| 摘要 |
PURPOSE:To form a noble metal plating layer having excellent adhesiveness and corrosion resistance by treating the surface of ornamental parts made of Ti or Ti alloy with a fluoride-contg. treating liquid and subjecting the surface to Pd strike plating in succession thereof, then plating the noble metal thereto. CONSTITUTION:The surface of the external parts of spectacle frames or wristwatches made of Ti or Ti alloy is first degreased and cleaned with an aq. alkaline soln. The parts are then immersed for 10-300sec into the treating liquid of <6pH and 1-60 deg.C contg. 0.1-20wt% fluoride such as acidic ammonium fluoride, hydrosilicofluoric acid or hydroborofluoric acid and thereafter the parts are washed. The washed parts are subjected to a plating treatment for 10-300sec at 0.1-5A/dm<2> current density in the plating liquid of 20-80 deg.C contg. Pd or Pd alloy to form a strike plating layer of Pd metal to 0.1-1mum thickness. The parts are then electroplated for 1-10min at 0.2-1.0A/dm<2> current density in the plating liquid of noble metal such as Au at 40-60 deg.C to form the noble metal plating layer having the excellent adhesiveness and corrosion resistance to Ti metals to 0.2-5mum thickness.
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