Ndc Company Ltd.

Yasukuni Hasegawa

Hiroyuki Sugawara

Koue Ohkawa

A composite strip of compacted powders, which has a three layers structure, is continuously obtained by means of a rolling machine for powder compacting. The composite strip is sintered at a temperature of 460&deg; C. to 550&deg; C. to form a sintered composite strip. The sintered composite strip is continuously bonded by rolling to a steel strip. The bonded composite strip is optionally subjected to a heat treatment of heating at a temperature of 250&deg; C. to 400&deg; C. followed by heating to a temperature of 400&deg; C. to 510&deg; C., holding the strip under the temperature for not less than 30 seconds, and rapidly cooling down to 300&deg; C. at a cooling rate of not lower than 50&deg; C./minute, whereby obtaining a multi-layered composite material consisting of the steel strip, a sintered bonding layer, a sintered sliding layer and a sintered sacrificial layer. At least one selected from a low-melting-point element group of Sn, In and Pb is added to raw powders to be formed to surface layers of the sintered composite strip, which are the sintered bonding layer and the sintered sacrificial layer, in an amount of 0.4 to 5 mass % and 0.4 to 25 mass %, respectively.

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Narashino, Japan

Yasukuni Hasegawa