Corrosion Analysis of AZ61 Alloy with Different Level of Ca Addition and Aging

2014 ◽  
Vol 592-594 ◽  
pp. 821-825
Author(s):  
S. Manivannan ◽  
M.P. Sathishkumar ◽  
S.P. Kumaresh Babu ◽  
Srinivasan Sundarrajan
Keyword(s):  
Electron Microscopy ◽  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
Microstructural Change ◽  
Nacl Solution ◽  
Ca Addition ◽  
Polarization Technique ◽  
Potentiostatic Polarization ◽  
Scanning Electron

The corrosion behavior of AZ61 alloyed with 0.5, 1.0, 1.5 and 2.0% Ca were studied by potentiostatic polarization technique in 3.5wt. % NaCl solution and the further effect of corrosion behavior have been studied after aging at different temperature in a controlled environment.The results show that the calcium addition enhances the corrosion resistance.Simultaneously when the alloy is aged at 180°C, the corrosion resistance has improved. This study also reveals the interesting microstructural change that isresponsible for the improved corrosion resistance. Themicrostructural characterization of this alloy was studied using Optical and Scanning Electron Microscopy (SEM).

Study on Corrosion Behavior of Al-Zn-In and Al-Zn-Ga Alloys in NaCl Solution

2011 ◽  
Vol 284-286 ◽  
pp. 1701-1704
Author(s):  
Jing Ling Ma ◽  
Jiu Ba Wen ◽  
Gao Lin Li
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Electrochemical Impedance Spectroscopy ◽  
Corrosion Behavior ◽  
Electrochemical Impedance ◽  
Nacl Solution ◽  
X Ray ◽  
Inductive Loop ◽  
Capacitive Loop ◽  
Scanning Electron

The corrosion behavior of Al-5Zn-0.03In and Al-5Zn-0.03Ga alloys in 3.5 % NaCl solution has been examined by electrochemical methods, scanning electron microscopy, X-ray microanalysis, electrochemical impedance spectroscopy. The results demonstrate that the alloys differ in the microstructure, corroded morphology and electrochemical properties. For Al-5Zn-0.03In alloy, the precipitates enriched in Al and Zn initiates pitting. For Al-5Zn-0.03Ga alloy, corrosion occurs more uniformly, the corrosion of the alloy occurred via the formation of a surface Ga-Al amalgam alloy. The EIS of Al-5Zn-0.03In alloy contains a capacitive loop and an inductive loop; the inductive loop can be attributed to the presence of the pitting. The EIS of Al-5Zn-0.03Ga alloy contains only a capacitive loop.

Effect of KI on the Corrosion Resistance of Ni-P Electroless Plating Coating

2014 ◽  
Vol 633-634 ◽  
pp. 817-820
Author(s):  
Ping Liang ◽  
Yun Xia Zhang ◽  
Yan Hua Shi
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Corrosion Resistance ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Phosphorus Content ◽  
Electrochemical Impedance ◽  
Nacl Solution ◽  
Electroless Coating ◽  
Scanning Electron

To improve the corrosion resistance of Ni-P electroless coating, the KI was added in the electroless solution. The surface micrograph was observed using scanning electron microscopy (SEM), and the corrosion resistance of Ni-P coatings in 3.5%NaCl solution was examined by polarization curves and electrochemical impedance spectroscopy (EIS). The experimental results showed that KI reduced the amount of defects and the size of crystal grain of Ni-P coating, and the surface of Ni-P coating became more homogenous, smoother and compact by KI. In addition, the phosphorus content of Ni-P coating was increased by KI. These factors increased the ability to corrosion protection of Ni-P coating.

scholarly journals Corrosion Behaviour of Zn-10Al-1.5Cu Alloy

2011 ◽  
Vol 2011 ◽  
pp. 1-6
Author(s):  
C. N. Panagopoulos ◽  
A. G. Tsopani
Keyword(s):  
Electron Microscopy ◽  
Corrosion Resistance ◽  
Corrosion Behaviour ◽  
Solution Concentration ◽  
Solution Temperature ◽  
Nacl Solution ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nacl Concentration ◽  
Scanning Electron

The corrosion behaviour of Zn-10Al-1.5Cu alloy in NaCl solution was examined. The used NaCl solution concentrations were 1M, 0.3M, and 0.003M for a constant temperature values of 7°C or 25°C or 45°C. The corrosion behaviour of this alloy was investigated under potentiodynamic corrosion conditions. The surface of the corroded alloy specimens was studied with the aid of scanning electron microscopy and X-ray diffraction techniques. It was observed that the increase of NaCl concentration in the corrosion solution for a constant value of temperature led to lower corrosion resistance of the alloy. For a constant value of solution concentration, the increase of solution temperature also led to the decrease of corrosion resistance of the same alloy.

scholarly journals Characterization of the Corrosion Resistance of Composite Peened Aluminum

2021 ◽  
Author(s):  
Malte L. Flachmann ◽  
Michael Seitz ◽  
Wilfried V. Liebig ◽  
Kay A. Weidenmann
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Corrosion Resistance ◽  
Chloride Solution ◽  
Base Material ◽  
Surface Modifications ◽  
Metallic Base ◽  
Corrosion Properties ◽  
Scanning Electron

AbstractComposite peening offers the opportunity to introduce ceramic blasting particles into metallic base material. By embedding Al2O3 particles, mechanical properties of aluminum can be improved. However, those surface modifications might negatively impact corrosion resistance and thus shorten the lifetime of components. This study analyzes corrosion properties of peened aluminum in chloride solution via immersion, scanning electron microscopy and polarization. The data of observed microstructures indicate that peening accelerates corrosion and that intergranular corrosion is the main force of degradation in contrast with pitting corrosion of monolithic aluminum.

scholarly journals Electrochemical corrosion study via linear polarization in peas can

2016 ◽  
Vol 9 (4) ◽  
pp. 145
Author(s):  
I. M. Costa ◽  
G. C. Taroco ◽  
E. M. Garcia ◽  
J. O. F. Melo ◽  
A. G. Souza ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Corrosion Rate ◽  
Linear Polarization ◽  
Energy Dispersive Spectroscopy ◽  
Electrochemical Corrosion ◽  
The Body ◽  
Energy Dispersive ◽  
Polarization Technique ◽  
Scanning Electron

The aim of this work is to study the corrosion of tinplate can for peas. Firstly, the characterization of canning solution was made. The values of pH, conductivity, Brix, viscosity, density and content of Fe were, respectively, 5.88; 32.6 mS/cm; 6.6%; 3,42cP; 1.026 g/ml; 12.05 mg/kg. The corrosion rate in the cans was determined by linear polarization technique. The electrodes with and without varnish were analyzed in the first and fifth day of the experiment for the 3 parts of the can. The corrosion rate increased significantly when the coating was removed and the body showed a higher corrosion rate, reaching 1.7 mm/year in the absence of varnish. The microstructure of the samples was evaluated by scanning electron microscopy (SEM) coupled with energy dispersive spectroscopy (EDS). The increase of iron on the surface, evidenced by energy dispersive spectroscopy (EDS) may have contributed to the corrosion in the samples without varnish.

Comparative Study of the Performance of SAE 1010, API K55 and API N80 Steels Regarding to Corrosion Resistance in the Presence of High CO2 Pressure

2016 ◽  
Vol 830 ◽  
pp. 71-77
Author(s):  
Adriana Lopes Barros ◽  
Eleani Maria da Costa ◽  
Natalia Lopes ◽  
Juliane Bernardes Marcolino ◽  
Martimiano K. Moraes ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Corrosion Resistance ◽  
Potentiodynamic Polarization ◽  
Corrosive Medium ◽  
Degree Of Protection ◽  
Corrosion Rates ◽  
Polarization Technique ◽  
Saline Solutions ◽  
Scanning Electron

The performance of SAE 1010, API K55 and API N80 steels were evaluated in terms of resistance to corrosion with the use of two CO2-saturated saline solutions (NaCl and CaCl2, both at the concentration of 0.5 M) and wet supercritical CO2 at a temperature of 90°C under 15 MPa for 07 days. Mass loss tests were performed to determine corrosion rates and the films of corrosion product evaluated by scanning electron microscopy and potentiodynamic polarization technique. Lower corrosion rates were obtained in a wet supercritical CO2 medium. The degree of protection offered by corrosion products films depended not only on the steel but also on the corrosive medium and kind of salt present.

scholarly journals Comparison of Corrosion Behavior of Electrochemically Deposited Nano-Cobalt-Coated Ni Sheet

2013 ◽  
Vol 2013 ◽  
pp. 1-6
Author(s):  
Nasser Al-Aqeeli ◽  
Ihsan-ul-Haq Toor
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
Room Temperature ◽  
Alloy Sheet ◽  
Nacl Solution ◽  
Pitting Potential ◽  
Eds Analysis ◽  
Ni Alloy ◽  
Polarization Technique ◽  
Electrochemically Deposited

Corrosion behavior of nano-coblat-coated Ni sheet was compared with pure Ni and 20% Fe-Ni alloy sheet using potentiodynamic polarization and linear polarization technique in 0.1 M NaCl solution at room temperature. Results showed that corrosion resistance properties of nano-Co-coated Ni sheet were almost same as that of pure Ni sheet, however corrosion resistance of 20% Fe-Ni sheet was decreased significantly. Pitting potential of 20% Fe-Ni sheet was subsequently decreased as compared to pure Ni sheet as well as nano-cobalt-coated Ni sheet. SEM/EDS analysis of the corroded surfaces showed that both pure Ni and nano-coblat-coated Ni sheet did not show any appreciable corrosion however significant corrosion was observed in the case of 20% Fe-Ni sheet.

Assessment of the Corrosion Behavior of Nd-Fe-B Magnets Used in Dentistry

2008 ◽  
Vol 587-588 ◽  
pp. 57-61
Author(s):  
E.A. Martins ◽  
Isolda Costa ◽  
J.L. Rossi ◽  
Hercílio G. De Melo
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
Permanent Magnets ◽  
Electrochemical Impedance ◽  
Test Solution ◽  
Potentiodynamic Polarization Curves ◽  
Diffusion Controlled ◽  
Scanning Electron

Permanent magnets based on intermetallic compounds are employed in dentistry to fix dental prosthesis. However, these materials are very sensitive to corrosion. In this study the corrosion behavior of a sintered commercial Nd-Fe-B magnet has been investigated at neutral pH in a phosphate buffered solution (PBS). With this aim demagnetized specimens were immersed in the test solution and their corrosion behavior were monitored at increasing test times by means of electrochemical impedance spectroscopy ( EIS ), potentiodynamic polarization curves and surface observation by scanning electron microscopy ( SEM ). Experimental results indicated that the corrosion resistance is seriously affected in this solution. Moreover, no decrease in the intensity of the corrosive attack was verified during test periods of up 4 hours. Impedance results have indicated the occurrence of diffusion controlled phenomenon, likely linked to the presence of pores in the magnet microstructure.

Effect of Current Density on Microstructure and Corrosion Resistance of Ni–W Alloy Coatings

2014 ◽  
Vol 1033-1034 ◽  
pp. 1241-1244
Author(s):  
Yi Xiao ◽  
Qiong Yu Zhou ◽  
Jian Hui Fang ◽  
Qing Dong Zhong
Keyword(s):  
Electron Microscopy ◽  
Corrosion Resistance ◽  
Corrosion Behavior ◽  
Current Density ◽  
Alloy Coating ◽  
Critical Value ◽  
Current Densities ◽  
Electroplated Coating ◽  
Deposition Current Density ◽  
Scanning Electron

Ni-W alloy coating was electroplated on the surface of mild steel and the effect of current density on its corrosion behavior was evaluated in this paper. The microstructure of the coatings were scanning electron microscopy (SEM) Polarization techniques have been used to investigate the corrosion behavior in 3.5wt.% NaCl. The results showed that the surface morphology of the coatings is strongly influenced by the deposition current density. And the increased of current densities is benefit for the Ni-W coating from0.5 to 4A/dm2, and the critical value of current densities is 4A/dm2, the corrosion resistance of electroplated coating present better worse when current densities exceeds the critical value or more.

Sem Studies of Co-Cr-Mo Surgical Implant Alloy Corrosion Behavior

1982 ◽  
Vol 40 ◽  
pp. 520-521
Author(s):  
Ann Chidester Van Orden ◽  
John L. Chidester ◽  
Anna C. Fraker ◽  
Pei Sung
Keyword(s):  
Electron Microscopy ◽  
Corrosion Behavior ◽  
Anodic Polarization ◽  
Saline Solution ◽  
Saturated Calomel Electrode ◽  
Physiological Saline ◽  
X Ray ◽  
Physiological Saline Solution ◽  
Scanning Electron

The influence of small variations in the composition on the corrosion behavior of Co-Cr-Mo alloys has been studied using scanning electron microscopy (SEM), energy dispersive x-ray analysis (EDX), and electrochemical measurements. SEM and EDX data were correlated with data from in vitro corrosion measurements involving repassivation and also potentiostatic anodic polarization measurements. Specimens studied included the four alloys shown in Table 1. Corrosion tests were conducted in Hanks' physiological saline solution which has a pH of 7.4 and was held at a temperature of 37°C. Specimens were mechanically polished to a surface finish with 0.05 µm A1203, then exposed to the solution and anodically polarized at a rate of 0.006 v/min. All voltages were measured vs. the saturated calomel electrode (s.c.e.).. Specimens had breakdown potentials near 0.47V vs. s.c.e.

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