Pub Date : 2024-11-01DOI: 10.1038/s41529-024-00530-1
Brandon Free, Gabriella C. Montiel, Gabriella A. Marino, Eric Schindelholz, Sarah Galyon Dorman, Jenifer S. Warner Locke
Corrosion fatigue (CF) crack growth is quantified as a function of relative humidity (RH) using AA7085-T7451 samples with NaCl deposited to understand the effect of deliquesced surface electrolyte droplets on CF performance when humidity varies. Fracture mechanics testing holding mechanical driving forces for cracking constant and incrementally increasing humidity show that crack growth rate (da/dN) more than doubles once RH moves above 78–80% RH. When decreasing RH, some amount of drying below the efflorescence RH (ERH) and/or a sufficient time is needed to pass in order for da/dN to return to that expected for a dry crack tip. All in all, this study establishes time of crack tip wetness as an important parameter for predicting fatigue lifetimes in atmospheric conditions, a parameter that cannot be solely predicted by RH, as accelerated cracking can continue for a limited amount of time even when RH is brought below the ERH.
{"title":"The effect of variable humidity on corrosion fatigue of AA7085-T7451 with surface salt deposits","authors":"Brandon Free, Gabriella C. Montiel, Gabriella A. Marino, Eric Schindelholz, Sarah Galyon Dorman, Jenifer S. Warner Locke","doi":"10.1038/s41529-024-00530-1","DOIUrl":"10.1038/s41529-024-00530-1","url":null,"abstract":"Corrosion fatigue (CF) crack growth is quantified as a function of relative humidity (RH) using AA7085-T7451 samples with NaCl deposited to understand the effect of deliquesced surface electrolyte droplets on CF performance when humidity varies. Fracture mechanics testing holding mechanical driving forces for cracking constant and incrementally increasing humidity show that crack growth rate (da/dN) more than doubles once RH moves above 78–80% RH. When decreasing RH, some amount of drying below the efflorescence RH (ERH) and/or a sufficient time is needed to pass in order for da/dN to return to that expected for a dry crack tip. All in all, this study establishes time of crack tip wetness as an important parameter for predicting fatigue lifetimes in atmospheric conditions, a parameter that cannot be solely predicted by RH, as accelerated cracking can continue for a limited amount of time even when RH is brought below the ERH.","PeriodicalId":19270,"journal":{"name":"npj Materials Degradation","volume":" ","pages":"1-12"},"PeriodicalIF":6.6,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41529-024-00530-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142574273","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 : 2024-11-01DOI: 10.1038/s41529-024-00523-0
Deni Jero, Nicolas Caussé, Nadine Pébère
This review summarizes the use of film-forming amines (FFAs) for corrosion protection in water/steam industrial circuits, focusing on carbon steel. It discusses industrial feedback on FFAs’ benefits and challenges, alongside experimental methods for studying their inhibition and structural properties. Key research areas include FFAs’ corrosion inhibition mechanisms, adsorption kinetics, and layer structures. The review also identifies knowledge gaps and suggests future research directions to deepen the understanding of FFAs.
{"title":"Film-forming amines as corrosion inhibitors: a state-of-the-art review","authors":"Deni Jero, Nicolas Caussé, Nadine Pébère","doi":"10.1038/s41529-024-00523-0","DOIUrl":"10.1038/s41529-024-00523-0","url":null,"abstract":"This review summarizes the use of film-forming amines (FFAs) for corrosion protection in water/steam industrial circuits, focusing on carbon steel. It discusses industrial feedback on FFAs’ benefits and challenges, alongside experimental methods for studying their inhibition and structural properties. Key research areas include FFAs’ corrosion inhibition mechanisms, adsorption kinetics, and layer structures. The review also identifies knowledge gaps and suggests future research directions to deepen the understanding of FFAs.","PeriodicalId":19270,"journal":{"name":"npj Materials Degradation","volume":" ","pages":"1-12"},"PeriodicalIF":6.6,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41529-024-00523-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142574246","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 research investigates a specific type of irregularly shaped inclusions in steel, which are typically considered detrimental. A comparative study of two steels, treated with different inclusion modification methods by oxide metallurgy technology, reveals that spherical inclusions with complex structures can provide beneficial multipoint trap sites for hydrogen, thereby reducing the risk of hydrogen-induced cracking (HIC). Notably, irregular stripe-shaped silicate-oxide inclusions with sharp tips, due to their hot-soft characteristics during the process of hot-rolling, do not exacerbate cracks but instead mitigate local stresses. Conversely, large single-phase hard inclusions are detrimental to HIC resistance. This investigation provides insights into the mechanisms behind why certain irregular inclusions do not trigger HIC crack after the NACE TM 0284-2016 standard test.
这项研究调查了钢中一种特殊的不规则夹杂物,这种夹杂物通常被认为是有害的。通过对采用氧化物冶金技术的不同夹杂物改性方法处理的两种钢材进行比较研究,发现具有复杂结构的球形夹杂物可以为氢提供有益的多点捕集点,从而降低氢致开裂(HIC)的风险。值得注意的是,具有尖锐尖端的不规则条纹状氧化硅夹杂物由于在热轧过程中具有热软特性,不仅不会加剧裂纹,反而会减轻局部应力。相反,大的单相硬夹杂物不利于抗 HIC 性能。这项调查有助于深入了解某些不规则夹杂物在经过 NACE TM 0284-2016 标准测试后不会引发 HIC 裂纹的机制。
{"title":"Unveiling the mechanism behind irregular inclusions triggering no HIC cracks in steels","authors":"Rongzhe Hu, Zhixian Peng, Shiqi Zhang, Liquan Ding, Feng Huang, Zhengliang Xue, Jing Liu","doi":"10.1038/s41529-024-00525-y","DOIUrl":"10.1038/s41529-024-00525-y","url":null,"abstract":"This research investigates a specific type of irregularly shaped inclusions in steel, which are typically considered detrimental. A comparative study of two steels, treated with different inclusion modification methods by oxide metallurgy technology, reveals that spherical inclusions with complex structures can provide beneficial multipoint trap sites for hydrogen, thereby reducing the risk of hydrogen-induced cracking (HIC). Notably, irregular stripe-shaped silicate-oxide inclusions with sharp tips, due to their hot-soft characteristics during the process of hot-rolling, do not exacerbate cracks but instead mitigate local stresses. Conversely, large single-phase hard inclusions are detrimental to HIC resistance. This investigation provides insights into the mechanisms behind why certain irregular inclusions do not trigger HIC crack after the NACE TM 0284-2016 standard test.","PeriodicalId":19270,"journal":{"name":"npj Materials Degradation","volume":" ","pages":"1-15"},"PeriodicalIF":6.6,"publicationDate":"2024-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41529-024-00525-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142574201","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 : 2024-10-30DOI: 10.1038/s41529-024-00529-8
Yang Hu, Kai Wang, Robert Spatschek
We propose a data-driven strategy for parameter selection in phase field nucleation models using machine learning and apply it to oxide nucleation in Fe-Cr alloys. A grand potential-based phase field model, incorporating Langevin noise, is employed to simulate oxide nucleation and benchmarked against the Johnson-Mehl-Avrami-Kolmogorov model. Three independent parameters in the phase field simulations (Langevin noise strength, numerical grid discretization and critical nucleation radius) are identified as essential for accurately modeling the nucleation behavior. These parameters serve as input features for machine learning classification and regression models. The classification model categorizes nucleation behavior into three nucleation density regimes, preventing invalid nucleation attempts in simulations, while the regression model estimates the appropriate Langevin noise strength, significantly reducing the need for time-consuming trial-and-error simulations. This data-driven approach improves the efficiency of parameter selection in phase field models and provides a generalizable method for simulating nucleation-driven microstructural evolution processes in various materials.
{"title":"A data-driven strategy for phase field nucleation modeling","authors":"Yang Hu, Kai Wang, Robert Spatschek","doi":"10.1038/s41529-024-00529-8","DOIUrl":"10.1038/s41529-024-00529-8","url":null,"abstract":"We propose a data-driven strategy for parameter selection in phase field nucleation models using machine learning and apply it to oxide nucleation in Fe-Cr alloys. A grand potential-based phase field model, incorporating Langevin noise, is employed to simulate oxide nucleation and benchmarked against the Johnson-Mehl-Avrami-Kolmogorov model. Three independent parameters in the phase field simulations (Langevin noise strength, numerical grid discretization and critical nucleation radius) are identified as essential for accurately modeling the nucleation behavior. These parameters serve as input features for machine learning classification and regression models. The classification model categorizes nucleation behavior into three nucleation density regimes, preventing invalid nucleation attempts in simulations, while the regression model estimates the appropriate Langevin noise strength, significantly reducing the need for time-consuming trial-and-error simulations. This data-driven approach improves the efficiency of parameter selection in phase field models and provides a generalizable method for simulating nucleation-driven microstructural evolution processes in various materials.","PeriodicalId":19270,"journal":{"name":"npj Materials Degradation","volume":" ","pages":"1-11"},"PeriodicalIF":6.6,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41529-024-00529-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142555537","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 : 2024-10-26DOI: 10.1038/s41529-024-00526-x
L. Brunswic, F. Angeli, S. Gin, E. D. van Hullebusch, M. Tarrago, L. Gautron, D. R. Neuville
Glass durability is one of the properties that can be affected by surface treatments such as coatings or chemical attacks. These treatments can be used to reduce the quantities of potentially toxic elements contained in glass that may be released in solution. Five surface treatments were selected: three different coatings (SnO2, TiO2, SiO2) and two acidic attacks (SO2 dealkalization and acid polishing). These treatments were performed on five glass compositions (soda-lime, borosilicate, barium silicate, opal, and lead crystal). Their effects on alteration rates and mechanisms were investigated through a single protocol (acetic acid 4%, 70 °C) simulating accelerated aging conditions for containers of beverages or food. The data collected over 1.3 years showed significant reduction of lead leaching with all treatments except acid polishing. The best reduction factor was obtained with SO2 dealkalization, which also demonstrated beneficial effects towards the retention of Ba by reducing the diffusion of alkalis.
{"title":"Surface treatments on commercial glasses: durable impact on the retention of lead, barium and boron","authors":"L. Brunswic, F. Angeli, S. Gin, E. D. van Hullebusch, M. Tarrago, L. Gautron, D. R. Neuville","doi":"10.1038/s41529-024-00526-x","DOIUrl":"10.1038/s41529-024-00526-x","url":null,"abstract":"Glass durability is one of the properties that can be affected by surface treatments such as coatings or chemical attacks. These treatments can be used to reduce the quantities of potentially toxic elements contained in glass that may be released in solution. Five surface treatments were selected: three different coatings (SnO2, TiO2, SiO2) and two acidic attacks (SO2 dealkalization and acid polishing). These treatments were performed on five glass compositions (soda-lime, borosilicate, barium silicate, opal, and lead crystal). Their effects on alteration rates and mechanisms were investigated through a single protocol (acetic acid 4%, 70 °C) simulating accelerated aging conditions for containers of beverages or food. The data collected over 1.3 years showed significant reduction of lead leaching with all treatments except acid polishing. The best reduction factor was obtained with SO2 dealkalization, which also demonstrated beneficial effects towards the retention of Ba by reducing the diffusion of alkalis.","PeriodicalId":19270,"journal":{"name":"npj Materials Degradation","volume":" ","pages":"1-12"},"PeriodicalIF":6.6,"publicationDate":"2024-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41529-024-00526-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142519205","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 : 2024-10-21DOI: 10.1038/s41529-024-00527-w
Long Jin, Kun Zhang, Ming-Liang Zhu, Fu-Zhen Xuan
The low alloy bainitic steel used in reactor pressure vessels deteriorates during thermal service while the macroscopic thermodynamic parameters that cause thermal aging remains unknown. In this work, a thermal aging restructuring scheme was proposed by step-up aging the steel from 350 °C to 490 °C, with a total duration of 7500 hours. Samples from varied thickness of the steel were characterized in terms of carbides evolution and Charpy impact toughness at 20 °C. The carbide size and its fraction were statistically analyzed showing partial coarsening and dissolution during aging, while the carbide fraction was found linearly correlated with the impact energy for the first time. The critical transition temperature parameter of the aging process was found to be 470 °C for the steel. The macroscopic thermodynamic parameters, including the thermal aging time and temperature, facilitate a comprehensive understanding of the material degradation mechanism and provide a basis for long-term safety of equipment.
反应堆压力容器中使用的低合金贝氏体钢在热使用过程中会发生劣化,而导致热老化的宏观热力学参数仍然未知。在这项工作中,提出了一种热老化重组方案,将钢材从 350 °C 逐步老化到 490 °C,总持续时间为 7500 小时。对不同厚度的钢材样品进行了碳化物演变和 20 °C 时夏比冲击韧性的表征。对碳化物尺寸及其组分进行了统计分析,结果表明碳化物在时效过程中发生了部分粗化和溶解,同时首次发现碳化物组分与冲击能量呈线性相关。发现该钢的时效过程临界转变温度参数为 470 ℃。包括热老化时间和温度在内的宏观热力学参数有助于全面了解材料的降解机理,为设备的长期安全提供依据。
{"title":"Evolution of carbides and Charpy toughness in a low alloy bainitic steel during step-up aging process","authors":"Long Jin, Kun Zhang, Ming-Liang Zhu, Fu-Zhen Xuan","doi":"10.1038/s41529-024-00527-w","DOIUrl":"10.1038/s41529-024-00527-w","url":null,"abstract":"The low alloy bainitic steel used in reactor pressure vessels deteriorates during thermal service while the macroscopic thermodynamic parameters that cause thermal aging remains unknown. In this work, a thermal aging restructuring scheme was proposed by step-up aging the steel from 350 °C to 490 °C, with a total duration of 7500 hours. Samples from varied thickness of the steel were characterized in terms of carbides evolution and Charpy impact toughness at 20 °C. The carbide size and its fraction were statistically analyzed showing partial coarsening and dissolution during aging, while the carbide fraction was found linearly correlated with the impact energy for the first time. The critical transition temperature parameter of the aging process was found to be 470 °C for the steel. The macroscopic thermodynamic parameters, including the thermal aging time and temperature, facilitate a comprehensive understanding of the material degradation mechanism and provide a basis for long-term safety of equipment.","PeriodicalId":19270,"journal":{"name":"npj Materials Degradation","volume":" ","pages":"1-11"},"PeriodicalIF":6.6,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41529-024-00527-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142519183","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}
The durability of polymer electrolyte fuel cells (PEFCs) in fuel cell electric vehicles is important for the shift from passenger cars to heavy-duty vehicles. The components of a PEFC, namely the proton exchange membrane (PEM), catalyst layer (CL), and gas diffusion layer (GDL), contribute to the degradation of the fuel cell performance. In this paper, we propose a method for simultaneously evaluating the degradation rates of these components by combining electrochemical characterization with operando synchrotron X-ray radiography. The open-circuit voltage, electrochemically active surface area (ECSA), and water saturation were used as the degradation indicators for the PEMs, CLs, and GDLs, respectively. The results of two accelerated stress tests (loading and start-stop cycles) after 10,000 cycles showed that the increase in water saturation owing to the loss of hydrophobicity due to carbon corrosion in the cathode GDL occurred on the same timescale as the degradation in the PEM and cathode CL. Specifically, during the load cycle AST, the cathode CL degraded with a 26% reduction in the ECSA along with the cathode GDL degradation with a 10% increase in water saturation. This suggests that more efforts should be devoted to studies on the durability of GDLs for heavy-duty applications.
{"title":"Simultaneous accelerated stress testing of membrane electrode assembly components in polymer electrolyte fuel cells","authors":"Wataru Yoshimune, Akihiko Kato, Tetsuichiro Hayakawa, Satoshi Yamaguchi, Satoru Kato","doi":"10.1038/s41529-024-00524-z","DOIUrl":"10.1038/s41529-024-00524-z","url":null,"abstract":"The durability of polymer electrolyte fuel cells (PEFCs) in fuel cell electric vehicles is important for the shift from passenger cars to heavy-duty vehicles. The components of a PEFC, namely the proton exchange membrane (PEM), catalyst layer (CL), and gas diffusion layer (GDL), contribute to the degradation of the fuel cell performance. In this paper, we propose a method for simultaneously evaluating the degradation rates of these components by combining electrochemical characterization with operando synchrotron X-ray radiography. The open-circuit voltage, electrochemically active surface area (ECSA), and water saturation were used as the degradation indicators for the PEMs, CLs, and GDLs, respectively. The results of two accelerated stress tests (loading and start-stop cycles) after 10,000 cycles showed that the increase in water saturation owing to the loss of hydrophobicity due to carbon corrosion in the cathode GDL occurred on the same timescale as the degradation in the PEM and cathode CL. Specifically, during the load cycle AST, the cathode CL degraded with a 26% reduction in the ECSA along with the cathode GDL degradation with a 10% increase in water saturation. This suggests that more efforts should be devoted to studies on the durability of GDLs for heavy-duty applications.","PeriodicalId":19270,"journal":{"name":"npj Materials Degradation","volume":" ","pages":"1-9"},"PeriodicalIF":6.6,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41529-024-00524-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142439145","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 : 2024-10-11DOI: 10.1038/s41529-024-00522-1
Patricia Jovičević-Klug, J. Manoj Prabhakar, Cristiano Kasdorf Giesbrecht, Tim M. Schwarz, Carsten Bonnekoh, Michael Rieth, Michael Rohwerder
The effect of hydrogen diffusion and trapping was studied in a high-Cr ferrous alloy using an inverted scanning Kelvin probe and thermal desorption spectroscopy in correlation with microstructure and residual stress study. In addition, different processing of ferritic/martensitic 9Cr1WTaV alloy (EUROFER97) was tested in correlation with observed selected properties to observe induced changes in material degradation and surface. The activation energies for hydrogen traps were shown to have distinct peaks corresponding to different trapping mechanisms, including matrix dislocations and grain boundaries. For the cryogenically treated sample, an additional peak was also identified and correlated with increased carbide precipitation.
{"title":"Hydrogen diffusion and trapping in a cryogenic processed high-Cr ferrous alloy","authors":"Patricia Jovičević-Klug, J. Manoj Prabhakar, Cristiano Kasdorf Giesbrecht, Tim M. Schwarz, Carsten Bonnekoh, Michael Rieth, Michael Rohwerder","doi":"10.1038/s41529-024-00522-1","DOIUrl":"10.1038/s41529-024-00522-1","url":null,"abstract":"The effect of hydrogen diffusion and trapping was studied in a high-Cr ferrous alloy using an inverted scanning Kelvin probe and thermal desorption spectroscopy in correlation with microstructure and residual stress study. In addition, different processing of ferritic/martensitic 9Cr1WTaV alloy (EUROFER97) was tested in correlation with observed selected properties to observe induced changes in material degradation and surface. The activation energies for hydrogen traps were shown to have distinct peaks corresponding to different trapping mechanisms, including matrix dislocations and grain boundaries. For the cryogenically treated sample, an additional peak was also identified and correlated with increased carbide precipitation.","PeriodicalId":19270,"journal":{"name":"npj Materials Degradation","volume":" ","pages":"1-9"},"PeriodicalIF":6.6,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41529-024-00522-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142439144","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 : 2024-10-11DOI: 10.1038/s41529-024-00517-y
J. I. Ahuir-Torres, S. Jabar, P. Franciosa, D. Ceglarek, H. R. Kotadia
This study investigated the corrosion behaviour of dissimilar steel-to-aluminium laser-welded conduction, and keyhole mode (partial- and full-penetration) lap joints through electrochemical techniques and advanced microstructural characterisation. The corrosion resistance of the weld was found to be higher than the base materials, primarily due to the presence of cathodic FexAly (η-Fe2Al5, θ-Fe4Al13, β-FeAl) intermetallic compounds (IMCs) with high corrosion potential. The different micro and macro-galvanic corrosion mechanisms were found at various interfaces around the weld, resulting in localised pitting corrosion. The keyhole mode welding showed improved corrosion resistance, primarily attributed to the type, size, and distribution of IMCs.
{"title":"The microstructure-corrosion relationships in laser-welded dissimilar steel-to-aluminium joints","authors":"J. I. Ahuir-Torres, S. Jabar, P. Franciosa, D. Ceglarek, H. R. Kotadia","doi":"10.1038/s41529-024-00517-y","DOIUrl":"10.1038/s41529-024-00517-y","url":null,"abstract":"This study investigated the corrosion behaviour of dissimilar steel-to-aluminium laser-welded conduction, and keyhole mode (partial- and full-penetration) lap joints through electrochemical techniques and advanced microstructural characterisation. The corrosion resistance of the weld was found to be higher than the base materials, primarily due to the presence of cathodic FexAly (η-Fe2Al5, θ-Fe4Al13, β-FeAl) intermetallic compounds (IMCs) with high corrosion potential. The different micro and macro-galvanic corrosion mechanisms were found at various interfaces around the weld, resulting in localised pitting corrosion. The keyhole mode welding showed improved corrosion resistance, primarily attributed to the type, size, and distribution of IMCs.","PeriodicalId":19270,"journal":{"name":"npj Materials Degradation","volume":" ","pages":"1-17"},"PeriodicalIF":6.6,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41529-024-00517-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142439132","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 : 2024-10-03DOI: 10.1038/s41529-024-00520-3
S. Choudhary, R. G. Kelly
Micro-segregation and resulting nanoscale microstructural heterogeneities are unavoidable in wrought 7xxx aluminum alloys produced using current casting and thermomechanical processes. This study demonstrates that these nanoscale heterogeneities significantly impact pit growth in an extruded, age-hardened aluminum alloy 7075-T651. The alloy exhibits a complex microstructure with heterogeneously distributed E-Al18Mg3Cr2 dispersoids, which promote the precipitation of coarse ƞ-Mg(ZnAlCu)2 nanoparticles resulting in the formation of solute-depleted regions both within the grain interior and along the grain boundaries in dispersoid-rich areas. These alterations affect resistance to pit growth at the nanoscale, governing the transition of micro-galvanic sites into large pits with potential for crack initiation. This work underscores the necessity for modifying alloy composition and casting processes to develop superior aluminum alloys for critical applications.
{"title":"Nanoscale heterogeneities dictate corrosion pathways in a high-strength aluminum alloy","authors":"S. Choudhary, R. G. Kelly","doi":"10.1038/s41529-024-00520-3","DOIUrl":"10.1038/s41529-024-00520-3","url":null,"abstract":"Micro-segregation and resulting nanoscale microstructural heterogeneities are unavoidable in wrought 7xxx aluminum alloys produced using current casting and thermomechanical processes. This study demonstrates that these nanoscale heterogeneities significantly impact pit growth in an extruded, age-hardened aluminum alloy 7075-T651. The alloy exhibits a complex microstructure with heterogeneously distributed E-Al18Mg3Cr2 dispersoids, which promote the precipitation of coarse ƞ-Mg(ZnAlCu)2 nanoparticles resulting in the formation of solute-depleted regions both within the grain interior and along the grain boundaries in dispersoid-rich areas. These alterations affect resistance to pit growth at the nanoscale, governing the transition of micro-galvanic sites into large pits with potential for crack initiation. This work underscores the necessity for modifying alloy composition and casting processes to develop superior aluminum alloys for critical applications.","PeriodicalId":19270,"journal":{"name":"npj Materials Degradation","volume":" ","pages":"1-10"},"PeriodicalIF":6.6,"publicationDate":"2024-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41529-024-00520-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142383589","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}