The influence of current density of deposition on Zn–Ni coatings properties

• Видавець: Фізико-механічний інститут ім. Г.В. Карпенка НАН України
• Дата: 2011
• Автори: Wykpis, K., Popczyk, M., Niedbała, J., Budniok, A., Łągiewka, E.
• Формат: Стаття
• Мова: English
• Опубліковано: Фізико-механічний інститут ім. Г.В. Карпенка НАН України 2011
• Назва видання: Фізико-хімічна механіка матеріалів
• Онлайн доступ: http://dspace.nbuv.gov.ua/handle/123456789/138346
• Цитувати: The influence of current density of deposition on Zn–Ni coatings properties / K. Wykpis, M. Popczyk, J. Niedbała, A. Budniok, E. Łągiewka // Фізико-хімічна механіка матеріалів. — 2011. — Т. 47, № 6. — С.107-114. — Бібліогр.: 12 назв. — англ.

Zn–Ni coatings were deposited under galvanostatic conditions at current density in the range of 20 to 60 mA⋅cm⁻². The influence of current density of deposition on the surface morphology, chemical and phase composition and corrosion resistance was investigated. Structural investigations were performed by the X-ray diffraction (XRD) method. The surface morphology and chemical composition of deposited coatings were studied using a scanning electron microscope JEOL JSM-6480. Studies of general electrochemical corrosion resistance were carried out in the 5% NaCl, using potentiodynamic and electrochemical impedance spectroscopy (EIS) methods. Local corrosion resistance was determined by Scanning Kelvin Probe (SKP) method. On the ground of the research, the possibility of deposition of Zn–Ni coatings containing 14…18 at.% Ni was shown. It was stated, that surface morphology, chemical and phase composition of these coatings to a small extent, depend on the current density of deposition. However, current density of deposition determines the quantity of zinc which is co-deposited with nickel and is bounded in the form of an intermetallic compound or a solid solution. Small differences in chemical composition and the uneven distribution of the Zn(Ni) and Ni₂Zn₁₁ phases on coatings surface may cause differences in the local Kelvin potential. As a result, the Zn–Ni coatings exhibit corrosion resistance that varies depending on the deposition current density. The optimal values of current density for the sake of corrosion resistance are found to be j = 30 and 40 mA⋅cm⁻².