Patent ID: 6120727
Filing Date: 2000-09-19
Classification: B22F

Abstract:
A method of manufacturing a machine component of sintered ferriferous composite comprising an outer part having a hole and an inner part having a shaft which is fitted into the hole of the outer part, comprising the steps of: preparing one of the outer part and the inner part as a green compact of ferriferous powdered metal and the other as one of a green compact of ferriferous powdered metal, a sintered compact of ferriferous powdered metal and a mass of ferriferous molten metal; inserting the shaft of the inner part into the hole of the outer part; and sintering the outer part and the inner part to bond the outer part and the inner part, whereinthe outer part and the inner part are prepared to have a fitting clearance of approximately -60 to +5 .mu.m, andwhen only the outer part is prepared as a green compact, the outer part is prepared to contain substantially no zinc, or the atmosphere at the sintering step is substantially non-carburizing atmosphere, and,when the inner part is prepared as a green compact, the outer and inner parts are prepared so that only the inner part contains zinc, and the atmosphere at the sintering step is substantially carburizing atmosphere.