Cu-Ni-Si-based copper alloy sheet material and method of manufacturing same

Abstract

This invention provides a copper alloy sheet material containing, in mass %, Ni: 0.7%-4.2% and Si: 0.2%-1.0%, optionally containing one or more of Sn: 1.2% or less, Zn: 2.0% or less, Mg: 1.0% or less, and Co: 2.0% or less, and a total of 3% or less of one or more of Cr, B, P, Zr, Ti, Mn and V, the balance being substantially Cu, and having a crystal orientation satisfying Expression (1): I{420} / I0{420}>1.0, (1) where I{420} is the x-ray diffraction intensity from the {420} crystal plane in the sheet plane of the copper alloy sheet material and I0{420} is the x-ray diffraction intensity from the {420} crystal plane of standard pure copper powder. The copper alloy sheet material has highly improved strength, post-notching bending workability, and stress relaxation resistance property.

Description

technical field [0001] The present invention relates to a Cu-Ni-Si-based copper alloy plate as a material for electrical and electronic components such as connectors, lead frames, relays, and switches, and a method for producing the same. This copper alloy has good electrical conductivity and high strength, and in particular has excellent bending workability and stress relaxation resistance. Background technique [0002] Materials for electrical and electronic components such as connectors, frame materials, relays, and switches are required to have good electrical conductivity in order to suppress the heat generated when electricity is applied. At the same time, in order to ensure that electrical and electronic components do not undergo plastic deformation during operation and assembly, materials are required to have sufficiently high strength. In addition, electrical and electronic components are generally formed by bending, and therefore, materials are required to have go...

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Problems solved by technology

[0025] These methods all require small grain size at the same time, which often easily leads to a decrease in stress relaxation resistance.

[0026] Moreover, even if the general bending workability of Cu-Ni-Si-based copper alloys is improved by the methods in Patent Documents 1 to 5, it is difficult to improve the above-mentioned groove bending method.

Although the groove bending method can greatly improve the shape and dimensional accuracy after bending, the problem of preventing cracks during groove bending is not considered in Patent Documents 1 to 5

[0027] In addition, as mentioned above, the grain refinement method, while beneficial for improving the bending workability, is detrimental to the stress relaxation resistance as a creep phenomenon

In such a situation where it is difficult to improve the bending workability alone, it is impossible to improve the stress relaxation resistance at the same time using the currently known technology.

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