Study Of Nickel-chromium Electrodeposition On Aluminum

Nickel-chromium alloys electrodeposition on aluminum have been studied. For the special physical and chemical character of aluminum, a nickel layer is deposited before electroplating. It can avoid the active surface of aluminum oxidized again or substitution reaction in the bath. By means of adding a certain a mount of appropriate complexing agent . the deposit electric potential of the two elements will be equal or approximation ,then the coating containing O?% of chromium is obtained. The experiment result shows that the operating conditions have a significant effect upon the chromium content, and it increased with the raise of current density and pH value, but decrease with the temperature raise of the bath.SEM (scanning electron microscope) and metallographical picture show the best alloys coating can be obtained by Ni depositing layer. Hot shock and cathode electrolysis experimental results indicate the interface adhesion strength between coating and aluminum matrix is excellent . the element electronic probe image provide that the two composition are co-deposition; structure analysis by XRD (X-ray diffraction ) demonstrated that Cr exists in the way of solid solution in the coating.