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.

The present invention relates to a compound for making high-temperature-resistant or refractory molded bodies, made up of a mixture of: a refractory or high-temperature-resistant inorganic powder, granules and/or granulate, including a free-flowing compound or a powder made of carbon or also without carbon, a binder,
the binder being made of a combination of tannin, lactose, fine-grained silica and aluminum powder, as well as the binder itself, and molded bodies produced from the compound including the binder, and a method of making same.

Methods of manufacturing a ceramic honeycomb body having a honeycomb structure with a matrix of intersecting walls, and a skin disposed on an outer peripheral portion of the matrix where the skin has a first average porosity and the interior portion of the matrix has a second average porosity that is greater than the first average porosity. The methods include coating at least the skin with a fluid formulation containing a sintering aid and subsequently firing the honeycomb structure. In certain embodiments, a glass layer is formed in the skin or in regions of the walls directly adjacent to the skin. In certain embodiments, the coating is applied to a green honeycomb structure, and in other embodiments the coating is applied to a ceramic honeycomb structure. Other honeycomb bodies and methods are described.

A composite dielectric ceramic material having anti-reduction and high temperature stability characteristics includes the main component of (1-x)(BaTiO.sub.3)-x(Ba.sub.2LiTa.sub.5O.sub.15) formulated in accordance with the relative molar ratio of up to 100 mole composite dielectric ceramics and a predetermined ratio of one or multiple oxide subcomponents corresponding to 100 moles of the main component. The oxide subcomponents of Li.sub.2TiO.sub.3, BaSiO.sub.3, (Ba.sub.0.6Ca.sub.0.4)SiO.sub.3 and SiO.sub.2 can be used as sintering aids to provide a sintering promotion effect. The oxide subcomponents of CaO, MnO, MgO can also be selected used to improve dielectric stability. More particularly, CaO has the advantages of improving the anti-reduction ability and increasing the coefficient of resistance. Therefore, with the adding of the oxide subcomponents and their interactions, the rate of change of the TCC curve of the composite dielectric ceramic material (1-x)(BaTiO.sub.3)-x(Ba.sub.2LiTa.sub.5O.sub.15) in the temperature range of 55 C.200 C. is significantly inhibited, and its dielectric constant (k-values) is also well improved.

A method of manufacturing a polycrystalline abrasive construction comprises providing a plurality of particles of a superhard material, the particles coated with a first matrix precursor material, providing a plurality of second matrix precursor particles having an average size less than 2 micron, the second matrix precursor particles including a liquid phase sintering agent, mixing together the plurality of particles of superhard material with particles of the second matrix precursor material and consolidating and sintering the particles of superhard material and the particles of matrix precursor material. A polycrystalline abrasive construction comprises a particles of a superhard material dispersed in a matrix material comprising a material derived from a liquid phase sintering aid and chemical barrier particles having an average particle size of less than 100 nm dispersed in the matrix. Greater than 50% of the chemical barrier particles are located substantially at boundaries between superhard particles and the matrix.

An unshaped product including, as weight percentages, A) particles (a) of at least one refractory material other than a glass and a glass-ceramic, and the main constituent(s) of which are alumina and/or zirconia and/or silica and/or chromium oxide: B) 2% to 15% of particles (b) of a hot binder chosen from glass-ceramic particles, particles made of a glass, and the mixtures of these particles, a glass being a noncrystalline material exhibiting a glass transition temperature of less than 1100 C., the hot binder not being in the solid state at 1500 C., C) less than 2% of particles (c) of hydraulic cement, D) less than 7% of other constituents, the combined particles (a) and (b) being distributed, as weight percentages in the following way: fraction <0.5 m: 1%, fraction <2 m: 4%, fraction <10 m: 13%, fraction <40 m: 25%-52%.

Methods of manufacturing a ceramic honeycomb body having a honeycomb structure with a matrix of intersecting walls, and a skin disposed on an outer peripheral portion of the matrix where the skin has a first average porosity and the interior portion of the matrix has a second average porosity greater than the first average porosity. The methods include coating at least the skin with a fluid formulation containing a sintering aid and subsequently firing the honeycomb structure. In certain embodiments, a glass layer is formed in the skin or in regions of the walls directly adjacent to the skin. In certain embodiments, the coating is applied to a green honeycomb body, and in other embodiments the coating is applied to a ceramic honeycomb body. Other honeycomb bodies and methods are described.

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.

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.

A composite dielectric ceramic material having anti-reduction and high temperature stability characteristics includes the main component of (1-x)(BaTiO.sub.3)-x(Ba.sub.2LiTa.sub.5O.sub.15) formulated in accordance with the relative molar ratio of up to 100 mole composite dielectric ceramics and a predetermined ratio of one or multiple oxide subcomponents corresponding to 100 moles of the main component. The oxide subcomponents of Li.sub.2TiO.sub.3, BaSiO.sub.3, (Ba.sub.0.6Ca.sub.0.4)SiO.sub.3 and SiO.sub.2 can be used as sintering aids to provide a sintering promotion effect. The oxide subcomponents of CaO, MnO, MgO can also be selected used to improve dielectric stability. More particularly, CaO has the advantages of improving the anti-reduction ability and increasing the coefficient of resistance. Therefore, with the adding of the oxide subcomponents and their interactions, the rate of change of the TCC curve of the composite dielectric ceramic material (1-x)(BaTiO.sub.3)-x(Ba.sub.2LiTa.sub.5O.sub.15) in the temperature range of 55 C.200 C. is significantly inhibited, and its dielectric constant (k-values) is also well improved.