Electrochemical and Tribological Behavior of Ni-Co/ZrO₂ Coatings Prepared by Ultrasound-Assisted Electrodeposition

摘要

Ni-Co composite coatings reinforced with ZrO2 were obtained by ultrasound-assisted electrodeposition.The electrodeposition kinetics were investigated using linear sweep and cyclic voltammetry. Themorphology and coating phases of the coatings were characterized by scanning electron microscopy andX-ray diffraction, respectively. Results indicated that the electrocrystallization of Co2+ was controlledby a three-dimensional “nucleation/growth” process. The initial co-deposition potentials of the alloy andcomposite coatings were ?0.72 V vs. SCE and ?0.70 V vs. SCE, respectively. During co-deposition,ZrO2 restrained the discharge of H+ and reduced the cathodic polarization. When the amount of addedZrO2 was 10 g L?1, the nanohardness, anti-corrosion and wear resistance of the Ni-Co/ZrO2 compositewere evidently improved compared with the Ni-Co alloy. The average nanohardness of the Ni-Co/ZrO2composite was 6.13 GPa, which was approximately 1.5 times higher than that of the Ni-Co alloy (4.12GPa). After 40 min of rotational wear testing, the wear loss of the Ni-Co alloy was approximately twicecompare with the Ni-Co/ZrO2 composite. The high hardness and low defect density in the compositecoatings reduced the plastic deformation and adhesive wear of the Cu substrates, leading to a significantimprovement wear properties.