Study On Cyanide - Free Copper Plating

At present, all kinds of copper plating process emerge in endlessly, but with the most or cyanide copper plating. However, the use of this copper plating process is the drawback of the cyanide inside the highly toxic.However, the cyanide process in wastewater emissions and in the environment, will not only pollution bad environment, but also affect people’s life. Therefore, in view of the above problems, the purpose of this paper is proposed a non cyanide copper plating process and the effect of the process to cyanide copper plating process and the effect of comparable. Compared with other non cyanide copper plating, the pollution rate of the environment and the cost of the subsequent wastewater treatment are decreased..The process requires the ability to plating on the iron and steel and meticulous, uniform, good toughness, bright, strong binding force of the copper coating. The potassium citrate as main complexing agent, together with appropriate auxiliary complexing agent, which can reduce the equilibrium potential of copper, but not with iron matrix occurred replacement reaction. Therefore, this overcomes the short comings of non cyanide copper plating, so that the bonding between the matrix and the coating is very good. In addition, the paper explores the plating time, current density, plating liquid temperature, adding amount of additives and intermediate layer on the overall performance of the coating appearance effects. Respectively in acidic sulfate copper plating system and alkaline citric acid salt copper plating system on iron substrate and copper, and to explore the plating liquid temperature, plating time, additives and current density on the coating morphology and properties of, in order to get the best plating parameters and operating conditions of producing an excellent coating. On sulfate copper plating solution and citric acid salt of copper plating solution for electrochemical analysis, test plating solution of linear sweep voltammetry (LSV), constant current polarization and AC impedance and analysis the electrochemical behavior of copper deposition mechanism of copper atoms and copper electroplating process. From the theory to guide the experiments, the best current potential polarization can be obtained by the linear sweep voltammetry curves, so as to correct the actual operation of the current density, and finally to obtain more precise electroplating parameters. (1) determine the steel substrate in alkaline citrate no cyanide copper plating, the optimum technological conditions: electroplating time for 5 minutes, cathode current density of 2.0 A/dm2, the bath temperature is 65 ℃; and make sure that the steel substrate on acidic sulfate copper plating the optimum conditions: electroplating time is 30 minutes, cathode current density 3.0 A/dm2, bath temperature is 40 ℃. The copper plating process can prepare bright copper plating with good adhesion, fine, uniform and good toughness.. (2) in sulfate solution, plating copper on iron matrix and stainless steel substrate, by electrochemical cathodic polarization curve, studies have shown that temperature should be elected 40 ℃ and pH1.