Sliding material made of copper alloy, method of producing same, and sliding bearing

Abstract

A copper alloy sliding material which can bring about superior resistance to fatigue as well as good anti-seizure property without containing any Pb. The copper alloy sliding material is made to have the structure in which both of the hard copper alloy phase and the soft copper alloy phase coexist in a mixture state. On the surface of the sliding material, the soft copper alloy phase comes to have a shape more concave than that of the hard copper alloy phase when receiving a load or when being in a sliding wear relation, in which concave portions is retained lubricant with the result that the anti-seizure property is enhanced. Further, since the soft phase and the hard phase are made of the same copper alloy, the wettability thereof becomes good, and Ni and etc. contained in the hard copper alloy phase are diffused into the soft copper alloy phase, so that the hardness of the boundary portion defined between the phases come to be gradually varied. Thus, because of the unclear boundary, the load received in the hard phase comes to be spread in a wide range without being concentrated at the boundary, so that the fatigue strength is enhanced.