprises mixing matrix precursor powder comprising particles having an average particle size no greater than 250 nm, with between 30 and 40 volume percent of cubic boron nitride (cBN) particles having an average particle size of at least 4 μm, and then spark plasma sintering the mixed particles. The spark plasma sintering occurs at a pressure of at least 500 MPa, a temperature of no less than 1050° C. and no more than 1500° C. and a time of no less than 1 minute and no more than 3 minutes.