| 摘要 |
PURPOSE:To obtain external parts for wristwatches having uniform quality and the good yield of production, by nitriding the surface of stainless steel with gaseous N2 plasma then forming TiN by a reactive ion plating method. CONSTITUTION:External parts for wristwatches are put into a vacuum vessel and after the inside thereof is evacuated to 10<-2> Torr, gaseous N2 is introduced to about 10<-1> Torr pressure, and a high voltage is applied between two electrodes to convert the gaseous N2 to plasma and nitride the surface of the external parts. The plasma treatment time is 5min-1hr. The above-described nitride film is then coated with TiN in a reaction vessel in which Ti is evaporated and N2 is introduced as ordinary ion plating. The drawback in the prior art, that is, the failure in sticking of the TiN film on the stainless steel owing to the defective adhesion in the stage of forming said film is eliminated by the above-mentioned treatment. The external parts for wristwatches having uniform quality and the good yield of production are thus obtained. |
