| 摘要 |
PURPOSE:To reduce the amt. of the gold to be used to a fraction of the amt. of the gold used in the prior art and to form a plating film having substantial resistance to wear by coating simultaneously a metal and transparent oxide or transparent carbon on a material to be plated by vacuum evaporation, sputtering, etc. CONSTITUTION:A wristwatch case formed of a stainless steel is first attached in a high-frequency sputtering device provided with two targets one of which is a gold target and the other is an SiO2 target. After the inside of the device in this state is sucked to 5X10<-7>Torr vacuum, gaseous Ar and a small amt. of O2 are introduced therein and a main valve is so adjusted to attain order of 10<-3>Torr. A high-frequency voltage 700V is then impressed to both target electrodes to generate discharge and to start sputtering. A shutter is opened to form the mixed film composed of gold and SiO2 on the watch case after preliminary sputtering for 30min. The hardness of the mixed film shows about 700HV. The wear loss of the gold plating of such watch case in the sand falling test thereof is as slight as <=1/30 the wear loss of the gold plating in the prior art and there is no fracture of the film. The color tone of the gold is maintained approximately as it is since SiO2 is transparent. |
