A grain-grade zirconia toughened alumina ceramic substrate and a method for preparing the same. The ceramic substrate is prepared from alumina power (main phase) and zirconia powder (secondary phase) in a binary azeotrope of anhydrous ethanol and butanone in the presence of magnesia-alumina spinel powder (as sintering aid), phosphate ester (as dispersant), polyvinyl butyral (as binder) and dibutyl phthalate (as plasticizer). In a mixture of the alumina power and the zirconia powder, a volume percentage of the alumina power is 82.44-96.7%, and a volume percentage of the zirconia powder is 3.30-17.56%. The magnesia-alumina spinel powder is 0.1-4.0% by weight of the mixture of the alumina power and the zirconia powder. A particle size ratio of the alumina powder to the zirconia powder is 2.415-4.444.

A paste for ceramic 3D shaping according to the present invention is a paste for ceramic 3D shaping containing a curable resin and inorganic particles, in which the inorganic particles contain ceramic particles and glass particles.

A paste for ceramic 3D shaping according to the present invention is a paste for ceramic 3D shaping containing a curable resin and inorganic particles, in which the inorganic particles contain ceramic particles and glass particles.

The present invention is directed to a method for producing a silicon nitride sintered material, the method including heating a molded article, which contains a silicon nitride powder having a β phase ratio of 80% or more, a dissolved oxygen content of 0.2% by mass or less, and a specific surface area of 5 to 20 m.sup.2/g, and a sintering auxiliary containing a compound having no oxygen bond, and which has an overall oxygen content controlled to be 1 to 15% by mass and an aluminum element overall content controlled to be 800 ppm or less, to a temperature of 1,200 to 1,800° C. in an inert gas atmosphere under a pressure of 0 MPa.Math.G or more and less than 0.1 MPa.Math.G to sinter the silicon nitride.

In the present invention, there can be provided a method for producing a silicon nitride sintered material, which method is advantageous in that a silicon nitride sintered material having high thermal conductivity can be obtained even when using a silicon nitride powder having a high β phase ratio and conducting calcination under normal pressure or substantially normal pressure.

The present invention is directed to a method for producing a silicon nitride sintered material, the method including heating a molded article, which contains a silicon nitride powder having a β phase ratio of 80% or more, a dissolved oxygen content of 0.2% by mass or less, and a specific surface area of 5 to 20 m.sup.2/g, and a sintering auxiliary containing a compound having no oxygen bond, and which has an overall oxygen content controlled to be 1 to 15% by mass and an aluminum element overall content controlled to be 800 ppm or less, to a temperature of 1,200 to 1,800° C. in an inert gas atmosphere under a pressure of 0 MPa.Math.G or more and less than 0.1 MPa.Math.G to sinter the silicon nitride.

In the present invention, there can be provided a method for producing a silicon nitride sintered material, which method is advantageous in that a silicon nitride sintered material having high thermal conductivity can be obtained even when using a silicon nitride powder having a high β phase ratio and conducting calcination under normal pressure or substantially normal pressure.

The present invention provides a method of preparing bulk BSCCO-based material, the method comprising: mixing a first solution with a second solution at a pre-determined temperature to form a gel, wherein the first solution comprises salts of at least bismuth, strontium, calcium and copper and the second solution comprises a precipitating agent; drying the gel to form a xerogel; grinding the xerogel to form a homogeneous metalorganic precursor; and calcining the homogeneous metalorganic precursor to form bulk BSCCO-based materials. Further steps may enable preparation of 2D BSCCO flakes.

The present invention provides a method of preparing bulk BSCCO-based material, the method comprising: mixing a first solution with a second solution at a pre-determined temperature to form a gel, wherein the first solution comprises salts of at least bismuth, strontium, calcium and copper and the second solution comprises a precipitating agent; drying the gel to form a xerogel; grinding the xerogel to form a homogeneous metalorganic precursor; and calcining the homogeneous metalorganic precursor to form bulk BSCCO-based materials. Further steps may enable preparation of 2D BSCCO flakes.

A shape forming tool for pre-carbonization compression of a fibrous preform is provided, comprising a female forming tool, a first plug, a second plug, and a wedge, each configured to be received by a die recess of the female forming tool. A first tapered surface of the wedge is configured to engage the first plug and the second tapered surface of the wedge is configured to engage the second plug. In response to the first tapered surface of the wedge engaging the first plug and the second tapered surface of the wedge engaging the second plug, the first plug and the second plug, respectively, are configured to move laterally towards opposing sides of the female forming tool and/or vertically toward a bottom side of the female forming tool to compress the fibrous preform into a shaped body.

A shape forming tool for pre-carbonization compression of a fibrous preform is provided, comprising a female forming tool, a first plug, a second plug, and a wedge, each configured to be received by a die recess of the female forming tool. A first tapered surface of the wedge is configured to engage the first plug and the second tapered surface of the wedge is configured to engage the second plug. In response to the first tapered surface of the wedge engaging the first plug and the second tapered surface of the wedge engaging the second plug, the first plug and the second plug, respectively, are configured to move laterally towards opposing sides of the female forming tool and/or vertically toward a bottom side of the female forming tool to compress the fibrous preform into a shaped body.

A ferrite sintered magnet 100 comprises M-type ferrite crystal grains 4 having a hexagonal structure, two-crystal grain boundaries 6a formed between two of the M-type ferrite crystal grains 4, and multiple-crystal grain boundaries 6b surrounded by three or more of the M-type ferrite crystal grains 4. This ferrite sintered magnet 100 contains at least Fe, Ca, B, and Si, and contains B in an amount of 0.005 to 0.9 mass % in terms of B.sub.2O.sub.3, the two-crystal grain boundaries 6a and the multiple-crystal grain boundaries 6b contain Si and Ca, and in a cross-section parallel to a c-axis of the ferrite sintered magnet, when the number of multiple-crystal grain boundaries 6b having a maximum length of 0.49 to 5 μm per cross-sectional area of 76 μm.sup.2 is N, N is 7 or less.