Effects of Co contents on the microstructures and properties of the electrodeposited NiCo–Zr composite coatings

Journal Article · Fri May 15 00:00:00 EDT 2015 · Materials Research Bulletin

DOI:https://doi.org/10.1016/J.MATERRESBULL.2015.01.046· OSTI ID:22475769

Cai, Fei ^[1]; Jiang, Chuanhai ^[1]; Zhao, Yuantao ^[1]; Ji, Vincent ^[2]

---

1. School of Materials Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240 (China)
2. ICMMO/LEMHE, UMR 8182, Université Paris-Sud 11, Orsay Cedex, 91405 France (France)

Highlights: • The novel NiCo–Zr coatings were prepared by electro-deposition. • Surface morphology, crystal structure, grain size and microstrain were examined. • Texture, residual stress and corrosion resistance were investigated. • Addition of Co increased the hardness and corrosion resistance of the coatings. - Abstract: In this study, the NiCo–Zr composite coatings were prepared from the electrolytes with different Co{sup 2+} concentrations by electrodeposition method. The effects of Co contents on the crystal structure, surface morphology, grain size, microstrain and residual stress were examined by X-ray diffractometer (XRD), field emission scanning electron microscopy (FESEM), Energy dispersive X-ray spectroscopy (EDX) and atomic force microscope (AFM). The corrosion resistance of the composite coatings was also examined by the potentiodynamic polarization and electrochemical impedance (EIS) measurements. The results revealed that the crystal structures of the coatings were dependent on the Co contents and addition of Co content of 58 wt% resulted in the formation of hexagonal (hcp) Co. The increasing Co contents in the NiCo–Zr composite coatings resulted in the smoother and more compact surface, decreased the grain size and increased the microstrain. The micro-hardness and residual stress also increased with increasing Co contents. The addition of Co increased the corrosion resistance of the NiCo–Zr composite coatings compared with the Ni–Zr coating while the corrosion resistance of the NiCo–Zr composite coatings decreased as the Co contents increased.

• OSTI ID: 22475769
• Journal Information: Materials Research Bulletin, Vol. 65; Other Information: Copyright (c) 2015 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0025-5408
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ATOMIC FORCE MICROSCOPY
COATINGS
COBALT COMPOUNDS
COMPOSITE MATERIALS
CORROSION RESISTANCE
ELECTROCHEMISTRY
ELECTRODEPOSITION
HARDNESS
HCP LATTICES
NICKEL COMPOUNDS
POLARIZATION
RESIDUAL STRESSES
SCANNING ELECTRON MICROSCOPY
SURFACE PROPERTIES
SURFACES
X-RAY DIFFRACTION
X-RAY DIFFRACTOMETERS
X-RAY SPECTROSCOPY
ZIRCONIUM