Mechanical properties of Ni-nano-Al₂O₃ composite coatings on AISI 304 stainless steel by pulsed electrodeposition

This article primarily focuses on investigating the feasibility of enhancing the mechanical properties of Al₂O₃ coatings on AISI 304 stainless steel specimen. Taguchi's L₂₇ orthogonal array was used to optimize the microhardness of Ni-nano-Al₂O₃ composite coatings over AISI 304 stainless steel specimen by pulsed electrodeposition method. Pulse frequency 10 Hz, duty cycle 20%, and peak current density 0.6 A/cm² are found to be optimal values. Moreover, the influences of the optimized pulse parameters over the microstructure, energy-dispersive X-ray spectroscopy (EDX), corrosion resistance, X-ray diffraction (XRD), and coating thickness of Ni-nano-Al₂O₃ composite coatings were also investigated. The microhardness, microstructure, and texture of the composite coatings were significantly influenced by pulse frequency. The EDX results confirmed that the composites were fairly dispersed over the specimen. The hardness as well the corrosion resistance of the specimen was greatly improved.