Assistant professor of mechanical engineering, Naval Postgraduate School, Monterey, Calif.
Associate professor of engineering mechanicsMember of ASTM, University of Wisconsin, Madison, Wis.
The fatigue life of nickel-plated copper depends upon the thickness of the nickel coating. Increases in life from 150 to 450 percent were obtained by increasing the thickness of the nickel from 0.0001 to 0.00025 in. (0.00254 to 0.00635 mm). A further increase in thickness to 0.005 in. (0.0127 mm) resulted in an increase in life of 200 percent. Interrupting the current during electroplating produces interfaces within the coating and increases the fatigue life for a given thickness. Increases in life of 110 percent were obtained by applying a 0.0005-in. thick coating in five layers, rather than in a single layer.
Paper ID: JTE10108J