Application Of Ion Implantation In Corrosion And Protection Of Lead, Nickel And Aluminium

Ion implantation is as a new technology for metal surface treatment. It's particular advantages have been regarded more and more. In this thesis, its superiority in metal surface treatment was explained with applications of ion implantation in metal corrosion and electrode characteristics improvement.Based on the flux transfer equation, this paper innovatively brings forward heat transfer equation in the ion injecting process, educes formula describing sample temperature and the methods to calculate the maximum allowable time of ion injection on different conditions.Effect of dosage of titanium and energy for speeding titanium ion on corrosion behaviors of lead and lead-4% antimony alloy was studied in this thesis. Implantation of titanium would restrain anodic process of lead corrosion, but it speeded up hydrogen emitting from solution. When the dosage was over high, surface concentration of titanium was very large, and its degradation happened seriously, the microcell was formed on the surface to accelerate the corrosion. At the same time, overpotential of emiting hydrogen was decreased. So, corrosion of lead in H2SO4 was speeded. When the dosage was too little, its surface concentration would be very low and good protective result could not be obtained.Transient technology with controlling current was applied in the study. The results indicate that decrease of overpotential of emitting hydrogen on lead surface is more series than which on lead-4% antimony alloy surface with different dosage titanium implanted. Specially, when the dosage is higher than 5X 10'6atoms.cm"2, the decrease was more fast on lead surface than which on lead-4% antimony alloy surface. Improvement of corrosion behavior with titanium ion implantation for lead-4% antimony alloy is more visible. The results indicate also that the 60 keV speeding energy for titanium ion is feasible.In the thesis, Auger electron spectroscopy, scanning electron microscopy, and energy dispersion x-ray spectroscopy were applied to study corrosion and protection of the metals with titanium ion implantation . And the obtained results are similar to that obtained from electrochemical technology.Some other metals were as ion sources to implanted into lead and lead-4% antimony alloy to study the effect of the elements on the corrosion behavior of lead andthe alloy. The results are almost same as above-mentioned results.Characteristics of nickel electrode in alkali solution were improved with cobalt ion implantation. Electrochemical reaction between Ni(OH)2 and NiOOH was studied with current step method, and measurement of charge and discharge currents. Size of the charge current affects the properties of the nickel electrode obviously. The affection was increase or decrease of overpotentials for emitting hydrogen and emitting of oxygen. Implantation of cobalt could raise the efficiency of charge of nickel electrode because the cobalt could make the reaction potential close to equilibrium potential and be far from the potential of oxygen emitting to decrease oxidation of O2" and restrain some other reactions. The experimental results indicated that amount of NiOOH transformed from Ni(OH)2 would be increased with cobalt ion implantation.It was proved that aluminum anti-pitting behavior of Cl~ was improved with implantation of titanium in the thesis.Anyway, with extension of the application of ion implantation in improvement of material surface properties and lucubrating to the technology, the technology will be a important method to improve surface properties of materials.