COPPER-TIN ALLOY PLATING

PROBLEM TO BE SOLVED: To provide copper-tin alloy plating solving the defect of a copper-tin alloy plating film produced with a non-cyanogen type plating bath (that, when a plating film thickness reaches ≥2 μm, the plating film is worn or peeled in an extremely early stage to continuous impact), improving the problem of discoloration with the lapse of time, and suitable for ornaments and accessories. SOLUTION: Disclosed is copper-tin alloy plating at least having a η-Cu6.26Sn5phase, and in which the intensity ratio between 2θpeak integrated intensity I(101)equivalent to the (101) face of η-Cu6.26Sn5and 2θpeak integrated intensity I(110)equivalent to the (110) face of η-Cu6.26Sn5according to X-ray diffraction, [I(110)/I(101)] is 0.9 to 20. Further, preferably, the copper-tin alloy plating has a β-Sn phase, and in which the intensity ratio between 2θ peak integrated intensity I(211)equivalent to the (211) face of β-Sn and 2θ peak integrated intensity I(101)equivalent to the (101) face of β-Sn according to X-ray diffraction, [I(101)/I(211)] is 1.0 to 20. COPYRIGHT: (C)2009,JPO&INPIT