The electrodeposition of aluminum on TiB2/A356 composite from ionic liquid as protective coating

The electrochemical deposition of aluminum using ionic liquid of AlCl3-1-ethtyl-3-methylimidazolium chloride (AlCl3-[EMIm]Cl) was studied to improve the corrosion resistance of TiB2/A356 composites. The effects of experimental parameters (e.g., current density, deposition time and electrolyte temperature) on the deposit morphology and cathode current efficiency were investigated. The results indicated that the experimental parameters can greatly affect the morphology of Al coatings. Sustaining at a relatively high percentage (≥ 97.0%), the cathode current efficiencies showed varied dependence on different parameters. The optimum conditions for producing dense and uniform Al coatings were determined, with the current density of 1.0 A/dm2, deposition time of 60 min and electrolyte temperature of 30 °C. The electrochemical behavior was evaluated by potentiodynamic polarization curves and cyclic voltammogram. It was found that the corrosion resistance of the TiB2/A356 composite was greatly enhanced by Al electrodeposition in ionic liquid.