*2.3. Jet Electrodeposition*

In this technique, a jet of plating solution is directed at the cathode surface directly. There exists an electrical field between the anode (located in the nozzle) and cathode (substrate). Figure 1 is a schematic representation of jet electrodeposition technique setup [4].

**Figure 1.** Schematic image of pulse jet electrodeposition.

As the plating solution flows, electric current is transferred along the stream of fluid to the substrate surface, thereby enabling deposition to occur on the cathode surface where the jet flows over [41]. Jet electrodeposition is a high-speed electroplating technique that offers a wide range of advantages [4]. These include: (i) a higher deposition rate compared to other conventional electrodeposition techniques, and (ii) a more efficient grain size refining effect. This is attributed to the cathode in the jet technique having a larger overpotential that can be used simultaneously with higher current densities. In this technique, Co content in the coatings increases with increases in electrolyte jet speed, Co2<sup>+</sup> ion concentration in the electrolyte, and cathodic current density.
