Experimental Research Of Gold Electric Plating Process Based On Gold Potassium Citrate

In the aviation industry and electronic industry, many precision electronic components work in the extreme environment. In order to ensure the corrosion resistance and stability of the electronic components, Gold-plated layer is often applied to the surface of components. Some cyanide compounds were used as the main salt in the electric gilding, such as Potassium dicyanoaurate and Potassium cyanide gold. Plating solution contains a large number of free cyanide ions. However, with the development of science and technology, people have paid more and more attention to the environmental problems and accepted the conception of green manufacturing. An experimental study on low hazard electric plating process has been conducted, given the disadvantages of the existing system for cyanide plating, which include containing toxic cyanide of the plating solution, the environment pollution, difficulties in disposing and et al. The following works have been done:(1) The potassium citrate has been used as the main salt in the solution for gold electrical plating, to reduce the free-state cyanide ions ionized from the solution in the experimental process.(2) According to the temperature needed for test condition, the copper base parts surface electric gilding processing system has been designed, including the high accuracy constant temperature water bath device.(3) Based on the established solution, experiments were carried out on the copper substrate. Influences of the electric field, flow field, the style of the flush and the distance between anode and cathode on the plating performance have been studied experimentally. With the optimized parameters, rather bright surfaces with smaller crystalline grain size and higher bonding strength were obtained.In order to ensure the quality of the coating is qualified, the related performance test of the samples have been conducted. For example, the microstructure of the surface and the substrate were tested by AFM, demonstrating that the gold-plated layer was effective copied and even reduced the roughness of the substrate surface. The composition of the plating was tested using SEM and the plating adhesion is tested by the WS-97 coating adhesion testing instrument, which indicated that the plating’s performance could meet the industry’s standard.