Pub Date : 2025-04-07DOI: 10.1016/j.mtla.2025.102408
Ethen Thomas Lund , Sungwoo Sohn , Axel van de Walle , Stefano Curtarolo , Douglas Hofmann , Jan Schroers
Shear band stability is measured for a Zr-based bulk metallic glass in compressive bending and compared with previous results in tension. Compressive failure is induced via bending of trapezoidal cross-section beams. This characterization is done at multiple fictive temperatures and compared with results in tension, revealing a compression-tension asymmetry in shear banding stability. Stability, indicated here as the ability to resist catastrophic shear bands in favor of stable, arrested shear bands, is higher in compression than tension at all measured fictive temperatures. This asymmetry suggests that shear band propagation is different in tension and compression, and possible mechanisms underlying this difference are suggested. Additionally, this stability measurement is shown to be consistent in uniaxial compression testing, demonstrating its potential for predicting a brittle vs. ductile response in different loading modes of bulk metallic glasses.
{"title":"Tension-compression asymmetry of shear band stability in bulk metallic glasses","authors":"Ethen Thomas Lund , Sungwoo Sohn , Axel van de Walle , Stefano Curtarolo , Douglas Hofmann , Jan Schroers","doi":"10.1016/j.mtla.2025.102408","DOIUrl":"10.1016/j.mtla.2025.102408","url":null,"abstract":"<div><div>Shear band stability is measured for a Zr-based bulk metallic glass in compressive bending and compared with previous results in tension. Compressive failure is induced via bending of trapezoidal cross-section beams. This characterization is done at multiple fictive temperatures and compared with results in tension, revealing a compression-tension asymmetry in shear banding stability. Stability, indicated here as the ability to resist catastrophic shear bands in favor of stable, arrested shear bands, is higher in compression than tension at all measured fictive temperatures. This asymmetry suggests that shear band propagation is different in tension and compression, and possible mechanisms underlying this difference are suggested. Additionally, this stability measurement is shown to be consistent in uniaxial compression testing, demonstrating its potential for predicting a brittle vs. ductile response in different loading modes of bulk metallic glasses.</div></div>","PeriodicalId":47623,"journal":{"name":"Materialia","volume":"40 ","pages":"Article 102408"},"PeriodicalIF":3.0,"publicationDate":"2025-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143807895","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study presents a systematic investigation of microstructure evolution and the mechanical response of a low-density steel during cold rolling with the thickness reduction of up to 90 %. With the strain increase, a three-stage deformation microstructural evolution from slip bands, to deformation twins, and eventually to shear bands has been observed based on detailed microstructure characterization. At the first stage (rolling reduction < 30 %), dislocation slip bands are the dominant deformation microstructure, due to the planar slip of dislocations. As strain increases, the band spacing is progressively refined with a saturation of ∼50 nm. These slip bands gradually evolved into microbands as a result of strain localization and plastic instability. At the second deformation stage (30 %–50 % rolling reduction), deformation twinning is activated, which was seldom reported in low-density steel due to its high stacking fault energy. The deformation twins were found to be preferentially nucleated in the grains with orientations approaching 〈001〉 // rolling direction and 〈111〉 // rolling direction. At the last deformation stage (60 %–90 % rolling reduction), the deformation was mainly controlled by the formation of shear bands, generated in the areas with orientations close to // normal direction. In the mechanical response aspect, the strength was progressively increased with increasing rolling reduction. The formation of deformation twins and shear bands could notably enhance the strength, exhibiting a distinct three-staged mechanical behavior during cold rolling. This research provided a thorough understanding of the distinct microstructure evolution and mechanical response of the low-density steel during cold rolling.
{"title":"Three-stage deformation behaviors of a austenitic Fe-Mn-Al-C low-density steel: slip bands–twinning–shear bands","authors":"Ziyuan Gao, Qingfeng Kang, Zexi Zhang, Hui Wang, Cunyu Wang, Zhengdong Liu, Wenquan Cao","doi":"10.1016/j.mtla.2025.102407","DOIUrl":"10.1016/j.mtla.2025.102407","url":null,"abstract":"<div><div>This study presents a systematic investigation of microstructure evolution and the mechanical response of a low-density steel during cold rolling with the thickness reduction of up to 90 %. With the strain increase, a three-stage deformation microstructural evolution from slip bands, to deformation twins, and eventually to shear bands has been observed based on detailed microstructure characterization. At the first stage (rolling reduction < 30 %), dislocation slip bands are the dominant deformation microstructure, due to the planar slip of dislocations. As strain increases, the band spacing is progressively refined with a saturation of ∼50 nm. These slip bands gradually evolved into microbands as a result of strain localization and plastic instability. At the second deformation stage (30 %–50 % rolling reduction), deformation twinning is activated, which was seldom reported in low-density steel due to its high stacking fault energy. The deformation twins were found to be preferentially nucleated in the grains with orientations approaching 〈001〉 // rolling direction and 〈111〉 // rolling direction. At the last deformation stage (60 %–90 % rolling reduction), the deformation was mainly controlled by the formation of shear bands, generated in the areas with orientations close to<span><math><mrow><mspace></mspace><mo>〈</mo><mn>111</mn><mo>〉</mo></mrow></math></span> // normal direction. In the mechanical response aspect, the strength was progressively increased with increasing rolling reduction. The formation of deformation twins and shear bands could notably enhance the strength, exhibiting a distinct three-staged mechanical behavior during cold rolling. This research provided a thorough understanding of the distinct microstructure evolution and mechanical response of the low-density steel during cold rolling.</div></div>","PeriodicalId":47623,"journal":{"name":"Materialia","volume":"40 ","pages":"Article 102407"},"PeriodicalIF":3.0,"publicationDate":"2025-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143807893","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-04-04DOI: 10.1016/j.mtla.2025.102406
Yonggang Wang , Liangliang Wei , Zhijian Tan , Junye Yang , Chaoju Yu , Shengxiang Wang , Lufeng Yang , Haibiao Zheng , Xitu Lei , R.D.K. Misra , Jie Chen
In this work, stress-controlled tension-compression fatigue and uniaxial tensile experiments were conducted at 550 °C on gradient-structured (GS) 321 austenitic stainless steel fabricated by surface mechanical rolling treatment (SMRT). The microstructural evolution, residual compressive stress (RCS) effect, cyclic deformation behavior, fracture and fatigue behavior were unraveled. Uniaxial results indicate that the yield strength and tensile strength of the GS321 specimen are improved by 112 % and 18.6 %, respectively, which is attributed to the thicker GS layer and SMRT-induced martensite strengthening. Fatigue results confirm that the fatigue strength of GS321 is improved and the fatigue life is increased by at least ∼ 10 times. During fatigue loading at 550 °C, the grain size within the surface layer of the GS321 specimen remains stable, but a significant reverse transformation of martensite to ultrafine austenite is observed. Additionally, the RCS within the GS surface relaxes by 67.2 % prior to fatigue, and it further rapidly relaxes with cyclic loading. These results suggest that the RCS had a limited effect on the fatigue properties of the GS321 specimen at 550 °C. The excellent fatigue property of the GS321 specimen is attributed to the thicker GS layer, martensitic phase transformation strengthening, and the synergistic effect. This study can provide guidance for the design and application of stainless steel with superior fatigue performance at elevated temperature.
{"title":"Unveiling the relationship of fatigue behavior with the microstructure of 321 stainless steel with gradient structure at 550 °C","authors":"Yonggang Wang , Liangliang Wei , Zhijian Tan , Junye Yang , Chaoju Yu , Shengxiang Wang , Lufeng Yang , Haibiao Zheng , Xitu Lei , R.D.K. Misra , Jie Chen","doi":"10.1016/j.mtla.2025.102406","DOIUrl":"10.1016/j.mtla.2025.102406","url":null,"abstract":"<div><div>In this work, stress-controlled tension-compression fatigue and uniaxial tensile experiments were conducted at 550 °C on gradient-structured (GS) 321 austenitic stainless steel fabricated by surface mechanical rolling treatment (SMRT). The microstructural evolution, residual compressive stress (RCS) effect, cyclic deformation behavior, fracture and fatigue behavior were unraveled. Uniaxial results indicate that the yield strength and tensile strength of the GS321 specimen are improved by 112 % and 18.6 %, respectively, which is attributed to the thicker GS layer and SMRT-induced martensite strengthening. Fatigue results confirm that the fatigue strength of GS321 is improved and the fatigue life is increased by at least ∼ 10 times. During fatigue loading at 550 °C, the grain size within the surface layer of the GS321 specimen remains stable, but a significant reverse transformation of martensite to ultrafine austenite is observed. Additionally, the RCS within the GS surface relaxes by 67.2 % prior to fatigue, and it further rapidly relaxes with cyclic loading. These results suggest that the RCS had a limited effect on the fatigue properties of the GS321 specimen at 550 °C. The excellent fatigue property of the GS321 specimen is attributed to the thicker GS layer, martensitic phase transformation strengthening, and the synergistic effect. This study can provide guidance for the design and application of stainless steel with superior fatigue performance at elevated temperature.</div></div>","PeriodicalId":47623,"journal":{"name":"Materialia","volume":"40 ","pages":"Article 102406"},"PeriodicalIF":3.0,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143807894","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-04-03DOI: 10.1016/j.mtla.2025.102403
Juliette Théodore , Baptiste Girault , Laurent Couturier , David Gloaguen , Emmanuel Bertrand , Pascal Paillard , Efthymios Polatidis , Jan Capek , Grégoire Bazin , Bruno Courant
Tungsten inert gas welding of thick components, such as baseplates or tubes, requires chamfering and multipass welding, which can induce significant residual strains and stresses. Strain might then be responsible for misalignments during welding and deviations from the desired part geometry while stress can compromise the integrity and service life. This study investigates the residual stresses, strains, microstructure, and mechanical properties of stainless steel multipass welds using the Dual-Wire Tungsten Inert Gas (DW-TIG) process. Two filler metals, austenitic 304 L and martensitic 415 stainless steels, were used to weld 20 mm thick 304 L baseplates, employing alternated and graded filling strategies compared to single-wire reference welds. Residual stress was determined using neutron diffraction and the contour method, with macroscopic distortion evaluated via profilometry. Microstructure was analyzed via electron backscatter diffraction, micrographs and Vickers hardness tests. Weld mechanical performances were assessed trough tensile tests and compared to standards. The results show strong agreement between the contour method and neutron diffraction, with discrepancies below 100 MPa. The alternated strategy achieved the most significant strain reduction (18 %) without amplifying stress, providing the best compromise between residual stress, strain, and mechanical performance. Martensitic transformation emerged as a key mechanism, introducing compressive stresses. The findings demonstrate the potential of DW-TIG welding to reduce distortions, minimize material waste, and enhance stress field control, making the process applicable to industrial settings (for thick components welding or part reloading). Future work will explore alternative filling strategies and lower-energy welding parameters to further enhance grain refinement and mechanical performance further.
{"title":"Investigation of the residual stresses and strains, microstructure and mechanical properties of stainless steel multipass welds produced using dual wire-tungsten inert gas process","authors":"Juliette Théodore , Baptiste Girault , Laurent Couturier , David Gloaguen , Emmanuel Bertrand , Pascal Paillard , Efthymios Polatidis , Jan Capek , Grégoire Bazin , Bruno Courant","doi":"10.1016/j.mtla.2025.102403","DOIUrl":"10.1016/j.mtla.2025.102403","url":null,"abstract":"<div><div>Tungsten inert gas welding of thick components, such as baseplates or tubes, requires chamfering and multipass welding, which can induce significant residual strains and stresses. Strain might then be responsible for misalignments during welding and deviations from the desired part geometry while stress can compromise the integrity and service life. This study investigates the residual stresses, strains, microstructure, and mechanical properties of stainless steel multipass welds using the Dual-Wire Tungsten Inert Gas (DW-TIG) process. Two filler metals, austenitic 304 L and martensitic 415 stainless steels, were used to weld 20 mm thick 304 L baseplates, employing alternated and graded filling strategies compared to single-wire reference welds. Residual stress was determined using neutron diffraction and the contour method, with macroscopic distortion evaluated via profilometry. Microstructure was analyzed via electron backscatter diffraction, micrographs and Vickers hardness tests. Weld mechanical performances were assessed trough tensile tests and compared to standards. The results show strong agreement between the contour method and neutron diffraction, with discrepancies below 100 MPa. The alternated strategy achieved the most significant strain reduction (18 %) without amplifying stress, providing the best compromise between residual stress, strain, and mechanical performance. Martensitic transformation emerged as a key mechanism, introducing compressive stresses. The findings demonstrate the potential of DW-TIG welding to reduce distortions, minimize material waste, and enhance stress field control, making the process applicable to industrial settings (for thick components welding or part reloading). Future work will explore alternative filling strategies and lower-energy welding parameters to further enhance grain refinement and mechanical performance further.</div></div>","PeriodicalId":47623,"journal":{"name":"Materialia","volume":"40 ","pages":"Article 102403"},"PeriodicalIF":3.0,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143792301","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-30DOI: 10.1016/j.mtla.2025.102401
Camila Torres , Emma C. Whitehead , Benjamin P. Le Monnier , Daniel Peña , Alan Palomino-Calderón , Miguel Neira , Patricio Romero-Hasler , Warren L. Grayson , Michael Tsapatsis , Cristian Covarrubias
Despite significant advancements in traditional bone repair bioceramics, developing materials with inherent osteoinductive capabilities remains a challenge, highlighting the need for innovative biomaterials that actively promote osteogenesis. In this study, aluminophosphate (SAPO) zeolites with nanometric dimensions were hydrothermally synthesized, structurally tailored, and characterized to develop osteoinductive properties. Their in vitro bioactivity was evaluated through assays of apatite mineralization, degradation, ion release, protein adsorption, cell adhesion, viability, and osteogenic differentiation using pre-osteoblast cells.
SAPO-34 and SAPO-5 crystals, engineered with nanosheet-like morphologies and sub-nanometer nanoporous topologies, incorporated calcium and lithium cations into intra- (CaSAPO, LiSAPO) and extraframework (Ca/CaSAPO, Li/LiSAPO) positions while preserving their crystalline nanoporous structure. These zeolites promoted apatite formation within 14 days, driven by their high surface area, optimized surface chemistry, and the presence of calcium as extraframework cations.
SAPO zeolites exhibited a degree of degradation (5–22 wt. %) under simulated physiological conditions, accompanied by the sustained release of Li⁺ and Ca²⁺ ions. Cytocompatibility studies confirmed pre-osteoblast viability and adhesion up to 250 µg/mL over 14 days, with Ca/CaSAPO and Li/LiSAPO forms showing enhanced biocompatibility. The nanosized SAPO particles stimulated osteogenic cell differentiation in the absence of osteogenic supplements, driven not only by the release of bioactive ions but also by their intrinsic physical and chemical characteristics, including their nanoporous structure and surface composition.
These findings identify SAPO zeolites, particularly those modified with lithium and calcium, as promising candidates for bone regeneration. Future in vivo studies are recommended to evaluate their integration into scaffolds and applications in orthopedic and regenerative medicine.
{"title":"Silicoaluminophosphate (SAPO) zeolites with nanometric dimensions: Structural tuning for osteoinductive applications in bone regeneration","authors":"Camila Torres , Emma C. Whitehead , Benjamin P. Le Monnier , Daniel Peña , Alan Palomino-Calderón , Miguel Neira , Patricio Romero-Hasler , Warren L. Grayson , Michael Tsapatsis , Cristian Covarrubias","doi":"10.1016/j.mtla.2025.102401","DOIUrl":"10.1016/j.mtla.2025.102401","url":null,"abstract":"<div><div>Despite significant advancements in traditional bone repair bioceramics, developing materials with inherent osteoinductive capabilities remains a challenge, highlighting the need for innovative biomaterials that actively promote osteogenesis. In this study, aluminophosphate (SAPO) zeolites with nanometric dimensions were hydrothermally synthesized, structurally tailored, and characterized to develop osteoinductive properties. Their in vitro bioactivity was evaluated through assays of apatite mineralization, degradation, ion release, protein adsorption, cell adhesion, viability, and osteogenic differentiation using pre-osteoblast cells.</div><div>SAPO-34 and SAPO-5 crystals, engineered with nanosheet-like morphologies and sub-nanometer nanoporous topologies, incorporated calcium and lithium cations into intra- (CaSAPO, LiSAPO) and extraframework (Ca/CaSAPO, Li/LiSAPO) positions while preserving their crystalline nanoporous structure. These zeolites promoted apatite formation within 14 days, driven by their high surface area, optimized surface chemistry, and the presence of calcium as extraframework cations.</div><div>SAPO zeolites exhibited a degree of degradation (5–22 wt. %) under simulated physiological conditions, accompanied by the sustained release of Li⁺ and Ca²⁺ ions. Cytocompatibility studies confirmed pre-osteoblast viability and adhesion up to 250 µg/mL over 14 days, with Ca/CaSAPO and Li/LiSAPO forms showing enhanced biocompatibility. The nanosized SAPO particles stimulated osteogenic cell differentiation in the absence of osteogenic supplements, driven not only by the release of bioactive ions but also by their intrinsic physical and chemical characteristics, including their nanoporous structure and surface composition.</div><div>These findings identify SAPO zeolites, particularly those modified with lithium and calcium, as promising candidates for bone regeneration. Future in vivo studies are recommended to evaluate their integration into scaffolds and applications in orthopedic and regenerative medicine.</div></div>","PeriodicalId":47623,"journal":{"name":"Materialia","volume":"40 ","pages":"Article 102401"},"PeriodicalIF":3.0,"publicationDate":"2025-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143767861","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this work we investigated correlation of the structure and magnetotransport properties of CdAs crystals with growth conditions in the framework of horizontal gas-transport method. As a precursor we used crystal with non-stoichiometric ratio of elements, which resulted in the formation of small amount of CdAs phase. We show that the latter can be used to obtain single phase CdAs crystal at higher growth rates. Obtained data suggests that the increase of condensation temperature do not affect lattice parameters or mean crystallite size of the CdAs phase, although it promotes the formation of the macroscopic defects. The latter increases observed resistivity values, without changing the relative amplitudes of its temperature and field dependences if the volume fraction of such defects remains constant. Carrier densities in studied crystals are substantially lower than typical values for crystals obtained from the melt. Estimated carrier mobility values are close for samples obtained at temperature below and above the polymorphic transition, suggesting its minor role in properties of crystals obtained via gas-transport method. Observed linear magnetoresistance is qualitatively identical in all studied samples, although its amplitude decreases along with carrier density.
{"title":"Structure and magnetotransport properties of Cd3As2 crystals synthesized via horizontal gas-transport method from non-stoichiometric precursor","authors":"L.N. Oveshnikov , A.I. Ril’ , A.B. Mekhiya , A.B. Davydov","doi":"10.1016/j.mtla.2025.102397","DOIUrl":"10.1016/j.mtla.2025.102397","url":null,"abstract":"<div><div>In this work we investigated correlation of the structure and magnetotransport properties of Cd<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span>As<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> crystals with growth conditions in the framework of horizontal gas-transport method. As a precursor we used crystal with non-stoichiometric ratio of elements, which resulted in the formation of small amount of CdAs<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> phase. We show that the latter can be used to obtain single phase Cd<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span>As<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> crystal at higher growth rates. Obtained data suggests that the increase of condensation temperature do not affect lattice parameters or mean crystallite size of the Cd<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span>As<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> phase, although it promotes the formation of the macroscopic defects. The latter increases observed resistivity values, without changing the relative amplitudes of its temperature and field dependences if the volume fraction of such defects remains constant. Carrier densities in studied crystals are substantially lower than typical values for crystals obtained from the melt. Estimated carrier mobility values are close for samples obtained at temperature below and above the <span><math><mrow><msup><mrow><mi>α</mi></mrow><mrow><mo>′</mo><mo>′</mo></mrow></msup><mo>−</mo><mi>β</mi></mrow></math></span> polymorphic transition, suggesting its minor role in properties of crystals obtained via gas-transport method. Observed linear magnetoresistance is qualitatively identical in all studied samples, although its amplitude decreases along with carrier density.</div></div>","PeriodicalId":47623,"journal":{"name":"Materialia","volume":"40 ","pages":"Article 102397"},"PeriodicalIF":3.0,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143747796","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-23DOI: 10.1016/j.mtla.2025.102399
Qianjin Yang , Zhiqiang Zhou , Pan Xie , Shuang He , Libo Fu , Yunsong Zhao , Ze Zhang , Cuilan Wu
The impurity sulfur embrittlement of Ni-based single alloys has long been wrapped in mystery. In this work, we report for the first time the sulfur-induced precipitation of brittle rhenium-rich δ phase in a model Ni-based single alloy. The results showed that the addition of sulfur gave rise to the precipitation of rhenium-rich δ phase with hexagonal close-packed (HCP) crystal structure in the dendritic cores. Besides, the enrichment of sulfur and nickel elements were detected in the δ phase. The behavior of sulfur-induced precipitation of δ phase was rationalized by the first-principles calculations, which indicates that there is a strong bonding interaction between sulfur and rhenium atoms. This work provides a novel perspective on the understanding of the sulfur embrittlement in Ni-based single alloys.
{"title":"The sulfur embrittlement in Ni-Al-Re model single crystal alloys: Sulfur-induced precipitation of Rhenium-rich δ phase","authors":"Qianjin Yang , Zhiqiang Zhou , Pan Xie , Shuang He , Libo Fu , Yunsong Zhao , Ze Zhang , Cuilan Wu","doi":"10.1016/j.mtla.2025.102399","DOIUrl":"10.1016/j.mtla.2025.102399","url":null,"abstract":"<div><div>The impurity sulfur embrittlement of Ni-based single alloys has long been wrapped in mystery. In this work, we report for the first time the sulfur-induced precipitation of brittle rhenium-rich δ phase in a model Ni-based single alloy. The results showed that the addition of sulfur gave rise to the precipitation of rhenium-rich δ phase with hexagonal close-packed (HCP) crystal structure in the dendritic cores. Besides, the enrichment of sulfur and nickel elements were detected in the δ phase. The behavior of sulfur-induced precipitation of δ phase was rationalized by the first-principles calculations, which indicates that there is a strong bonding interaction between sulfur and rhenium atoms. This work provides a novel perspective on the understanding of the sulfur embrittlement in Ni-based single alloys.</div></div>","PeriodicalId":47623,"journal":{"name":"Materialia","volume":"40 ","pages":"Article 102399"},"PeriodicalIF":3.0,"publicationDate":"2025-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143724672","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-22DOI: 10.1016/j.mtla.2025.102396
Seyed Moien Faregh , Daniel Larouche , X. Grant Chen
The precipitation kinetics of a foundry Al-Si-Mg-(Cu) alloy containing excess Si and impurity levels of Cu were investigated on the atomic scale. A combination of APT, STEM and DSC analysis was used to characterize the evolution of chemical composition and crystal structure of the precipitates during artificial aging. It was observed that even at trace levels (0.02 wt. %), Cu has the capability to alter the precipitation sequence of the Al-Si-Mg alloy, where instead of pure β″, hybrid phases containing unit cells of β″, B′ and Q′ form during age hardening of the alloy in large number densities. APT investigation confirmed the incorporation of Cu in precipitates during peak-aging and its enrichment to maximum values during over-aging. Observance of more Q′ unit cells in the hybrid phases after over-aging was related to this Cu enrichment. Coarse Cu-free U1 phases nucleating predominantly on grain-boundaries were observed in the over-aged condition. Interfacial energies were calculated to explain the large number densities of the hybrid B′/Q′ precipitates and coarsening of the U1 phases.
{"title":"Atomic scale characterization of precipitates in an Al-Si-Mg alloy containing excess Si and trace amounts of Cu","authors":"Seyed Moien Faregh , Daniel Larouche , X. Grant Chen","doi":"10.1016/j.mtla.2025.102396","DOIUrl":"10.1016/j.mtla.2025.102396","url":null,"abstract":"<div><div>The precipitation kinetics of a foundry Al-Si-Mg-(Cu) alloy containing excess Si and impurity levels of Cu were investigated on the atomic scale. A combination of APT, STEM and DSC analysis was used to characterize the evolution of chemical composition and crystal structure of the precipitates during artificial aging. It was observed that even at trace levels (0.02 wt. %), Cu has the capability to alter the precipitation sequence of the Al-Si-Mg alloy, where instead of pure <em>β</em>″, hybrid phases containing unit cells of <em>β</em>″, B′ and Q′ form during age hardening of the alloy in large number densities. APT investigation confirmed the incorporation of Cu in precipitates during peak-aging and its enrichment to maximum values during over-aging. Observance of more Q′ unit cells in the hybrid phases after over-aging was related to this Cu enrichment. Coarse Cu-free U1 phases nucleating predominantly on grain-boundaries were observed in the over-aged condition. Interfacial energies were calculated to explain the large number densities of the hybrid B′/Q′ precipitates and coarsening of the U1 phases.</div></div>","PeriodicalId":47623,"journal":{"name":"Materialia","volume":"40 ","pages":"Article 102396"},"PeriodicalIF":3.0,"publicationDate":"2025-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143814815","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-22DOI: 10.1016/j.mtla.2025.102391
Marc Laub , Eric Detemple , Sebastian Scholl , Christian Motz
A new grain growth model is proposed that extends classical mean-field models to include the local neighborhood of grains. The theoretical basis of the approach is the equilibrium angle of grain boundaries at triple junctions, which is estimated to be 120°considering 2 dimensions, in the case of isotropic grain boundary energy. Based on this fact and a size comparison of individual grains, an algorithm is developed that assigns a discrete neighborhood relationship to all grains, resulting in the generation of an artificial microstructure. For validation, samples of a CMn steel were examined in different states after heat treatments and the microstructure was characterized using deep learning approaches to extract grain boundaries from etched samples with excellent statistics and reliability. The properties and statistical characteristics of the artificial and real microstructures are presented and compared. It is shown that simple topological approaches, such as the linear relationship between the number of grain neighbors and the relative grain size, are good only in a first approximation, but collapse in detail. The proposed model is able to resemble these small deviations of a real microstructure from topological models. Furthermore, the grain growth behavior of such an artificial microstructure is compared with real grain growth experiments. The comparison shows that by implementing the discrete neighborhood of grains, behaviors such as abnormal grain growth seem to be covered to a certain extent without additional treatment as required in other models.
{"title":"Grain growth simulation of steels during heat treatment with statistically modeled discrete neighborhood","authors":"Marc Laub , Eric Detemple , Sebastian Scholl , Christian Motz","doi":"10.1016/j.mtla.2025.102391","DOIUrl":"10.1016/j.mtla.2025.102391","url":null,"abstract":"<div><div>A new grain growth model is proposed that extends classical mean-field models to include the local neighborhood of grains. The theoretical basis of the approach is the equilibrium angle of grain boundaries at triple junctions, which is estimated to be 120°considering 2 dimensions, in the case of isotropic grain boundary energy. Based on this fact and a size comparison of individual grains, an algorithm is developed that assigns a discrete neighborhood relationship to all grains, resulting in the generation of an artificial microstructure. For validation, samples of a CMn steel were examined in different states after heat treatments and the microstructure was characterized using deep learning approaches to extract grain boundaries from etched samples with excellent statistics and reliability. The properties and statistical characteristics of the artificial and real microstructures are presented and compared. It is shown that simple topological approaches, such as the linear relationship between the number of grain neighbors and the relative grain size, are good only in a first approximation, but collapse in detail. The proposed model is able to resemble these small deviations of a real microstructure from topological models. Furthermore, the grain growth behavior of such an artificial microstructure is compared with real grain growth experiments. The comparison shows that by implementing the discrete neighborhood of grains, behaviors such as abnormal grain growth seem to be covered to a certain extent without additional treatment as required in other models.</div></div>","PeriodicalId":47623,"journal":{"name":"Materialia","volume":"40 ","pages":"Article 102391"},"PeriodicalIF":3.0,"publicationDate":"2025-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143687956","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Masonry construction, a time-tested method, remains relevant due to its exceptional durability, strength, fire resistance, and low maintenance requirements. However, conventional practices often rely on river sand, a resource with environmental drawbacks like disrupted ecosystems and riverbed depletion. This research investigates the potential of quarry waste, manufactured sand (M-sand), and quarry dust as sustainable replacements for river sand in cement mortar. The study analyzes the impact of these alternatives on the hardened mortar's physical, mechanical, and durability properties. The results indicate that quarry waste exhibits improved water absorption and strength compared to river sand mortar, albeit with slightly reduced durability and increased density. M-sand offers lower water absorption and enhanced durability but marginally lower strength. Quarry dust, while reducing embodied energy and CO2 emissions significantly, performs poorly in strength and durability. Quarry waste substantially reduces energy consumption and CO2 emissions while maintaining acceptable strength and durability. Utilizing quarry by-products, M-sand, or a combination of these alternatives can minimize environmental damage caused by river sand extraction. Quarry waste is a promising option due to its improved strength, durability, and lower environmental impact than conventional river sand.
{"title":"Comparative study on quarry waste, manufactured sand, quarry dust as river sand replacement in cement mortar: Mechanical characteristics, durability, and eco-benefit","authors":"Mathurshika Pakkiyachandran, Navaratnarajah Sathiparan","doi":"10.1016/j.mtla.2025.102395","DOIUrl":"10.1016/j.mtla.2025.102395","url":null,"abstract":"<div><div>Masonry construction, a time-tested method, remains relevant due to its exceptional durability, strength, fire resistance, and low maintenance requirements. However, conventional practices often rely on river sand, a resource with environmental drawbacks like disrupted ecosystems and riverbed depletion. This research investigates the potential of quarry waste, manufactured sand (M-sand), and quarry dust as sustainable replacements for river sand in cement mortar. The study analyzes the impact of these alternatives on the hardened mortar's physical, mechanical, and durability properties. The results indicate that quarry waste exhibits improved water absorption and strength compared to river sand mortar, albeit with slightly reduced durability and increased density. M-sand offers lower water absorption and enhanced durability but marginally lower strength. Quarry dust, while reducing embodied energy and CO<sub>2</sub> emissions significantly, performs poorly in strength and durability. Quarry waste substantially reduces energy consumption and CO<sub>2</sub> emissions while maintaining acceptable strength and durability. Utilizing quarry by-products, M-sand, or a combination of these alternatives can minimize environmental damage caused by river sand extraction. Quarry waste is a promising option due to its improved strength, durability, and lower environmental impact than conventional river sand.</div></div>","PeriodicalId":47623,"journal":{"name":"Materialia","volume":"40 ","pages":"Article 102395"},"PeriodicalIF":3.0,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143683608","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
扫码关注我们
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号