Ultrasonic-assisted electrodeposition of Ni-Al2O3 nanocomposites at various ultrasonic powers

Abstract

In this study, nanometer-sized γ-Al2O3 particles were embedded in nickel matrix to fabricate Ni-Al2O3 nanocomposites using ultrasonic-assisted electrodeposition (UAED) technique. Influence of ultrasonic power on microstructure, surface morphology, phase structure, and properties of nanocomposites were investigated using scanning electron microscope (SEM), atomic force microscope (AFM), X-ray diffractometer (XRD), microhardness tester, abrasion tester, and electrochemical workstation. Results demonstrate that S-300 nanocomposite had compact, smooth, and fine surface morphology, and Al2O3 nanoparticle content in S-300 nanocomposite that was obtained at 300 W had maximum value of 9.87 wt%. Peaks of nickel grains first became broader and then became slightly narrower when ultrasonic power increased from 100 W to 400 W. This illustrates that suitable ultrasonic power (such as 300 W) can obviously refine nickel grains in Ni-Al2O3 nanocomposites. S-300 nanocomposite had maximum microhardness value of 905.4 Hv. Average wear rate of S-300 nanocomposite was only 18.7 mg/min, and this illustrates that among Ni-Al2O3 nanocomposites, S-300 had outstanding wear resistance. S-300 nanocomposite had the smallest corrosion current density of 0.033 μA/mm2, demonstrating that S-300 had the best corrosion resistance.