Production of Nano-Composite Hydroxyapatite-Based Coatings through Reverse Pulse Electroplating
Authors: Sakib S M Nazmuz 
Published: October 2021

Since the discovery of synthetic HAp in the 1950s, hydroxyapatite is becoming a significant covering material for bio implants. A regulated surface roughness/porosity, appropriate chemical resistance, and a desirable tri-biological behavior are required for HAp coatings. On substrates with a variety of structure, composition, size, and shape, the coating process must be applied at varied scales and at a fast enough rate. There is a full description of both dry and wet coating procedures included in this article. Cathode efficiency fell as tc- increased, although it was still better than DC coatings. In this paper, the mechanism of HAp electrodeposition is examined, as well as the effect of operational variables on deposit characteristics. Recent advances in the field are critically examined. HAp composite coatings, including those reinforced with metallic, ceramic, and polymeric particles, as well as nanotubes, modified graphene’s, chitosan, and heparin, are discussed in depth. On the other hand, a glance towards the future in the field of electrodeposited HAp coatings is taken. Different experimental parameters were explored to establish the optimal reaction conditions for HA-Ag nanocomposites. Pulse reverse plating (PRP) in combination with an anionic surfactant, sodium dodecylsulphate (SDS), was utilized for the first time to generate nanocomposite Co-Al2O3 electrodeposited coatings, using a technique similar to that used for Co – IF WS2 deposition in prior work. The optimal plating setups in the pulse-reverse electroplating (PRP) mechanism for non-anomalous plating of Co–Ni deposits (i.e., the metal composition of deposits equals that of the plating solutions) from chloride solutions were determined using experimental strategies such as fractional factorial design (FFD), path of steepest ascent, and central composite design (CCD) combined with the response surfaces (RSM). The FFD research found that the potentials and time duration of pulse-plating had a significant impact on the composition of Co–Ni deposits. The two parameters were the sharpest ascending route and the best circumstances for non-anomalous plating of Co–Ni layers. NiFe thin films produced by pulse reverse (PR) electrodeposition are potential alternatives for the next phase of core magnetic materials that will be utilized in high shifting frequency magnetic elements. For statistical modeling and analysis of the nickel electroplating process outcomes, the central composite experimental design and response surface technique were used. The empirical models developed in terms of design variables (current density J (A/dm2), temperature T (C), and pH) were found to be statistically adequate to describe the process responses, namely cathode efficiency Y%, coating thickness U (m), brightness V%, and hardness W%. (HV). The response surfaces were explored and analyzed using graphical representations consisting of 2D contour plots and 3D surface plots in order to determine the main, quadratic, and interaction effects. The desirability function method was used to do multi-response optimization of the nickel electroplating process. To this aim, a genetic algorithm was employed to solve the multi-response issue mathematically. The optimization method resulted in the Pareto optimum set, which is a collection of similar solutions.