Magneto-electrodeposition of (Ni–V) Alloy Coatings for Improved Corrosion Protection
摘要
The objective of this study is to develop (Ni–V) alloy coatings of high corrosion resistance using advent of magneto-electrodeposition. The magnetic field of varying intensity (B) was applied, both parallel (||) and perpendicular (⊥) to the direction of diffusion of metal ions. The corrosion protection efficacy of conventionally electrodeposited (Ni–V) alloy coatings has been increased substantially by increasing their Ni content by inducing the magnetic field, parallel to the process of deposition. Electrochemical corrosion study demonstrated that magneto-electrodeposited (MED) coatings, developed under optimal conditions of || and ⊥ magnetic field, are respectively about 2 times and 7 times more corrosion resistant than its electrodeposited (ED) (Ni–V) alloy coatings, developed from same bath. The improved corrosion resistance of magneto-electrodeposited (MED) (Ni–V) alloy coatings is due to increase of their Ni content, affected due to increased mass transport of Ni+ 2 ions towards cathode, bestowed by higher magnetic moment of Ni+ 2 ions (2.83 BM), compared to V+ 4 ions (1.73 BM) in the electrolyte. Experimental results are discussed in the light of enhanced the mass transport of Ni+ 2 ions towards cathode, compared to V+ 4 ions. Higher corrosion protection of MED⊥ (Ni–V)0.1T, coatings, compared to MED || (Ni–V)0.1T coatings is found to be the combined effect of both paramagnetic susceptibility (FP) and Lorentz force (FL) acting on metal ions. The improved corrosion resistance of MED (Ni–V) alloy coatings was also attributed to changed surface morphology, composition and phase structure, confirmed by FESEM, EDX and XRD analyses, and results are discussed.
Graphical Abstract