Pub Date : 2024-12-04DOI: 10.1016/j.jma.2024.11.018
Yao Chen, Fulin Liu, Yujuan Wu, Liming Peng, Lang Li, Chao He, Qiang Chen, Yongjie Liu, Qingyuan Wang
Both solute-segregated long-period stacking ordered (LPSO) structure and stacking faults (SFs) are essential in strengthening rare-earth (RE) Mg alloys. Herein, LPSO-enriched Mg and SFs-enriched Mg are fabricated and comparably investigated for fatigue performances. During fatigue, the Mg nanolayers between LPSO lamellae or SFs act as the gliding channels of dislocations. However, SFs-enriched Mg exhibits outstanding fatigue strength due to solute strengthening within Mg nanolayers. Solute strengthening is assumed to contribute to the local accumulation of basal dislocations and the activation of non-basal dislocations. Dislocations are restricted locally and cannot glide long distances to specimen surfaces, which mitigates fatigue-induced extrusions and slip markings, ultimately leading to an increase in fatigue strength. These findings guide the development of RE-Mg alloys towards a synergy between high tensile and high fatigue performances.
{"title":"Outstanding fatigue performance of Mg-Gd-Zn-Zr alloy enriched with SFs rather than LPSO Structure","authors":"Yao Chen, Fulin Liu, Yujuan Wu, Liming Peng, Lang Li, Chao He, Qiang Chen, Yongjie Liu, Qingyuan Wang","doi":"10.1016/j.jma.2024.11.018","DOIUrl":"https://doi.org/10.1016/j.jma.2024.11.018","url":null,"abstract":"Both solute-segregated long-period stacking ordered (LPSO) structure and stacking faults (SFs) are essential in strengthening rare-earth (RE) Mg alloys. Herein, LPSO-enriched Mg and SFs-enriched Mg are fabricated and comparably investigated for fatigue performances. During fatigue, the Mg nanolayers between LPSO lamellae or SFs act as the gliding channels of dislocations. However, SFs-enriched Mg exhibits outstanding fatigue strength due to solute strengthening within Mg nanolayers. Solute strengthening is assumed to contribute to the local accumulation of basal dislocations and the activation of non-basal dislocations. Dislocations are restricted locally and cannot glide long distances to specimen surfaces, which mitigates fatigue-induced extrusions and slip markings, ultimately leading to an increase in fatigue strength. These findings guide the development of RE-Mg alloys towards a synergy between high tensile and high fatigue performances.","PeriodicalId":16214,"journal":{"name":"Journal of Magnesium and Alloys","volume":"89 1","pages":""},"PeriodicalIF":17.6,"publicationDate":"2024-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142776640","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mg/MgH2 has garnered significant attention primarily due to its abundant availability and high gravimetric density. Nevertheless, its practical implementation hindered by its high thermodynamic stability and sluggish kinetics. Fortunately, the introduction of transition metal single atom (TM SA) catalysts has emerged as an effective method to enhance the hydrogen storage properties of Mg/MgH2. Among these catalysts, the synergistic effect of nanoconfinement and TM SAs plays a pivotal role in the hydriding/dehydriding kinetics of Mg/MgH2. However, the effects of varying TM SAs interacting with N modified confined materials on H2 adsorption and desorption and underlying mechanisms remain enigmatic. Leveraging DFT calculations, we investigated the potential of combining TM SA catalysts with N-modified Carbon nanomaterials (CNT) to enhance the hydrogenation/dehydrogenation of Mg/MgH2. TM SA NCNTs-Mg/MgH2 heterojunction systems encompassing ten 3d/4d transition metals were designed and constructed. We systematically investigated the impact of TM SA NCNTs on the hydrogen absorption and desorption properties of Mg/MgH2 by examining parameters such as the electronic localization function (ELF), distorted charge density distributions, adsorption energies, dissociation energies, electronegativity, and the d-band center. Notably, the energy barriers for Mg/MgH2 hydrogenation and dehydrogenation were significantly reduced by 0.2–0.7 eV and 1.6–2.2 eV, respectively, through the catalytic promotion of TM SA NCNTs. Herein, a novel “electronic-ropeway” effect was proposed to elucidate the underlying mechanism responsible for enhancing the hydrogen absorption and desorption kinetics in Mg/MgH2. Specifically, the contribution degree of TM SA NCNTs and system electronegativity emerged as effective descriptors for predicting the reduced hydrogenation/dehydrogenation energy barriers. It is anticipated that elucidating the role of TM SA-N-CNTs will pave the way for developing innovative strategies to enhance the hydrogen absorption and desorption kinetics of Mg/MgH2 systems, thereby providing valuable design principles for the construction of novel Mg/MgH2 hydrogen storage materials.
Mg/MgH2由于其丰富的可用性和高的重量密度而引起了广泛的关注。然而，它的实际应用受到其高热力学稳定性和缓慢动力学的阻碍。幸运的是，引入过渡金属单原子（TM SA）催化剂已成为提高Mg/MgH2储氢性能的有效方法。在这些催化剂中，纳米约束和TM SAs的协同作用对Mg/MgH2的加氢/脱氢动力学起关键作用。然而，不同的TM sa与N修饰的受限材料相互作用对H2吸附和解吸的影响及其潜在机制仍然是谜。利用DFT计算，我们研究了将TM SA催化剂与n改性碳纳米材料（CNT）结合以增强Mg/MgH2加氢/脱氢的潜力。设计并构建了包含10种3d/4d过渡金属的TM SA NCNTs-Mg/MgH2异质结体系。我们通过考察电子定位函数（ELF）、畸变电荷密度分布、吸附能、解离能、电负性和d带中心等参数，系统地研究了TM SA NCNTs对Mg/MgH2吸氢和解吸性能的影响。值得注意的是，通过TM SA NCNTs的催化促进，Mg/MgH2加氢和脱氢的能垒分别显著降低了0.2 ~ 0.7 eV和1.6 ~ 2.2 eV。本文提出了一种新的“电子索道”效应，以阐明增强Mg/MgH2中氢吸收和解吸动力学的潜在机制。具体而言，TM SA NCNTs的贡献程度和系统电负性成为预测氢化/脱氢能垒降低的有效描述符。预计阐明TM SA-N-CNTs的作用将为开发提高Mg/MgH2体系吸氢和解吸动力学的创新策略铺平道路，从而为构建新型Mg/MgH2储氢材料提供有价值的设计原则。
{"title":"The TM single-atom catalytic system bidirectionally enhances the hydrogen absorption/desorption kinetics of Mg/MgH2: An insight into the synergetic enhancement mechanism and underlying principle","authors":"Congwen Duan, Haimei Wang, Xinya Wang, Yupeng Liu, Jinhui Wu, Lianxi Hu, Bogu Liu, Haixiang Huang, Fei Wang, Ying Wu","doi":"10.1016/j.jma.2024.11.020","DOIUrl":"https://doi.org/10.1016/j.jma.2024.11.020","url":null,"abstract":"Mg/MgH<sub>2</sub> has garnered significant attention primarily due to its abundant availability and high gravimetric density. Nevertheless, its practical implementation hindered by its high thermodynamic stability and sluggish kinetics. Fortunately, the introduction of transition metal single atom (TM SA) catalysts has emerged as an effective method to enhance the hydrogen storage properties of Mg/MgH<sub>2</sub>. Among these catalysts, the synergistic effect of nanoconfinement and TM SAs plays a pivotal role in the hydriding/dehydriding kinetics of Mg/MgH<sub>2</sub>. However, the effects of varying TM SAs interacting with N modified confined materials on H<sub>2</sub> adsorption and desorption and underlying mechanisms remain enigmatic. Leveraging DFT calculations, we investigated the potential of combining TM SA catalysts with N-modified Carbon nanomaterials (CNT) to enhance the hydrogenation/dehydrogenation of Mg/MgH<sub>2</sub>. TM SA N<img alt=\"single bond\" src=\"https://sdfestaticassets-us-east-1.sciencedirectassets.com/shared-assets/55/entities/sbnd.gif\" style=\"vertical-align:middle\"/>CNTs-Mg/MgH<sub>2</sub> heterojunction systems encompassing ten 3d/4d transition metals were designed and constructed. We systematically investigated the impact of TM SA N<img alt=\"single bond\" src=\"https://sdfestaticassets-us-east-1.sciencedirectassets.com/shared-assets/55/entities/sbnd.gif\" style=\"vertical-align:middle\"/>CNTs on the hydrogen absorption and desorption properties of Mg/MgH<sub>2</sub> by examining parameters such as the electronic localization function (ELF), distorted charge density distributions, adsorption energies, dissociation energies, electronegativity, and the <span>d</span>-band center. Notably, the energy barriers for Mg/MgH<sub>2</sub> hydrogenation and dehydrogenation were significantly reduced by 0.2–0.7 eV and 1.6–2.2 eV, respectively, through the catalytic promotion of TM SA N<img alt=\"single bond\" src=\"https://sdfestaticassets-us-east-1.sciencedirectassets.com/shared-assets/55/entities/sbnd.gif\" style=\"vertical-align:middle\"/>CNTs. Herein, a novel “electronic-ropeway” effect was proposed to elucidate the underlying mechanism responsible for enhancing the hydrogen absorption and desorption kinetics in Mg/MgH<sub>2</sub>. Specifically, the contribution degree of TM SA N<img alt=\"single bond\" src=\"https://sdfestaticassets-us-east-1.sciencedirectassets.com/shared-assets/55/entities/sbnd.gif\" style=\"vertical-align:middle\"/>CNTs and system electronegativity emerged as effective descriptors for predicting the reduced hydrogenation/dehydrogenation energy barriers. It is anticipated that elucidating the role of TM SA-N-CNTs will pave the way for developing innovative strategies to enhance the hydrogen absorption and desorption kinetics of Mg/MgH<sub>2</sub> systems, thereby providing valuable design principles for the construction of novel Mg/MgH<sub>2</sub> hydrogen storage materials.","PeriodicalId":16214,"journal":{"name":"Journal of Magnesium and Alloys","volume":"14 1","pages":""},"PeriodicalIF":17.6,"publicationDate":"2024-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142776642","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The passivation of magnesium (Mg)-based alloys is an electrochemical behavior. The formation of a protective surface film results in passivation. The composition of this surface layer is influenced by the substrate alloy, which in turn affects the passive behavior. Recent studies have examined the composition of the surface film when Mg alloys undergo corrosion. Most of these studies have focused on the presence of Mg hydroxide (Mg(OH)2) and MgO in the layer. However, a systematic examination of the impact of alloying elements on the stability of the passive layer is lacking. The essential question for developing a corrosion-resistant Mg-based alloy with passive protection is: which are the best and most efficient elements that can form a passive layer when alloyed with Mg? Passivity in a Mg alloy could be achieved by using a non-equilibrium technique to supersaturate the matrix phase with a high concentration of a strong passivating element. This review paper examines and explores the potential of creating a passive Mg-based alloy using metallurgical methods, like alloying and purification. Additionally, this paper explains key concepts about the passivity of Mg alloys and proposes possible methods to create a passive Mg alloy.
{"title":"Unraveling the impact of purification and alloying elements on corrosion performance and passivation of magnesium alloys","authors":"Arash Fattah-alhosseini, Razieh Chaharmahali, Alireza Askari, Sajad Alizad, Mosab Kaseem","doi":"10.1016/j.jma.2024.11.023","DOIUrl":"https://doi.org/10.1016/j.jma.2024.11.023","url":null,"abstract":"The passivation of magnesium (Mg)-based alloys is an electrochemical behavior. The formation of a protective surface film results in passivation. The composition of this surface layer is influenced by the substrate alloy, which in turn affects the passive behavior. Recent studies have examined the composition of the surface film when Mg alloys undergo corrosion. Most of these studies have focused on the presence of Mg hydroxide (Mg(OH)<sub>2</sub>) and MgO in the layer. However, a systematic examination of the impact of alloying elements on the stability of the passive layer is lacking. The essential question for developing a corrosion-resistant Mg-based alloy with passive protection is: which are the best and most efficient elements that can form a passive layer when alloyed with Mg? Passivity in a Mg alloy could be achieved by using a non-equilibrium technique to supersaturate the matrix phase with a high concentration of a strong passivating element. This review paper examines and explores the potential of creating a passive Mg-based alloy using metallurgical methods, like alloying and purification. Additionally, this paper explains key concepts about the passivity of Mg alloys and proposes possible methods to create a passive Mg alloy.","PeriodicalId":16214,"journal":{"name":"Journal of Magnesium and Alloys","volume":"85 1","pages":""},"PeriodicalIF":17.6,"publicationDate":"2024-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142763119","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-04DOI: 10.1016/j.jma.2024.11.019
Min-Seok Yoon, Jae Hur, Seo-Hui Park, Ui-Jong Lee, Guanglong Xu, Hyung-Ki Park, Byeong-Chan Suh, Young Min Kim, Won-Seok Ko
The effects of various alloying elements on the performance of Mg-Mg2Ni hydrogen storage alloys were investigated by performing first-principles density functional theory calculations. We examined the important characteristics of hydrogen storage alloys by considering both Mg-based solid solution and Mg2Ni-based intermetallic compound phases, where the hydride forms are MgH2 and Mg2NiH4, respectively. In particular, qualitatively valid information for predicting changes in plateau pressures in the pressure-composition-temperature (PCT) curve was provided by calculating changes in the energy of related hydrogenation reactions. The effects of alloying elements on volume changes due to hydrogenation reactions were also obtained to provide additional criteria for the practical use of hydrogen storage alloys. For the Mg2Ni-based intermetallic compound, we examined the site preference of each alloying element, considering the designated stoichiometry of the base alloy. Based on the revealed site preferences, the effects of various possible alloying elements on the properties of Mg2Ni-based hydrides were also examined. Electronic structure analyses were further conducted to elucidate the detailed mechanisms underlying the role of the additional solute elements.
{"title":"Role of solute elements in Mg-Mg2Ni hydrogen storage alloys: A first-principles calculation study","authors":"Min-Seok Yoon, Jae Hur, Seo-Hui Park, Ui-Jong Lee, Guanglong Xu, Hyung-Ki Park, Byeong-Chan Suh, Young Min Kim, Won-Seok Ko","doi":"10.1016/j.jma.2024.11.019","DOIUrl":"https://doi.org/10.1016/j.jma.2024.11.019","url":null,"abstract":"The effects of various alloying elements on the performance of Mg-Mg<sub>2</sub>Ni hydrogen storage alloys were investigated by performing first-principles density functional theory calculations. We examined the important characteristics of hydrogen storage alloys by considering both Mg-based solid solution and Mg<sub>2</sub>Ni-based intermetallic compound phases, where the hydride forms are MgH<sub>2</sub> and Mg<sub>2</sub>NiH<sub>4</sub>, respectively. In particular, qualitatively valid information for predicting changes in plateau pressures in the pressure-composition-temperature (PCT) curve was provided by calculating changes in the energy of related hydrogenation reactions. The effects of alloying elements on volume changes due to hydrogenation reactions were also obtained to provide additional criteria for the practical use of hydrogen storage alloys. For the Mg<sub>2</sub>Ni-based intermetallic compound, we examined the site preference of each alloying element, considering the designated stoichiometry of the base alloy. Based on the revealed site preferences, the effects of various possible alloying elements on the properties of Mg<sub>2</sub>Ni-based hydrides were also examined. Electronic structure analyses were further conducted to elucidate the detailed mechanisms underlying the role of the additional solute elements.","PeriodicalId":16214,"journal":{"name":"Journal of Magnesium and Alloys","volume":"12 1","pages":""},"PeriodicalIF":17.6,"publicationDate":"2024-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142763121","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The favorable properties of Mg alloys, such as their lightweight and robust nature, are driving an increase in interest in their development for industrial and biomedical applications. These benefits aren't enough to make them widely used; problems like poor corrosion resistance and no antibacterial qualities call attention to the need for improved coating methods. Because of its distinct characteristics and efficacy in surface modification, plasma electrolytic oxidation (PEO) has emerged as a preferred coating process. But protective coatings can only become better with time if we keep pushing them to new limits. PEO coatings on Mg alloys may be made more protective by using metal-organic frameworks (MOFs). Hybrid crystalline MOFs have been popular in inorganic and organic chemistry in recent decades. These complexes include organic ligands and metal ions or clusters. Large specific surface areas, customizable topologies and functionalities, ordered pore structures, and many reactive sites make these materials famous. Preventing corrosion using MOFs seems promising. This study analyzes MOF-led corrosion protection material advances and their efficacy in tackling corrosion challenges. A comprehensive review of numerous production techniques employed with MOFs for corrosion protection highlights their pros and cons. The report also discusses MOFs' potential corrosion-prevention functions and the challenges that must be overcome to make them viable. The corrosion-preventive ways of MOFs as inhibitors, nano-fillers, nano-containers, and surface-coating agents are also examined. As we conclude our detailed analysis, we provide a future-oriented vision of MOFs' undiscovered corrosion prevention potential. This exposition illustrates corrosion protection material advances employing cutting-edge MOF-based anticorrosion breakthroughs. It encourages creative ways to corrosion protection's future.
{"title":"Advancements in integrating MOFs into micro-arc oxidation coatings on Mg alloys: A perspective on PEO-MOF coatings as innovative corrosion inhibitors","authors":"A.G. Ramu, Daejeong Yang, Minjung Song, Dongjin Choi","doi":"10.1016/j.jma.2024.11.029","DOIUrl":"https://doi.org/10.1016/j.jma.2024.11.029","url":null,"abstract":"The favorable properties of Mg alloys, such as their lightweight and robust nature, are driving an increase in interest in their development for industrial and biomedical applications. These benefits aren't enough to make them widely used; problems like poor corrosion resistance and no antibacterial qualities call attention to the need for improved coating methods. Because of its distinct characteristics and efficacy in surface modification, plasma electrolytic oxidation (PEO) has emerged as a preferred coating process. But protective coatings can only become better with time if we keep pushing them to new limits. PEO coatings on Mg alloys may be made more protective by using metal-organic frameworks (MOFs). Hybrid crystalline MOFs have been popular in inorganic and organic chemistry in recent decades. These complexes include organic ligands and metal ions or clusters. Large specific surface areas, customizable topologies and functionalities, ordered pore structures, and many reactive sites make these materials famous. Preventing corrosion using MOFs seems promising. This study analyzes MOF-led corrosion protection material advances and their efficacy in tackling corrosion challenges. A comprehensive review of numerous production techniques employed with MOFs for corrosion protection highlights their pros and cons. The report also discusses MOFs' potential corrosion-prevention functions and the challenges that must be overcome to make them viable. The corrosion-preventive ways of MOFs as inhibitors, nano-fillers, nano-containers, and surface-coating agents are also examined. As we conclude our detailed analysis, we provide a future-oriented vision of MOFs' undiscovered corrosion prevention potential. This exposition illustrates corrosion protection material advances employing cutting-edge MOF-based anticorrosion breakthroughs. It encourages creative ways to corrosion protection's future.","PeriodicalId":16214,"journal":{"name":"Journal of Magnesium and Alloys","volume":"200 1","pages":""},"PeriodicalIF":17.6,"publicationDate":"2024-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142760044","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-03DOI: 10.1016/j.jma.2024.11.004
Yu Zhang, Yang Liu, Zhuoran Zeng, Nick Birbilis, Philip N.H. Nakashima, Laure Bourgeois
Determining the distribution of alloying elements, particularly lithium, is crucial for a holistic understanding of magnesium-lithium-based alloys. In this work, a bespoke ratio spectrum-imaging method based on electron energy-loss spectroscopy, in combination with time-of-flight secondary ion mass spectrometry, energy-dispersive X-ray spectroscopy and Z-contrast imaging, was applied to an as-rolled LAZ941 alloy (Mg-9Li-4Al-1Zn in wt.%). This was done to characterize the distribution of alloying elements, including the distribution of solute in the magnesium matrix. The applications of different mapping techniques revealed that precipitates with two different morphologies are rich in Li, Al and Zn, compared to their surrounding matrix. Additionally, it was confirmed that the β-phase of the alloy contains higher Li and lower Mg concentrations when compared to the α-phase. This study demonstrated the effectiveness and accuracy of the ratio spectrum-imaging method for mapping the elemental distribution (including lithium) in a range of Li-containing materials.
{"title":"Multimodal element (including lithium) mapping in a Mg-9Li-4Al-1Zn alloy","authors":"Yu Zhang, Yang Liu, Zhuoran Zeng, Nick Birbilis, Philip N.H. Nakashima, Laure Bourgeois","doi":"10.1016/j.jma.2024.11.004","DOIUrl":"https://doi.org/10.1016/j.jma.2024.11.004","url":null,"abstract":"Determining the distribution of alloying elements, particularly lithium, is crucial for a holistic understanding of magnesium-lithium-based alloys. In this work, a bespoke ratio spectrum-imaging method based on electron energy-loss spectroscopy, in combination with time-of-flight secondary ion mass spectrometry, energy-dispersive X-ray spectroscopy and Z-contrast imaging, was applied to an as-rolled LAZ941 alloy (Mg-9Li-4Al-1Zn in wt.%). This was done to characterize the distribution of alloying elements, including the distribution of solute in the magnesium matrix. The applications of different mapping techniques revealed that precipitates with two different morphologies are rich in Li, Al and Zn, compared to their surrounding matrix. Additionally, it was confirmed that the β-phase of the alloy contains higher Li and lower Mg concentrations when compared to the α-phase. This study demonstrated the effectiveness and accuracy of the ratio spectrum-imaging method for mapping the elemental distribution (including lithium) in a range of Li-containing materials.","PeriodicalId":16214,"journal":{"name":"Journal of Magnesium and Alloys","volume":"8 1","pages":""},"PeriodicalIF":17.6,"publicationDate":"2024-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142760048","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Magnesium, being the lightest structural metal, faces limitations in alloy development due to its inherently low elastic modulus. Therefore, this study develops high-performance, high-modulus Mg-15Gd-8Y-xAl-0.3Mn (wt.%) (x = 6, 8, 10) alloys and investigates their microstructure and mechanical properties. The findings indicate that the alloys primarily consist of Al2RE and α-Mg phases, with both the amount and size of Al2RE phase increasing as the Al content rises. After extrusion, both the grains and the Al2RE phase are refined. The increased modulus of the alloys is mainly due to the formation of the high-modulus Al2RE phase. When the Al content is 6 %, 8 %, and 10 %, the modulus of the alloys is 51.8 GPa, 53.8 GPa, and 56.1 GPa, respectively. Additionally, the Al2RE and Mg5RE phases can jointly regulate the microstructure and mechanical properties of the alloys. As the Al content increases, the amount of Al2RE phase increases, consuming the rare earth elements in the alloy and reducing the nano-precipitated Mg5RE phase. Consequently, with the increase in Al content, the recrystallization rate increases, and the recrystallized grains become larger. When the Al content is 6 %, the alloy exhibits a bimodal structure with the smallest recrystallized grains, resulting in the highest yield strength of 341 MPa. When the Al content is 8 %, the alloy has a fine, fully recrystallized structure, leading to a relatively high elongation of 9.1 %. These findings provide valuable insights for designing high-modulus magnesium alloys with optimized yield strength and elongation for structural applications.
{"title":"High-modulus magnesium alloy: Control of microstructure and mechanical properties via in-situ synthesis of the Al2RE phase","authors":"Xuhui Feng, Xiaojun Wang, Chao Xu, Xiaoshi Hu, Hailong Shi, Xuejian Li, Zhen Lu","doi":"10.1016/j.jma.2024.11.017","DOIUrl":"https://doi.org/10.1016/j.jma.2024.11.017","url":null,"abstract":"Magnesium, being the lightest structural metal, faces limitations in alloy development due to its inherently low elastic modulus. Therefore, this study develops high-performance, high-modulus Mg-15Gd-8Y-xAl-0.3Mn (wt.%) (<em>x</em> = 6, 8, 10) alloys and investigates their microstructure and mechanical properties. The findings indicate that the alloys primarily consist of Al<sub>2</sub>RE and α-Mg phases, with both the amount and size of Al<sub>2</sub>RE phase increasing as the Al content rises. After extrusion, both the grains and the Al<sub>2</sub>RE phase are refined. The increased modulus of the alloys is mainly due to the formation of the high-modulus Al<sub>2</sub>RE phase. When the Al content is 6 %, 8 %, and 10 %, the modulus of the alloys is 51.8 GPa, 53.8 GPa, and 56.1 GPa, respectively. Additionally, the Al<sub>2</sub>RE and Mg<sub>5</sub>RE phases can jointly regulate the microstructure and mechanical properties of the alloys. As the Al content increases, the amount of Al<sub>2</sub>RE phase increases, consuming the rare earth elements in the alloy and reducing the nano-precipitated Mg<sub>5</sub>RE phase. Consequently, with the increase in Al content, the recrystallization rate increases, and the recrystallized grains become larger. When the Al content is 6 %, the alloy exhibits a bimodal structure with the smallest recrystallized grains, resulting in the highest yield strength of 341 MPa. When the Al content is 8 %, the alloy has a fine, fully recrystallized structure, leading to a relatively high elongation of 9.1 %. These findings provide valuable insights for designing high-modulus magnesium alloys with optimized yield strength and elongation for structural applications.","PeriodicalId":16214,"journal":{"name":"Journal of Magnesium and Alloys","volume":"20 1","pages":""},"PeriodicalIF":17.6,"publicationDate":"2024-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142756304","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-30DOI: 10.1016/j.jma.2024.11.021
Qiankun Li, Li Jin, Fenghua Wang, Shuai Dong, Jian Zeng, Fulin Wang, Jie Dong
The poor fracture toughness limits the widespread application of high-strength cast Mg-Re-Zn alloys. Regulating the alloy microstructure, with phases such as α-Mg, blocky LPSO (long-period stacking order), and lamellar LPSO, offers various possibilities to enhance ductility by casting and heat treatment. This study categorizes different interface types concerning crack initiation, propagation, and ultimate fracture toughness. It distinctly presents the results of interface modulation related to alloy composition and heat treatment, elucidating the influence on crack initiation and propagation paths. Consequently, it proposes structural configurations rule and relevant heat treatment processes that can optimize and improve alloy fracture toughness. Blocky LPSO should have appropriate dispersion and size while avoiding lamellar LPSO.
{"title":"Crack propagation path deflection induced by α-Mg / LPSO interface and its effect on the fracture toughness of cast Mg-RE-Zn alloys","authors":"Qiankun Li, Li Jin, Fenghua Wang, Shuai Dong, Jian Zeng, Fulin Wang, Jie Dong","doi":"10.1016/j.jma.2024.11.021","DOIUrl":"https://doi.org/10.1016/j.jma.2024.11.021","url":null,"abstract":"The poor fracture toughness limits the widespread application of high-strength cast Mg-Re-Zn alloys. Regulating the alloy microstructure, with phases such as α-Mg, blocky LPSO (long-period stacking order), and lamellar LPSO, offers various possibilities to enhance ductility by casting and heat treatment. This study categorizes different interface types concerning crack initiation, propagation, and ultimate fracture toughness. It distinctly presents the results of interface modulation related to alloy composition and heat treatment, elucidating the influence on crack initiation and propagation paths. Consequently, it proposes structural configurations rule and relevant heat treatment processes that can optimize and improve alloy fracture toughness. Blocky LPSO should have appropriate dispersion and size while avoiding lamellar LPSO.","PeriodicalId":16214,"journal":{"name":"Journal of Magnesium and Alloys","volume":"1 1","pages":""},"PeriodicalIF":17.6,"publicationDate":"2024-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142756302","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Poor corrosion resistance is a critical barrier to the widespread application of magnesium alloys. Statistically, the literature reported that approximately 70 % of as-cast AZ31 magnesium alloys exhibit corrosion rates exceeding 1 mm ·y−1 in 3.5 wt.% NaCl solution, which is unacceptable for industrial use. Furthermore, there is a considerable discrepancy in the corrosion rates reported by different studies (as-cast alloys ranging from 0.4 to 215 mm ·y−1). These phenomena may be attributed to the uncontrollable content of impurity elements in commercial magnesium alloys, which fluctuate widely between batches. In the present work, we prepared as-cast AZ31 magnesium alloys with different impurity contents using two different purities of raw magnesium (Mg-99.9% and Mg-99.99%). The impact of impurity contents on the corrosion resistance of AZ31 magnesium alloys was then analyzed. The AZ31 magnesium alloy prepared with 99.99% raw magnesium showed superior corrosion resistance compared with that prepared with 99.9% raw magnesium, with a reduction in corrosion rate by approximately 98 % and a decrease in the fluctuation range of corrosion rate by 91 %. Thus, enhancing the purity of raw magnesium is an effective method to improve both the corrosion resistance and consistency of magnesium alloys.
{"title":"Enhanced corrosion resistance of AZ31 magnesium alloys through the use of high-purity raw magnesium","authors":"Xin-Yu Peng, De-Gang Xie, Long-Qi Bai, Zhang Liu, Zhi-Wei Shan","doi":"10.1016/j.jma.2024.10.018","DOIUrl":"https://doi.org/10.1016/j.jma.2024.10.018","url":null,"abstract":"Poor corrosion resistance is a critical barrier to the widespread application of magnesium alloys. Statistically, the literature reported that approximately 70 % of as-cast AZ31 magnesium alloys exhibit corrosion rates exceeding 1 mm ·<em>y</em><sup>−1</sup> in 3.5 wt.% NaCl solution, which is unacceptable for industrial use. Furthermore, there is a considerable discrepancy in the corrosion rates reported by different studies (as-cast alloys ranging from 0.4 to 215 mm ·<em>y</em><sup>−1</sup>). These phenomena may be attributed to the uncontrollable content of impurity elements in commercial magnesium alloys, which fluctuate widely between batches. In the present work, we prepared as-cast AZ31 magnesium alloys with different impurity contents using two different purities of raw magnesium (Mg-99.9% and Mg-99.99%). The impact of impurity contents on the corrosion resistance of AZ31 magnesium alloys was then analyzed. The AZ31 magnesium alloy prepared with 99.99% raw magnesium showed superior corrosion resistance compared with that prepared with 99.9% raw magnesium, with a reduction in corrosion rate by approximately 98 % and a decrease in the fluctuation range of corrosion rate by 91 %. Thus, enhancing the purity of raw magnesium is an effective method to improve both the corrosion resistance and consistency of magnesium alloys.","PeriodicalId":16214,"journal":{"name":"Journal of Magnesium and Alloys","volume":"69 1","pages":""},"PeriodicalIF":17.6,"publicationDate":"2024-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142752910","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
CNTs-Mg/MgH2 heterojunction systems encompassing ten 3d/4d transition metals were designed and constructed. We systematically investigated the impact of TM SA N
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