scholarly journals Mechanical and Corrosion Properties of Mg-Based Alloys with Gd Addition

Materials ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 1775 ◽  
Author(s):  
Aneta Kania ◽  
Ryszard Nowosielski ◽  
Agnieszka Gawlas-Mucha ◽  
Rafał Babilas
Keyword(s):  
Open Circuit Potential ◽  
Corrosion Potential ◽  
Orthopedic Implants ◽  
Corrosion Current ◽  
Medical Application ◽  
Open Circuit ◽  
Dendritic Microstructure ◽  
Corrosion Properties ◽  
Electrochemical Parameters ◽  
Mechanical And Corrosion Properties

Magnesium alloys with rare earth metals are very attractive materials for medical application because of satisfactory mechanical properties. Nevertheless, low corrosion resistance is an obstacle in the use of Mg alloys as resorbable orthopedic implants. The paper presents results of mechanical and corrosion properties of MgCa5-xZn1Gdx (x = 1, 2, and 3 wt. %) alloys. Based on the microscopic observations it was stated that the studied alloys show a dendritic microstructure with interdendritic solute rich regions. The phase analysis reveals an occurrence of α-Mg and Mg2Ca, Ca2Mg6Zn3 phases that are thermodynamic predictions, and stated Mg26Zn59Gd7 phases in MgCa5-xZn1Gdx (x = 1, 2, and 3 wt. %) alloys. The Mg26Zn59Gd7 phases are visible as lamellar precipitations along interdendritic regions. It was confirmed that an increase of Gd content from 1 to 3 wt. % improves ultimate tensile (Rm; from 74 to 89 MPa) and compressive strength (Rc; from 184 to 221 MPa). Moreover, the studied alloys are active in Ringer’s solution. They are characterized by an increase of corrosion potential (Ecorr) of about 150 mV in comparison with values of open circuit potential (EOCP). The best electrochemical parameters (e.g., corrosion current density, icorr, polarization resistance, Rp, and Ecorr) were obtained for the MgCa3Zn1Gd2 alloy.

scholarly journals Experimental evaluation of corrosion resistance of the alloys used in the fixed dental prosthesis

2015 ◽  
Vol 61 (2) ◽  
pp. 117-120
Author(s):  
Costin Coman ◽  
◽  
Raluca Monica Comăneanu ◽  
Violeta Hâncu ◽  
Horia Mihail Barbu ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Current Density ◽  
Applied Research ◽  
Open Circuit Potential ◽  
Corrosion Potential ◽  
Artificial Saliva ◽  
Corrosion Current ◽  
Open Circuit ◽  
Metal Alloys ◽  
Fixed Dental Prosthesis

Objectives. In this study we evaluated corrosion resistance of three types of metal alloys (two NiCr and one CoCr). Methods. Samples (coded A, B, C) of circular shape, with dimensions 13 x 1.5 mm, sanded and polished, were introduced in Fusayama Meyer artificial saliva at pH 5.2 and 37 ± 0.5°C and tested in terms of corrosion resistance with a potentiostat/galvanostat (model 4000 PARSTAT, Princeton Applied Research). Results. Open circuit potential EOC [mV] ranged between 21.316 and 5.75. Corrosion potential Ecor [mV] was between -73.536 and -395.662, and the corrosion current density icor [A/cm2] was between 1.237 x 10-6 and 905.13 x 10-9. Conclusion. The best corrosion behavior in Fusayama Meyer artificial saliva at pH 5.2 and at a temperature of 37 ± 0.5°C is the alloy A, followed by the alloy C.

Study on the Impact of Welding on the Corrosion Properties of AA 6061 T6

2014 ◽  
Vol 575 ◽  
pp. 210-213
Author(s):  
Elsadig Mahdi ◽  
E. Eltai
Keyword(s):  
Pitting Corrosion ◽  
Heat Affected Zone ◽  
Open Circuit Potential ◽  
Welding Process ◽  
Corrosion Current ◽  
Open Circuit ◽  
Nacl Solution ◽  
Corrosion Properties ◽  
The Impact ◽  
Alloy 6061

Aluminium alloy 6061 T6 circular specimens were joined using TIG welding method. AlMg5 was used as filler. The corrosion behavior of welded and un-welded AA 6061 T6 was investigated using potentiodynamic and open circuit potential (OCP) measurements. Specimens were immersed in 3.5 (wt %) NaCl solution. Different zones with different corrosion properties were created as a result of the welding process. Results reveals that sever pitting corrosion has taken place on the heat affected zone (HAZ); the corrosion current of HAZ was increased. The measured potential of HAZ was more negative and largely fluctuated comparing to base metal (BM).

scholarly journals Galvanic Corrosion of Copper / Nickel-Chrome Alloy in an Agitated Sulfuric Acid Solution

2018 ◽  
Vol 21 (1) ◽  
pp. 133
Author(s):  
Samar S. Hussein ◽  
Basim O. Hasan ◽  
Naseer A. Al-Haboubi
Keyword(s):  
Sulfuric Acid ◽  
Acid Solution ◽  
Sulfuric Acid Solution ◽  
Open Circuit Potential ◽  
Corrosion Potential ◽  
Galvanic Corrosion ◽  
Corrosion Current ◽  
Open Circuit ◽  
Flow Conditions ◽  
Galvanic Current

Galvanic corrosion of Nickel-Chrome alloy (Ni-Cr alloy) and Copper (Cu) coupled in 5% sulfuric acid solution was investigated. The effects of agitation velocity, temperature, and time on the galvanic corrosion current and the weight loss of both metals in both free corrosion and galvanic corrosion were investigated. The trends of open circuit potential (OCP) of each metal and galvanic potential (Eg) of the couple were also determined. The results showed that Cu was cathodic relative to Ni-Cr alloy in galvanic couple and the corrosion potential of the couple (Ni- Cr alloy /Cu) was between the values of the two single components because the OCP of copper shifted to positive with the increase in velocity. Under stagnant conditions initially the galvanic current was more negative then shifted to the positive with time. The corrosion of Ni-Cr alloy decreased with time because the passivation layer was formed on the surface. Under flow conditions, the galvanic current sharply shifted to the negative direction (increase galvanic current from Ni-Cr alloy (anode) to Cu (cathode) during the first few minutes.

Effects of Ti-1023 Anodized Coating on Corrosion Behavior of Ti-1023/30CrMnSiA and Ti-1023/LY12 Galvanic Couples

2007 ◽  
Vol 546-549 ◽  
pp. 1821-1826
Author(s):  
Jian Hua Liu ◽  
Jun Xiu Shi ◽  
Song Mei Li ◽  
Jun Lan Yi
Keyword(s):  
Corrosion Potential ◽  
Galvanic Corrosion ◽  
Corrosion Current ◽  
Optical Microscope ◽  
Open Circuit ◽  
Corrosion Properties ◽  
Corrosion Morphology ◽  
Average Value ◽  
Galvanic Couples ◽  
Corrosion Mechanisms

Galvanic properties were evaluated on bare and anodized Ti-1023 titanium alloy which coupled to Ni-electroplated, Zn-electroplated, Cd-electroplated 30CrMnSiA and anodized LY12, respectively. Corrosion properties including open circuit potential (Eoc) of each material, galvanic corrosion potential (Eg), and corrosion current (Ig) of the couples were monitored in conjunction with a Model 263A potentiostat system. Corrosion current density (Īg) and average value of corrosion potential (Ēg) were calculated from Ig-time and Eg-time curves, respectively. Corrosion morphology was observed on a optical microscope (OM) and corrosion mechanisms were analyzed and discussed. The corrosion resistance of Ti-1023/LY12 couple was significantly improved by Ti-1023 anodized coating. However, the coating accelerated the dissolve of the three electroplated coatings in the other galvanic couples, resulting in a heavy corrosion attack on 30CrMnSiA steel.

Experimental Study of Propagation Stage of Pitting Corrosion of 20Cr13 Steel

2008 ◽  
Vol 38 ◽  
pp. 238-247
Author(s):  
A.D. Davydov ◽  
V.S. Shaldaev
Keyword(s):  
Pitting Corrosion ◽  
Open Circuit Potential ◽  
Corrosion Potential ◽  
Ph Value ◽  
Open Circuit ◽  
Effect Of Temperature ◽  
Pitting Potential ◽  
Free Corrosion Potential ◽  
External Power Source ◽  
Corrosion Of Steel

The initiation and development of pitting corrosion of steel 20Cr13 in the NaCl solutions with various concentrations, temperatures, and pH values are studied under the potentiostatic conditions and at the free-corrosion potential. The pitting and repassivation potentials are determined using the method of cycling voltammetry. In spite of the fact that thus determined pitting potential is more positive than the corrosion potential (the open-circuit potential Eo.c.), the long-term experiments, which were performed at the free-corrosion potential, showed that pitting corrosion takes place without imposing a potential using an external power source. It is concluded that the probability of pitting corrosion of steel should be determined by comparing the corrosion potential (the open-circuit potential) with the repassivation potential Erp. Steel 20Cr13 is prone to the pitting corrosion, because Erp is more negative than Eo.c.. In the potentiostatic experiments, the variation of the depth and diameter of pits and their number with the time and the effect of temperature and electrode rotation on the pit propagation are studied. The results, which were obtained at the free-corrosion potential, are much less reproducible. In this case, in contrast to the potentiostatic conditions, the pit depth increased only slightly and the pit width increased to a larger extent. The effect of concentration, pH value, and temperature of NaCl solutions on the pit propagation is considered. It is concluded that the data on the development of pitting corrosion under the potentiostatic conditions can be hardly extended to the conditions of free corrosion potential.

Experimental study of the mechanical and corrosion properties of ethyl silicate resin applied on low carbon steel

2021 ◽  
Vol 2 (108) ◽  
pp. 68-74
Author(s):  
M. Ali ◽  
J.H. Mohmmed ◽  
A.A. Zainulabdeen
Keyword(s):  
Heat Treatment ◽  
Carbon Steel ◽  
Open Circuit Potential ◽  
Low Carbon Steel ◽  
Open Circuit ◽  
Treatment Temperature ◽  
Ethyl Silicate ◽  
Low Carbon ◽  
Corrosion Properties ◽  
Mixture Ratio

Purpose: This work aimed at evaluating the properties of the ethyl silicate-based coating that can be applied on low carbon steel. Design/methodology/approach: Two mixture ratio types (2:1, and 3:2) of resin and hardener respectively were used to prepared two specimen models (A and B). Findings: It found that some mechanical properties (tensile, hardness, and impact strength) of ethyl silicate resin were evaluated according to standard criteria. Research limitations/implications: The effect of heat treatments at various temperatures (100, 150, and 200°C) and holding at different times (10, 20 & 30) min on hardness was investigated. Practical implications: Moreover, an open circuit potential corrosion test with a solution of 3.5% Sodium Chloride at room temperature and 60°C was used to determine the corrosion resistance of low carbon steel specimens coated with the two mixture types. Originality/value: The effects of mixture ratios (for resin and hardener) and heat treatment conditions on properties of ethyl silicate-based coating were studied. From obtained results, acceptable values of tensile, hardness, and toughness were recorded. Increasing heat treatment temperature and holding time leads to enhance hardness for both model types. An open circuit potential (OCP) tests show that there is an enhancement of protective properties of ethyl silicate coatings with mixture type B in comparison with type A was achieved. Generally, the results indicate that specimen model B has higher properties as compared with specimen model A.

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.

scholarly journals From Waste to Valuable Resource: Lignin as a Sustainable Anti-Corrosion Coating

Coatings ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 454 ◽  
Author(s):  
Arman Dastpak ◽  
Kirsi Yliniemi ◽  
Mariana de Oliveira Monteiro ◽  
Sarah Höhn ◽  
Sannakaisa Virtanen ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Open Circuit Potential ◽  
Electrochemical Impedance ◽  
Steel Corrosion ◽  
Linear Sweep Voltammetry ◽  
Corrosion Current ◽  
Polymer Coatings ◽  
Open Circuit ◽  
Linear Sweep ◽  
Cyclic Potentiodynamic Polarization

In this study, a waste of biorefinery—lignin—is investigated as an anticorrosion coating on stainless steel. Corrosion behavior of two lignin types (hardwood beech and softwood spruce) was studied by electrochemical measurements (linear sweep voltammetry, open circuit potential, potentiostatic polarization, cyclic potentiodynamic polarization, and electrochemical impedance measurements) during exposure to simulated body fluid (SBF) or phosphate buffer (PBS). Results from linear sweep voltammetry of lignin-coated samples, in particular, demonstrated a reduction in corrosion current density between 1 and 3 orders of magnitude cf. blank stainless steel. Furthermore, results from cross cut adhesion tests on lignin-coated samples demonstrated that the best possible adhesion (grade 0) of ISO 2409 standard was achieved for the investigated novel coatings. Such findings suggest that lignin materials could transform the field of organic coatings towards more sustainable alternatives by replacing non-renewable polymer coatings.

scholarly journals The Effect of the Action of Impurities Present in Methanol as a Basis for Automobile Fuel and Their Impact on the Environment

2020 ◽  
Vol 70 (12) ◽  
pp. 4260-4265
Keyword(s):  
Air Pollution ◽  
Aluminum Alloy ◽  
Acid Chloride ◽  
Considerable Increase ◽  
Open Circuit Potential ◽  
Corrosion Potential ◽  
Open Circuit ◽  
Sulfur Oxides ◽  
Pitting Potential ◽  
Hydroxyl Ion

Corrosion of the tank made of aluminum alloy AlMg2,7Mn (5454) has been studied by electrochemical methods in methanolic solution containing different concentrations of acid, chloride, sulphate and water as impurities. In all these cases, the alloy exhibited a sponge passivity. Adding a 1mM solution in fuel leads to a considerable increase in corrosion potential, a 1 mM chlorine solution decreases the pitting potential, and a 1 mM solution of sulfate concentrations does not show any change. In the first phase, due to the hydroxyl ion that surrounds the aluminum, the present water leads to a decrease in the pitting potential.At the same time, the combustion of fuel remains the biggest source of air pollution. The air is polluted by impurities (acids, chlorides, sulphates and water) present in fuels, smoke (incomplete combustion) or nitrogen and sulfur oxides, so it is required to keep them within the limits set by the rules in force. Keywords: aluminium alloy, pitting potential, impurities, polarization curves, open circuit potential

Corrosion Properties of 20# Pipelines Steel in Near-Neutral Soils

2010 ◽  
Vol 129-131 ◽  
pp. 312-316
Author(s):  
Wen He Wang ◽  
Jun Yi ◽  
Shi Ming Shen
Keyword(s):  
Open Circuit Potential ◽  
Low Carbon Steel ◽  
Open Circuit ◽  
Corrosion Mechanism ◽  
Low Carbon ◽  
Corrosion Properties ◽  
Corrosion Rates ◽  
Cathode Area ◽  
Neutral Soil ◽  
Anode Area

Corrosion law and mechanism of 20# low-carbon steel in near-neutral soil along Yangtze River in Nanjing are studied by experiments of buried specimens in laboratory. In three kinds of soils, the corrosion features and products are analyzed by EDS and XRD, and the relation of corrosion rates, open-circuit potential and polarization curve with times are tested. The results indicated that corrosion rates changed incessantly along. On the condition of the same times, specimens and different soil samples, the corrosive degree of 1# and 2# specimens are serious, but 3# specimen is serious lightly. The corrosion products are main non-crystalloid, Fe (OH) 3 and Fe2O3.The changing tendency of different times and soils is different, and accordant with that of corrosion rates. The corrosion mechanism is discussed lastly, in near-neutral soils, oxygen is deoxidized and OH- ions are created in cathode area, iron is oxidized and the hydration of Fe2+ ions is created with water from soil in anode area, and Fe2+ are converted into more steady products Fe（OH）3 and Fe2O3.

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