Pub Date : 2024-06-07DOI: 10.1038/s41529-024-00472-8
Margherita Gnemmi, Laura Fuster-Lòpez, Marion Mecklenburg, Alison Murray, Sarah Sands, Greg Watson, Francesca Caterina Izzo
The study of film-formation processes of oil paints has been extensively addressed over the last decade and the influence of metal ions in the drying and degradation stages of oil paints has been demonstrated. This research aimed to determine a suitable methodology for monitoring the early drying stages of selected commercial oil paint films and to gain an insight into the migration mechanisms of material degradation taking place between adjacent paint films, with special attention to the influence of the lead white. For this purpose, a hybrid approach was adopted to characterize the composition of the paint and highlight failure mechanisms in the paint films through a wide range of time. The methods included scribe tests, percentage weight variation (ΔW%), attenuated reflectance Fourier transform infrared spectrophotometry (ATR-FTIR), gas chromatography-mass spectrometry (GC-MS), and thermal analysis with differential scanning calorimetry (TG-DSC). The results show how metal ions interact with the oil binder and the pigment in the adjacent paint film: the transverse migration of lead white is shown to affect the reactivity of polyunsaturated triglycerides, increasing the rate of oxygen uptake and promoting the formation of radicals and bonds between polymer chains, depending on the pigment with which it interacts.
{"title":"Ion migration mechanisms in the early stages of drying and degradation of oil paint films","authors":"Margherita Gnemmi, Laura Fuster-Lòpez, Marion Mecklenburg, Alison Murray, Sarah Sands, Greg Watson, Francesca Caterina Izzo","doi":"10.1038/s41529-024-00472-8","DOIUrl":"10.1038/s41529-024-00472-8","url":null,"abstract":"The study of film-formation processes of oil paints has been extensively addressed over the last decade and the influence of metal ions in the drying and degradation stages of oil paints has been demonstrated. This research aimed to determine a suitable methodology for monitoring the early drying stages of selected commercial oil paint films and to gain an insight into the migration mechanisms of material degradation taking place between adjacent paint films, with special attention to the influence of the lead white. For this purpose, a hybrid approach was adopted to characterize the composition of the paint and highlight failure mechanisms in the paint films through a wide range of time. The methods included scribe tests, percentage weight variation (ΔW%), attenuated reflectance Fourier transform infrared spectrophotometry (ATR-FTIR), gas chromatography-mass spectrometry (GC-MS), and thermal analysis with differential scanning calorimetry (TG-DSC). The results show how metal ions interact with the oil binder and the pigment in the adjacent paint film: the transverse migration of lead white is shown to affect the reactivity of polyunsaturated triglycerides, increasing the rate of oxygen uptake and promoting the formation of radicals and bonds between polymer chains, depending on the pigment with which it interacts.","PeriodicalId":19270,"journal":{"name":"npj Materials Degradation","volume":" ","pages":"1-18"},"PeriodicalIF":5.1,"publicationDate":"2024-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41529-024-00472-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141294997","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-07DOI: 10.1038/s41529-024-00481-7
Daniel A. Britton, David Penney, Amar D. Malla, Shahin Mehraban, James Sullivan, Mathew Goldsworthy, James McGettrick, Richard Johnston, Ria L. Mitchell, Clive Challinor
Microscopy, electrochemical techniques and mechanical testing are used to investigate the effect of varying antimony additions (0.45–1.8 wt%) on the microstructure and corrosion properties of zinc-magnesium-aluminium coating alloys. Samples were produced by splat casting to produce high cooling rates similar to those seen in a continuous galvanising line. X-Ray Microscopy reveals that the Sb additions produce disk-shaped Mg3Sb2 intermetallics, subsequently reducing or eliminating the MgZn2 eutectic. Electrochemical testing in 1 wt% NaCl shows that the Mg3Sb2 phase is cathodic with respect to the bulk alloy with slower oxygen reduction kinetics. The decrease in eutectic content leads to less intense anodic activity. The combined effect is anodic and cathodic deactivation, which leads to a 43% reduction in corrosion rate as measured through LPR compared to the base alloy. This work shows that quaternary additions to ZMA coating alloys can be a potential route to improved corrosion resistance for galvanic protection.
{"title":"Effect of antimony additions on the microstructure and performance of Zn–Mg–Al alloy coatings","authors":"Daniel A. Britton, David Penney, Amar D. Malla, Shahin Mehraban, James Sullivan, Mathew Goldsworthy, James McGettrick, Richard Johnston, Ria L. Mitchell, Clive Challinor","doi":"10.1038/s41529-024-00481-7","DOIUrl":"10.1038/s41529-024-00481-7","url":null,"abstract":"Microscopy, electrochemical techniques and mechanical testing are used to investigate the effect of varying antimony additions (0.45–1.8 wt%) on the microstructure and corrosion properties of zinc-magnesium-aluminium coating alloys. Samples were produced by splat casting to produce high cooling rates similar to those seen in a continuous galvanising line. X-Ray Microscopy reveals that the Sb additions produce disk-shaped Mg3Sb2 intermetallics, subsequently reducing or eliminating the MgZn2 eutectic. Electrochemical testing in 1 wt% NaCl shows that the Mg3Sb2 phase is cathodic with respect to the bulk alloy with slower oxygen reduction kinetics. The decrease in eutectic content leads to less intense anodic activity. The combined effect is anodic and cathodic deactivation, which leads to a 43% reduction in corrosion rate as measured through LPR compared to the base alloy. This work shows that quaternary additions to ZMA coating alloys can be a potential route to improved corrosion resistance for galvanic protection.","PeriodicalId":19270,"journal":{"name":"npj Materials Degradation","volume":" ","pages":"1-11"},"PeriodicalIF":5.1,"publicationDate":"2024-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41529-024-00481-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141287028","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-06-01DOI: 10.1038/s41529-024-00474-6
Hyun-Kyu Hwang, Seong-Jong Kim
In this investigation, electropolishing and plasma ion nitriding are applied to super austenitic stainless steel for the purpose of improving its corrosion and pitting resistance. Electrochemical experiments are conducted with washing water collected directly from the ship’s scrubber. After electropolishing, the surface roughness is improved by about 73.6% compared to mechanical polishing. After plasma ion nitriding, CrN (precipitate), Fe4N (compound), and γN (solid solution) are observed on the surface. The thickness of the layer formed on the surface is measured to be about 10 μm. A hysteresis loop is observed in the cyclic potentiodynamic polarization curves of mechanical polishing and electropolishing, and the areas are calculated as 23.33 mW cm−2 and 0.17 mW cm−2, respectively. The polarization curve of plasma ion nitriding presents perfect passivation characteristics. Accordingly, mechanical polishing and electropolishing reveal local corrosion, whereas plasma ion nitriding presents a tendency towards general corrosion. In the mechanical polishing, electropolishing, and plasma ion nitriding, the corrosion current densities are 0.665 μA cm−2, 0.093 μA cm−2, and 16.47 μA cm−2, respectively, and the maximum damage depth is observed to grow progressively smaller from plasma ion nitriding to electropolishing and then mechanical polishing.
{"title":"Electrochemical characteristics and damage mechanism in scrubber washing water of UNS N08367 with plasma ion nitriding and electropolishing","authors":"Hyun-Kyu Hwang, Seong-Jong Kim","doi":"10.1038/s41529-024-00474-6","DOIUrl":"10.1038/s41529-024-00474-6","url":null,"abstract":"In this investigation, electropolishing and plasma ion nitriding are applied to super austenitic stainless steel for the purpose of improving its corrosion and pitting resistance. Electrochemical experiments are conducted with washing water collected directly from the ship’s scrubber. After electropolishing, the surface roughness is improved by about 73.6% compared to mechanical polishing. After plasma ion nitriding, CrN (precipitate), Fe4N (compound), and γN (solid solution) are observed on the surface. The thickness of the layer formed on the surface is measured to be about 10 μm. A hysteresis loop is observed in the cyclic potentiodynamic polarization curves of mechanical polishing and electropolishing, and the areas are calculated as 23.33 mW cm−2 and 0.17 mW cm−2, respectively. The polarization curve of plasma ion nitriding presents perfect passivation characteristics. Accordingly, mechanical polishing and electropolishing reveal local corrosion, whereas plasma ion nitriding presents a tendency towards general corrosion. In the mechanical polishing, electropolishing, and plasma ion nitriding, the corrosion current densities are 0.665 μA cm−2, 0.093 μA cm−2, and 16.47 μA cm−2, respectively, and the maximum damage depth is observed to grow progressively smaller from plasma ion nitriding to electropolishing and then mechanical polishing.","PeriodicalId":19270,"journal":{"name":"npj Materials Degradation","volume":" ","pages":"1-13"},"PeriodicalIF":5.1,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41529-024-00474-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141187659","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-29DOI: 10.1038/s41529-024-00457-7
Jaewoo Park, Amanda Leong, Jinsuo Zhang
The purification of salt is indispensable for mitigating the corrosion of structural materials for molten salt reactors or other molten salt applications. This study develops a salt-purification system to synthesize and purify NaF-KF-UF4 salt (FUNaK) using Ar purging and hydrofluorination of impurities. Chronoamperometry is also used to remove metallic impurities in the hydrofluorinated FUNaK. This purified FUNaK is then used for a static corrosion test of stainless steel 316H (SS316H) to study the effectiveness of salt purification in mitigating its corrosion. For comparison, results from a previous study about the corrosion of SS316H by thermally purified FUNaK are used. FUNaK with UF3 is also synthesized for a static corrosion test with the same condition to investigate the impact of UF3 on corrosion. The results show that the corrosion of SS316H is significantly reduced by using the chemically purified FUNaK compared to thermally purified FUNaK.
{"title":"Static corrosion of stainless steel 316H in chemically purified molten NaF-KF-UF4 salt","authors":"Jaewoo Park, Amanda Leong, Jinsuo Zhang","doi":"10.1038/s41529-024-00457-7","DOIUrl":"10.1038/s41529-024-00457-7","url":null,"abstract":"The purification of salt is indispensable for mitigating the corrosion of structural materials for molten salt reactors or other molten salt applications. This study develops a salt-purification system to synthesize and purify NaF-KF-UF4 salt (FUNaK) using Ar purging and hydrofluorination of impurities. Chronoamperometry is also used to remove metallic impurities in the hydrofluorinated FUNaK. This purified FUNaK is then used for a static corrosion test of stainless steel 316H (SS316H) to study the effectiveness of salt purification in mitigating its corrosion. For comparison, results from a previous study about the corrosion of SS316H by thermally purified FUNaK are used. FUNaK with UF3 is also synthesized for a static corrosion test with the same condition to investigate the impact of UF3 on corrosion. The results show that the corrosion of SS316H is significantly reduced by using the chemically purified FUNaK compared to thermally purified FUNaK.","PeriodicalId":19270,"journal":{"name":"npj Materials Degradation","volume":" ","pages":"1-10"},"PeriodicalIF":5.1,"publicationDate":"2024-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41529-024-00457-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141182305","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-28DOI: 10.1038/s41529-024-00477-3
Jiajiao Wei, Ke Hou, Feng Yang, Zhipeng Chang, Ju Li, Yunliang Shao, Mengjia Li, Xiaomei Yu, Jinyou Zheng, Yutao Zhou, Yongpeng Yang, Dehai Ping, Yong Liu, Min Li, Songjie Li
The influence of hydrogen charging potentials on the hydrogen embrittlement susceptibility of R6 ultra-high strength mooring chain steel was investigated via constant potential hydrogen charging slow strain rate tensile tests combined with thermal desorption analysis. The results reveal that hydrogen charging leads to a 38.94% decrease in elongation, while the impact on tensile strength is relatively minor. Furthermore, the specimens experienced intergranular cracking at the critical potential of −1150 mV, with the size of the brittle region increasing as the negative charging potential becomes more negative. And, hydrogen atoms can cause local embrittlement of materials and increase KAM value.
通过恒电位充氢慢应变速率拉伸试验结合热脱附分析，研究了充氢电位对 R6 超高强度系泊链钢氢脆敏感性的影响。结果表明，充氢导致伸长率下降 38.94%，而对拉伸强度的影响相对较小。此外，试样在临界电位 -1150 mV 时出现晶间开裂，脆性区域的大小随着负充电电位的增加而增大。而且，氢原子会导致材料局部脆化并增加 KAM 值。
{"title":"Delayed fracture behavior of ultra-high-strength mooring chain steel evaluated by potentiostatic hydrogen-charging combined with SSRT","authors":"Jiajiao Wei, Ke Hou, Feng Yang, Zhipeng Chang, Ju Li, Yunliang Shao, Mengjia Li, Xiaomei Yu, Jinyou Zheng, Yutao Zhou, Yongpeng Yang, Dehai Ping, Yong Liu, Min Li, Songjie Li","doi":"10.1038/s41529-024-00477-3","DOIUrl":"10.1038/s41529-024-00477-3","url":null,"abstract":"The influence of hydrogen charging potentials on the hydrogen embrittlement susceptibility of R6 ultra-high strength mooring chain steel was investigated via constant potential hydrogen charging slow strain rate tensile tests combined with thermal desorption analysis. The results reveal that hydrogen charging leads to a 38.94% decrease in elongation, while the impact on tensile strength is relatively minor. Furthermore, the specimens experienced intergranular cracking at the critical potential of −1150 mV, with the size of the brittle region increasing as the negative charging potential becomes more negative. And, hydrogen atoms can cause local embrittlement of materials and increase KAM value.","PeriodicalId":19270,"journal":{"name":"npj Materials Degradation","volume":" ","pages":"1-11"},"PeriodicalIF":5.1,"publicationDate":"2024-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41529-024-00477-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141165083","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-28DOI: 10.1038/s41529-024-00467-5
Peter Rodič, Barbara Kapun, Ingrid Milošev
Aluminium cast alloy AlSi7Mg0.3 is a lightweight metal commonly used in automotive, aeronautical and mechanical applications. It has good corrosion resistance but, under harsh operative conditions, would benefit from additional protection. In this study, a corrosion-protective multilayer coating system for AlSi7Mg0.3 based on hexafluoro-zirconated trivalent chromium coating (Zr-CrCC) and polyacrylic/siloxane-silica (PEHA-SS) coating was developed. The Zr-CrCC was formed by immersion of the substrate in a commercial conversion bath (SurTec® 650). PEHA-SS synthesis was based on organic precursors (2-ethylhexyl acrylate and [3-(methacryloyloxy)propyl]trimethoxysilane) and an inorganic precursor, tetraethyl orthosilicate. After deposition on AlSi7Mg0.3, each coating was first characterised individually, followed by the analysis of the multilayer using scanning electron microscopy and energy-dispersive X-ray spectroscopy. The adhesion of the coatings was evaluated with a cross-hatch cut test. The corrosion studies in sodium chloride solution using electrochemical impedance spectroscopy and salt spray testing showed that the multilayer system is superior to individual Zr-CrCC and PEHA-SS coatings. After 4 months in 0.1 M NaCl, the multilayer-coated samples exhibited the impedance at 10 mHz in the range of GΩ cm2, while scribed samples withstood the corrosion attack in a salt spray chamber for one week. Thus, albeit only about 100 nm thick, the Zr-CrCC deposited between the substrate and a 9-micrometre thick barrier sol-gel PEHA-SS coating acts as an active corrosion protection interlayer and contributes to the overall protectiveness of the multilayer system.
{"title":"Complementary corrosion protection of cast AlSi7Mg0.3 alloy using Zr-Cr conversion and polyacrylic/siloxane-silica multilayer coatings","authors":"Peter Rodič, Barbara Kapun, Ingrid Milošev","doi":"10.1038/s41529-024-00467-5","DOIUrl":"10.1038/s41529-024-00467-5","url":null,"abstract":"Aluminium cast alloy AlSi7Mg0.3 is a lightweight metal commonly used in automotive, aeronautical and mechanical applications. It has good corrosion resistance but, under harsh operative conditions, would benefit from additional protection. In this study, a corrosion-protective multilayer coating system for AlSi7Mg0.3 based on hexafluoro-zirconated trivalent chromium coating (Zr-CrCC) and polyacrylic/siloxane-silica (PEHA-SS) coating was developed. The Zr-CrCC was formed by immersion of the substrate in a commercial conversion bath (SurTec® 650). PEHA-SS synthesis was based on organic precursors (2-ethylhexyl acrylate and [3-(methacryloyloxy)propyl]trimethoxysilane) and an inorganic precursor, tetraethyl orthosilicate. After deposition on AlSi7Mg0.3, each coating was first characterised individually, followed by the analysis of the multilayer using scanning electron microscopy and energy-dispersive X-ray spectroscopy. The adhesion of the coatings was evaluated with a cross-hatch cut test. The corrosion studies in sodium chloride solution using electrochemical impedance spectroscopy and salt spray testing showed that the multilayer system is superior to individual Zr-CrCC and PEHA-SS coatings. After 4 months in 0.1 M NaCl, the multilayer-coated samples exhibited the impedance at 10 mHz in the range of GΩ cm2, while scribed samples withstood the corrosion attack in a salt spray chamber for one week. Thus, albeit only about 100 nm thick, the Zr-CrCC deposited between the substrate and a 9-micrometre thick barrier sol-gel PEHA-SS coating acts as an active corrosion protection interlayer and contributes to the overall protectiveness of the multilayer system.","PeriodicalId":19270,"journal":{"name":"npj Materials Degradation","volume":" ","pages":"1-16"},"PeriodicalIF":5.1,"publicationDate":"2024-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41529-024-00467-5.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141165079","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-25DOI: 10.1038/s41529-024-00475-5
Thomas L. Goût, Anamul H. Mir, Simon M. Fairclough, Dimitri Pletser, Ian Farnan
Zirconolite ceramics present a chemically durable host matrix for waste actinides, but zirconolite dissolution rates reported in the literature often vary significantly. Here, the release of Ca and Al from a hot isostatically pressed zirconolite (Ca0.8Zr0.9Ce0.3Ti1.6Al0.4O7.0) was shown to be predominantly driven by preferential dissolution of minor perovskite and alumina phases. Both phases were undetectable by XRD, and the perovskite was difficult to detect by SEM-EDS. Whilst the zirconolite phase exhibited no signs of alteration, dissolution of the perovskite proceeded congruently without forming a hydrated altered layer or diffusion of protons into the solid that would be indicative of an ion-exchange mechanism. The weak temperature dependence of dissolution (40, 90 and 150 °C) showed that kinetics were limited by transport and a mixed transport-surface controlled reaction for Ca and Al, respectively. A significant H2O-D2O isotope effect on dissolution was observed for Ca but not for Al at all temperatures. The former was consistent with an abated rate of hydrolysis in the absence of a contribution from diffusion, whilst the latter could be attributed to differences in the activated complex for Ca and Al release through hydrolysis. These results demonstrate the role of a secondary phase perovskite in the dissolution kinetics of zirconolite even when perovskite occurs at low concentration and evades detection by bulk techniques such as XRD. This study provides a potential explanation of variations in zirconolite ceramic dissolution rates present in the literature and provides a null result to tests of an incongruent Ca release mechanism from zirconolite.
{"title":"Undetected perovskite phase interference with zirconolite dissolution measurements","authors":"Thomas L. Goût, Anamul H. Mir, Simon M. Fairclough, Dimitri Pletser, Ian Farnan","doi":"10.1038/s41529-024-00475-5","DOIUrl":"10.1038/s41529-024-00475-5","url":null,"abstract":"Zirconolite ceramics present a chemically durable host matrix for waste actinides, but zirconolite dissolution rates reported in the literature often vary significantly. Here, the release of Ca and Al from a hot isostatically pressed zirconolite (Ca0.8Zr0.9Ce0.3Ti1.6Al0.4O7.0) was shown to be predominantly driven by preferential dissolution of minor perovskite and alumina phases. Both phases were undetectable by XRD, and the perovskite was difficult to detect by SEM-EDS. Whilst the zirconolite phase exhibited no signs of alteration, dissolution of the perovskite proceeded congruently without forming a hydrated altered layer or diffusion of protons into the solid that would be indicative of an ion-exchange mechanism. The weak temperature dependence of dissolution (40, 90 and 150 °C) showed that kinetics were limited by transport and a mixed transport-surface controlled reaction for Ca and Al, respectively. A significant H2O-D2O isotope effect on dissolution was observed for Ca but not for Al at all temperatures. The former was consistent with an abated rate of hydrolysis in the absence of a contribution from diffusion, whilst the latter could be attributed to differences in the activated complex for Ca and Al release through hydrolysis. These results demonstrate the role of a secondary phase perovskite in the dissolution kinetics of zirconolite even when perovskite occurs at low concentration and evades detection by bulk techniques such as XRD. This study provides a potential explanation of variations in zirconolite ceramic dissolution rates present in the literature and provides a null result to tests of an incongruent Ca release mechanism from zirconolite.","PeriodicalId":19270,"journal":{"name":"npj Materials Degradation","volume":" ","pages":"1-16"},"PeriodicalIF":5.1,"publicationDate":"2024-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41529-024-00475-5.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141149251","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In order to make magnesium alloys better used in aviation, electronic information and other fields, it is necessary to improve their corrosion resistance and wave absorption properties. In this paper, a composite coating with corrosion resistance and wave absorption properties was prepared on magnesium alloy by micro-arc oxidation-organic coating technology. An organic absorbing coating with a thickness of about 40 μm was sprayed on the MAO coating containing Yb2O3 nanoparticles. Among them, the absorbing fillers in the organic coating are mainly SiO2 and α-Fe2O3. Three different mass ratios of SiO2 and α-Fe2O3 were set to 20%, 22.5% and 25%, respectively, to prepare three different MAO/SiO2@α-Fe2O3 organic composite coatings. The morphology, roughness, microstructure and chemical composition of the organic composite coating are characterized. The results show that after coating the organic composite coating, the roughness of the coating is significantly reduced, and the compactness and interlayer adhesion of the coating are significantly improved. The electrochemical test and SKPFM test of the organic composite coating were carried out. The results showed that with the increase of the mass ratio of SiO2 and α-Fe2O3, the corrosion resistance and stability of the organic composite coating increased, and the Volta potential also gradually moved up. The microwave absorbing properties of organic composite coatings were studied by vector network analyzer. The results show that the microwave absorbing properties of the coatings are positively correlated with the mass ratio of SiO2 and α-Fe2O3.
{"title":"Preparation and properties of Mg-Nd binary alloy MAO/SiO2@α-Fe2O3 organic composite coating","authors":"Qiang Sun, Quantong Jiang, Siwei Wu, Chang Liu, Heng Tang, Hao Shi, Liying Song, Jizhou Duan, Baorong Hou","doi":"10.1038/s41529-024-00473-7","DOIUrl":"10.1038/s41529-024-00473-7","url":null,"abstract":"In order to make magnesium alloys better used in aviation, electronic information and other fields, it is necessary to improve their corrosion resistance and wave absorption properties. In this paper, a composite coating with corrosion resistance and wave absorption properties was prepared on magnesium alloy by micro-arc oxidation-organic coating technology. An organic absorbing coating with a thickness of about 40 μm was sprayed on the MAO coating containing Yb2O3 nanoparticles. Among them, the absorbing fillers in the organic coating are mainly SiO2 and α-Fe2O3. Three different mass ratios of SiO2 and α-Fe2O3 were set to 20%, 22.5% and 25%, respectively, to prepare three different MAO/SiO2@α-Fe2O3 organic composite coatings. The morphology, roughness, microstructure and chemical composition of the organic composite coating are characterized. The results show that after coating the organic composite coating, the roughness of the coating is significantly reduced, and the compactness and interlayer adhesion of the coating are significantly improved. The electrochemical test and SKPFM test of the organic composite coating were carried out. The results showed that with the increase of the mass ratio of SiO2 and α-Fe2O3, the corrosion resistance and stability of the organic composite coating increased, and the Volta potential also gradually moved up. The microwave absorbing properties of organic composite coatings were studied by vector network analyzer. The results show that the microwave absorbing properties of the coatings are positively correlated with the mass ratio of SiO2 and α-Fe2O3.","PeriodicalId":19270,"journal":{"name":"npj Materials Degradation","volume":" ","pages":"1-13"},"PeriodicalIF":5.1,"publicationDate":"2024-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41529-024-00473-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141103241","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-21DOI: 10.1038/s41529-024-00476-4
Aditya Venkatraman, Ryan Michael Katona, Demitri Maestas, Matthew Roop, Philip Noell, David Montes de Oca Zapiain
The current present in a galvanic couple can define its resistance or susceptibility to corrosion. However, as the current is dependent upon environmental, material, and geometrical parameters it is experimentally costly to measure. To reduce these costs, Finite Element (FE) simulations can be used to assess the cathodic current but also require experimental inputs to define boundary conditions. Due to these challenges, it is crucial to accelerate predictions and accurately predict the current output for different environments and geometries representative of in-service conditions. Machine learned surrogate models provides a means to accelerate corrosion predictions. However, a one-time cost is incurred in procuring the simulation and experimental dataset necessary to calibrate the surrogate model. Therefore, an active learning protocol is developed through calibration of a low-cost surrogate model for the cathodic current of an exemplar galvanic couple (AA7075-SS304) as a function of environmental and geometric parameters. The surrogate model is calibrated on a dataset of FE simulations, and calculates an acquisition function that identifies specific additional inputs with the maximum potential to improve the current predictions. This is accomplished through a staggered workflow that not only improves and refines prediction, but identifies the points at which the most information is gained, thus enabling expansion to a larger parameter space. The protocols developed and demonstrated in this work provide a powerful tool for screening various forms of corrosion under in-service conditions.
电偶中的电流可以确定其电阻或易腐蚀性。然而，由于电流取决于环境、材料和几何参数，因此测量的实验成本很高。为了降低成本，可以使用有限元（FE）模拟来评估阴极电流，但也需要实验输入来定义边界条件。由于这些挑战，加速预测并准确预测不同环境下的电流输出以及代表在役条件的几何形状至关重要。机器学习代用模型为加速腐蚀预测提供了一种方法。然而，购买校准代用模型所需的模拟和实验数据集会产生一次性成本。因此，我们开发了一种主动学习协议，通过校准低成本的代理模型，将示范电偶（AA7075-SS304）的阴极电流作为环境和几何参数的函数。代用模型在 FE 模拟数据集上进行校准，并计算出一个获取函数，该函数可识别出具有最大潜力改进电流预测的特定额外输入。这是通过一个交错的工作流程实现的，该流程不仅能改进和完善预测，还能确定获得最多信息的点，从而扩展到更大的参数空间。这项工作中开发和演示的规程为在役条件下筛查各种形式的腐蚀提供了一个强大的工具。
{"title":"An active learning framework for the rapid assessment of galvanic corrosion","authors":"Aditya Venkatraman, Ryan Michael Katona, Demitri Maestas, Matthew Roop, Philip Noell, David Montes de Oca Zapiain","doi":"10.1038/s41529-024-00476-4","DOIUrl":"10.1038/s41529-024-00476-4","url":null,"abstract":"The current present in a galvanic couple can define its resistance or susceptibility to corrosion. However, as the current is dependent upon environmental, material, and geometrical parameters it is experimentally costly to measure. To reduce these costs, Finite Element (FE) simulations can be used to assess the cathodic current but also require experimental inputs to define boundary conditions. Due to these challenges, it is crucial to accelerate predictions and accurately predict the current output for different environments and geometries representative of in-service conditions. Machine learned surrogate models provides a means to accelerate corrosion predictions. However, a one-time cost is incurred in procuring the simulation and experimental dataset necessary to calibrate the surrogate model. Therefore, an active learning protocol is developed through calibration of a low-cost surrogate model for the cathodic current of an exemplar galvanic couple (AA7075-SS304) as a function of environmental and geometric parameters. The surrogate model is calibrated on a dataset of FE simulations, and calculates an acquisition function that identifies specific additional inputs with the maximum potential to improve the current predictions. This is accomplished through a staggered workflow that not only improves and refines prediction, but identifies the points at which the most information is gained, thus enabling expansion to a larger parameter space. The protocols developed and demonstrated in this work provide a powerful tool for screening various forms of corrosion under in-service conditions.","PeriodicalId":19270,"journal":{"name":"npj Materials Degradation","volume":" ","pages":"1-11"},"PeriodicalIF":5.1,"publicationDate":"2024-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41529-024-00476-4.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141118022","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Short-time oxidation behavior of nanocrystalline Ta coating is studied at 850 °C in comparison with that of the Ta sheet. Owing to the large PBR value and insufficient expansion space, the oxide scale on Ta sheet is dramatically cracked, delaminated and pulverized, resulting in rapid deterioration. For nanocrystalline Ta coatings with columnar structures and quantitative grain boundaries, a rapid oxygen diffusion rate causes no initial Ta2O5 to form. The gap between columns provides spaces for bulk expansion, resulting in few opening cracks and delamination. Ta oxidation experiences a crystallization course from amorphous Ta oxide, leading to in situ temperature surging and thus pulverization.
研究了纳米晶 Ta 涂层在 850 ℃ 下的短时氧化行为，并与 Ta 板的短时氧化行为进行了比较。由于 PBR 值较大且膨胀空间不足，Ta 片上的氧化鳞片出现了明显的裂纹、分层和粉化，从而导致快速劣化。对于具有柱状结构和定量晶界的纳米晶 Ta 涂层，快速的氧扩散速度不会形成初始的 Ta2O5。柱状结构之间的间隙为体积膨胀提供了空间，因此很少出现开口裂纹和分层。Ta 氧化经历了从无定形 Ta 氧化物结晶的过程，导致原位温度骤升，进而粉碎。
{"title":"Short-time high-temperature oxidation behavior of nanocrystalline Ta coating at 850 °C","authors":"Yunsong Niu, Lingling Xing, Shenglong Zhu, Jinfeng Huang, Minghui Chen, Fuhui Wang, Qiang Chen","doi":"10.1038/s41529-024-00465-7","DOIUrl":"10.1038/s41529-024-00465-7","url":null,"abstract":"Short-time oxidation behavior of nanocrystalline Ta coating is studied at 850 °C in comparison with that of the Ta sheet. Owing to the large PBR value and insufficient expansion space, the oxide scale on Ta sheet is dramatically cracked, delaminated and pulverized, resulting in rapid deterioration. For nanocrystalline Ta coatings with columnar structures and quantitative grain boundaries, a rapid oxygen diffusion rate causes no initial Ta2O5 to form. The gap between columns provides spaces for bulk expansion, resulting in few opening cracks and delamination. Ta oxidation experiences a crystallization course from amorphous Ta oxide, leading to in situ temperature surging and thus pulverization.","PeriodicalId":19270,"journal":{"name":"npj Materials Degradation","volume":" ","pages":"1-9"},"PeriodicalIF":5.1,"publicationDate":"2024-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41529-024-00465-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140962311","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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