Papers by Keyword: Zinc Plating

Abstract: This paper presents an analysis of the current density distribution in the zinc plating process, using a two-dimension approach. The simulation presents a model based on COMSOL Multi-physics software. The simulation neglected the effect of mass transfer and production of gaseous species, in order to simplify the resolution. Additionally, a validation from the simulation through a comparison with the experimental data at similar conditions was performed. The results presented a good agreement between the experimental and simulated data. The graphics from both approaches showed a decreasing trend in the current density along the cathode length. This trend arises from the electrons movement in the electrodes; electrons flow through the least resistive path. Given the fact that zinc electroplating incurs an important industrial application, simulation is becoming a promising way to optimization and improvement.

Abstract: For more environmental friendly study, commonly undesired natural process which is corrosion will present. Thus, in this century there is a serious effort in ongoing analysis in order to prevent this phenomenon occurring. The challenge of corrosion in manufacturing and domestic sector is enormous. Thus, corrosion can be defined as the deterioration and destruction of a material because of reaction with the environment. Replacing a corroded pipeline can cost about $643,000 per kilometer. The application of the traffic sign or a road sign that embedded in soil usually can withstand for two to three years until it will corrode and then fracture. The main objectives of this study is to increase the protection on the surface of the materials towards corrosion and to improve the appearance of the product or serves as an effective undercoat for paints which can reduce the cost of using expensive material by using the other method; electroplating process. The samples were plated with zinc at 2, 4 and 6 A/dm² for 20 minutes for every sample. Then, the samples were immersed in the artificial soil solution for 30 days, then the testing to measure the corrosion rate, phase analysis, morphological analysis and hardness test were conducted. From all the tests, sample with 6 A/dm² got the best results with 5.2059 mpy and 80.6 HV hardness strength. It is because by increasing the current density, the thickness will then increase the zinc plating will not easily peel off and attack by corrosive agent.

Abstract: The corrosion resistance of blackishgreen passivation films on zinc-plated steel sheet was studied by polarization curve measurement, electrochemical impedance spectroscopy and neutral salt spray test. The passivated sample featured a more positive corrosion potential and much lower corrosion current density as compared to non-passivated sample in 5% (mass fraction) NaCl solution. The Nyquist plots of the samples with and without passivation were characterized as two complete capacitive arcs, indicating that the corrosion is controlled by electrochemical process. The radii of capacitive arcs of the passivated sample are larger than those of non-passivated sample, because the passivation film formed on the sample surface increases the reaction resistance in corrosion process, thus the corrosion resistance of the sample is improved. The anti-white rust time of the passivation film in neutral salt spray test is 400 h.

Abstract: In order to reduce the environmental pollution from chromate used in plating factories, one new kind of non-chromium passivation solution containing silicate, hydrogen peroxide and fluoride ion, etc. has been explored to form blue-white conversion film on alkaline electrodeposited zinc coatings. The conversion films on zinc coatings with both glossy blue-white surface and high anti-corrosion performance have been obtained by optimizing the experimental conditions. The results show that silicate-based passivation technique is able to be widely applied to solve the problem of pollution caused by waste from plating industry in the future.

Abstract: The effect of some process parameters on the weight of zinc deposited on mild steel in a typical electroplating process is reported. The study indicates that the weight of zinc deposited on mild steel during the process is affected by plating temperature, current density, plating bath pH and plating time. The study established that optimum deposition of zinc is achieved at plating temperature of 320C, plating bath pH of 4.4, current density 40mA/cm2 and plating time of 30 minutes. 8.7mg of zinc was deposited at optimum deposition conditions. The profile of the zinc deposited decreases after optimum deposition is attained.