Izvorni znanstveni članak
https://doi.org/10.5599/jese.2013.0036
Effect of heat treatment on structure and properties of multilayer Zn-Ni alloy coatings
Vaishaka R. Rao
; Electrochemistry Research Laboratory, Department of Chemistry, National Institute of Technology Karnataka, Surathkal, Srinivasnagar-575025, India
Chitharanjan A. Hegde
; Electrochemistry Research Laboratory, Department of Chemistry, National Institute of Technology Karnataka, Surathkal, Srinivasnagar-575025, India
K. Udaya Bhat
; Department of Metallurgy and Materials Engineering, National Institute of Technology Karnataka, Surathkal, Srinivasnagar-575025, India
Sažetak
Composition modulated multilayer alloy (CMMA) coatings of Zn-Ni were electrodeposited galvanostatically on mild steel (MS) for enhanced corrosion protection using single bath technique. Successive layers of Zn-Ni alloys, having alternately different composition were obtained in nanometer scale by making the cathode current to cycle between two values, called cyclic cathode current densities (CCCD’s). The coatings configuration, in terms of compositions and thicknesses were optimized, and their corrosion performances were evaluated in 5 % NaCl by electrochemical methods. The corrosion rates (CR)’s of multilayer alloy coatings were found to decrease drastically (35 times) with increase in number of layers (only up to 300 layers), compared to monolayer alloy deposited from the same bath. Surface study was carried with SEM, while XRD was used to determine metal lattice parameters, texture and phase composition of the coatings. The effect of heat treatment on surface morphology, thickness, hardness and corrosion behaviour of multilayer Zn-Ni alloy coatings were studied. The significant structural modification due to heat treatment is not accompanied by any decrease in corrosion rate. This effect is related to the formation of a less disordered lattice for multilayer Zn-Ni alloy coatings.
Ključne riječi
Multilayer Zn-Ni alloy; Corrosion study; Heat treatment; SEM; XRD
Hrčak ID:
110245
URI
Datum izdavanja:
9.11.2013.
Posjeta: 1.758 *