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As one of the most important surface treatment technologies, electroplating is an electrochemical method, which can modify the surface characteristic, such as anti-corrosion, micro-hardness, abrasion, electrical conductivity, lubricity, heat resistance and decorative properties.Recently, the electrodeposition on aluminium alloy and stainless steel is applied widely. But the conventional method has many disadvantages such as complex operating process, bad adhesion for complex workpiece geometry, expensive cost and environment pollution. In this paper, new electroplating baths for electroplating on aluminium alloy 3005 and stainless steel 304 were studied. Also, morphology, element component and corrosion resistance of the electrodeposits were analyzed. The main results obtained are presented as follows:1. An effective anodic complex to eliminate the oxidation film was studied. After moderate membrane -eliminating, the power supply turns to reverse for cathodic electroplating. Then, a plating membrane with uniform and compact crystal was obtained, which could be only prepared as preliminary nickel layer. The excellent continuative membrane could be obtained by electroplating on the bottom nickel layer. The influences of operating condition and electroplating parameters on the coating properties were investgated and the surface micrographs were analyzed by scanning electron microscope (SEM). This process not only gets rid of the conventional zincing process, but also has many advantages, for example, low cost and easy operating.2. A process of electrodepositing after anodization was studied in this paper. A thin aluminum oxide film could be attained by anodizing in phosphoric acid solution. The microstructure of the anodic film was observed by SEM, the result shows that the anodic film presents big and uniform pores,which lead to bigger specific surface area and better adhesion for the following electroplating nickel. Nickel-electroplating can operate on the anodic film without reverse turning of power supply. The complex agent added in the electroplating solution can make the crystallization much more compact by enhancing the cathodic polarization and overpotential,and thus the continuative plating on the anodic film could be much effective. 3. Stainless steel 304 was treated primarily by anodic electrolytic activation-nickel electrodepositing,whith could carry out the two sections in the same solution by adding an additive to eliminate the oxide film. After anodic activation, the power supply turned to reverse for nickel electroplating. Then, the oxide on stainless steel could be eliminated and a nickel film with good adhesion could be obteined. Based on that, coatings with excellent properties could be attained by the continuative plating on the nickel film. Morever,the bath composition and electroplating process parameters were optimized.
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