Deposition, Characterization and Evaluation of Monolayer and Multilayer Ni, Ni-P and Ni-P-Nano ZnOp Coatings

作者：Varmazyar Ali; Allahkaram Saeed Reza^*; Mahdavi Soheil

来源：Transactions of the Indian Institute of Metals, 2018, 71(6): 1301-1309.

DOI：10.1007/s12666-018-1279-y

• Ni-P
• Ni-P-ZnOp
• Multilayer coatings
• Electrodeposition
• Electroless deposition
• Corrosion

Ni, Ni-P and Ni-P-ZnOp monolayer films along with multilayer coatings containing different arrangements of these layers were produced on steel substrates by electrodeposition and electroless deposition techniques. Co-deposition of ZnO nano-particles, as well as morphology, cross-section, microstructure and microhardness of coatings were investigated. Corrosion behaviors of monolayer coatings were studied by potentiodynamic polarization and electrochemical impedance spectroscopy techniques, and the results were compared to multilayer films. Results revealed that, Ni-P-1.5 vol% ZnOp monolayer film obtained from a bath with 4 g L-1 of these particles had the highest hardness between all samples. Further addition of nano-particles to the bath lead to the formation of discontinuous films. Most of the multilayer coatings with different arrangements exhibited higher corrosion resistance as compared to monolayer films. Corrosion current density of three-layer Ni-P-ZnOp/Ni/Ni-P coating, considered as the most corrosion resistant film, was about 538 times lower than monolayer Ni-P coating.

• 出版日期2018-6