Simulation assisted design and manufacturing of anode for the hard chrome plating of components with complex geometry

Hard chrome plating is a widespread coating technique for applying a protective coating layer to the surface of components. Due to the simplicity of industry-applied lead anodes, components with complex geometry are often plated with a non-uniform layer of chrome. In this work, a cost-effective process based on thermal arc spraying and additive manufacturing for fabricating anode with complex geometry is presented. A simulation-based approach was employed to design the anode geometry. The influence of anode-cathode distance and shielding on coating thickness was examined using a developed simulation model. The designed anode structure was additively manufactured using Multi-Jet-Fusion (MJF) process and subsequently arc sprayed with an electrically conductive coating system. The test samples were both plated with conventional lead anodes and the developed anode under the same industrial conditions to validate the simulation model. The coating thickness of the plated samples was characterized using an optical microscope. The results concluded that the developed simulation model can give a precise prediction of the thickness of the deposited coating. The strategy of varying anode-cathode distance is able to optimize small thickness inhomogeneity. To eliminate the edge effect, the shielding strategy is more effective. Chrome-plated samples using the developed anode show more homogenous coating distribution compared to those chrome-plated samples using conventional lead anodes.