ELECTRODEPOSITION BEHAVIOR OF Mn WITH Ni IN ACIDIC SULFATE SOLUTIONS

2014 ◽  
Vol 21 (06) ◽  
pp. 1450083 ◽  
Author(s):  
DAN JI ◽  
XIAWEN LE ◽  
QINGDONG ZHONG ◽  
QIONGYU ZHOU
Keyword(s):  
Corrosion Potential ◽  
Corrosion Current ◽  
Cyclic Voltammogram ◽  
Deposition Mechanism ◽  
Alloy Electrodeposition ◽  
Good Corrosion Resistance ◽  
Sulfate Solutions ◽  
Acidic Sulfate ◽  
Alloy Deposit ◽  
Mn Content

The influence of Mn 2+/ Ni 2+ mole ratio in electrolytes on the Ni – Mn alloy deposits was studied. The electrodeposition mechanism of Mn with Ni is analyzed by the cyclic voltammogram (CV) and an "induced co-deposition" mechanism is proposed for Ni – Mn alloy electrodeposition. The results show that the Mn content in Ni – Mn alloy deposit and the hardness increased with the increase of Mn 2+/ Ni 2+ mole ratio in electrolytes. When the Mn 2+/ Ni 2+ mole ratio in bath was 2/1, the corrosion current density of the deposit coating was the lowest and the corresponding corrosion potential was higher, and under these conditions the coating with a Mn content of 1.20 wt.% showed good corrosion resistance. The scanning electron microscopy (SEM) of the alloy coatings exhibited that the morphology of Ni – Mn alloy coatings were different from Pure Ni coating, and when Mn 2+/ Ni 2+ was 2/1, the surface was compact and homogeneous.

Electrochemical Evaluation on the Corrosion Properties of Welding Zones of 304 Stainless Steel

2010 ◽  
Vol 146-147 ◽  
pp. 1238-1242
Author(s):  
Kyung Man Moon ◽  
Yun Hae Kim ◽  
Sung Jin Kim ◽  
Ji Hyeong Yoon ◽  
Youn Chang Lee ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Laser Welding ◽  
Corrosion Potential ◽  
Corrosion Current ◽  
304 Stainless Steel ◽  
Cyclic Voltammogram ◽  
Chromium Depletion ◽  
Corrosion Properties ◽  
Current Densities ◽  
Electrochemical Evaluation

Two types of welding methods were performed on austenitic 304 stainless steel: laser welding and TIG welding. The differences of the corrosion characteristics of the welded zones from the two welding methods were investigated with electrochemical methods, such as measurement of the corrosion potential, polarization curves, cyclic voltammogram, etc. The Vickers hardness of all laser-welded zones (WM:Weld Metal, HAZ:Heat-Affected Zone, BM:Base Metal) was relatively higher while their corrosion current densities exhibited a comparatively lower value than those which were TIG welded. In particular, the corrosion current density of the TIG-welded HAZ had the highest value among all other welding zones, which suggests that chromium depletion due to the formation of chromium carbide occurs in the HAZ, which is in the sensitization temperature range, thus it can easily be corroded with an active anode. Intergrenular corrosion was also observed at the TIG-welded HAZ and WM zones. Consequently, we can see that corrosion resistance of all austenitic 304 stainless steel welding zones can be improved via the use of laser welding.

Codeposition of copper and tin from acidic sulfate solutions containing polyethylene glycols. Effect of length of the hydrocarbon chain

2008 ◽  
Vol 14 (4) ◽  
pp. 507-514 ◽  
Author(s):  
Arvydas Survila ◽  
Dalia Bražinskienė ◽  
Stasė Kanapeckaitė ◽  
Zenius Mockus ◽  
Vitalija Jasulaitienė
Keyword(s):  
Hydrocarbon Chain ◽  
Polyethylene Glycols ◽  
Sulfate Solutions ◽  
Acidic Sulfate

scholarly journals An electrochemical method to investigate the effects of compound composition on gold dissolution in thiosulfate solution

2020 ◽  
Vol 9 (1) ◽  
pp. 496-502 ◽  
Author(s):  
Zhaohui Zhang ◽  
Bailong Liu ◽  
Mei Wu ◽  
Longxin Sun
Keyword(s):  
Dissolution Rate ◽  
Current Density ◽  
Polarization Resistance ◽  
Electrochemical Method ◽  
Corrosion Current Density ◽  
Corrosion Potential ◽  
Corrosion Current ◽  
Gold Dissolution ◽  
Tafel Polarization ◽  
Edta Solution

AbstractThe electrochemical behavior of gold dissolution in the Cu2+–NH3–S2O32−–EDTA solution has been investigated in detail by deriving and analyzing the Tafel polarization curve, as this method is currently widely implemented for the electrode corrosion analysis. The dissolution rate of gold in Cu2+–NH3–S2O32−–EDTA solution was determined based on the Tafel polarization curves, and the effects of various compound compositions in a Cu2+–NH3–S2O32−–EDTA mixture on the corrosion potential and corrosion current density were analyzed. The results showed that the corrosion potential and polarization resistance decreased, whereas the corrosion current density increased for certain concentrations of S2O32−–NH3–Cu2+ and EDTA, indicating that the dissolution rate of gold had changed. The reason for promoting the dissolution of gold is also discussed.

scholarly journals Microstructure of Al-5Cu-1Li-0.6Mg-0.5Ag-0.5Mn Alloys

Metals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 37
Author(s):  
Wenzheng Chen ◽  
Wenlong Zhang ◽  
Dongyan Ding ◽  
Daihong Xiao
Keyword(s):  
Mechanical Properties ◽  
Corrosion Current Density ◽  
Corrosion Potential ◽  
Aging Treatment ◽  
Corrosion Current ◽  
Homogenization Temperature ◽  
Tafel Polarization ◽  
Al2cu Phase ◽  
Different Temperatures ◽  
Microstructural Optimization

Microstructural optimization of Al-Li alloys plays a key role in the adjustment of mechanical properties as well as corrosion behavior. In this work, Al-5Cu-1Li-0.6Mg-0.5Ag-0.5Mn alloy was homogenized at different temperatures and holding times, followed by aging treatment. The microstructure and composition of the homogenized alloys and aged alloys were investigated. There were Al7Cu4Li phase, Al3Li phase, and Al2CuLi phases in the homogenized alloys. The Al7Cu4Li phase was dissolved with an increase in homogenization temperature and holding time. Al2Cu phase and Al2CuLi phase coarsened during the homogenization process. The alloy homogenized at 515 °C for 20 h was subjected to a two-stage aging treatment. Peak-age alloy, which had gone through age treatment at 120 °C for 4 h and 180 °C for 6 h, was mainly composed of α-Al, Al20Cu2Mn3, Al2CuLi, Al2Cu, and Al3Li phases. Tafel polarization of the peak-age alloys revealed the corrosion potential and corrosion current density to be −779 mV and 2.979 μA/cm2, respectively. The over-age alloy had a more positive corrosion potential of −658 mV but presented a higher corrosion current of 6.929 μA/cm2.

Study on schwertmannite production from copper heap leach solutions and its efficiency in arsenic removal from acidic sulfate solutions

2014 ◽  
Vol 147-148 ◽  
pp. 30-40 ◽  
Author(s):  
Sengpasith HoungAloune ◽  
Takahiro Kawaai ◽  
Naoki Hiroyoshi ◽  
Mayumi Ito
Keyword(s):  
Arsenic Removal ◽  
Heap Leach ◽  
Sulfate Solutions ◽  
Acidic Sulfate

Corrosion Behaviour of In Situ AlxNiy Reinforced AA6061 Composite

2021 ◽  
Vol 882 ◽  
pp. 96-103
Author(s):  
A.D. Vishwanatha ◽  
D.M. Shivanna ◽  
Bijayani Panda
Keyword(s):  
Corrosion Potential ◽  
Corrosion Behaviour ◽  
Corrosion Current ◽  
Open Circuit ◽  
Homogeneous Distribution ◽  
Initial Increase ◽  
Weight Percentage ◽  
Aa6061 Alloy ◽  
Ni Addition

In-situ AlxNiy reinforced aluminium matrix composites (AMCs) were produced by stir-casting route by adding 5, 10 and 15 weight percentage (wt.%) of Ni to AA6061 aluminum alloy. The density, porosity, microstructure, hardness and corrosion behaviour of the as-cast AMCs was studied and compared with that of the as-cast AA6061 alloy. The porosity in all the castings was found to be less than 0.1%. Further, the porosity was found to decrease with increase in Ni addition. Optical microscopy studies showed that in-situ formed AlxNiy was distributed along the dendritic arms. The distribution became non-homogeneous and coarse with increase in AlxNiy content. The coarse distribution of AlxNiy in the AA6061 matrix also resulted in the decrease in hardness of the composite, after an initial increase in hardness till 10 wt.% Ni addition. The open circuit potential (OCP) and corrosion potential (Ecorr) of the AMCs with 5, 10 and 15 wt. of % Ni addition was noble than that of the AA6061 alloy. This was understood to be due to the presence of AlxNiy intermetallic which is known to have a noble corrosion potential than the aluminium alloy. However, the corrosion current (icorr) increased while the polarization resistance (Rp) decreased with increase in Ni addition in the AMC. This indicates that the coarse non-homogeneous distribution of in-situ AlxNiy had a detrimental effect on the corrosion performance of the AMCs.

Effects of Additives in KOH Based Electrolytes on Cu ECMP

2007 ◽  
Vol 991 ◽  
Author(s):  
Tae-Young Kwon ◽  
In-Kwon Kim ◽  
Jin-Goo Park
Keyword(s):  
Citric Acid ◽  
Applied Voltage ◽  
Counter Electrode ◽  
Corrosion Potential ◽  
Removal Rate ◽  
Chemical Mechanical Planarization ◽  
Corrosion Current ◽  
Dynamic State ◽  
Static State ◽  
Potentiodynamic Curves

ABSTRACTThe purpose of this study was to characterize KOH based electrolytes and effects of additives on electro-chemical mechanical planarization. The electrochemical mechanical polisher was made to measure the potentiodynamic curve and removal rate of Cu. The potentiodynamic curves were measured in static and dynamic states in investigated electrolytes using a potentiostat. Cu disk of 2 inch was used as a working electrode and Pt electroplated platen was used as a counter electrode. KOH was used as the electrolyte. H2O2 and citric acid were used as additives for the ECMP of Cu. In static and dynamic potentiodynamic measurements, the corrosion potential decreased and corrosion current increased as a function of KOH concentration. In dynamic state, different potentiodynamic curve was obtained when compared to the static state. The current density did not decrease in passivation region by mechanical polishing effect. The static etch and removal rate were measured as function of KOH concentration and applied voltage. In ECMP system, polishing was performed at 30 rpm and 1 psi. The removal rate was about 60 nm/min at 0.3 V when 5 wt% KOH was used. Also, the effect of additive was investigated in KOH based electrolyte on removal rates. As a result, The removal rate was increased to 350 nm/min when 5wt% KOH, 5vol% H2O2, 0.3 M citric acid were used.

scholarly journals The oxidation of Fe(II) with Cu(II) in acidic sulfate solutions with air at elevated pressures

2018 ◽  
Vol 206 (4) ◽  
pp. 454-475
Author(s):  
Wouter N. Wermink ◽  
Dmitri Spinu ◽  
Geert F. Versteeg
Keyword(s):  
Elevated Pressures ◽  
Sulfate Solutions ◽  
Acidic Sulfate
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