Patent ID: 6696168
Filing Date: 2004-02-24
Classification: B22F,B32B,Y10S,Y10T

Abstract:
A method of producing an aluminum-base composite bearing material made by powder sintering, wherein the aluminum-base composite bearing material consists of an aluminum-base metallic layer made by powder sintering and a back metal, wherein the aluminum-base metallic layer consists of a bonding layer, a sliding layer and a sacrificial layer which are arranged in this order, wherein the aluminum-base metallic layer is bonded by rolling to the back metal at the side of the bonding layer, and wherein the method comprises the steps of:(a) preparing a first powder to be formed to the bonding layer, which consists of 0.4 to 5 mass % in total of at least one selected from a first element group of Sn, In and Pb, from zero to 2 mass % in total of at least one selected from a second element group of Si, Mn, Ni, Cr, Zn, Fe, Zr, Ti and Sb, from zero to 1 mass % in total of at least one selected from a third element group of Cu and Mg, and the balance of Al and incidental impurities; (b) preparing a second powder to be formed to the sliding layer, which consists of 2 to 20 mass % in total of at least one selected from the first element group, 2 to 8 mass % in total of at least one selected from the second element group, 0.5 to 2 mass % in total of at least one selected from the third element group, and the balance of Al and incidental impurities; (c) preparing a third powder to be formed to the sacrificial layer, which consists of 0.4 to 25 mass % in total of at least one selected from the first element group, from zero to 4 mass % in total of at least one selected from the second element group, from zero to 1 mass % in total of at least one selected from the third element group, and the balance of Al and incidental impurities; (d) continuously forming an elongated multi-layered body of three powder layers so that the second powder is positioned between the first and second powders, whereby obtaining a first to third powder layers; (e) continuously forming a composite strip of compacted powders, which has a three layers structure, by continuously feeding the elongated multi-layered body into a rolling machine for powder compacting to press and form it; (f) producing a sintered composite strip by heating the continuous composite strip of compacted powders to a temperature of 460Â° C. to 550Â° C. to continuously sinter it; (g) continuously laying the sintered composite strip on a steel strip to be the back metal, which is fed separately, so as to bring the first powder layer side of the sintered composite strip to contact with the steel strip, and feeding the combined strips into a rolling machine to continuously rolling-bond the sintered composite strip to the steel strip; and (h) subjecting the thus obtained rolling-bonded composite strip to a heat treatment of heating it to a temperature of 400Â° C. to 510Â° C. and holding it under the temperature for not less than 30 seconds, and of rapidly cooling it down to 300Â° C. at a cooling rate of not lower than 50Â° C./minute, whereby obtaining a multi-layered composite material having a layered structure consisting of the back metal of the steel strip, the bonding layer of the sintered first powder layer, the sliding layer of the sintered second powder layer, and the sacrificial layer of the sintered third powder layer which are arranged in this order.