Improvement of corrosion resistance of Zn-Ni alloy coatings by anodizing in selected alcoholic solutions

2019 ◽  
Vol 158 ◽  
pp. 108107 ◽  
Author(s):  
A. Maciej ◽  
A. Wadas ◽  
M. Sowa ◽  
R. Socha ◽  
G. Dercz ◽  
...  
2019 ◽  
Vol 31 (4) ◽  
pp. 891-895
Author(s):  
Dinesh Kumar Chelike ◽  
K. Juliet Gnana Sundari

Considering the good corrosion resistance of Zn-Ni alloy, it is selected in the present study to be the protective coating on mild steel and it is considered as a strong candidate for the replacement of environmentally hazardous cadmium. Zn-Ni alloy coating is applied by electrodeposition at optimum temperature, current density and time. The bath solution used is consisting of EDTA as complexing agent. The electrodeposition is also carried out with tartaric acid and benzaldehyde additives to have good corrosion resistance and brightness. The electrodeposits obtained with and without additives are examined for nature and alloy composition. The corrosion behaviour of the electrodeposits is studied by Tafel polarization and electrochemical impedance spectroscopy.


1989 ◽  
Vol 33 ◽  
pp. 171-175
Author(s):  
Toshihiko Sasaki ◽  
Makoto Kuramoto ◽  
Yasuo Yoshioka

Zn-Ni-alloy electroplated steels are one of the surface-treated materials with a high corrosion resistance and are mostly used for automobiles. It is said that the corrosion resistance is more than four times as great as that of Zn-plated steels. Concerning x-ray stress measurement, Kyono et al reported the result of measurement on y (552) planes and showed that the sin2φ diagram was severely curved.X-ray stress analysis in surface-treated materials will become more important. Some problems, however, remain to be studied when we apply the x-ray method to thin layers. For example, the effective x-ray penetration depth may be different from that in ordinary materials. And complex gradients of stresses and compositions may exist.


2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Nabeel Alharthi ◽  
El-Sayed M. Sherif ◽  
Hany S. Abdo ◽  
S. Zein El Abedin

The effect of Ni content on the resistance against corrosion of Fe-36% Ni and Fe-45% Ni alloys in 1 M hydrochloric acid pickling solution was reported. Various electrochemical and spectroscopic techniques such as potentiodynamic cyclic polarization (CPP), open-circuit potential (OCP), electrochemical impedance spectroscopy (EIS), potentiostatic current-time (PCT), and scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS) have been employed. CPP measurements indicated that the corrosion current and corrosion rate recorded lower values for the alloy that had higher nickel content. OCP curves proved that the presence of high Ni content shifts the absolute potential to the positive potential direction. EIS results revealed that the surface and polarization resistances were much higher for the alloy with higher Ni content. PCT curves also showed that the absolute currents were lower for Fe-45% Ni alloy. All results were in good agreement with others and confirmed clearly that the corrosion resistance in HCl solutions for Fe-45% Ni alloy was higher than that obtained for Fe-45% Ni alloy.


1970 ◽  
Vol 24 ◽  
pp. 3-11
Author(s):  
Pom Lal Kharel ◽  
Jagadish Bhattarai

The synergistic effect of chromium addition in the sputter-deposited amorphous or nanocrystalline W-Cr-(4-15)Ni alloys is studied in alkaline NaOH solutions at 25°C, open to air using immersion tests and electrochemical measurements. In 1 M NaOH solution, the addition of chromium to W-Cr-(4-15)Ni alloys containing 42-75 at % chromium increased the corrosion resistance and shifted the open circuit potential more noble so as to show higher corrosion resistance than those of alloy-constituting elements (that is, tungsten, chromium and nickel). The corrosion rates (that is, about 2-5 x 10-3 mm.y-1) of all the examined W-Cr-(4-15)Ni alloys are about two orders of magnitude lower than that of tungsten and nearly one order of magnitude lower than that of chromium metal. The open circuit potential of the W-Cr-(4-15)Ni alloys is generally increased with increasing chromium content in different concentrations of NaOH solutions. The passivity of the WCr-(4-15)Ni alloys is increased with decreasing the concentration of NaOH solutions at 25°C. Keywords: Corrosion resistance; Sputter deposition;  W-Cr-Ni alloy;  NaOH solution; Open Circuit  potential. DOI: 10.3126/jncs.v24i0.2380Journal of Nepal Chemical Society, Vol. 24, 2009 Page: 3-11


1970 ◽  
Vol 40 (1) ◽  
pp. 9-14 ◽  
Author(s):  
M J Rahman ◽  
S R Sen ◽  
M Moniruzzaman ◽  
K M Shorowordi

Zinc-nickel alloys electrochemically deposited on mild steel under various deposition conditions were investigated. The effect of plating variables (bath composition, pH, current density) on the coating composition, morphology, corrosion property and microhardness were investigated. Modified morphology with perfect crystal growth, uniform arrangement of crystals, refinement in crystal size and hence bright deposit was obtained from sulfate Bath-3 containing 30 g/l H3BO3 at a current density of 75 mA/cm2. Corrosion resistance as well as microhardness of Zn-Ni alloy coatings increased with the increase of %Ni in the deposit for all the sulphate baths studied. Optimum conditions for good deposition are also discussed. Keywords: Zn-Ni alloy, electrodeposition, morphology, corrosion resistance.   doi: 10.3329/jme.v40i1.3468 Journal of Mechanical Engineering, Vol. ME40, No. 1, June 2009 9-14


2018 ◽  
Vol 736 ◽  
pp. 62-70 ◽  
Author(s):  
Tengfei Xiang ◽  
Manxin Zhang ◽  
Cheng Li ◽  
Chundong Dong ◽  
Ling Yang ◽  
...  

2018 ◽  
Vol 18 ◽  
pp. 19-26
Author(s):  
Nadjette Belhamra ◽  
Abd Raouf Boulebtina ◽  
Khadidja Belassadi ◽  
Abdelouahed Chala ◽  
Malika Diafi

The purpose of this paper was to investigate the effect of Al2O3 and TiO2 nanoparticles contents on structural proporties, microhardness and corrosion resistance of Zn-Ni alloy coationg. Zn-Ni, Zn-Ni-Al2O3 and Zn-Ni-TiO2 composite coatings were electrodeposited on steel substrate by direct current in sulphate bath.The structure of the coatings was studied by X-ray diffration and by scaning electron miroscopy. The results showed the appearance of Ni5Zn21 phases and that the incrorporation of Al2O3 and TiO2 in the Zn-Ni coating refined the crystal grain size.The corrosion performance of coating in the 0.6M NaCl as a corrisive solution was investigated by potentiodynamic polarization and electrochemical impedance spectroscopy EIS methods. It was found that the incorporation of nanoparticules in Zn-Ni alloy coating have better corrosion resistance and the values of Rct and Zw increase, while the values of Cdl decrease with increasing of nanoparticules.


Sign in / Sign up

Export Citation Format

Share Document