RESIDUAL-STRESS MEASUREMENTS IN ELECTROLYTIC COPPER-NICKEL COMPOSITIONALLY MODULATED MULTILAYERS

Residual stresses in electrolyte copper-nickel compositionally modulated multilayers (CMM) deposited from sulfate plating solutions on low carbon steel substrates have been determined using a low incident beam angle x-ray diffraction technique. The sublayer thickness was Varied from 0.1 to 1.5 mu m, while the total thickness of the compositionally modulated multilayer was kept at 3 mu m. For reference, residual stress measurements were performed on electrolytic nickel deposited from Watts' nickel plating solutions. The evolution of the residual stresses in the compositionally modulated multilayers was measured as a function of the copper and nickel sublayer thicknesses. A general formula to calculate the x-ray information depth in CMMs was derived and used to obtain the residual stress depth profile in electrolytic copper-nickel CMMs.