Copper-based alloy

Abstract

This invention has for an object thereof the provision of a leadless copper-based alloy which mends the deterioration of tensile strength at elevated temperatures and enables the mechanical properties thereof to approximate the CAC406 by forming in the alloy texture thereof an alloy or an intermetallic compound with Bi and Pb existing independently or in a mutually joined state. For the purpose of accomplishing the object, this invention incorporates in the copper-based alloy an additive element capable of forming an alloy or an intermetallic compound with Bi and Pb existing independently or in a mutually joined state. The additive element is one or more members selected from the group consisting of Te, P, Zr, Ti, Co, In, Ca, B and misch metal.

1 . A copper-based alloy containing 2.8 to 6.0 mass % of Sn, 1.0 to 12.0 mass % of Zn, 0.1 to 3.0 mass % of Bi, 0.05 to 0.1 mass % of P, 0.25 mass % or less of Pb excluding 0 mass % of Pb, and the balance of Cu and unavoidable impurities, whereby said P suppresses generation of a Bi—Pb binary eutectic crystal in a texture of the copper-based alloy. 
     
     
         2 . A copper-based alloy according to  claim 1 , further containing 0.05 to 1.2 mass % of Se. 
     
     
         3 . A copper-based alloy according to  claim 1 , wherein the copper-based alloy contains 0.05 to 0.09 mass % of P. 
     
     
         4 . A copper-based alloy according to  claim 2 , wherein the copper-based alloy contains 0.05 to 0.09 mass % of P. 
     
     
         5 . A copper-based alloy according to  claim 1 , wherein the copper-based alloy contains 3.5 to 4.5 mass % of Sn. 
     
     
         6 . A copper-based alloy according to  claim 2 , wherein the copper-based alloy contains 3.5 to 4.5 mass % of Sn.