Microstructure and Electrochemical Properties of Ce-Containing 7072 Al Alloy

2013 ◽  
Vol 704 ◽  
pp. 114-119
Author(s):  
Jing Feng ◽  
Dong Yan Ding ◽  
Wen Long Zhang ◽  
Yong Jin Gao ◽  
Guo Zhen Chen ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Electrochemical Properties ◽  
Corrosion Potential ◽  
Corrosion Current ◽  
Al Alloy ◽  
Nacl Solution ◽  
Tafel Polarization ◽  
Electrochemical Testing ◽  
Transmission Electron ◽  
Positive Effect

The microstructure and electrochemical properties of Ce-containing 7072 Al alloy were investigated through transmission electron microscopy (TEM), scanning electron microscopy (SEM) and Tafel polarization analysis. It was found that Ce alloying could result in a formation of finer grains in the simulated brazing alloys. The 7072 Al alloy with 0.15% Ce had desirable distribution of precipitates. The electrochemical testing results indicated that Ce element had a great impact on the corrosion potential of the alloy tested in 0.5% NaCl solution. Alloying with 0.15% Ce element could make the corrosion potential shift to inert direction and reduce the corrosion current density. An excessive Ce addition could weaken its positive effect on the corrosion resistance of the Ce-containing alloy.

Effect of Zn Addition on the Microstructure and Properties of Simulated-Brazing 7072Al Alloy

2016 ◽  
Vol 852 ◽  
pp. 33-37
Author(s):  
Xing Long Xu ◽  
Dong Yan Ding ◽  
Wen Long Zhang ◽  
Yong Jin Gao ◽  
Guo Zhen Chen ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Electron Microscopy ◽  
Mechanical Properties ◽  
Transmission Electron Microscopy ◽  
Tensile Testing ◽  
Corrosion Potential ◽  
Cladding Layer ◽  
Electrochemical Testing ◽  
Transmission Electron ◽  
Zn Addition

7072Al is widely used as cladding layer for heat-transfer components. In this paper, the microstructure, mechanical properties and electrochemical properties of simulated-brazing 7072Al alloy with Zn addition were investigated. Transmission electron microscopy (TEM) observations revealed that, in the simulated-brazing state, Zn-addition could promote the precipitation in the 7072Al alloy. Tensile testing results indicated that, in comparison with 7072Al alloy, the mechanical properties were improved after Zn-addition. Electrochemical testing results revealed that the simulated-brazing alloy showed a negative shift of the corrosion potential with the addition of Zn element.

Influence of Triethylamine Inhibitor Addition on the Sealing Process of 6063 Al Alloy

2012 ◽  
Vol 538-541 ◽  
pp. 230-234
Author(s):  
Hui Cheng Yu ◽  
Xiao Xiao Huang ◽  
Yan Yan Han ◽  
Dong Ping Wei
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Potential ◽  
Electrochemical Impedance ◽  
Corrosion Current ◽  
Al Alloy ◽  
Test Results ◽  
Electrochemical Test ◽  
Tafel Polarization ◽  
Electrochemical Parameters ◽  
6063 Al Alloy

To improve the corrosion resistance of Al alloy, triethylamine (TEN) was added into the sealing solutions. Tafel polarization and electrochemical impedance spectroscopy(EIS) techniques were used to investigate the electrochemical behavior of sealing coatings formed in different concentrations of triethylamine(TEN). Compared with the coatings with D. I. water and the bare aluminum alloy, the polarization curves show that the sealing coatings formed in 5.0 – 7 .0 g.L-1 triethylamine (TEN) solutions have more positive corrosion potential (Ecorr) and pitting corrosion potential (Epit), and lower corrosion current density (icorr). Electrochemical parameters of EIS indicate that the sealing coatings have higher corrosion resistance. The electrochemical test results show the prepared sealing coatings have better corrosion resistance.

scholarly journals Corrosion Resistance of Modified Hexagonal Boron Nitride (h-BN) Nanosheets Doped Acrylic Acid Coating on Hot-Dip Galvanized Steel

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2340 ◽  
Author(s):  
Yongzhe Fan ◽  
Huazhen Yang ◽  
Haisheng Fan ◽  
Qi Liu ◽  
Chuang Lv ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Corrosion Resistance ◽  
Boron Nitride ◽  
Acrylic Acid ◽  
Hexagonal Boron Nitride ◽  
Corrosion Current ◽  
Galvanized Steel ◽  
Electrochemical Testing ◽  
Transmission Electron ◽  
Acid Coating

The hexagonal boron nitride (h-BN) nanosheets modified by silane coupling agent (KH560) were doped into acrylic acid coating on the surface of galvanized steel to improve its corrosion resistance. H-BN nanosheets modified by KH560 were prepared and characterised by scanning electron microscopy, transmission electron microscopy, atomic force microscopy, X-ray diffraction, and Fourier-transform infrared spectroscopy. The corrosion resistance of the acrylic acid coatings was measured by electrochemical testing. The results show that the corrosion current density of the coating with modified h-BN nanosheets was reduced from 2.2 × 10−5 A/cm2 to 2.3 × 10−7 A/cm2 compared with the acrylic acid coating. The impedance of the composite coating with modified h-BN is 4435 Ω·cm2, higher than the BNNS coating (2500 Ω·cm2) and the acrylic acid coating (1500 Ω·cm2). This is due to the physical barrier and electrical insulation properties of the hexagonal boron nitride (h-BN) nanosheets.

scholarly journals Enhancement of Photoelectrochemical Cathodic Protection of Copper in Marine Condition by Cu-Doped TiO2

Catalysts ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 146 ◽  
Author(s):  
Pailin Ngaotrakanwiwat ◽  
Piyapol Heawphet ◽  
Pramoch Rangsunvigit
Keyword(s):  
Uv Irradiation ◽  
Tio2 Film ◽  
Cathodic Protection ◽  
Corrosion Potential ◽  
Corrosion Current ◽  
Nanocomposite Films ◽  
Nacl Solution ◽  
Doped Tio2 ◽  
Tafel Polarization ◽  
Bare Copper

Photochemical cathodic protection (PEC) efficiency was enhanced by doping TiO2 with Cu (Cu/TiO2) through impregnation and reduction under hydrogen. The Cu loading was vaired from 0.1 to 1.0 mol% (0.1 Cu/TiO2, 0.5 Cu/TiO2, 1 Cu/TiO2). Then, up to 50 wt% Cu/TiO2 was mixed with TiO2 to form nanocomposite films. The film photocurrent and photopotential were measured under 1 mW/cm2 UV irradiation. The Cu/TiO2 film with 10 wt% of 0.5 Cu/TiO2 exhibited the highest photocurrent of 29.0 mA/g, which was three times higher than the TiO2 film. The underlying reason for the high photocurrent was the lower photopotential of film than the corrosion potential of copper for PEC. This film was also applied on copper terminal lug for anti-corrosion measurement by Tafel polarization in 3.5 wt% NaCl solution. The results showed that the photopotential of terminal lug coated with the film was −0.252 V vs. Ag/AgCl, which was lower than the corrosion potential of copper (−0.222 V vs. Ag/AgCl). Furthermore, the film can protect the corrosion of copper in the dark with 86.7% lower corrosion current (icorr) than that of bare copper.

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.

Effect of the sample form on the corrosion behavior of steels for concrete in 3% NaCl medium

2021 ◽  
Vol 109 (2) ◽  
pp. 201
Author(s):  
Laidi Babouri ◽  
Cheikh Mokrani ◽  
Yassine El Mendili
Keyword(s):  
Electron Microscopy ◽  
Linear Polarization ◽  
Saline Solution ◽  
Electrochemical Impedance ◽  
Nacl Solution ◽  
Tafel Polarization ◽  
Eds Analysis ◽  
Corrosion Of Steel ◽  
Surface Morphologies ◽  
Scanning Electron

Corrosion of steel constitutes a major preoccupation in the field of civil engineering and the building sector. In this paper, we investigated the electrochemical behavior of two steel specimens with different forms (latched steel and smooth steel) in a 3 wt.% NaCl solution. For this purpose, we studied the steel samples by linear polarization, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The surface morphologies of the substrates were examined by scanning electron microscopy coupled with energy diffraction spectroscopy (SEM/EDS). Results of linear polarization, Tafel polarization curves and EIS show that latched steel (LS) is more susceptible to corrosion than smooth steel (SS) in saline solution. Gravimetric and SEM/EDS analysis after 10 days of immersion confirmed the results obtained by electrochemical methods. All of our results are in agreement and demonstrate that the sample form plays a key role in corrosion resistance.

scholarly journals Age Hardening of Extruded AA 6005A Aluminium Alloy Powders

Materials ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2316
Author(s):  
Feijoo ◽  
Cabeza ◽  
Merino ◽  
Pena ◽  
Rey
Keyword(s):  
Electron Microscopy ◽  
Heating Temperature ◽  
Hot Extrusion ◽  
Atomic Ratio ◽  
Age Hardening ◽  
Al Alloy ◽  
Ingot Metallurgy ◽  
Scanning Calorimetry ◽  
Transmission Electron ◽  
Peak Aging

Pre-alloyed micron-sized 6005A Al alloy (AA 6005A) powders, with a Mg/Si atomic ratio of 0.75, obtained by high pressure inert gas atomization were consolidated by uniaxial cold pressing at 200 MPa into cylindrical Al containers and hot extruded at 450, 480 and 500 °C with an extrusion rate of 7:1, followed by artificial T6 precipitation hardening. Ageing conditions were varied between 170 °C and 190 °C and times of 6, 7 and 8 hours. The microstructure of the extruded profiles was analysed using X-Ray diffractometry (XRD), light optical microscopy (LOM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Differential scanning calorimetry (DSC) was used to study the possible phase transformations. After our results, the peak-aging hardness condition was achieved at 180 °C for 6 h. Mechanical properties of the powder metallurgy (P/M) aluminium alloys consolidated by hot extrusion were superior to those of the extruded profiles of wrought alloy using conventional ingot metallurgy (I/M) billets. AA 6005A wrought P/M alloy via T6 heat treatment shown yield stress of 317 MPa and elongation of 21% at the extrusion pre-heating temperature of 500 °C.

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