Dissertation > Industrial Technology > Metallurgy and Metal Craft > Metallurgy and Heat Treatment > Metal corrosion protection,metal surface treatment > Corrosion control and protection > Metal surface protection technology

Preparation and Microstructure of Nano-crystalline Zn-Ni Alloy by Jet Electrodeposition

Author LiNing
Tutor GaoZuoWei
School Yanshan University
Course Materials Science
Keywords In Jet - Electrodeposition The alloy of the Zn-Ni Corrosion resistance Microstructure Grain size
CLC TG174.4
Type Master's thesis
Year 2010
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This paper studies the electrodeposition prepared nanocrystalline Zn-Ni alloy , the alloy 's corrosion resistance and passivation mechanism of From the jet velocity , current density , electrolyte , chemical composition and other parameters of the Zn-Ni alloy morphology , chemical composition , phase composition , grain size and performance impact study . Use of EDS spectrometer and FMSEM Zn-Ni alloy composition and surface morphology analysis ; discuss with the change of process parameters using X-ray diffraction phase structure of Zn-Ni alloy deposition layer ; electrochemical workstation and microhardness meter and other instruments for the determination of the corrosion and mechanical properties of the alloy . The results showed that : 1 using the electrodeposition method can significantly improve the quality of the liquid phase transfer process , so that the electrodeposited copper deposited in a high current density range . When the current density of 30 A / dm 2 , the ejection speed of 3.33 m / s , the deposition rate of 47.33μm/min, the total current efficiency of 80% or more . 2 in the T = 30 ° C the the D_k = 30 A / dm - 2 , pH = 11.5 conditions , the ejection speed is increased to 5.00 m by 0.83 m / s / s , the grain size of the deposited layer is from 6.5 nm to 9.8 nm, total polarization effects when a small amount of THF was added in the electrolyte and the adjacent benzene sulfonyl imide cause enhanced deposition layer has an average grain size of about 7 nm . When the ejection speed of 3.33 m / s when the alloy , Ni content was 13.20 wt % . 3 in T = 30 ° C , u = 3.33 m / s , pH = 11.5 Condition , with the current density increases, the deposition speed increases , the deposited layer of zinc decreased when the current density of from 20 A / dm 2 increased to 40 A / dm sediments preferential growth along the (330 ) crystal surface normal direction . Microhardness increases gradually with the increase in current density , a current density of 40 A / dm ~ 2 , microhardness 334.92 HV . 4 selects the optimal sample , the alloy deposition layer after passivation of the electrode potential from -0.796 V to -0.623 V , When in good passivation deposition layer seal processing , the electrode potential increase in magnitude -0.796 V to -0.512 V .

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