Effect of Pulse Parameters on the Microstructural Evolution and Properties of Jet Electrodeposited Cu–Al₂O₃ Nanocomposite Coating

Abstract

Cu–Al₂O₃ composite coatings were prepared in the use of pulse jet electrodeposition technology. Pulse current parameters including duty cycle and frequency were researched about their effects on the microstructure variation and Al₂O₃ nanoparticles content of the composite coating. The mechanical properties and anti-corrosion resistance of the composite coating were examined. The results show that properly decreasing the duty cycle and raising the pulse frequency are able to generate a compact and fine nanocrystalline microstructure and increase the incorporation of Al₂O₃ nanoparticles in the composite coating, which is beneficial to strengthen the coating properties. With the optimal parameter combination as duty cycle 30% and pulse frequency 11000 Hz, the co-deposited Al₂O₃ content in the composite coating reaches a maximum of 14.4 at%, with the highest hardness of 308 HV and tensile strength of 755 MPa. The composite coating with optimized pulse parameters also displays improved corrosion resistance.

Nanocrystalline microstructure of the coating prepared at pulse duty cycle 30%.