Abstract: A process for producing a powder of composite oxide which includes cerium and zirconium, or which includes cerium, zirconium and further a rare-earth element other cerium. The process includes: dissolving nitrate, sulfate and/or acetate of constituent elements of the composite oxide into water in a predetermined ratio; and spraying and heating a resulting aqueous solution to oxidize the constituent elements of the composite oxide for converting them into a powder of a composite oxide. The thus produced composite oxide powder is micro-fine, homogeneous, and heat resistant.

Abstract: A catalyst for purifying exhaust gases comprises a catalyst carrier made of potassium titanate and a noble metal loaded on the catalyst carrier. The catalyst carrier is substantially free from alumina. This catalyst can oxidize at least hydrocarbons in exhaust gases at a high catalytic activity even at low temperatures, and at the same time can suppress SO.sub.2 from converting into sulfates. This catalyst does not employ substance like alumina exhibiting solid acidity as a catalyst carrier. Further, this catalyst can be used for purifying exhaust gases from diesel engines to suppress particulates and sulfates from being emitted, and to improve conversions of hydrocarbons and carbon monoxide.

Abstract: A TiAl base alloy containing 46 to 54 mol % of Ti and 46 to 52 mol % of Al in which Sb is added within a range of 0.1 to 1 mol %, at least one element of Hf and/or Zr is further added within a range of 0 to 3 mol %, and three phases of a .gamma. phase, an .alpha..sub.2 phase and Sb-rich phase coexist.

Abstract: A direct current voltage is applied between an anodic portion containing an oxidizing catalyst provided on one surface of a proton conductive solid electrolyte which separates the flow path of the gas to be treated into two parts, and a cathodic portion containing a reducing catalyst provided on the other surface of the solid electrolyte, the reducing catalyst comprising at least one selected from oxides of elements of Group 5A, Group 6A, and Group 7A of the periodic table, palladium, palladium alloys, transition elements carried on alumina, cerium oxide, and La.sub.1-x Sr.sub.x Co.sub.1-y Fe.sub.y O.sub.3 (where, 0.ltoreq.x.ltoreq.1, 0.ltoreq.y.ltoreq.1), while bringing a gas containing water vapor into contact with the anodic portion and bringing a gas containing nitrogen oxides into contact with the cathodic portion.

Abstract: A process for producing a clay mineral of chain structure such as sepiolite and attapulgite. The process comprises suspending a metal silicate gel in an aqueous solution which has a pH value of 3-11 at room temperature and contains a clay mineral of chain structure suspending therein, and then heating the resulting suspension at a temperature below 350.degree. C. According to this process, it is possible to produce a clay mineral of chain structure in a simple, stable manner.

Abstract: An unlubricated sliding member composed of a pair of sliding bodies. The sliding part of one sliding body is composed of a ceramic base portion and a thin film of, for example, Nb, which is integrally provided on the surface of the base portion. The sliding part of the other sliding body is composed of a diamond containing surface.The sliding member enables the coefficient of the friction caused when the pair of sliding bodies slide to be reduced, thereby keeping a long life of the sliding member.If the ceramic base portion is further subjected to ion implantation, the wear resistance of the sliding member is enhanced.

Abstract: Silicon and nitrogen ions are implanted in a ceramic body of silicon carbide and the ceramic body is heated in a nonoxidizing atmosphere, whereby it is reinforced.

Abstract: A method for joining a ceramic material to a metallic material includes: forming a metallic film on the surface of the joining area of the ceramic material; irradiating the metallic film with high energy ions to allow the metallic film to stick firm to the surface of the ceramic material and to strengthen the surface of the ceramic material; and mechanically joining the ceramic material to the counterpart metallic material through the metallic film. The ceramic material subjected to these steps hardly breaks at the joining area where breaking otherwise occurs easily, thus enabling high-strength joining of ceramic and metallic materials.

Abstract: A method of strengthening ceramic material by forming a metal film on the surface of the ceramic material and irradiating ions of high energy on the surface of the film. For further improvement, the material may be heat treated at a temperature of 600.degree. C. to 1600.degree. C. after the ion irradiation.

Abstract: A method of producing a composite ceramic body which is comprises forming an amorphous ceramic film on the surface of a ceramic substrate; and irradiating said film with ions of high energy to cause atom mixing between said ceramic substrate and said amorphous ceramic film and to allow said film to adhere firmly and integrally to said substrate.

Abstract: A heat-resistant alloy comprising an alloy based on an intermetallic compound TiAl composed of 60 to 70% by weight of titanium and 30 to 36% by weight of aluminum, and 0.1 to 5.0% by weight of manganese.

Abstract: Fast union of a ceramic article to an opposed material is attained by a method which comprises forming a film of metal on the surface of the ceramic article, irradiating the surface of the metallic film with high-energy ions to bind the metallic film fast to the ceramic article, and supplying solder or brazing alloy to the surface of the metallic film and soldering or brazing the ceramic article to the opposed article. The high-energy ions for the irradiation has a magnitude of 30 to 800 keV and the dosage of the high-energy ions is in the range of 5.times.10.sup.15 to 2.times.10.sup.18 ions/cm.sup.2.

Abstract: There is provided a method for preparation of porous glass films, preferably in the form of a hollow filament, comprising heating glass films, formed from sodium borosilicate glass having a composition which can be phase-separated by heat-treatment into a soft phase easily eluted with a hot acid solution and a hard phase not easily eluted with the same solution, to separate the glass phase into the two phases and then subjecting the glass film to plasma etching in an atmosphere containing gaseous fluorine-containing compound(s) before or after acid elution of the soft phase. The thus obtained porous glass films have a uniform pore diameter and smooth surfaces and can be used as a variety of separating membranes.

Abstract: A formed product of vermiculite comprising thin leaves of vermiculite containing cations of one or more elements selected from the group consisting of copper, aluminum, manganese, II group elements, IV group elements and VIII group elements, substituted for exchangeable cations retained in vermiculite. Such a formed vermiculite product has high strength as well as excellent heat resistance. The formed product of vermiculite can be obtained by a method comprising the steps of crushing vermiculite to obtain thin leaves thereof, subjecting the thin leaves to ion exchange to substitute exchangeable cations retained therein by cations of one or more elements selected from the group consisting of copper, aluminum, manganese, II group elements, IV group elements and VIII group elements, and forming the resulting thin leaves into a stack or laminate. The formed vermiculite product thus obtained can retain further properties, such as an ability to expand and water resistance.

Abstract: The vermiculite sheet is immersed in a silane compound in liquid state so that the silane compound is permeated into the sheet to react with the water absorbed on the whole surface of each thin leave of vermiculite and to form silanol. Thin leaves of vermiculite are strongly bonded with one another through such silanol to form a strong composite sheet.

Abstract: Impurities are removed from chaff by acid treatment, and the chaff is heated for carbonization. Silicon is reduced from the carbonized chaff, and nitrided to form silicon nitride.

Abstract: A composite material is provided by contacting a clay mineral having laminated aluminum silicate layers with an organic monomer to allow the organic monomer to be adsorbed on or intercalated between the aluminum silicate layers, and contacting the clay mineral with a silane compound having 2 to 4 chlorine atoms to promote polymerization of the organic monomer, thereby forming a composite material composed of a clay mineral having organic high polymer adsorbed thereon or intercalated therebetween. The composite material thus obtained has a strong chemical bond between inorganic clay mineral and organic high polymer.

Abstract: A process for producing a cordierite ceramic product comprises blending a starting cordierite composition which comprises:(a) a clay formulation having a cordierite composition comprising kaolin, talc and aluminium oxide and/or an aluminium compound which is convertible into aluminium oxide;(b) a glass having a cordierite composition;(c) an organic binder; and,(d) water.

Abstract: Semiconductive barium titanate having a positive temperature coefficient of resistance comprises a barium titanate semiconductor including barium titanate and a small quantity of a doping element, and at least one additive selected from among silicon nitride, titanium nitride, zirconium nitride and silicon carbide. The semiconductive barium titanate of this invention has a sharp rise in the variation of specific resistivity with temperature change and a large specific resistivity ratio in the PTC temperature region, and can be produced with high reproducibility, since a widely differing quantity of the doping element can be effectively added to barium titanate.

Abstract: A converter for the purification of exhaust gases from internal combustion engines and the like which comprises a first converting layer of a catalyst of a sintered body structure selected from the group consisting of nickel oxide-copper oxide; manganese oxide-cerium oxide; manganese oxide-lanthanum oxide; manganese oxide-iron oxide; manganese oxide-niobium oxide; manganese oxide-nickel oxide; and either niobium oxide or yttrium oxide or mixtures of both with cobalt oxide; and a second converting layer of a catalyst selected from the group consisting of platinum; platinum-rhodium; platinum-palladium; and nickel oxide, chromium oxide, copper oxide, iron oxide and barium oxide; wherein the converter is constructed so that the exhaust gases pass through said first converting layer and then through said second converting layer. A copper-filled layer consisting of a copper-containing material may be further provided upstream of said first and second converting layers.