| 摘要 |
PURPOSE:To prevent deterioration in an ornamentation effect on account of rusting occurring in the contact potential difference between different metals in the stage of producing a material for ornamentation joined with the different metals by providing an insulating layer to the joint part in contact with the corrosive environment of the outside part. CONSTITUTION:Ornamental parts such as external parts for a portable watch, etc. are manufactured by the combination of gold and a metal such as stainless steel having the color tone different from the color tone of gold to provide the ornamental effect thereof. The stainless steel as the metal on the anode side is rusted owing to a large difference in the contact potential between both metals and the decreased ornamental effect resulted in this case. A long groove having 0.5mm. depth is formed to the stainless steel 2 and a transparent SiO2 insulating layer 4 is calcined by 0.2mm. over the entire outside circumferential part thereof. Gold 1 is then polished by sandpaper to the same shape adapted to the shape of the groove. Such gold 1 is brazed to the groove by 18K gold solder 3. The gold and the stainless steel in the part facing the outside world of corrosive environment are insulated by the SiO2 insulating layer and therefore the decrease in the ornamental effect by rusting is obviated. |
