Localised electrochemical additive manufacturing via microjet electrochemical deposition

Abstract

The current study presents a novel process developed in-house for microjet electrochemical additive manufacturing (Microjet-ECAM) of pure copper strips on a nano-polished brass substrate. A two-dimensional numerical model was developed to identify the stable material deposition zone, deposition height, potential, and current density distributions as the printing head traverses over the substrate. An experimental parametric study was conducted to assess the printability and the effect of parameters such as voltage, feed rate, and electrolyte flow rate. The parameters were varied at three levels, and linear features were printed layer-by-layer for 100 passes at each parameter combination according to the L27 orthogonal array. Numerical results estimated a deposition height of 72.2 μm and a steady material deposition of 1.33 to 4.33 mm along the substrate due to stray depositions at the initial and final microjet positions. The experimental results recorded voltage as the most influential parameter and flow and feed rates as the most interdependent during Microjet-ECAM. The microstructure of the material deposition showed a polycrystalline structure of the copper and a decrease in grain size on increasing feed and flow rates. A confined deposition having a refined grain structure with a deposition height of 70.4 μm was achieved.