A thin film silver-nickel coating for use as a protective coating on electrical terminals of separable electrical connectors. The silver-nickel coating is a silver-nickel nano-composite material characterized by silver and nickel grains having an average grain size of about five to about fifty nanometers, yielding a silver-rich phase and a harder nickel-rich phase as a result of silver and nickel being immiscible. In accordance with this invention, the volume fraction of nickel significantly influences the fretting wear resistance of the coating, with a preferred nickel content being resulting in the presence of disconnected islands of the nickel phase dispersed within a relatively softer silver matrix.