Structure, Microhardness and Magnetic Properties of Electroplated Ni-Cu Alloys

Ni-Cu alloys were electroplated from sulphate bath using addition agents including sodium gluconate, boric acid and cysteine on a copper sheet by the galvanostaticmethod and ultrasound waves. The surface morphology, chemical composition, crystalline structure, magnetic properties and hardness of the Ni-Cu alloys were investigated using scanning electron microscope, energy dispersive spectroscopy, X-ray diffraction, vibrating sample magnetometer and Vickers testing method. The use of the appropriate concentrations of the addition agent simultaneously with the conventional ultrasound waves (CUW) during sample preparation was found to produce nanocrystallineNi-Cu alloys. XRD patterns showed the existence of two planes of 111 and 200 for the Ni–Cu alloys. The microhardness of the Ni-Cu alloys varied between 150 HV and 440 HV. The mechanical properties of nanocrystalline Ni-Cu alloys showed an increase of the hardness with increasing Ni content. The surface morphology of the coatings seemed to be the cauliflower and spherical grains. The increase of Ni content in the Ni-Cu alloys led to the formation of soft magnetic materials.