Effect of Borax Pentahydrate Addition to Acid Bath on the Microstructure and Corrosion Resistance of Zn-Co Coating
Yükleniyor...
Dosyalar
Tarih
2015
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Polish Acad Sciences Inst Physics
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
In this work, the Zn-Co coatings were synthesized on AISI 4140 steel and aluminum plates by using potentio-static electrodeposition technique in sulphate-based acidic baths with 0, 20, 40 and 60 gl(-1) of borax pentahydrate, as additive. The effect of borax pentahydrate on the microstructure of the samples was observed using scanning electron microscopy and X-ray diffractometer. The deposition process was investigated by cyclic voltammetry. The effect of borax pentahydrate on the corrosion resistance of the samples was studied by potentiodynamic polarization technique. The results have demonstrated, that the addition of borax pentahydrate was in favor of the growth of grains. The morphology of pyramidal islands on the surface was changed to a more flat structure. The results have also demonstrated that the effect of borax pentahydrate was not monotonous. With increasing concentration, the corrosion potential was at minimum and the charge transfer resistance R-t was at maximum for the sample obtained from the bath with 60 gl(-1) of borax pentahydate, indicating that this sample showed the best corrosion resistance. It was found that current density first decreased and than increased, due to adsorption of a complex of borax pentahydrate and/or changes in the morphology, however, the initial deposition potential was not affected. The addition of borax pentahydrate to the bath led to formation of the best Zn-Co deposits, composed of coalesced globular fine grains, smaller than approximate to 2 mu m in diameter. In addition, all of the studied Zn-Co deposits consisted of eta phases. It is suggested that Zn-Co deposits produced in the bath containing 60 gl(-1) of borax pentahydrate probably offer sacrificial protection to the steel substrate.
Açıklama
International Conference on Computational and Experimental Science and Engineering (ICCESEN) -- OCT 25-29, 2014 -- Antalya, TURKEY
Anahtar Kelimeler
Zinc Alloy Coatings, Cobalt Alloy, Protective Ability, Chloride Bath, Boric-Acid, Electrodeposition, Coumarin, Behavior, Growth, Agents
Kaynak
Acta Physica Polonica A
WoS Q Değeri
Q4
Scopus Q Değeri
Q3
Cilt
128
Sayı
2B
