Hitachi, Ltd.

Hitachi Powdered Metals Co., Ltd.

Hitachi Chemical Company, Ltd.

Mitsuo Chigasaki

Jiro Kuniya

Yoshihisa Kiyotoki

Yoshiteru Chiba

Shizuo Matsushita

Takahiko Kato

Kunihiro Tamahashi

Keiichi Nakamura

Masateru Suwa

Tadashi Iizuka

Toshiyuki Ohno

Yusaku Nakagawa

Yasuo Kamitsuma

Tsuyoshi Kagaya

Kooichi Inaba

Masaki Minabe

Kenichi Onisawa

Noboru Baba

Masanobu Hanazono

Akira Sakamoto

Ko Soeno

Masayasu Nihei

Akira Okayama

Makoto Fujikura

Shigeharu Onuma

Kiyoshi Otaka

Kikuo Takeshima

Yasuo Shimamura

Yozo Kumagai

Megumi Naruse

Katsuhiko Komuro

Mashayoshi Kainuma

Masaru Sakakura

A valve which is cobalt-free excellent in wear resistance and seizure resistance manufactured by forming valve seats for a valve disc and a valve body with a nickel base alloy in which silicide particles or boride particles of small particle size are finely dispersed, and the valve seat is bonded to the valve disc or the valve body by way of an insert material comprising a nickel base alloy of a lower melting point by transient liquid phase diffusion bonding.

Valve and manufacturing method thereof

In the joint construction of cobalt-based alloy, a cobalt-based alloy layer, in which granular or massive eutectic carbidedisperses, is joined to a metal of a base metalvia an insert metal layer. For the joint construction of cobalt-based alloy, liquid phase diffusion bonding is performed at a temperature of 1100&#xb0; C. for a retention time of 1 hour with an insert metal with a thickness of about 40 &#x3bc;m being interposed between the base metal, which is S45C carbon steel, and a cobalt-based alloy material which has granular or massive eutectic carbide with a grain size not larger than 30 &#x3bc;m in a matrix of cast structure and contains 1.03 wt % C, 29.73 wt % Cr, 3.86 wt % W, 2.59 wt % Ni, 2.67 wt % Fe, 0.59 wt % Si, and 0.07 wt % Mo, the balance substantially being Co. The cobalt-based alloy layerafter bonding contains granular or massive eutectic carbide.

Joint construction of cobalt-based alloy

In the joint construction of cobalt-based alloy, a cobalt-based alloy layerin which granular or massive eutectic carbidedisperses, is joined to a metal of a base metalvia an insert metal layerFor the joint construction of cobalt-based alloy, liquid phase diffusion bonding is performed at a temperature of 1100&#xb0; C. for a retention time of 1 hour with an insert metal with a thickness of about 40 &#x3bc;m being interposed between the base metal, which is S45C carbon steel, and a cobalt-based alloy material which has granular or massive eutectic carbide with a grain size not larger than 30 &#x3bc;m in a matrix of cast structure and contains 1.03 wt % C, 29.73 wt % Cr, 3.86 wt % W, 2.59 wt % Ni, 2.67 wt % Fe, 0.59 wt % Si, and 0.07 wt % Mo, the balance substantially being Co. The cobalt-based alloy layerafter bonding contains granular or massive eutectic carbide.

A valve is characterized by excellent corrosion and wear resistance and maintainability due to use of a bonding corrosion and wear proof alloy containing non-continuously distributed eutectic carbide on the sliding portions of various types of apparatuses and valves by diffusion bonding. This serves to improve the maintainability of a thermal and nuclear power plant and to provide a nuclear power plant using recirculating water, which ensures excellent working safety, in particular. The corrosion and wear proof alloy is characterized in that network-formed eutectic carbide in the alloy containing the cast structure base metal and eutectic carbide is formed into(multiple) granules or lumps having a particle size of 30 microns or less so that said eutectic carbide is non-continuously distributed.

Valve bonded with corrosion and wear proof alloy and apparatuses using said valve

The present invention provides an Al--Si based sintered alloy of high strength and high ductility, a method for production thereof and use thereof. The alloy comprises 1-45% of Si, 0.1-20% of an element of Group IIIa, 0.01-5% of at least one element of Groups IVa and Va, the balance of substantially Al. This alloy can further contain at least one of 0.01-5% of Cu, 0.01-5% of Mg, 2.0% or less of Fe, 1.5% or less of Mn and 1.5% or less of Co and the oxygen content is reduced to 0.15% or less by sintering under vacuum. The present invention is applied to automobile parts such as a piston and scroll compressors. The alloy has a tensile strength of about 40 kg/mm.sup.2 or higher and an elongation of 1.5% or more at 150.degree. C.

Compressor scroll made of silicon containing aluminum alloy

The present invention provides an Al-Si based sintered alloy of high strength and high ductility, a method for production thereof and use thereof. The alloy comprises 1-45% of Si, 0.1-20% of an element of Group IIIa, 0.01-5% of at least one element of Groups IVa and Va, the balance of substantially Al. This alloy can further contain at least one of 0.01-5% of Cu, 0.01-5% of Mg, 2.0% or less of Fe, 1.5% or less of Mn and 1.5% or less of Co and the oxygen content is reduced to 0.15% or less by sintering under vacuum. The present invention is applied to automobile parts such as a piston and scroll compressors. The alloy has a tensile strength of about 40 kg/mm.sup.2 or higher and an elongation of 1.5% or more at 150.degree. C.

Highly ductile sintered aluminum alloy, method for production thereof

The object of the present invention is to provide an abrasion resistant aluminum bronze alloy for sliding members of various industrial machines. The abrasion resistant aluminum bronze alloy consists of Al: 7-12%, Mn: 1.5-5.5%, Si: 0.45-2.7%, respectively in weight, and the rest is substantially Cu, wherein metallic compound of Mn and Si is dispersed among said alloy structure, and elongation percentage is at least 5%. The abrasion resistant aluminum bronze alloy is superior to conventional aluminum bronze alloy (JIS-ALBC2) in seizure resistance and abrasion resistance by more than two times.

High abrasion resistant aluminum bronze alloy, and sliding members using

In an electrophotographic photosensitive device, which comprises an electroconductive support, a photoconductive layer provided thereon, and a surface protective layer provided on the photoconductive layer, the surface protective layer being made from a film having a density of localized states of not more than 5.times.10.sup.17 cm.sup.-3 and a higher dark resistance than that of the photoconductive layer, the surface protective layer is less susceptible to deterioration, adhesion to the photoconductive layer is enhanced, and thus the device has a prolonged life.

Method of annealing electrophotographic photosensitive device

An electrophotographic sensitized body having a photoconductive layer comprising hydrogenated amorphous silicon on a substrate which comprises conductive material selected from the group consisting of A1, A1-Si (0.2-1.2 wt. %) - Mg (0.45-1.2 wt. %) alloy, super duralmine and extra super duralmine. Provided between the substrate and the photoconductive layer is a diffusion blocking layer 0.005-5 microns in thickness comprising a material selected from the group consisting of titanium nitride, tantalum nitride, hafnium nitride, platinum silicide, nickel silicide, palladium silicide, titanium silicide, hafnium silicide, tantalum silicide, tungsten silicide, vanadium silicide, niobium silicide, molybdenum silicide, zirconium silicide, tungsten carbide, titanium carbide, molybdenum carbide, hafnium carbide, vanadium carbide, niobium carbide, tantalum carbide and metallic chrome. The decrease in specific resistance of the photoconductive layer caused by diffusion of the substrate constituent to the photoconductive layer is prevented and the sensitivity to the light in the region of oscillatory wavelength of semiconductor is remarkably improved.

Electrophotographic sensitized body having a diffusion blocking layer

The photoconductive layer (3) has a triple-layer structure comprised of an upper layer (33) made of amorphous silicon containing germanium and carbon, a middle layer (32) made of amorphous silicon containing germanium, and a lower layer (31) made of amorphous silicon. The upper layer (33) formed between a surface layer (4) and the middle layer (32), and the lower layer (31) formed between the middle layer (32) and a barrier layer (2) serve to reduce the energy difference and the interfacial state between respective layers thus, high electrophotographic sensitivity for a longer wavelength light can be obtained, and sensitivity in the oscillation wavelength of a GaAlAs diode laser improves effectively.

Multilayered electrophotographic photosensitive member

A method for forming a thin film wherein plural targets of different materials are alternately sputtered througth the switching of the electric powers supplied thereto, the particles produced from the sputtering are ionized and thereafter deposited on a substrate. This method provides an alloy thin film, compound thin film or multi-layer thin film of any composition and enhances adhesion among the particles. A sputtering device for practicing this method is also disclosed.

Thin film forming method through sputtering and sputtering device

A structure comprising a main body formed of a nickel base alloy, and a NiAl coating applied to the main body, wherein the NiAl coating includes a nickel rich NiAl layer and an aluminum rich NiAl layer and the thickness ratio of the nickel rich NiAl layer to the whole NiAl coating is in a range between 20 and 40%. A method of applying an aluminum coating to a nickel base alloy comprising the steps of forming an aluminide layer of Ni.sub.2 Al.sub.3 on the surface portion of the nickel base alloy by the diffusion and penetration of aluminum, and subjecting the alumide layer to heat treatment to change the aluminide layer to a monoaluminide layer and making the thickness ratio of a nickel rich NiAl layer to the whole monoaluminide layer be in the range between 20 and 40%.

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Hitachi, Japan

Mitsuo Chigasaki