Process for the application of precious metals to base or less precious metals

摘要

A coating of precious metal, namely Ag, Au or Pt metals, is applied to a substrate metal, e.g. Cu, Al, Fe or brass, particularly for electric relay contacts, e.g. in telecommunication installations, by producing an electric spark by vibrating electrodes fed with an impulse current, such as generated in a motor, valve oscillator or by using a condenser, the precious metal attached to or constituting the anode being transferred to the substrate metal constituting the cathode in the form of a thin, rough, firmly burnt-in surface coating. A manually operated vibrating device may be used or vibrator means may be affixed to the relay system.