Abstract: A Cu-based material 5 is immersed into an alkali hydroxide solution with a concentration of 3.0 to 37.5 mass % and a H2O2 solution with a concentration of 3.0 to 50.0 mass % is added in the alkali hydroxide solution, a temperature of the alkali hydroxide solution when the Cu-based material is immersed ranges from 60 to 105° C., a ratio A/B between a mol number A of alkali hydroxide in the alkali hydroxide solution and a mol number B of H2O2 in the H2O2 solution is 10 or more, and where a mol number of Sn in the Sn layer is C and a mol number of Sn in the CuSn layer is D, B?C×2+D×6.

Abstract: Provided is a Cu—Ti-based copper alloy sheet material that satisfies all the requirements of high strength, excellent bending workability and stress relaxation resistance and has excellent sprig-back resistance. The copper alloy sheet material has a composition containing, by mass, from 1.0 to 5.0% of Ti, and optionally containing at least one of at most 0.5% of Fe, at most 1.0% of Co and at most 1.5% of Ni, and further optionally containing at least one of Sn, Zn, Mg, Zr, Al, Si, P, B, Cr, Mn and V in an amount within a suitable range, with the balance of Cu and inevitable impurities, and having a crystal orientation satisfying the following expression (1) and preferably also satisfying the following expression (2). The mean crystal grain size of the material is controlled to be from 10 to 60 ?m. I{420}/I0{420}>1.0??(1) I{220}/I0{220}?3.

Abstract: A Cu-based material 5 is immersed into an alkali hydroxide solution with a concentration of 3.0 to 37.5 mass % and a H2O2 solution with a concentration of 3.0 to 50.0 mass % is added in the alkali hydroxide solution, a temperature of the alkali hydroxide solution when the Cu-based material is immersed ranges from 60 to 105° C., a ratio A/B between a mol number A of alkali hydroxide in the alkali hydroxide solution and a mol number B of H2O2 in the H2O2 solution is 10 or more, and where a mol number of Sn in the Sn layer is C and a mol number of Sn in the CuSn layer is D, B?C×2+D×6.

Abstract: A copper alloy sheet has a chemical composition containing 0.7 to 4.0 wt % of Ni, 0.2 to 1.5 wt % of Si, and the balance being copper and unavoidable impurities, the copper alloy sheet having a crystal orientation which satisfies I{200}/I0{200}?1.0, assuming that the intensity of X-ray diffraction on the {200} crystal plane on the surface of the copper alloy sheet is I{200} and that the intensity of X-ray diffraction on the {200} crystal plane of the standard powder of pure copper is I0{200}, and which satisfies I{200}/I{422}?15, assuming that the intensity of X-ray diffraction on the {422} crystal plane on the surface of the copper alloy sheet is I{422}.

Abstract: Provided is a Cu—Ti-based copper alloy sheet material that satisfies all the requirements of high strength, excellent bending workability and stress relaxation resistance and has excellent sprig-back resistance. The copper alloy sheet material has a composition containing, by mass, from 1.0 to 5.0% of Ti, and optionally containing at least one of at most 0.5% of Fe, at most 1.0% of Co and at most 1.5% of Ni, and further optionally containing at least one of Sn, Zn, Mg, Zr, Al, Si, P, B, Cr, Mn and V in an amount within a suitable range, with the balance of Cu and inevitable impurities, and having a crystal orientation satisfying the following expression (1) and preferably also satisfying the following expression (2). The mean crystal grain size of the material is controlled to be from 10 to 60 ?m. I{420}/I0{420}>1.0 ??(1) I{220}/I0{220}?3.

Abstract: A sheet material of a copper alloy has a chemical composition comprising 1.2 to 5.0 wt % of titanium, and the balance being copper and unavoidable impurities, the material having a mean crystal grain size of 5 to 25 ?m and (maximum crystal grain size?minimum crystal grain size)/(mean crystal grain size) being 0.20 or less, assuming that the maximum, minimum and mean values of mean values, each of which is the mean value of crystal grain sizes in a corresponding one of a plurality of regions which are selected from the surface of the sheet material at random and which have the same shape and size, are the maximum, minimum and mean crystal grain sizes, respectively, and the material having a crystal orientation satisfying I{420}/I0{420}>1.0, assuming that the intensities of X-ray diffraction on the {420} crystal plane of the surface of the material and the standard powder of pure copper are I{420} and I0{420}, respectively.

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.

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, Co: 2.0% or less, and Fe: 1.0% 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.