Pub Date : 2024-08-17DOI: 10.1038/s41529-024-00502-5
Léa Brunswic, Frédéric Angeli, Thibault Charpentier, Stéphane Gin, Pierre Asplanato, Huseyin Kaya, Seong H. Kim
Four commercial glass compositions were investigated to understand their mechanisms of alteration in light of the current and future regulations on food contact materials. Lead crystal (fine glassware), soda-lime (food and cosmetic containers), borosilicate (cookware) and barium glass (tableware) powders and slabs were altered for 3 years, in acetic acid (4% vol) at pH = 2.4 and 70 °C. The leaching solution was analyzed by ICP-AES while glass slabs were investigated by ToF-SIMS and Spectroscopic Ellipsometry. As a result, in acidic medium, the polymerization of the silicate network as well as the glass composition impacted the alteration rates and depleted depths of alkalis and earth-alkalis elements. Yet the rate of hydrolysis measured from the release of Si, remained similar under identical alteration conditions, whatever the glass structure and composition. For lead crystal glass, repolymerization of the silicate network was observed in the course of alteration.
{"title":"Comparative study of the structure and durability of commercial silicate glasses for food consumption and cosmetic packaging","authors":"Léa Brunswic, Frédéric Angeli, Thibault Charpentier, Stéphane Gin, Pierre Asplanato, Huseyin Kaya, Seong H. Kim","doi":"10.1038/s41529-024-00502-5","DOIUrl":"10.1038/s41529-024-00502-5","url":null,"abstract":"Four commercial glass compositions were investigated to understand their mechanisms of alteration in light of the current and future regulations on food contact materials. Lead crystal (fine glassware), soda-lime (food and cosmetic containers), borosilicate (cookware) and barium glass (tableware) powders and slabs were altered for 3 years, in acetic acid (4% vol) at pH = 2.4 and 70 °C. The leaching solution was analyzed by ICP-AES while glass slabs were investigated by ToF-SIMS and Spectroscopic Ellipsometry. As a result, in acidic medium, the polymerization of the silicate network as well as the glass composition impacted the alteration rates and depleted depths of alkalis and earth-alkalis elements. Yet the rate of hydrolysis measured from the release of Si, remained similar under identical alteration conditions, whatever the glass structure and composition. For lead crystal glass, repolymerization of the silicate network was observed in the course of alteration.","PeriodicalId":19270,"journal":{"name":"npj Materials Degradation","volume":" ","pages":"1-12"},"PeriodicalIF":6.6,"publicationDate":"2024-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41529-024-00502-5.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142002632","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 : 2024-08-14DOI: 10.1038/s41529-024-00501-6
Nicolas Pinochet, Lucie Pirot-Berson, Romain Couderc, Sandrine Therias
Encapsulation polymers in terrestrial solar modules degrade due to ultraviolet radiation from the sun. To assess a polymer’s durability under UV light, accelerated aging tests can be conducted. A new LEDs device allows us to investigate the effects of temperature, irradiation, and UV source spectrum on the photooxidation mechanism and kinetics of two polyethylene-based commercial encapsulants, differentiated by the presence or absence of UV absorbers. The photooxidation rate of the polymer matrix increases as the temperature and irradiance increase between 62 and 82 °C, and 12 and 28 W.m−2, respectively. In the last case, the photooxidation rate is not proportional to the number of photons. Finally, we observed different distributions of degradation products under UVB radiation at 305 nm compared to those under UVA radiation at 365 nm. UVB photons enable Norrish reactions that are not possible with UVA alone. Special care is needed to maintain a balance between UVA and UVB photons to ensure representative durability tests. With a few adjustments to their emission spectrum, UV LED devices appear to be good candidates for accelerated aging of encapsulation polymers.
{"title":"UV LED ageing of polymers for PV cell encapsulation","authors":"Nicolas Pinochet, Lucie Pirot-Berson, Romain Couderc, Sandrine Therias","doi":"10.1038/s41529-024-00501-6","DOIUrl":"10.1038/s41529-024-00501-6","url":null,"abstract":"Encapsulation polymers in terrestrial solar modules degrade due to ultraviolet radiation from the sun. To assess a polymer’s durability under UV light, accelerated aging tests can be conducted. A new LEDs device allows us to investigate the effects of temperature, irradiation, and UV source spectrum on the photooxidation mechanism and kinetics of two polyethylene-based commercial encapsulants, differentiated by the presence or absence of UV absorbers. The photooxidation rate of the polymer matrix increases as the temperature and irradiance increase between 62 and 82 °C, and 12 and 28 W.m−2, respectively. In the last case, the photooxidation rate is not proportional to the number of photons. Finally, we observed different distributions of degradation products under UVB radiation at 305 nm compared to those under UVA radiation at 365 nm. UVB photons enable Norrish reactions that are not possible with UVA alone. Special care is needed to maintain a balance between UVA and UVB photons to ensure representative durability tests. With a few adjustments to their emission spectrum, UV LED devices appear to be good candidates for accelerated aging of encapsulation polymers.","PeriodicalId":19270,"journal":{"name":"npj Materials Degradation","volume":" ","pages":"1-8"},"PeriodicalIF":6.6,"publicationDate":"2024-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41529-024-00501-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141986147","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 : 2024-08-07DOI: 10.1038/s41529-024-00497-z
Nakkyu Chae, Seungjin Seo, Richard I. Foster, Sungyeol Choi
The durability of copper (Cu) canisters against corrosion is critical for the licensing of deep geological repositories. Assessing oxic corrosion, a primary degradation mechanism, is essential for ensuring the reliability of such repositories. Due to the complex interactions influencing oxic corrosion, a comprehensive model is necessary for evaluating Cu canister corrosion. This study develops a model for the KAERI Reference Disposal System (KRS), incorporating mixed-potential theory with key O2 consumption reactions, including Cu corrosion, Cu(I) oxidation, FeS2 oxidation, aerobic microbial activity, and O2 dissolution and consumption. Simulation of 11 scenarios revealed that the representative KRS case would experience a maximum corrosion depth of 9.3 μm on the Cu canister after 2.3 years due to oxic corrosion, under conditions that are unfavorable for the initiation of pitting corrosion. These results suggest that oxic corrosion is not a threat to the isolation of spent nuclear fuels in KRS.
{"title":"Oxic corrosion model for KAERI Reference disposal system via O2 consumption reactions and mixed-potential theory","authors":"Nakkyu Chae, Seungjin Seo, Richard I. Foster, Sungyeol Choi","doi":"10.1038/s41529-024-00497-z","DOIUrl":"10.1038/s41529-024-00497-z","url":null,"abstract":"The durability of copper (Cu) canisters against corrosion is critical for the licensing of deep geological repositories. Assessing oxic corrosion, a primary degradation mechanism, is essential for ensuring the reliability of such repositories. Due to the complex interactions influencing oxic corrosion, a comprehensive model is necessary for evaluating Cu canister corrosion. This study develops a model for the KAERI Reference Disposal System (KRS), incorporating mixed-potential theory with key O2 consumption reactions, including Cu corrosion, Cu(I) oxidation, FeS2 oxidation, aerobic microbial activity, and O2 dissolution and consumption. Simulation of 11 scenarios revealed that the representative KRS case would experience a maximum corrosion depth of 9.3 μm on the Cu canister after 2.3 years due to oxic corrosion, under conditions that are unfavorable for the initiation of pitting corrosion. These results suggest that oxic corrosion is not a threat to the isolation of spent nuclear fuels in KRS.","PeriodicalId":19270,"journal":{"name":"npj Materials Degradation","volume":" ","pages":"1-12"},"PeriodicalIF":6.6,"publicationDate":"2024-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41529-024-00497-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141939484","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 : 2024-08-05DOI: 10.1038/s41529-024-00498-y
D. C. Williams, A. Riahi, A. Carcea, J. D. Giallonardo, P. Keech, S. Y. Persaud, M. R. Daymond, R. C. Newman
Slow strain rate tensile testing was conducted on electrodeposited copper, which is a candidate coating material for used nuclear fuel containers. Embrittlement was observed in electrodeposited copper containing 26.4 ± 1.0 ppm hydrogen, with a strain rate sensitivity such that the embrittlement was exacerbated at lower strain rate (5 × 10−7 s−1). Tensile tests conducted at 100° and 200 °C also intensified embrittlement when compared with tests conducted at room temperature. In contrast, electrodeposited copper containing only 5.25 ± 0.97 ppm hydrogen exhibited ductile behavior at all tested strain rates and temperatures. These findings suggest that a previously unexplained slow strain rate hydrogen embrittlement can operate in electrodeposited copper provided that the hydrogen concentration is sufficiently high. Further analyses revealed that the deformation of embrittled copper is achieved by the formation of internal microcracks which coalesce at the point of failure.
{"title":"Hydrogen embrittlement and strain rate sensitivity of electrodeposited copper: part I – the effect of hydrogen content","authors":"D. C. Williams, A. Riahi, A. Carcea, J. D. Giallonardo, P. Keech, S. Y. Persaud, M. R. Daymond, R. C. Newman","doi":"10.1038/s41529-024-00498-y","DOIUrl":"10.1038/s41529-024-00498-y","url":null,"abstract":"Slow strain rate tensile testing was conducted on electrodeposited copper, which is a candidate coating material for used nuclear fuel containers. Embrittlement was observed in electrodeposited copper containing 26.4 ± 1.0 ppm hydrogen, with a strain rate sensitivity such that the embrittlement was exacerbated at lower strain rate (5 × 10−7 s−1). Tensile tests conducted at 100° and 200 °C also intensified embrittlement when compared with tests conducted at room temperature. In contrast, electrodeposited copper containing only 5.25 ± 0.97 ppm hydrogen exhibited ductile behavior at all tested strain rates and temperatures. These findings suggest that a previously unexplained slow strain rate hydrogen embrittlement can operate in electrodeposited copper provided that the hydrogen concentration is sufficiently high. Further analyses revealed that the deformation of embrittled copper is achieved by the formation of internal microcracks which coalesce at the point of failure.","PeriodicalId":19270,"journal":{"name":"npj Materials Degradation","volume":" ","pages":"1-9"},"PeriodicalIF":6.6,"publicationDate":"2024-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41529-024-00498-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141939417","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 : 2024-07-29DOI: 10.1038/s41529-024-00494-2
A. D. Malla, J. H. Sullivan, D. J. Penney, M. Goldsworthy, D. Britton, G. Williams, F. Goodwin, A. P. Cardoso
Time-lapse Microscopy, scanning vibrating electrode technique and potentiodynamic methods were used to study the influence of increasing coating weight (80–310 gm–2) on microstructure, cut-edge and surface corrosion of Zn-Mg-Al coatings in 0.17 M NaCl. Cut-edge corrosion was similar for all coatings due to the oxygen reduction reaction becoming diffusion-limited. A 64% reduction in surface corrosion was observed for high coating weights through increases in eutectic volume fraction. Spatial and temporal corrosion mechanisms were controlled by microstructural morphological differences as coating weight varied. 80 g.m–2 coatings demonstrated lateral anodic spreading potentially reducing coating penetration rates despite their higher surface corrosion rate.
{"title":"Mechanistic investigation on the influence of coating weights on the corrosion behaviour of hot-dip-galvanised Zn-Mg-Al coatings","authors":"A. D. Malla, J. H. Sullivan, D. J. Penney, M. Goldsworthy, D. Britton, G. Williams, F. Goodwin, A. P. Cardoso","doi":"10.1038/s41529-024-00494-2","DOIUrl":"10.1038/s41529-024-00494-2","url":null,"abstract":"Time-lapse Microscopy, scanning vibrating electrode technique and potentiodynamic methods were used to study the influence of increasing coating weight (80–310 gm–2) on microstructure, cut-edge and surface corrosion of Zn-Mg-Al coatings in 0.17 M NaCl. Cut-edge corrosion was similar for all coatings due to the oxygen reduction reaction becoming diffusion-limited. A 64% reduction in surface corrosion was observed for high coating weights through increases in eutectic volume fraction. Spatial and temporal corrosion mechanisms were controlled by microstructural morphological differences as coating weight varied. 80 g.m–2 coatings demonstrated lateral anodic spreading potentially reducing coating penetration rates despite their higher surface corrosion rate.","PeriodicalId":19270,"journal":{"name":"npj Materials Degradation","volume":" ","pages":"1-14"},"PeriodicalIF":6.6,"publicationDate":"2024-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41529-024-00494-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141871726","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 : 2024-07-24DOI: 10.1038/s41529-024-00495-1
Xinpeng Zhao, Haiyou Huang, Yanjing Su, Lijie Qiao, Yu Yan
Refractory high-entropy alloys (HEAs) have attracted considerable attention due to their stable phase structure and excellent high-temperature properties. In this work, we performed first-principles calculations, coupled with experiments, to explore HEAs with high corrosion resistance. The results revealed that TiNbTa-based HEAs exhibited a lower tendency for corrosion. However, the appearance of local chemical fluctuations (LCFs) increased the corrosion tendency of TiNbTa-based HEAs. Comprehensive SHapley Additive exPlanations analyses uncovered that in a sample with configurational LCFs, the atomic order near the surface was altered. Therefore, corrosion behavior was affected. Based on experiments, the annealed samples exhibited typical chemical segregation and declined corrosion resistance.
{"title":"Exploring high corrosion-resistant refractory high-entropy alloy via a combined experimental and simulation study","authors":"Xinpeng Zhao, Haiyou Huang, Yanjing Su, Lijie Qiao, Yu Yan","doi":"10.1038/s41529-024-00495-1","DOIUrl":"10.1038/s41529-024-00495-1","url":null,"abstract":"Refractory high-entropy alloys (HEAs) have attracted considerable attention due to their stable phase structure and excellent high-temperature properties. In this work, we performed first-principles calculations, coupled with experiments, to explore HEAs with high corrosion resistance. The results revealed that TiNbTa-based HEAs exhibited a lower tendency for corrosion. However, the appearance of local chemical fluctuations (LCFs) increased the corrosion tendency of TiNbTa-based HEAs. Comprehensive SHapley Additive exPlanations analyses uncovered that in a sample with configurational LCFs, the atomic order near the surface was altered. Therefore, corrosion behavior was affected. Based on experiments, the annealed samples exhibited typical chemical segregation and declined corrosion resistance.","PeriodicalId":19270,"journal":{"name":"npj Materials Degradation","volume":" ","pages":"1-11"},"PeriodicalIF":6.6,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41529-024-00495-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141770823","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 : 2024-07-22DOI: 10.1038/s41529-024-00493-3
Zeyun Zeng, Shangjun Gu, Jie Wang, Fulong Wei, Zhiying Li, Hui Yang, Changrong Li
In this study, the immersion test, surface analysis, cross-section analysis, quantitative analysis and electrochemical analysis were used to study the influence of Nb/V on the corrosion behavior of high-strength anti-seismic rebar in marine environments. The corrosion results clarified that the addition of Nb/V improved the corrosion resistance of the rebar, thereby reducing the corrosion rate of the rebar and improving the stability of corrosion layers. Firstly, the addition of Nb/V promoted the transformation of unstable Fe oxyhydroxides to stable Fe oxyhydroxides in the surface corrosion layers of the rebar, thus increasing the α/(β + γ) ratio, corrosion potential and total impedance value. Secondly, the addition of Nb/V induced the formation of Nb oxides and V oxides in the surface corrosion layers of the rebar, and the existence of these oxides repaired the surface defects of corrosion layers, thus enhancing the corrosion resistance performance of surface corrosion layers of the rebar.
本研究采用浸泡试验、表面分析、截面分析、定量分析和电化学分析等方法，研究了 Nb/V 对海洋环境中高强度抗震钢筋腐蚀行为的影响。腐蚀结果表明，添加 Nb/V 提高了螺纹钢的耐腐蚀性，从而降低了螺纹钢的腐蚀速率，提高了腐蚀层的稳定性。首先，Nb/V 的添加促进了钢筋表面腐蚀层中不稳定的铁氧氢氧化物向稳定的铁氧氢氧化物转化，从而提高了 α/（β + γ）比值、腐蚀电位和总阻抗值。其次，Nb/V 的加入诱导了钢筋表面腐蚀层中 Nb 氧化物和 V 氧化物的形成，这些氧化物的存在修复了腐蚀层的表面缺陷，从而提高了钢筋表面腐蚀层的耐腐蚀性能。
{"title":"Influence of Nb/V on the corrosion behavior of high-strength anti-seismic rebar in marine environments","authors":"Zeyun Zeng, Shangjun Gu, Jie Wang, Fulong Wei, Zhiying Li, Hui Yang, Changrong Li","doi":"10.1038/s41529-024-00493-3","DOIUrl":"10.1038/s41529-024-00493-3","url":null,"abstract":"In this study, the immersion test, surface analysis, cross-section analysis, quantitative analysis and electrochemical analysis were used to study the influence of Nb/V on the corrosion behavior of high-strength anti-seismic rebar in marine environments. The corrosion results clarified that the addition of Nb/V improved the corrosion resistance of the rebar, thereby reducing the corrosion rate of the rebar and improving the stability of corrosion layers. Firstly, the addition of Nb/V promoted the transformation of unstable Fe oxyhydroxides to stable Fe oxyhydroxides in the surface corrosion layers of the rebar, thus increasing the α/(β + γ) ratio, corrosion potential and total impedance value. Secondly, the addition of Nb/V induced the formation of Nb oxides and V oxides in the surface corrosion layers of the rebar, and the existence of these oxides repaired the surface defects of corrosion layers, thus enhancing the corrosion resistance performance of surface corrosion layers of the rebar.","PeriodicalId":19270,"journal":{"name":"npj Materials Degradation","volume":" ","pages":"1-20"},"PeriodicalIF":6.6,"publicationDate":"2024-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41529-024-00493-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141770824","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 : 2024-07-17DOI: 10.1038/s41529-024-00488-0
Sylvain Grangeon, Mathieu Debure, Valerie Montouillout, Erik Elkaim, Catherine Lerouge, Nicolas Maubec, Nicolas Michau, Xavier Bourbon, Christelle Martin, Benoit Cochepin, Nicolas Marty
In the present study, the chemical composition, mineralogy, and mechanisms of alteration of a cementitious grout based on a CEM III/C with addition of smectite, hydrotalcite, and silica fume, are studied using a combination of chemical and physical methods. This material was designed in the context of geological repository of radioactive wastes, with a twofold aim: first, to fill the technical voids left by drilling operations at the interface between the geological formation and the disposal galleries. Second, to neutralize a potential acidic transient due to pyrite oxidation, and to create an environment that favors low corrosion rates of carbon steels. The grout is mainly composed of calcium silicate hydrates having a Ca/Si ratio of ~0.8, incorporating Al in the bridging site of the Si chains (C-A-S-H), and accounting for 29–36 wt.% of the sample. It also contains silica fume (38–48 wt.%), smectite with interlayer Na (11–17 wt.%), hydrotalcite with interlayer CO32− (3–4 wt.%), and lower amounts of portlandite, calcite, and possibly gibbsite and gypsum. Upon alteration by water in a flow-through reactor, the main modifications affecting the sample are calcite and gypsum dissolution, hence releasing aqueous Ca2+ that is adsorbed in smectite interlayer by replacing Na+, and stoichiometric C-A-S-H dissolution. The evolution of solution chemistry and of the solid phase composition are reproduced successfully using a thermokinetic model.
本研究采用化学和物理相结合的方法，研究了基于 CEM III/C 的水泥基灌浆料的化学成分、矿物学和变化机理，并添加了埃克石、水滑石和硅灰。这种材料是在放射性废物地质处置库的背景下设计的，有两个目的：第一，填补地质构造和处置廊道之间的界面上钻孔作业留下的技术空隙。其次，中和黄铁矿氧化可能产生的瞬时酸性，并创造有利于降低碳钢腐蚀率的环境。灌浆料主要由硅酸钙水合物组成，Ca/Si 比约为 0.8，在硅链（C-A-S-H）的桥接部位含有 Al，占样品的 29-36%。它还含有硅灰（38-48 重量%）、含层间 Na 的闪长岩（11-17 重量%）、含层间 CO32- 的水滑石（3-4 重量%），以及较少量的波长岩、方解石，可能还有辉绿岩和石膏。水在流动反应器中改变样品时，影响样品的主要变化是方解石和石膏的溶解，从而释放出水溶液中的 Ca2+，Ca2+通过取代 Na+吸附在辉绿岩夹层中，以及化学计量的 C-A-S-H 溶解。利用热动力学模型成功地再现了溶液化学和固相组成的演变过程。
{"title":"Mineralogical and geochemical composition of a cementitious grout and its evolution during interaction with water","authors":"Sylvain Grangeon, Mathieu Debure, Valerie Montouillout, Erik Elkaim, Catherine Lerouge, Nicolas Maubec, Nicolas Michau, Xavier Bourbon, Christelle Martin, Benoit Cochepin, Nicolas Marty","doi":"10.1038/s41529-024-00488-0","DOIUrl":"10.1038/s41529-024-00488-0","url":null,"abstract":"In the present study, the chemical composition, mineralogy, and mechanisms of alteration of a cementitious grout based on a CEM III/C with addition of smectite, hydrotalcite, and silica fume, are studied using a combination of chemical and physical methods. This material was designed in the context of geological repository of radioactive wastes, with a twofold aim: first, to fill the technical voids left by drilling operations at the interface between the geological formation and the disposal galleries. Second, to neutralize a potential acidic transient due to pyrite oxidation, and to create an environment that favors low corrosion rates of carbon steels. The grout is mainly composed of calcium silicate hydrates having a Ca/Si ratio of ~0.8, incorporating Al in the bridging site of the Si chains (C-A-S-H), and accounting for 29–36 wt.% of the sample. It also contains silica fume (38–48 wt.%), smectite with interlayer Na (11–17 wt.%), hydrotalcite with interlayer CO32− (3–4 wt.%), and lower amounts of portlandite, calcite, and possibly gibbsite and gypsum. Upon alteration by water in a flow-through reactor, the main modifications affecting the sample are calcite and gypsum dissolution, hence releasing aqueous Ca2+ that is adsorbed in smectite interlayer by replacing Na+, and stoichiometric C-A-S-H dissolution. The evolution of solution chemistry and of the solid phase composition are reproduced successfully using a thermokinetic model.","PeriodicalId":19270,"journal":{"name":"npj Materials Degradation","volume":" ","pages":"1-11"},"PeriodicalIF":6.6,"publicationDate":"2024-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41529-024-00488-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141730367","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 : 2024-07-16DOI: 10.1038/s41529-024-00486-2
Dong Zhao, Heng Ban, Kun Yang, Andre Broussard, Mingxin Li, Edward J. Lahoda, Jie Lian
Microstructure and Cr2O3 doping profoundly impact the thermal-mechanical properties and fracture of oxides fuels. It is a challenge to study the transient behavior of nuclear fuels under loss-of-coolant-event (LOCA). In this study, the crack behavior of UO2 pellets with controlled grain structure and Cr2O3 doping was tested with rapid power ramping (300−900 °C per min) mimicking a prototypical LOCA heating profile. Dense micron-sized UO2 pellets display well-maintained integrity without cracking with the ramping up to 1500 °C at a heating rate of 8 °C per second. Fracture occurs in both pure and Cr2O3-doped dense nano-sized UO2 pellets. The Cr2O3 doped oxide fuel pellet with a larger grain size (~ 22.2 μm) displays the best performance under LOCA testing due to its highest thermal conductivity under high temperature. FEA calculations suggest a temperature gradient across the fuel pellet during transient testing, resulting in residual stress and cracking, which can be correlated with their thermal-mechanical properties.
{"title":"Transient behavior of oxide fuels with controlled microstructure and Cr2O3 additive","authors":"Dong Zhao, Heng Ban, Kun Yang, Andre Broussard, Mingxin Li, Edward J. Lahoda, Jie Lian","doi":"10.1038/s41529-024-00486-2","DOIUrl":"10.1038/s41529-024-00486-2","url":null,"abstract":"Microstructure and Cr2O3 doping profoundly impact the thermal-mechanical properties and fracture of oxides fuels. It is a challenge to study the transient behavior of nuclear fuels under loss-of-coolant-event (LOCA). In this study, the crack behavior of UO2 pellets with controlled grain structure and Cr2O3 doping was tested with rapid power ramping (300−900 °C per min) mimicking a prototypical LOCA heating profile. Dense micron-sized UO2 pellets display well-maintained integrity without cracking with the ramping up to 1500 °C at a heating rate of 8 °C per second. Fracture occurs in both pure and Cr2O3-doped dense nano-sized UO2 pellets. The Cr2O3 doped oxide fuel pellet with a larger grain size (~ 22.2 μm) displays the best performance under LOCA testing due to its highest thermal conductivity under high temperature. FEA calculations suggest a temperature gradient across the fuel pellet during transient testing, resulting in residual stress and cracking, which can be correlated with their thermal-mechanical properties.","PeriodicalId":19270,"journal":{"name":"npj Materials Degradation","volume":" ","pages":"1-11"},"PeriodicalIF":6.6,"publicationDate":"2024-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41529-024-00486-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141631245","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}
This paper provides a study for crystallographic orientation-dependent corrosion rate of aluminum employing an ab initio model with inputs from first-principles calculations. Results showed that the sequence of corrosion rate is in the order of (111) < (410) < (331) < (221) < (321) < (211) < (110) < (100) < (210) < (320) < (310) < (311) for aluminum. The predicted corrosion current densities for (111), (110), and (100) surfaces are in general agreement with the experimental results. The alloying effects were further investigated employing this model with results validated via the polarization curves of alloyed aluminum.
{"title":"Study on the crystallographic orientation dependent electrochemical corrosion rates of aluminum and its binary alloys","authors":"Haini Jin, Yudong Sui, Xiaohua Yu, Hao Zhou, Jing Feng, Yehua Jiang","doi":"10.1038/s41529-024-00490-6","DOIUrl":"10.1038/s41529-024-00490-6","url":null,"abstract":"This paper provides a study for crystallographic orientation-dependent corrosion rate of aluminum employing an ab initio model with inputs from first-principles calculations. Results showed that the sequence of corrosion rate is in the order of (111) < (410) < (331) < (221) < (321) < (211) < (110) < (100) < (210) < (320) < (310) < (311) for aluminum. The predicted corrosion current densities for (111), (110), and (100) surfaces are in general agreement with the experimental results. The alloying effects were further investigated employing this model with results validated via the polarization curves of alloyed aluminum.","PeriodicalId":19270,"journal":{"name":"npj Materials Degradation","volume":" ","pages":"1-11"},"PeriodicalIF":6.6,"publicationDate":"2024-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41529-024-00490-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141631257","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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