There has been considerable research into the use of powdered photocatalysts for their potential to remove a range of contaminants. However, the use of photocatalytic nanoparticles in real-world applications faces several challenges, including a tendency to clump together and issues with separating and reclaiming them. Of the various strategies for securing nanoparticles to a substrate, photocatalytic coatings have emerged as a promising solution to overcome the common limitations associated with powdered forms. Coatings produced through PEO have attracted considerable interest as versatile surface treatments. They hold the potential to improve the photocatalytic efficiency of magnesium alloys. Assessments of photocatalytic activity were carried out to examine the degradation of organic dyes when exposed to both visible light and UV. The findings show that the photocatalytic performance of PEO layers is improved, a feature that can be attributed to their distinct surface structure, composition, and properties related to light absorption. This research provides a deeper understanding of the photocatalytic properties of PEO layers applied to magnesium alloys. It underscores their potential use in environmental cleanup and energy transformation applications.
{"title":"An examination of the enhanced photocatalytic performance of PEO coatings applied on Mg alloys: A review","authors":"Arash Fattah-alhossein, Stevan Stojadinović, Razieh Chaharmahali, Andrey Gnedenkov","doi":"10.1016/j.jma.2024.11.002","DOIUrl":"https://doi.org/10.1016/j.jma.2024.11.002","url":null,"abstract":"There has been considerable research into the use of powdered photocatalysts for their potential to remove a range of contaminants. However, the use of photocatalytic nanoparticles in real-world applications faces several challenges, including a tendency to clump together and issues with separating and reclaiming them. Of the various strategies for securing nanoparticles to a substrate, photocatalytic coatings have emerged as a promising solution to overcome the common limitations associated with powdered forms. Coatings produced through PEO have attracted considerable interest as versatile surface treatments. They hold the potential to improve the photocatalytic efficiency of magnesium alloys. Assessments of photocatalytic activity were carried out to examine the degradation of organic dyes when exposed to both visible light and UV. The findings show that the photocatalytic performance of PEO layers is improved, a feature that can be attributed to their distinct surface structure, composition, and properties related to light absorption. This research provides a deeper understanding of the photocatalytic properties of PEO layers applied to magnesium alloys. It underscores their potential use in environmental cleanup and energy transformation applications.","PeriodicalId":16214,"journal":{"name":"Journal of Magnesium and Alloys","volume":"1 1","pages":""},"PeriodicalIF":17.6,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142742633","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 deposition of ultrafine single-atom nickel particles on Nb2C (MXene) was successfully achieved using a wet chemistry method to synthesize Ni@Nb2C composite. This study explored the effect of Ni@Nb2C on the hydrogen absorption and desorption properties of MgH2 through theoretical calculations and experimental investigations. Under the catalytic action of Ni@Nb2C, the initial dehydrogenation temperature of MgH2 was reduced by 121°C, with approximately 4.26 wt.% of H2 desorbed at 225°C in 100 min. The dehydrogenation activation energy of the MgH2 + Ni@Nb2C composite dropped to 86.7 kJ·mol−1, a reduction of 60.5 kJ·mol−1 compared to pure MgH2. Density functional theory calculations indicated that the incorporation of Ni@Nb2C enhanced the performance of MgH2 performance by improving interactions among Nb2C, Ni, Mg, and H atoms. In the Ni@Nb2C + MgH2 system, the lengths of Mg-H bonds (1.91–1.99 Å) were found to be longer than those observed in pure MgH2 (1.71 Å). The dehydrogenation energy for this system (1.08 eV) was lower than that for Nb2C (1.52 eV). These findings suggest that the synergistic effect of Ni and Nb2C significantly enhances the hydrogenation/dehydrogenation kinetics of MgH2, thereby introducing a novel approach for catalytic modification of solid hydrogen storage materials through synergistic actions.
{"title":"An experimental and theoretical investigation of the enhanced effect of Ni atom-functionalized MXene composite on the mechanism for hydrogen storage performance in MgH2","authors":"Zhiqiang Lan, Jiakun Yang, Xiaobin Wen, Ruojiang Liu, Ziqi Liu, Sizhi Ding, Hua Ning, Haizhen Liu, I.P. Jain, Jin Guo","doi":"10.1016/j.jma.2024.11.003","DOIUrl":"https://doi.org/10.1016/j.jma.2024.11.003","url":null,"abstract":"The deposition of ultrafine single-atom nickel particles on Nb<sub>2</sub>C (MXene) was successfully achieved using a wet chemistry method to synthesize Ni@Nb<sub>2</sub>C composite. This study explored the effect of Ni@Nb<sub>2</sub>C on the hydrogen absorption and desorption properties of MgH<sub>2</sub> through theoretical calculations and experimental investigations. Under the catalytic action of Ni@Nb<sub>2</sub>C, the initial dehydrogenation temperature of MgH<sub>2</sub> was reduced by 121°C, with approximately 4.26 wt.% of H<sub>2</sub> desorbed at 225°C in 100 min. The dehydrogenation activation energy of the MgH<sub>2</sub> + Ni@Nb<sub>2</sub>C composite dropped to 86.7 kJ·mol<sup>−1</sup>, a reduction of 60.5 kJ·mol<sup>−1</sup> compared to pure MgH<sub>2</sub>. Density functional theory calculations indicated that the incorporation of Ni@Nb<sub>2</sub>C enhanced the performance of MgH<sub>2</sub> performance by improving interactions among Nb<sub>2</sub>C, Ni, Mg, and H atoms. In the Ni@Nb<sub>2</sub>C + MgH<sub>2</sub> system, the lengths of Mg-H bonds (1.91–1.99 Å) were found to be longer than those observed in pure MgH<sub>2</sub> (1.71 Å). The dehydrogenation energy for this system (1.08 eV) was lower than that for Nb<sub>2</sub>C (1.52 eV). These findings suggest that the synergistic effect of Ni and Nb<sub>2</sub>C significantly enhances the hydrogenation/dehydrogenation kinetics of MgH<sub>2</sub>, thereby introducing a novel approach for catalytic modification of solid hydrogen storage materials through synergistic actions.","PeriodicalId":16214,"journal":{"name":"Journal of Magnesium and Alloys","volume":"207 1","pages":""},"PeriodicalIF":17.6,"publicationDate":"2024-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142735586","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 : 2024-11-28DOI: 10.1016/j.jma.2024.11.011
Xinzhi Li, Mugong Zhang, Xuewei Fang, Xiaochuan Liu, You Zhou, Tianxing Chang, Ke Huang
Research on the preparation of over-sized lightweight magnesium rare-earth (Mg-RE) components using the wire-arc directed energy deposition (WA-DED) is progressively gaining attention in the advanced manufacturing fields. Herein, to satisfy the demand of ultrahigh load-bearing, the Zn-modified Mg-10Gd-2Y-1Zn-0.5Zr (GWZ1021K) alloy was designed for exploring the influence pattern of Zn element on the microstructure and properties of Mg-10Gd-2Y-0.5Zr (GW102K) with high RE content. Specifically, the Zn element enables finer and more homogeneous grains in the as-built GWZ1021K (18.2 µm) than that in the as-built GW102K (23.9 µm), owing to more nucleation sites and precipitation of nano-γ" and nano-γ' to impede grain growth during the intrinsic heat treatment. After solution treatment, the eutectic phases and RE-rich regions completely disappear in both GW102K and GWZ1021K, yielding elongations of up to 14.6% and 13.2%, respectively. Notably, the high-temperature solution process allows the growth of nano-γ" and nano-γ', as well as the segregation of RE/Zn clusters and subsequent atomic rearrangements to form the 14H long period stacking ordered (LPSO) structures. Following peak-aging treatment, although dense nano-β' is precipitated in both GW102K and GWZ1021K, the Zn element facilitates the precipitation of nano-β1 to relieve the stress concentration induced by the two adjacent nano-β'. Generally, Zn elemental addition enhances strength with a sacrifice of ductility, which can be ascribed to the prismatic nano-β′ and basal 14H-LPSO structures work together to hinder the movement of both basal and non-basal dislocations. As a result, the GWZ1021K alloy achieves an ultra-high strength with an ultimate tensile strength of 403 MPa and a yield strength of 278 MPa, which far exceeds the reported average level of the WA-DED Mg-RE alloys. This study thus sheds new light on the fabrication of ultrahigh-strength Mg-RE alloy components by WA-DED process through appropriate composition modification.
{"title":"The origin of ultrahigh-strength in GWZ1021K alloy fabricated by wire-arc directed energy deposition","authors":"Xinzhi Li, Mugong Zhang, Xuewei Fang, Xiaochuan Liu, You Zhou, Tianxing Chang, Ke Huang","doi":"10.1016/j.jma.2024.11.011","DOIUrl":"https://doi.org/10.1016/j.jma.2024.11.011","url":null,"abstract":"Research on the preparation of over-sized lightweight magnesium rare-earth (Mg-RE) components using the wire-arc directed energy deposition (WA-DED) is progressively gaining attention in the advanced manufacturing fields. Herein, to satisfy the demand of ultrahigh load-bearing, the Zn-modified Mg-10Gd-2Y-1Zn-0.5Zr (GWZ1021K) alloy was designed for exploring the influence pattern of Zn element on the microstructure and properties of Mg-10Gd-2Y-0.5Zr (GW102K) with high RE content. Specifically, the Zn element enables finer and more homogeneous grains in the as-built GWZ1021K (18.2 µm) than that in the as-built GW102K (23.9 µm), owing to more nucleation sites and precipitation of nano-γ\" and nano-γ' to impede grain growth during the intrinsic heat treatment. After solution treatment, the eutectic phases and RE-rich regions completely disappear in both GW102K and GWZ1021K, yielding elongations of up to 14.6% and 13.2%, respectively. Notably, the high-temperature solution process allows the growth of nano-γ\" and nano-γ', as well as the segregation of RE/Zn clusters and subsequent atomic rearrangements to form the 14H long period stacking ordered (LPSO) structures. Following peak-aging treatment, although dense nano-β' is precipitated in both GW102K and GWZ1021K, the Zn element facilitates the precipitation of nano-β<sub>1</sub> to relieve the stress concentration induced by the two adjacent nano-β'. Generally, Zn elemental addition enhances strength with a sacrifice of ductility, which can be ascribed to the prismatic nano-β′ and basal 14H-LPSO structures work together to hinder the movement of both basal and non-basal dislocations. As a result, the GWZ1021K alloy achieves an ultra-high strength with an ultimate tensile strength of 403 MPa and a yield strength of 278 MPa, which far exceeds the reported average level of the WA-DED Mg-RE alloys. This study thus sheds new light on the fabrication of ultrahigh-strength Mg-RE alloy components by WA-DED process through appropriate composition modification.","PeriodicalId":16214,"journal":{"name":"Journal of Magnesium and Alloys","volume":"35 1","pages":""},"PeriodicalIF":17.6,"publicationDate":"2024-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142735742","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 : 2024-11-28DOI: 10.1016/j.jma.2024.11.005
Wenjing Ju, Mei Zhang, Liping Zhong, Yuchen Dou, Yongjian Wang
Regulating the precipitation behavior of Mg alloys to overcome the strength-ductility trade-off puzzle is a long-thought pursuit in the materials community. With this purpose, external stress has been recently applied during aging and shows immense potential in affecting atomic diffusion, and regulating the coherence of the phase boundaries. In this study, elastic tensile (TSA) and compressive stress aging (CSA) of Mg-1.1Gd-0.6Zn-0.3Mn alloy are carried out and the competition of precipitation between multiple precipitates occurs during stress aging. A significant quantity of β’ precipitates primarily distribute along grain boundaries in conventional peak aging alloy. Whereas high density of γ’ phases rather than β’ phase precipitate in both TSA and CSA alloys. The first-principle calculations reveal that the application of external stress introduces shear strain, which decreases unstable stacking fault energies, and thereby promoting the precipitation of γ’ phase and impeding the precipitation of β’ phase. Furthermore, the sequential transformation from γ’ phase to Long Period Stacking Ordered (LPSO) phase occurs in CSA sample, due to the release of elastic local strain at phase boundaries. After subjected to TSA treatment, the sample possesses an ultimate tensile strength of 356 MPa, a yield strength of 294 MPa, and a total elongation of ∼14.3 %. The excellent strength-ductility synergy of TSA sample is primarily contributed to the profuse γ’ precipitates hindering the motion of large number of pyramidal 〈c + a〉 dislocations during tensile deformation. This study offers new insights on regulating the precipitation behavior of Mg alloys containing multiple types of precipitates through the application of external stress, and extends the potential window for obtaining an excellent strength-ductility synergy in age-hardenable Mg alloys.
{"title":"Achieving strength-ductility synergy in Mg-1.1Gd-0.6Zn-0.3Mn alloy by regulating precipitation behavior via stress aging strategy","authors":"Wenjing Ju, Mei Zhang, Liping Zhong, Yuchen Dou, Yongjian Wang","doi":"10.1016/j.jma.2024.11.005","DOIUrl":"https://doi.org/10.1016/j.jma.2024.11.005","url":null,"abstract":"Regulating the precipitation behavior of Mg alloys to overcome the strength-ductility trade-off puzzle is a long-thought pursuit in the materials community. With this purpose, external stress has been recently applied during aging and shows immense potential in affecting atomic diffusion, and regulating the coherence of the phase boundaries. In this study, elastic tensile (TSA) and compressive stress aging (CSA) of Mg-1.1Gd-0.6Zn-0.3Mn alloy are carried out and the competition of precipitation between multiple precipitates occurs during stress aging. A significant quantity of β’ precipitates primarily distribute along grain boundaries in conventional peak aging alloy. Whereas high density of γ’ phases rather than β’ phase precipitate in both TSA and CSA alloys. The first-principle calculations reveal that the application of external stress introduces shear strain, which decreases unstable stacking fault energies, and thereby promoting the precipitation of γ’ phase and impeding the precipitation of β’ phase. Furthermore, the sequential transformation from γ’ phase to Long Period Stacking Ordered (LPSO) phase occurs in CSA sample, due to the release of elastic local strain at phase boundaries. After subjected to TSA treatment, the sample possesses an ultimate tensile strength of 356 MPa, a yield strength of 294 MPa, and a total elongation of ∼14.3 %. The excellent strength-ductility synergy of TSA sample is primarily contributed to the profuse γ’ precipitates hindering the motion of large number of pyramidal 〈<em>c</em> + <em>a</em>〉 dislocations during tensile deformation. This study offers new insights on regulating the precipitation behavior of Mg alloys containing multiple types of precipitates through the application of external stress, and extends the potential window for obtaining an excellent strength-ductility synergy in age-hardenable Mg alloys.","PeriodicalId":16214,"journal":{"name":"Journal of Magnesium and Alloys","volume":"14 1","pages":""},"PeriodicalIF":17.6,"publicationDate":"2024-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142735740","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 : 2024-11-28DOI: 10.1016/j.jma.2024.11.012
Jialuo Huang, Zuxiang Sun, Jianxin Tan, Can Sun, Xingpeng Liao, Tao Ying, Fuyong Cao
This study exhibits a design of the discharge product film of a bulk AZ63-Ce-La-Ca (AZ63X) anode for Mg-air battery. An ideal discharge product film for Mg anode is that it could inhibit the anodic hydrogen evolution but does not hinder the transfer of the electrons at the interface. Fortunately, the addition of Ce, La, and Ca into AZ63 alloy achieves this goal. The Mg-air battery with AZ63X anode in 3.5 % NaCl has an ultrahigh anodic efficiency of 85.7 ± 1.7 % and energy-density of 2431 ± 53 mWh g-1 with the unique discharge product film, surpassing the values of most reported Mg-air batteries. Furthermore, the alloying elements reduce the anode delamination effect significantly by transforming the block Mg17Al12 phase into the connected Mg17Al12 structure and fine rod Al2RE and Al2Ca.
{"title":"Achieving ultrahigh anodic-efficiency and energy-density Mg–air battery via the discharge product film design of bulk Mg anode","authors":"Jialuo Huang, Zuxiang Sun, Jianxin Tan, Can Sun, Xingpeng Liao, Tao Ying, Fuyong Cao","doi":"10.1016/j.jma.2024.11.012","DOIUrl":"https://doi.org/10.1016/j.jma.2024.11.012","url":null,"abstract":"This study exhibits a design of the discharge product film of a bulk AZ63-Ce-La-Ca (AZ63X) anode for Mg-air battery. An ideal discharge product film for Mg anode is that it could inhibit the anodic hydrogen evolution but does not hinder the transfer of the electrons at the interface. Fortunately, the addition of Ce, La, and Ca into AZ63 alloy achieves this goal. The Mg-air battery with AZ63X anode in 3.5 % NaCl has an ultrahigh anodic efficiency of 85.7 ± 1.7 % and energy-density of 2431 ± 53 mWh g<sup>-1</sup> with the unique discharge product film, surpassing the values of most reported Mg-air batteries. Furthermore, the alloying elements reduce the anode delamination effect significantly by transforming the block Mg<sub>17</sub>Al<sub>12</sub> phase into the connected Mg<sub>17</sub>Al<sub>12</sub> structure and fine rod Al<sub>2</sub>RE and Al<sub>2</sub>Ca.","PeriodicalId":16214,"journal":{"name":"Journal of Magnesium and Alloys","volume":"25 1","pages":""},"PeriodicalIF":17.6,"publicationDate":"2024-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142735739","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 : 2024-11-28DOI: 10.1016/j.jma.2024.11.008
Tianping Huang, Yingyan Zhao, Bolun Wang, Yinghui Li, Jiaqi Zhang, Xusheng Wang, Yanyue Wang, Hao Du, Manquan Fang, Jianxin Zou
In the present work, highly effective Ni-MnO binary nanocomposite catalysts were designed and synthesized using a one-pot method from Ni-Mn based bi-metal organic frameworks (MOFs). These nanocomposites were introduced into MgH2 through ball milling as catalysts to enhance the hydrogen storage properties of MgH2. Through varying the Ni/Mn ratio in the bimetal MOFs, it is found that the Ni1Mn1−MOF derived catalyst showed the best promotion effect on MgH2. The MgH2–10 wt.% Ni1Mn1−MOF derivative demonstrated favorable overall performance with the low desorption peak temperature (218.2 °C) with a saturated hydrogen capacity of 6.42 wt.% and rapid hydrogen release/uptake kinetics. It can still reabsorb about 1.15 wt.% H2 within 30 min at a temperature as low as 50 °C. Both performance tests (DSC and TPD) and structural characterizations (XRD, HRTEM, etc.) revealed that the synergistic role of in situ formed Mg6MnO8 and Mg2NiH4/Mg2Ni phases for improving the hydrogen sorption properties of MgH2. Theoretical calculations reveal that Mg6MnO8 destabilizes metal-H bonds in MgH2 and Mg2NiH4, leading to an enhanced “hydrogen pump” effect of Mg2NiH4 for MgH2. This research provides a strategy to rational design and preparation of bimetal MOF derivatives for the development of advanced hydrogen storage materials.
{"title":"MOFs derived Ni-Mn bimetal nano-catalysts with enhanced hydrogen pump effect for boosting hydrogen sorption performance of MgH2","authors":"Tianping Huang, Yingyan Zhao, Bolun Wang, Yinghui Li, Jiaqi Zhang, Xusheng Wang, Yanyue Wang, Hao Du, Manquan Fang, Jianxin Zou","doi":"10.1016/j.jma.2024.11.008","DOIUrl":"https://doi.org/10.1016/j.jma.2024.11.008","url":null,"abstract":"In the present work, highly effective Ni-MnO binary nanocomposite catalysts were designed and synthesized using a one-pot method from Ni-Mn based bi-metal organic frameworks (MOFs). These nanocomposites were introduced into MgH<sub>2</sub> through ball milling as catalysts to enhance the hydrogen storage properties of MgH<sub>2</sub>. Through varying the Ni/Mn ratio in the bimetal MOFs, it is found that the Ni<sub>1</sub>Mn<sub>1−</sub>MOF derived catalyst showed the best promotion effect on MgH<sub>2</sub>. The MgH<sub>2</sub>–10 wt.% Ni<sub>1</sub>Mn<sub>1−</sub>MOF derivative demonstrated favorable overall performance with the low desorption peak temperature (218.2 °C) with a saturated hydrogen capacity of 6.42 wt.% and rapid hydrogen release/uptake kinetics. It can still reabsorb about 1.15 wt.% H<sub>2</sub> within 30 min at a temperature as low as 50 °C. Both performance tests (DSC and TPD) and structural characterizations (XRD, HRTEM, etc.) revealed that the synergistic role of in situ formed Mg<sub>6</sub>MnO<sub>8</sub> and Mg<sub>2</sub>NiH<sub>4</sub>/Mg<sub>2</sub>Ni phases for improving the hydrogen sorption properties of MgH<sub>2</sub>. Theoretical calculations reveal that Mg<sub>6</sub>MnO<sub>8</sub> destabilizes metal-H bonds in MgH<sub>2</sub> and Mg<sub>2</sub>NiH<sub>4</sub>, leading to an enhanced “hydrogen pump” effect of Mg<sub>2</sub>NiH<sub>4</sub> for MgH<sub>2</sub>. This research provides a strategy to rational design and preparation of bimetal MOF derivatives for the development of advanced hydrogen storage materials.","PeriodicalId":16214,"journal":{"name":"Journal of Magnesium and Alloys","volume":"115 3 1","pages":""},"PeriodicalIF":17.6,"publicationDate":"2024-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142735788","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}
Accurate predictions of the dislocation behavior of magnesium (Mg) by molecular dynamics (MD) simulations are essential for studying the fundamental mechanisms of deformation and designing high plasticity Mg alloys. However, existing atomic potentials in MD simulation for Mg are not sufficiently quantitative for many dislocations-associated phenomena, such as stacking fault energy (SFE) and dislocation core structures. Here, by combining 468 density functional theory (DFT) calculated data points and a machine learning method, we create a broadly applicable deep learning potential (DLP) to study the dislocation behavior of Mg. We demonstrate that our DLP reproduces the SFE, lattice constants, elastic constants, and surface energies in reasonable agreement with experimental or DFT data. Furthermore, the DLP predicted basal 〈a〉, prismatic 〈a〉, pyramidal 〈c + a〉 dislocations all agree well with DFT results on dissociation distance and core structures. Importantly, the DLP has a superior performance on distinguishing the pyramidal I and II 〈c + a〉 screw dislocation core structures. Our results show that the DLP is suitable for investigating the dislocation behavior of Mg, making it valuable for future realistic atomistic studies of general deformation problems.
{"title":"A machine learning potential for simulation the dislocation behavior of magnesium","authors":"Jincheng Kan, Zhigang Ding, Xiang Chen, Huaiyu Hou, Yonghao Zhao, Wei Liu","doi":"10.1016/j.jma.2024.11.009","DOIUrl":"https://doi.org/10.1016/j.jma.2024.11.009","url":null,"abstract":"Accurate predictions of the dislocation behavior of magnesium (Mg) by molecular dynamics (MD) simulations are essential for studying the fundamental mechanisms of deformation and designing high plasticity Mg alloys. However, existing atomic potentials in MD simulation for Mg are not sufficiently quantitative for many dislocations-associated phenomena, such as stacking fault energy (SFE) and dislocation core structures. Here, by combining 468 density functional theory (DFT) calculated data points and a machine learning method, we create a broadly applicable deep learning potential (DLP) to study the dislocation behavior of Mg. We demonstrate that our DLP reproduces the SFE, lattice constants, elastic constants, and surface energies in reasonable agreement with experimental or DFT data. Furthermore, the DLP predicted basal 〈<em>a</em>〉, prismatic 〈<em>a</em>〉, pyramidal 〈<em>c</em> + <em>a</em>〉 dislocations all agree well with DFT results on dissociation distance and core structures. Importantly, the DLP has a superior performance on distinguishing the pyramidal I and II 〈<em>c</em> + <em>a</em>〉 screw dislocation core structures. Our results show that the DLP is suitable for investigating the dislocation behavior of Mg, making it valuable for future realistic atomistic studies of general deformation problems.","PeriodicalId":16214,"journal":{"name":"Journal of Magnesium and Alloys","volume":"19 1","pages":""},"PeriodicalIF":17.6,"publicationDate":"2024-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142735743","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 : 2024-11-27DOI: 10.1016/j.jma.2024.11.006
Dexi Xu, Xinxi Liu, Huiping Wu, Dayong An, Qi Hu, Xifeng Li, Jun Chen
The Mg-4Y-3RE (WE43) magnesium alloy possesses significant advantages such as high specific strength, excellent shock absorption, strong electromagnetic shielding capabilities and recyclability. However, its close-packed hexagonal structure leads to poor plasticity at room temperature, which limits its broader engineering applications. Therefore, superplastic forming at high temperatures is used to manufacture the components from this alloy. This study conducted tensile tests on hot-rolled WE43 rare-earth magnesium alloy with coarse grains at various temperatures and strain rates. The high-temperature superplastic properties were characterized, revealing the intrinsic mechanisms of thermal deformation behavior. The results indicate that the best superplasticity is achieved at 460 °C. This is attributed to the smallest grain size, the weakest texture, and the relatively uniform distribution of the second phase at this temperature. The influence of strain rate on elongation at temperatures among 440 °C∼500 °C is not significant as the impact of strain rate is multifaceted. Meanwhile, the elongation can reach up to 367.7 ± 3.7 % at a strain rate of 0.01s−1, which exhibits the high strain rate superplasticity (HSRS). Under these conditions, the deformation of coarse-grained WE43 rare-earth magnesium alloy is controlled by grain boundary sliding (GBS) and solute drag dislocation creep. Furthermore, the GBS involves deformation coordination mechanisms such as grain boundary diffusion, lattice diffusion, dislocation climbing, and dynamic recrystallization accommodation mechanisms.
{"title":"Superplastic deformation mechanisms of coarse-grained rolled Mg-4Y-3RE magnesium alloy","authors":"Dexi Xu, Xinxi Liu, Huiping Wu, Dayong An, Qi Hu, Xifeng Li, Jun Chen","doi":"10.1016/j.jma.2024.11.006","DOIUrl":"https://doi.org/10.1016/j.jma.2024.11.006","url":null,"abstract":"The Mg-4Y-3RE (WE43) magnesium alloy possesses significant advantages such as high specific strength, excellent shock absorption, strong electromagnetic shielding capabilities and recyclability. However, its close-packed hexagonal structure leads to poor plasticity at room temperature, which limits its broader engineering applications. Therefore, superplastic forming at high temperatures is used to manufacture the components from this alloy. This study conducted tensile tests on hot-rolled WE43 rare-earth magnesium alloy with coarse grains at various temperatures and strain rates. The high-temperature superplastic properties were characterized, revealing the intrinsic mechanisms of thermal deformation behavior. The results indicate that the best superplasticity is achieved at 460 °C. This is attributed to the smallest grain size, the weakest texture, and the relatively uniform distribution of the second phase at this temperature. The influence of strain rate on elongation at temperatures among 440 °C∼500 °C is not significant as the impact of strain rate is multifaceted. Meanwhile, the elongation can reach up to 367.7 ± 3.7 % at a strain rate of 0.01s<sup>−1</sup>, which exhibits the high strain rate superplasticity (HSRS). Under these conditions, the deformation of coarse-grained WE43 rare-earth magnesium alloy is controlled by grain boundary sliding (GBS) and solute drag dislocation creep. Furthermore, the GBS involves deformation coordination mechanisms such as grain boundary diffusion, lattice diffusion, dislocation climbing, and dynamic recrystallization accommodation mechanisms.","PeriodicalId":16214,"journal":{"name":"Journal of Magnesium and Alloys","volume":"16 1","pages":""},"PeriodicalIF":17.6,"publicationDate":"2024-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142718667","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 : 2024-11-27DOI: 10.1016/j.jma.2024.11.007
Yi Wang, Fei Guo, Luyao Jiang, Hang Yu, Gege Wang, Congren Shen, Zhongwei Wang, Linjiang Chai, Yanlong Ma
Mechanism of discontinuous precipitation (DP) in AZ80 alloy was investigated by phase-orientation correlated characterization. The results show DPs nucleate by turning the original grain boundaries (GBs) as reaction front (RF), and further driving the RF to realize their growth. The DPs regions retained the same orientations as their parent grains. The misorientation angle and rotation axis of RFs had strong influence on DPs nucleation. The low-angle GBs, twin boundaries (TBs) and the GBs with specific misorientation axis which are known as low energy and low mobility GBs can hardly initiate DPs. In addition, the TBs had a strong ability to inhibit the growth of DPs, but it should be noticed that the growth of DPs cannot be totally inhibited by TBs. DPs can engulf the twins when the growth direction is approximately parallel to the long axis of TBs. The inhibition behavior is related to the distribution of Al solute atoms near the RF, boundary interactions of the TBs and twin tips with the RF, and the morphology of the continuous precipitations within the twins.
{"title":"The role of grain and twin boundaries on discontinuous precipitation of Mg17Al12 phase in Mg-Al alloy","authors":"Yi Wang, Fei Guo, Luyao Jiang, Hang Yu, Gege Wang, Congren Shen, Zhongwei Wang, Linjiang Chai, Yanlong Ma","doi":"10.1016/j.jma.2024.11.007","DOIUrl":"https://doi.org/10.1016/j.jma.2024.11.007","url":null,"abstract":"Mechanism of discontinuous precipitation (DP) in AZ80 alloy was investigated by phase-orientation correlated characterization. The results show DPs nucleate by turning the original grain boundaries (GBs) as reaction front (RF), and further driving the RF to realize their growth. The DPs regions retained the same orientations as their parent grains. The misorientation angle and rotation axis of RFs had strong influence on DPs nucleation. The low-angle GBs, twin boundaries (TBs) and the GBs with specific misorientation axis which are known as low energy and low mobility GBs can hardly initiate DPs. In addition, the TBs had a strong ability to inhibit the growth of DPs, but it should be noticed that the growth of DPs cannot be totally inhibited by TBs. DPs can engulf the twins when the growth direction is approximately parallel to the long axis of TBs. The inhibition behavior is related to the distribution of Al solute atoms near the RF, boundary interactions of the TBs and twin tips with the RF, and the morphology of the continuous precipitations within the twins.","PeriodicalId":16214,"journal":{"name":"Journal of Magnesium and Alloys","volume":"1 1","pages":""},"PeriodicalIF":17.6,"publicationDate":"2024-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142718664","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}
Nanoparticle-reinforced Mg matrix composites (NPMMCs) capitalize on the synergistic properties of nanoparticles and Mg matrix, resulting in enhanced mechanical attributes compared to matrix. Nonetheless, effective high-temperature dispersion of nanoparticles remains challenging. This study employs a molten salt dispersant (NaCl-KCl-MgCl2) effectively mitigating the oxidation and combustion of TiC nanoparticles (TiCnp). Compared with the atmosphere, the molten salt facilitates the pre-dispersion of TiCnp through thermal motion at elevated temperatures, thereby reducing agglomeration between the TiCnp. Simultaneously, the molten salt effectively wets and disrupts the oxide layer on the surface of Mg melt, facilitating the wetting of TiCnp by the Mg melt. The successful incorporation of 3 vol.% TiCnp into the Mg matrix is achieved by utilizing molten salt, and the addition of TiCnp increases the viscosity of mg melt. Further dispersed by ultrasonic dispersion, the unique distribution of TiCnp within ring-like structures was obtained which was attributed to the increase of viscosity. As a configurational distribution, the ring-like TiCnp distribution morphology significantly enhances the mechanical properties of composites, as evidenced by an approximate 50 % increase in compressive strength (UCS).
{"title":"Overcoming oxidation and enhancing dispersion of nanoparticles via molten salt: Configurational distribution of TiCnp in pure Mg","authors":"Xuanchang Zhang, Xiaojun Wang, Nodir Turakhodjaevr, Xuejian Li, Hailong Shi, Yuanyuan Zhang, Xiaoshi Hu, Chao Xu","doi":"10.1016/j.jma.2024.10.010","DOIUrl":"https://doi.org/10.1016/j.jma.2024.10.010","url":null,"abstract":"Nanoparticle-reinforced Mg matrix composites (NPMMCs) capitalize on the synergistic properties of nanoparticles and Mg matrix, resulting in enhanced mechanical attributes compared to matrix. Nonetheless, effective high-temperature dispersion of nanoparticles remains challenging. This study employs a molten salt dispersant (NaCl-KCl-MgCl<sub>2</sub>) effectively mitigating the oxidation and combustion of TiC nanoparticles (TiC<sub>np</sub>). Compared with the atmosphere, the molten salt facilitates the pre-dispersion of TiC<sub>np</sub> through thermal motion at elevated temperatures, thereby reducing agglomeration between the TiC<sub>np</sub>. Simultaneously, the molten salt effectively wets and disrupts the oxide layer on the surface of Mg melt, facilitating the wetting of TiC<sub>np</sub> by the Mg melt. The successful incorporation of 3 vol.% TiC<sub>np</sub> into the Mg matrix is achieved by utilizing molten salt, and the addition of TiC<sub>np</sub> increases the viscosity of mg melt. Further dispersed by ultrasonic dispersion, the unique distribution of TiC<sub>np</sub> within ring-like structures was obtained which was attributed to the increase of viscosity. As a configurational distribution, the ring-like TiC<sub>np</sub> distribution morphology significantly enhances the mechanical properties of composites, as evidenced by an approximate 50 % increase in compressive strength (UCS).","PeriodicalId":16214,"journal":{"name":"Journal of Magnesium and Alloys","volume":"33 1","pages":""},"PeriodicalIF":17.6,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142673012","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}
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