Abstract: An electric field device is obtained by the steps of employing a highly pure and mechanically electrically chemically and thermally extremely durable ceramic material, such as a high purity alumina porcelain, as a dielectric material, disposing electrodes on the shaped material before sintering by a thick film printing technique, such as screen printing, with a dispersion ink of finely divided metal, e.g. tungsten, and sintering the shaped material integrally with the electrodes. The product is extremely dense, mechanically electrically chemically and thermally durable and highly reliable.

Abstract: An electric field forming unit that has a long surface life, high reliability, and provides a uniform surface corona discharge along the entire length of the discharge electrode. The electric field forming unit includes a dielectric substrate made of a fine ceramic having a discharge electrode and an inductive electrode formed on opposite sides thereof. The discharge electrode has peripheral edges which are provided with a better linearity than a discharge electrode formed from an electroconductive paste by screen printing. The discharge electrode may be formed of a metalized tape in a thin line form.

Abstract: A process for producing a silicon carbide heating element is disclosed comprising: adding boron or a boron compound in an amount corresponding to from 0.3 to 3.0% by weight as boron, and carbon or a carbon compound in an amount corresponding to from 0.1 to 6.0% by weight as carbon, to a SiC powder having an average particle size of 1.0.mu. or less; blending and molding the mixture; conducting a primary sintering in vacuum or in an inert atmosphere, except nitrogen; and thereafter conducting a secondary sintering at from 1500.degree. to 2300.degree. C. in a pressurized nitrogen atmosphere to produce a silicon carbide heating element having a density of at least 80% based on the theoretical density and an electrical resistivity of 1.0 .OMEGA.-cm or less.

Abstract: A compact, large capacity ozonizer device includes an insulated first ceramic substrate provided with an electrode on one or both sides, and a support such as a corrugated member attached to the first substrate and on which is mounted a second substrate composed of metal or insulating ceramic with an electrode mounted thereon, the first and second substrates and the first support means forming a space through which a gas is passed to be oxidized when a high voltage is applied across the two electrodes or the electrode and the metal plate. A third substrate is supported by a second support member mounted on the second substrate to form a space through which cooling fluid is passed, the cooling fluid moving in a direction different from the direction that the gas to be oxidized flows.

Abstract: An electric field device is obtained by the steps of employing a highly pure and mechanically electrically chemically and thermally extremely durable ceramic material, such as a high purity alumina porcelain, as a dielectric material, disposing electrodes on the shaped material before sintering by a thick film printing technique, such as screen printing, with a dispersion ink of finely divided metal, e.g. tungsten, and sintering the shaped material integrally with the electrodes. The product is extremely dense, mechanically electrically chemically and thermally durable and highly reliable.

Abstract: An artificial articulation includes a socket which has a spherical inner surface, a bone head ball member which is pivotably, slidably received in the spherical inner surface of the socket, and a stem which is connected to the ball head bone member. The socket is made of polycrystal alumina porcelain, the bone head ball member is made of dense silicon nitride porcelain, and the stem is made of either silicon nitride porcelain or partially stabilized zirconia porcelain. An outer surface of the stem and outer surface of the socket are coated with first and second cover layer.

Abstract: Sintered cubic boron nitride consisting of 80 to 20% by volume of the following component (a), with the balance being essentially the following component (b), and a process for producing such nitride are disclosed:(a) cubic boron nitride;(b) a cermet containing the following sub-components (1), (2) and (3):(1) TiC and/or TiC-TiN, part of which may be replaced by a carbide, a nitride, a boride and/or a silicide of a transition metal of the group IVa, Va and VIa of the Periodic Table;(2) Fe, Co and/or Ni; and(3) Mo and/or Mo.sub.2 C.

Abstract: A silicon nitride based ceramic tool is disclosed which is prepared from the starting powder compositions surrounded by and including the lines defined by the points A, B, and C and preferably D, E, and F in the FIGURE.