Hitachi Metals, Ltd.

Hisao Hara

Yasuo Tsukuda

Hirohide Yamada

Hideki Harada

Yasuo Iizuka

Yutaka Kubo

A conductive ceramic sintered body substantially free from large variation of electric resistivity, which consists essentially of: (a) a silicon nitride-base ceramic as a matrix; (b) 10-70 volume % of a first conductive material which consists of one or more conductive compounds selected from carbides, nitrides, oxides and their composite compounds of transition metals in Groups IVa, Va and VIa of the Periodic Table; and (c) 0.1-50 volume % of a second conductive material consisting of SiC; the first conductive material and the second conductive material serving to form paths for electric conduction.

Conductive ceramic sintered body

A film resistor heater comprising a sprayed film resistor comprisng NiCr particles uniformly dispersed and partly contacted with each other in an insulating ceramic matrix. The film resistor heater may further comprise a bonding layer, an insulating layer and a protective layer. The film resistor heater is prepared by spraying, particularly plasma spraying. It may be used advantageously for home electric appliances such as hot plates, rice cookers and vacuum kettles, heat rolls for electrostatic copiers, etc.

Plasma sprayed film resistor heater

An improved exhaust port assembly, for an internal combustion engine comprises a port pipe made of heat resistance steel covered by a fibrous ceramic sheet which is covered by an aluminum foil to prevent molten aluminum from penetrating the fibrous ceramic sheet when aluminum casting.

Exhaust port assembly

Non-oxide powders such as carbides, nitrides, carbides/nitrides and borides are obtained by reducing an oxide powder in a reducing atmosphere, and after or concurrently with the reduction, treating the reduced powder in a carbonizing atmosphere, a nitrogenizing atmosphere, a carbonizing and nitrogenizing atmosphere, or a boronizing atmosphere. As the above oxide powder, there is used a brittle material obtained by rapid cooling of a melted oxide. The non-oxide powders obtained are utilized as a hard component of cemented carbides and cermet. These powders are fine particles having a particle size of 1.0 .mu.m or smaller and a high purity.

Growing community of inventors

Kumagaya, Japan

Hisao Hara