COPPER BASE ALLOY

A copper base alloy, characterized in that it comprises an added metal which forms an alloy or an intermetallic compound with Bi, Pb and a substance formed by the binding of Bi and Pb, and exhibits improved mechanical properties, in particular tensile strength, at a high temperature due to the incorporation of the added metal, wherein the added metal is preferably one or more metals selected from the group consisting of Te, P, Zr, Ti, Co, In, Ca, B and mish metal. The formation of an alloy or an intermetallic compound of the added metal with Bi, Pb and a substance formed by the binding of Bi and Pb in the structure of the copper alloy results in the improvement of the tensile strength at a high temperature, which leads to the preparation of a Pb-substantially free copper alloy having mechanical properties being further near to those of CAC406.