Ube Industries, Inc.

Kenji Matsunaga

Shinji Kajii

Toshihiko Hogami

Tsutomu Kodama

Mitsuhiko Sato

Toshihiro Ishikawa

Masahiro Tokuse

Michiyuki Suzuki

Shohei Suizu

Provided is a method for producing an inorganic fiber-bonded ceramic material, which can produce, at a high yield, an inorganic fiber-bonded ceramic material with fewer defects, and with an end part and a central part equivalent to each other in microstructure and mechanical properties, and also makes it possible to increase the ceramic material in size. The method for producing an inorganic fiber-bonded ceramic material is characterized in that it includes: a first pressing step of setting, in a carbon die, a laminate to be surrounded by a ceramic powder, the laminate obtained by stacking a coated inorganic fiber shaped product including an inorganic fiber part of inorganic fibers that have a pyrolysis initiation temperature of 1900&#xb0; C. or lower, and a surface layer of an inorganic substance for bonding the inorganic fibers to each other, and pressing the laminate at a temperature of 1000 to 1800&#xb0; C. and a pressure of 5 to 50 MPa in an inert gas atmosphere; and a second pressing step of pressing a ceramic coated laminate obtained in the first pressing step at a temperature of 1600 to 1900&#xb0; C., which is higher than that in the first pressing step, and at a pressure of 5 to 100 MPa in an inert gas atmosphere.

Method for producing inorganic fiber-bonded ceramic material

Provided is a process for producing dense SiC fiber-bonded ceramics excellent in heat resistance and having a shape hard to form by hot pressing such as an elongated shape. The process for producing SiC fiber-bonded ceramics composed of: inorganic fiber made of SiC; and interfacial layers mainly made of carbon includes vacuum-sealing a preform, prepared by forming specific silicon carbide-based inorganic fiber into a certain shape, into a capsule and hot-isostatic-pressing the preform. The process is characterized in that the ratio of the number of carbon atoms to the number of silicon atoms in the preform is 1.02 to 1.20, and before the hot isostatic pressing, the preform is heated in an inert gas atmosphere or a reducing gas atmosphere at a temperature of 1200&#xb0; C. to 1800&#xb0; C. to adjust the oxygen content in the inorganic fiber to 6.0% by weight or lower, and then the hot isostatic pressing is carried out.

Process for producing SiC fiber-bonded ceramics

An SiC fiber bonded ceramic constituted of both a base material which comprises both inorganic fibers made mainly of a sintered SiC structure containing 0.01 to 1 wt % of oxygen (O) and at least one of Groups 2A, 3A and 3B metals and a 1 to 100-nm and carbon (C)-base boundary layer formed among the fibers and a surface part which is made mainly of an SiC-base ceramic structure and formed on at least part of the surface of the base material, characterized in that the boundary portion between the surface part and the base material takes such a gradient structure that the structure of the base material changes into the structure of the surface part gradually and continuously.

SiC fiber-bonded ceramic and process for production of the same

Production processes of an inorganic fiber-bonded ceramic component comprising inorganic fibers mainly comprising Si, M, C and O, an inorganic substance mainly comprising Si and O and boundary layers comprising carbon as a main component; and an inorganic fiber-bonded ceramic component comprising inorganic fibers which are composed mainly of a sintered structure of SiC and contain specific metal atoms and boundary layers composed mainly of carbon, wherein a preliminary shaped material is set in a carbon die, covered with a carbon powder and then hot-pressed to load a pseudo-isotropic pressure on the preliminary shaped material; and a highly heat-resistant inorganic fiber-bonded ceramic component almost free from the occurrence of peelings of surface fibers or delamination, wherein fibers are aligned in a surface shape.

Highly heat-resistant inorganic fiber-bonded ceramic component and process for the production thereof

A highly heat-resistant sintered SiC fiber bonded material free of a decrease in strength and less breakable at an ultra-high temperature over 1,400.degree. C., comprising inorganic fibers which are composed mainly of a sintered SiC crystal, contain at least one kind of metal atoms selected from the class consisting of metal atoms of the 2A, 3A and 3B groups of the periodic table and are bonded nearly in the close-packed structure and 1 to 50 nm boundary layers composed mainly of carbon which are present at the interface of fibers, the less breakable highly heat-resistant sintered SiC fiber-bonded material having a density of at least 2.7 g/cm.sup.3 and an elastic modulus of at least 200 GPa, and a process for the production thereof.

Sintered SIC fibers bonded material

Disclosed are water soluble core wherein a particulate refractory material is combined with a binding agent comprising Na.sub.2 CO.sub.3, Na.sub.2 O . NSiO.sub.2 where n is 0.5 to 4, and SiO.sub.2 as ingredients and a process for producing the water soluble core. The process comprises mixing the particulate refractory material with a water glass, casting the mixture of the particulate refractory material and the water glass, hardening the casting by CO.sub.2 gas, and calcining the casting at between 100.degree. C. and a temperature less than that of an endothermic peak of the water glass in differential thermal analysis. Also, a process for die casting a metal is disclosed using the water soluble core which process comprises pre-heating the water soluble core from a temperature of 300.degree. C. below a melting point of the metal to a temperature of the endothermic peak.

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Ube, Japan

Kenji Matsunaga