Hitachi Powdered Metals Co., Ltd.

Hitachi Construction Machinery Co., Ltd.

Michiharu Mogami

Hideaki Kawata

Koichiro Hayashi

Motohiro Miyasaka

Hideki Akita

Osamu Gokita

Kazuo Maruyama

Junichi Kobayashi

Yutaka Kimura

Disclosed are a sintered composite machine part as a cylinder block for piston pumps or piston motors, and a manufacturing method thereof. The machine part has an air-tight main body of sintered porous iron alloy and having an iron oxide layer on the surface; and a sliding part of sintered porous copper alloy being bonded direct to the main body. The sliding part is to be slid in tight contact with a fluid supply/return device. The manufacturing is made by preparing a main body of sintered porous iron alloy and a green compact for sliding part from a raw material metal powder having a composition corresponding to the copper alloy; sintering the green compact for sliding part in contact with the main body to bond the sliding part to the main body by diffused junction; and subjecting the main body to steam treatment to provide an iron oxide layer.

Sintered composite machine part and manufacturing method thereof

An oil-impregnated sintered sliding bearing formed of a porous iron-based sintered alloy with quenched structure and receiving a high surface pressure capable of reducing the number of finishing steps by cutting and grinding and providing a bearing performance equivalent to or higher than that of conventional bearings, wherein a plurality of ridge-and-groove lines having a height difference of 2 to 12.5 &#x3bc;m and extending in circumferential direction are axially arranged in parallel with each other by boring the bearing surface thereof to form a wavy surface in axial direction, and the portion thereof deeper by 10 to 60 &#x3bc;m from the outer layer of the bearing surface is formed dense to seal surface pores so as to reduce the pores opening to the outer surface to 1 to 10 percent by area, whereby the bearing can be used at a surface pressure of 6 kgf/mm(58.5 MPa) or higher and a sliding speed of 2 to 5 cm/s.

Oil-impregnated sintered sliding bearing

A turbo component for a turbocharger in which heat resistance, corrosion resistance, and wear resistance is superior, and in which the cost is further lowered, is provided. In the turbo component, the overall composition is, in ratio by mass, Cr: 23.8 to 44.3%, Mo: 1.0 to 3.0%, Si: 1.0 to 3.0%, P: 0.1 to 1.0%, C: 1.0 to 3.0%, and the balance of Fe and inevitable impurities, and carbide is dispersed in the matrix at a density ratio of 95% or more.

Turbo component for turbocharger

Growing community of inventors

Kashiwa, Japan

Michiharu Mogami