Study Of Molecule Resonance Electroless Plating Ni On Aluminum And Subpressure Electroless Plating

In this paper, Ly12 aluminum alloy was used as the substrate. The radiation, whose wavelength was close to the optimal absorption wavelength of the electroless plating solution, was introduced into the process. So the molecules of the solution became resonated, and temperature of the bath reached plating temperature quickly. Then, under the continuous action of the radiation wave, the redox reaction happened at the metal surface. The metal ions deposited on the surface of the metal, and formed the coating. This new, efficient, energy saving process was called molecular resonance aluminum alloy electroless plating. Optical microscope, X-ray diffraction, Scanning Electron Microscopy, Microhardness tester and VMP3 multi-channel electrochemical workstation were used. By adjusting the process parameters and experimental methods, the coating formed dynamic behavior, coating structure, coating performance and energy saving effect of the molecular resonance aluminum alloy electroless plating process, and vacuum plating were studied. The results show that:The influence of temperature and pH to deposition rate of molecular resonance aluminum alloy electroless nickel plating was great. Base on this formula, the empirical equation of deposition rate was put forward.With the same formula and process conditions, the deposition rate of aluminum molecular resonance electroless plating was 20% faster than deposition rate of conventional water bath, and saving energy 87.5%.In the case of the trend of microcrystalline growth and amorphization, the molecular resonance electroless plating was more obvious than the common water bath plating, but the phosphorus content of both coatings were almost the same.Molecular Resonance radiation heating didn't affect the growth pattern of the coating, but let the coating particles became larger. The coating and aluminum substrate combined well. With heating treatment temperature increases, hardness increases, and reached the peak when the heating temperature was 400℃.As the electroless plating layer of molecular resonance grew faster than water bath heating, the porosity of the former was larger. So the corrosion current density shifted positively. The relative corrosion resistance was lower, but the difference was not significant.The effect of pressure to the deposition process was obvious. The lower of the surface pressure decreased, the higher, the deposition rate increased, and the coating tend to be refined or amorphous orientation. As the pressure decreases, the corrosion potential of the coating did not change, but its corrosion current density shifted plus, and the corrosion resistance decreased.