| 摘要 |
PURPOSE:To obtain excellent conductivity and strength, and to improve even repeated flexing properties and plating properties by using a three-layer clad material manufactured through a cold pressure-welding method by the constitution of pure copper/ phosphor bronze/pure copper or phosphor bronze/pure copper/phosphor bronze. CONSTITUTION:In a clad material consisting of three layers in which a phosphor bronze plate, which contains 5.5-9.0wt% Sn and 0.03-0.35wt% P and the remainder thereof is composed substantially of Cu, is used as a core material and pure copper plates in the same plate thickness are superposed on both surfaces of the phosphor bronze plate and joined through cold pressure-welding, the clad rate of phosphor bronze is brought to 15-60%, and final cold working of a working ratio of 40% or more is executed. When the clad rate of phosphor bronze is less than 15%, the tensile strength of the clad material is insufficient to a characteristic demand value, or heat resistance is imperfect even when strength is sufficient at room temperature. When the clad rate of phosphor bronze is exceeds 60%, the conductivity of the clad material is in short supply to the characteristic demand value. The clad rate of phosphor bronze must be reduced in order to obtain comparatively high conductivity, but a final cold working ratio for supplementing the lowering of strength is brought to 40% or more. |
