P. Nguyen-Tri, T. Nguyen, Pascal Carrière, Cuong Ngo Xuan
Incorporation of nanofillers into the organic coatings might enhance their barrier performance, by decreasing the porosity and zigzagging the diffusion path for deleterious species. Thus, the coatings containing nanofillers are expected to have significant barrier properties for corrosion protection and reduce the trend for the coating to blister or delaminate. On the other hand, high hardness could be obtained for metallic coatings by producing the hard nanocrystalline phases within a metallic matrix. This article presents a review on recent development of nanocomposite coatings, providing an overview of nanocomposite coatings in various aspects dealing with the classification, preparative method, the nanocomposite coating properties, and characterization methods. It covers potential applications in areas such as the anticorrosion, antiwear, superhydrophobic area, self-cleaning, antifouling/antibacterial area, and electronics. Finally, conclusion and future trends will be also reported.
{"title":"Nanocomposite Coatings: Preparation, Characterization, Properties, and Applications","authors":"P. Nguyen-Tri, T. Nguyen, Pascal Carrière, Cuong Ngo Xuan","doi":"10.1155/2018/4749501","DOIUrl":"https://doi.org/10.1155/2018/4749501","url":null,"abstract":"Incorporation of nanofillers into the organic coatings might enhance their barrier performance, by decreasing the porosity and zigzagging the diffusion path for deleterious species. Thus, the coatings containing nanofillers are expected to have significant barrier properties for corrosion protection and reduce the trend for the coating to blister or delaminate. On the other hand, high hardness could be obtained for metallic coatings by producing the hard nanocrystalline phases within a metallic matrix. This article presents a review on recent development of nanocomposite coatings, providing an overview of nanocomposite coatings in various aspects dealing with the classification, preparative method, the nanocomposite coating properties, and characterization methods. It covers potential applications in areas such as the anticorrosion, antiwear, superhydrophobic area, self-cleaning, antifouling/antibacterial area, and electronics. Finally, conclusion and future trends will be also reported.","PeriodicalId":13893,"journal":{"name":"International Journal of Corrosion","volume":"2018 1","pages":"1-19"},"PeriodicalIF":3.1,"publicationDate":"2018-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2018/4749501","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45822104","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The tensile behaviors of corroded steel bars are important in the capacity evaluation of corroded reinforced concrete structures. The present paper studies the mechanical behavior of the corroded high strength reinforcing steel bars under static and dynamic loading. High strength reinforcing steel bars were corroded by using accelerated corrosion methods and the tensile tests were carried out under different strain rates. The results showed that the mechanical properties of corroded high strength steel bars were strain rate dependent, and the strain rate effect decreased with the increase of corrosion degree. The decreased nominal yield and ultimate strengths were mainly caused by the reduction of cross-sectional areas, and the decreased ultimate deformation and the shortened yield plateau resulted from the intensified stress concentration at the nonuniform reduction. Based on the test results, reduction factors were proposed to relate the tensile behaviors with the corrosion degree and strain rate for corroded bars. A modified Johnson-Cook strength model of corroded high strength steel bars under dynamic loading was proposed by taking into account the influence of corrosion degree. Comparison between the model and test results showed that proposed model properly describes the dynamic response of the corroded high strength rebars.
{"title":"Experimental Investigation into Corrosion Effect on Mechanical Properties of High Strength Steel Bars under Dynamic Loadings","authors":"Hui Chen, Jinjin Zhang, Jin Yang, F. Ye","doi":"10.1155/2018/7169681","DOIUrl":"https://doi.org/10.1155/2018/7169681","url":null,"abstract":"The tensile behaviors of corroded steel bars are important in the capacity evaluation of corroded reinforced concrete structures. The present paper studies the mechanical behavior of the corroded high strength reinforcing steel bars under static and dynamic loading. High strength reinforcing steel bars were corroded by using accelerated corrosion methods and the tensile tests were carried out under different strain rates. The results showed that the mechanical properties of corroded high strength steel bars were strain rate dependent, and the strain rate effect decreased with the increase of corrosion degree. The decreased nominal yield and ultimate strengths were mainly caused by the reduction of cross-sectional areas, and the decreased ultimate deformation and the shortened yield plateau resulted from the intensified stress concentration at the nonuniform reduction. Based on the test results, reduction factors were proposed to relate the tensile behaviors with the corrosion degree and strain rate for corroded bars. A modified Johnson-Cook strength model of corroded high strength steel bars under dynamic loading was proposed by taking into account the influence of corrosion degree. Comparison between the model and test results showed that proposed model properly describes the dynamic response of the corroded high strength rebars.","PeriodicalId":13893,"journal":{"name":"International Journal of Corrosion","volume":"70 1","pages":"1-12"},"PeriodicalIF":3.1,"publicationDate":"2018-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2018/7169681","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64736045","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The galvanic corrosion of a bolt joint combining carbon steel end plate and low alloy steel bolt was investigated electrochemically in a 1 M HCl solution. The corrosion parameters of the joint components were used for numerical simulation using Comsol Multiphysics software to analyze the galvanic corrosion behavior at the contact zone between the head bolt and the end plate. In this research work we evaluate the variation of the corrosion rate in the steel end plate considered as the anode, in order to determine the lifetime of the bolted assembly used in steel structures. Three materials (20MnCr5, 42CrMo4, and 32CrMoV13) and three bolts (M12, M16, and M20) were tested in two thicknesses of electrolyte 1 M HCl ( = 1 mm, = 20 mm). It is found that the corrosion rate of the anode part (end plate) is higher for 32CrMoV13 materials and it increases if both diameter of the bolt and thickness of the electrolyte increase (Cr(M20) > Cr(M16) > Cr(M12) and Cr( = 20 mm) > Cr( = 1 mm)). This corrosion rate is higher in the contact area between the bolt head and the end plate, and it decreases if we move away from this contact area.
用电化学方法研究了碳钢端板与低合金钢螺栓连接处的电化学腐蚀 M HCl溶液。使用Comsol Multiphysics软件对接头部件的腐蚀参数进行数值模拟，以分析头部螺栓和端板之间接触区的电偶腐蚀行为。在这项研究工作中，我们评估了作为阳极的钢端板中腐蚀速率的变化，以确定钢结构中使用的螺栓组件的寿命。三种材料（20MnCr5、42CrMo4和32CrMoV13）和三种螺栓（M12、M16和M20）在两种厚度的电解质1中进行了测试 M盐酸（=1 mm，=20 mm）。研究发现，对于32CrMoV13材料，阳极部分（端板）的腐蚀速率更高，并且如果螺栓直径和电解质厚度都增加（Cr（M20）>Cr（M16）>铬（M12）和Cr（=20 mm）>Cr（=1 mm））。这种腐蚀率在螺栓头和端板之间的接触区域更高，如果我们离开这个接触区域，腐蚀率就会降低。
{"title":"Numerical Simulation of Galvanic Corrosion between Carbon Steel and Low Alloy Steel in a Bolted Joint","authors":"R. Radouani, Y. Ech-Charqy, M. Essahli","doi":"10.1155/2017/6174904","DOIUrl":"https://doi.org/10.1155/2017/6174904","url":null,"abstract":"The galvanic corrosion of a bolt joint combining carbon steel end plate and low alloy steel bolt was investigated electrochemically in a 1 M HCl solution. The corrosion parameters of the joint components were used for numerical simulation using Comsol Multiphysics software to analyze the galvanic corrosion behavior at the contact zone between the head bolt and the end plate. In this research work we evaluate the variation of the corrosion rate in the steel end plate considered as the anode, in order to determine the lifetime of the bolted assembly used in steel structures. Three materials (20MnCr5, 42CrMo4, and 32CrMoV13) and three bolts (M12, M16, and M20) were tested in two thicknesses of electrolyte 1 M HCl ( = 1 mm, = 20 mm). It is found that the corrosion rate of the anode part (end plate) is higher for 32CrMoV13 materials and it increases if both diameter of the bolt and thickness of the electrolyte increase (Cr(M20) > Cr(M16) > Cr(M12) and Cr( = 20 mm) > Cr( = 1 mm)). This corrosion rate is higher in the contact area between the bolt head and the end plate, and it decreases if we move away from this contact area.","PeriodicalId":13893,"journal":{"name":"International Journal of Corrosion","volume":"2017 1","pages":"1-10"},"PeriodicalIF":3.1,"publicationDate":"2017-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2017/6174904","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45010420","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The formation and breakdown of passive layers due to pitting corrosion are a major cause of failure of metal structures. The investigation of passivation and pitting corrosion requires two different electrochemical measurements and is therefore a time consuming process. To reduce time in material characterization and to study the interactions of both mechanisms, here, a combined experiment addressing both phenomena is introduced. In the presented electrolyte the different corrosion mechanisms are distinguished and investigated by cyclic voltammograms and polarization scans. The measurements show a passive area, metastable pit growth, and pitting corrosion as well as repassivation. The pitting corrosion is separated from additional dissolution processes and the standard deviation of the corrosion potential is smaller than in other electrolytes. Both passivation and pitting corrosion can be observed in one measurement without additional corrosion attacks. The deviation between different measurements of the same steel is small; this is helpful for the screening of similar materials.
{"title":"Electrolyte Composition for Distinguishing Corrosion Mechanisms in Steel Alloy Screening","authors":"Ingmar Bösing, J. Thöming, M. Baune","doi":"10.1155/2017/9425864","DOIUrl":"https://doi.org/10.1155/2017/9425864","url":null,"abstract":"The formation and breakdown of passive layers due to pitting corrosion are a major cause of failure of metal structures. The investigation of passivation and pitting corrosion requires two different electrochemical measurements and is therefore a time consuming process. To reduce time in material characterization and to study the interactions of both mechanisms, here, a combined experiment addressing both phenomena is introduced. In the presented electrolyte the different corrosion mechanisms are distinguished and investigated by cyclic voltammograms and polarization scans. The measurements show a passive area, metastable pit growth, and pitting corrosion as well as repassivation. The pitting corrosion is separated from additional dissolution processes and the standard deviation of the corrosion potential is smaller than in other electrolytes. Both passivation and pitting corrosion can be observed in one measurement without additional corrosion attacks. The deviation between different measurements of the same steel is small; this is helpful for the screening of similar materials.","PeriodicalId":13893,"journal":{"name":"International Journal of Corrosion","volume":"2017 1","pages":"1-8"},"PeriodicalIF":3.1,"publicationDate":"2017-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2017/9425864","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41969728","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Qing-Miao Ding, Li-Chun Fang, Yanyu Cui, Yujun Wang
A rectangle disbonded coating simulation device was used to research the effect of sulfate reducing bacteria (SRB) on the metallic corrosion behavior under disbonded coating by the electrochemical method. The results showed that the metal self-corrosion potential at the same test point had little change in the initial experiment stage, whether the solution was without or with SRB. The potential amplitude in the solution with SRB was larger than that without SRB in the later corrosion period. The corrosion current density of the metal at the same test point increased gradually over time in the solution with or without SRB, and SRB could accelerate the corrosion of the metal in the disbonded crevice. The metal self-corrosion potential in the crevice had little change in the SRB solution environment after adding the fungicide, but the corrosion current density decreased significantly. That meant the growth and reproduction of SRB were inhibited after adding the fungicide, so the metal corrosion rate slowed down. Among the three kinds of solution environment, increasing the coating disbonded thickness could accelerate the corrosion of the metal in the crevice, and it was the largest in the solution with SRB.
{"title":"Experimental Study on the Influence of Sulfate Reducing Bacteria on the Metallic Corrosion Behavior under Disbonded Coating","authors":"Qing-Miao Ding, Li-Chun Fang, Yanyu Cui, Yujun Wang","doi":"10.1155/2017/9740817","DOIUrl":"https://doi.org/10.1155/2017/9740817","url":null,"abstract":"A rectangle disbonded coating simulation device was used to research the effect of sulfate reducing bacteria (SRB) on the metallic corrosion behavior under disbonded coating by the electrochemical method. The results showed that the metal self-corrosion potential at the same test point had little change in the initial experiment stage, whether the solution was without or with SRB. The potential amplitude in the solution with SRB was larger than that without SRB in the later corrosion period. The corrosion current density of the metal at the same test point increased gradually over time in the solution with or without SRB, and SRB could accelerate the corrosion of the metal in the disbonded crevice. The metal self-corrosion potential in the crevice had little change in the SRB solution environment after adding the fungicide, but the corrosion current density decreased significantly. That meant the growth and reproduction of SRB were inhibited after adding the fungicide, so the metal corrosion rate slowed down. Among the three kinds of solution environment, increasing the coating disbonded thickness could accelerate the corrosion of the metal in the crevice, and it was the largest in the solution with SRB.","PeriodicalId":13893,"journal":{"name":"International Journal of Corrosion","volume":" ","pages":"1-13"},"PeriodicalIF":3.1,"publicationDate":"2017-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2017/9740817","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49297151","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
R. C. Souza, L. R. Pereira, L. M. Starling, J. N. Pereira, T. A. Simões, J. Gomes, A. Bueno
The aim of this research was to evaluate the influence of microstructure on hydrogen permeation of weld and API X52 base metal under cathodic protection. The microstructures analyzed were of the API X52, as received, quenched, and annealed, and the welded zone. The test was performed in base metal (BM), quenched base metal (QBM), annealed base metal (ABM), and weld metal (WM). Hydrogen permeation flows were evaluated using electrochemical tests in a Devanathan cell. The potentiodynamic polarization curves were carried out to evaluate the corrosion resistance of each microstructure. All tests were carried out in synthetic soil solutions NS4 and NS4 + sodium thiosulfate at 25°C. The sodium thiosulfate was used to simulate sulfate reduction bacteria (SRB). Through polarization, assays established that the microstructure does not influence the corrosion resistance. The permeation tests showed that weld metal had lower hydrogen flow than base metal as received, quenched, and annealed.
{"title":"Effect of Microstructure on Hydrogen Diffusion in Weld and API X52 Pipeline Steel Base Metals under Cathodic Protection","authors":"R. C. Souza, L. R. Pereira, L. M. Starling, J. N. Pereira, T. A. Simões, J. Gomes, A. Bueno","doi":"10.1155/2017/4927210","DOIUrl":"https://doi.org/10.1155/2017/4927210","url":null,"abstract":"The aim of this research was to evaluate the influence of microstructure on hydrogen permeation of weld and API X52 base metal under cathodic protection. The microstructures analyzed were of the API X52, as received, quenched, and annealed, and the welded zone. The test was performed in base metal (BM), quenched base metal (QBM), annealed base metal (ABM), and weld metal (WM). Hydrogen permeation flows were evaluated using electrochemical tests in a Devanathan cell. The potentiodynamic polarization curves were carried out to evaluate the corrosion resistance of each microstructure. All tests were carried out in synthetic soil solutions NS4 and NS4 + sodium thiosulfate at 25°C. The sodium thiosulfate was used to simulate sulfate reduction bacteria (SRB). Through polarization, assays established that the microstructure does not influence the corrosion resistance. The permeation tests showed that weld metal had lower hydrogen flow than base metal as received, quenched, and annealed.","PeriodicalId":13893,"journal":{"name":"International Journal of Corrosion","volume":"2017 1","pages":"1-14"},"PeriodicalIF":3.1,"publicationDate":"2017-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2017/4927210","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46866561","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The surface analysis techniques and chemical technical means (polarization curves and AC impedance technique) were applied to research the corrosion characteristics of microorganisms SRB of 2024-T31 aluminum-magnesium alloy in the oil-water system, and the corrosion mechanism was finally analyzed. The results showed that SRB accelerate the corrosion process and cause uneven pitting on the surface of the metal matrix. Passive and biological films control the corrosion of the metal substrate in bacterial oil-water system. In the initial stage of immersion, a loose and uneven biofilm formed on the surface of substrate which accelerated its corrosion. In the midterm, the effect of biofilm gradually weakened while the protective effect of the passive film grew more insistently; the rate of corrosion slowed down. In the later period, localized corrosion cell of large cathode/small anode formed on the surface of the substrate which accelerates the corrosion.
{"title":"Research of Microorganism Corrosion Properties of 2024-T31 Aluminum-Magnesium Alloy in Oil-Water System","authors":"Yanyu Cui, Jia Li, Qing-Miao Ding","doi":"10.1155/2017/5041347","DOIUrl":"https://doi.org/10.1155/2017/5041347","url":null,"abstract":"The surface analysis techniques and chemical technical means (polarization curves and AC impedance technique) were applied to research the corrosion characteristics of microorganisms SRB of 2024-T31 aluminum-magnesium alloy in the oil-water system, and the corrosion mechanism was finally analyzed. The results showed that SRB accelerate the corrosion process and cause uneven pitting on the surface of the metal matrix. Passive and biological films control the corrosion of the metal substrate in bacterial oil-water system. In the initial stage of immersion, a loose and uneven biofilm formed on the surface of substrate which accelerated its corrosion. In the midterm, the effect of biofilm gradually weakened while the protective effect of the passive film grew more insistently; the rate of corrosion slowed down. In the later period, localized corrosion cell of large cathode/small anode formed on the surface of the substrate which accelerates the corrosion.","PeriodicalId":13893,"journal":{"name":"International Journal of Corrosion","volume":"2017 1","pages":"1-9"},"PeriodicalIF":3.1,"publicationDate":"2017-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2017/5041347","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41525714","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abdulkareem M. A. Al-Sammarraie, Mazin Hasan Raheema
The enhancement of corrosion protection of metals and alloys by coating with simple, low cost, and highly adhered layer is still a main goal of many workers. In this research graphite flakes converted into graphene oxide using modified Hammers method and then reduced graphene oxide was electrodeposited on stainless steel 316, copper, and aluminum for corrosion protection application in seawater at four temperatures, namely, 20, 30, 40, and 50°C. All corrosion measurements, kinetics, and thermodynamics parameters were established from Tafel plots using three-electrode potentiostat. The deposited films were examined by FTIR, Raman, XRD, SEM, and AFM techniques; they revealed high percentages of conversion to the few layers of graphene with confirmed defects.
{"title":"Electrodeposited Reduced Graphene Oxide Films on Stainless Steel, Copper, and Aluminum for Corrosion Protection Enhancement","authors":"Abdulkareem M. A. Al-Sammarraie, Mazin Hasan Raheema","doi":"10.1155/2017/6939354","DOIUrl":"https://doi.org/10.1155/2017/6939354","url":null,"abstract":"The enhancement of corrosion protection of metals and alloys by coating with simple, low cost, and highly adhered layer is still a main goal of many workers. In this research graphite flakes converted into graphene oxide using modified Hammers method and then reduced graphene oxide was electrodeposited on stainless steel 316, copper, and aluminum for corrosion protection application in seawater at four temperatures, namely, 20, 30, 40, and 50°C. All corrosion measurements, kinetics, and thermodynamics parameters were established from Tafel plots using three-electrode potentiostat. The deposited films were examined by FTIR, Raman, XRD, SEM, and AFM techniques; they revealed high percentages of conversion to the few layers of graphene with confirmed defects.","PeriodicalId":13893,"journal":{"name":"International Journal of Corrosion","volume":" ","pages":"1-8"},"PeriodicalIF":3.1,"publicationDate":"2017-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2017/6939354","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42257725","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The efficiency of 1,3-benzodioxole derivatives as corrosion inhibitors is theoretically studied using quantum chemical calculation and Quantitative Structure Activity Relationship (QSAR). Different semiempirical methods (AM1, PM3, MNDO, MINDO/3, and INDO) are applied in order to determine the relationship between molecular structure and their corrosion protection efficiencies. Different quantum parameters are obtained as the energy of highest occupied molecular orbital , the energy of the lowest unoccupied molecular orbital , energy gap , dipole moment μ, and Mulliken charge on the atom. QSAR approach is applied to elucidate some important parameters as the hydrophobicity (Log P), surface area (S.A), polarization , and hydration energy ().
{"title":"Semiempirical Theoretical Studies of 1,3-Benzodioxole Derivatives as Corrosion Inhibitors","authors":"O. El-Shamy","doi":"10.1155/2017/8915967","DOIUrl":"https://doi.org/10.1155/2017/8915967","url":null,"abstract":"The efficiency of 1,3-benzodioxole derivatives as corrosion inhibitors is theoretically studied using quantum chemical calculation and Quantitative Structure Activity Relationship (QSAR). Different semiempirical methods (AM1, PM3, MNDO, MINDO/3, and INDO) are applied in order to determine the relationship between molecular structure and their corrosion protection efficiencies. Different quantum parameters are obtained as the energy of highest occupied molecular orbital , the energy of the lowest unoccupied molecular orbital , energy gap , dipole moment μ, and Mulliken charge on the atom. QSAR approach is applied to elucidate some important parameters as the hydrophobicity (Log P), surface area (S.A), polarization , and hydration energy ().","PeriodicalId":13893,"journal":{"name":"International Journal of Corrosion","volume":" ","pages":"1-10"},"PeriodicalIF":3.1,"publicationDate":"2017-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2017/8915967","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47619295","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
L. Pezzato, K. Brunelli, Riccardo Babbolin, P. Dolcet, M. Dabalà
In this work, solutions containing lanthanum salts were used for a post-treatment of sealing to increase the corrosion resistance of PEO coated AZ91 alloy. PEO coatings were produced on samples of AZ91 magnesium alloy using an alkaline solution containing sodium hydroxide, sodium phosphates, and sodium silicates. The sealing treatment was performed in a solution containing 12 g/L of La(NO3)3 at pH 4 at different temperatures and for different treatment times. Potentiodynamic polarization test, an EIS test, showed that the sealing treatment with solution containing lanthanum nitrate caused a remarkable increase in the corrosion resistance. The corrosion behavior was correlated with the surface morphology and elemental composition evaluated with scanning electron microscope (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). In particular, the sealing treatment at 50°C for 30 min resulted in being the most promising to increase the corrosion properties of PEO treated samples because of the formation of a homogeneous sealing layer, mainly composed of La(OH)3.
{"title":"Sealing of PEO Coated AZ91 Magnesium Alloy Using La-Based Solutions","authors":"L. Pezzato, K. Brunelli, Riccardo Babbolin, P. Dolcet, M. Dabalà","doi":"10.1155/2017/5305218","DOIUrl":"https://doi.org/10.1155/2017/5305218","url":null,"abstract":"In this work, solutions containing lanthanum salts were used for a post-treatment of sealing to increase the corrosion resistance of PEO coated AZ91 alloy. PEO coatings were produced on samples of AZ91 magnesium alloy using an alkaline solution containing sodium hydroxide, sodium phosphates, and sodium silicates. The sealing treatment was performed in a solution containing 12 g/L of La(NO3)3 at pH 4 at different temperatures and for different treatment times. Potentiodynamic polarization test, an EIS test, showed that the sealing treatment with solution containing lanthanum nitrate caused a remarkable increase in the corrosion resistance. The corrosion behavior was correlated with the surface morphology and elemental composition evaluated with scanning electron microscope (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). In particular, the sealing treatment at 50°C for 30 min resulted in being the most promising to increase the corrosion properties of PEO treated samples because of the formation of a homogeneous sealing layer, mainly composed of La(OH)3.","PeriodicalId":13893,"journal":{"name":"International Journal of Corrosion","volume":"2017 1","pages":"1-13"},"PeriodicalIF":3.1,"publicationDate":"2017-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2017/5305218","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44715253","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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