Pub Date : 2025-12-05DOI: 10.1016/j.scriptamat.2025.117123
Chiharu Ota, Johji Nishio, Ryosuke Iijima
We discovered previously unreported defects in the 4H-SiC epilayers that do not lie along the [0001] direction or on the () plane. Each defect consists of a pair of partial dislocations separated by a stacking fault rather than forming a perfect dislocation. Because they have inclination angles of 52° and 65° from the [0001] direction toward the [] direction, we refer to them as “pseudo- threading edge dislocations (TEDs).” The spacing between partial dislocations in the pseudo-TEDs also increases, reaching up to 12 nm at an inclination angle of 90° Based on the observed crystallographic orientation, the pseudo-TEDs appear to stabilize along the () planes. Furthermore, comparison of the elastic strain energy between TEDs in the form of perfect dislocations and the total energy of basal plane dislocations suggests that as the inclination angle increases, the pseudo-TED structure becomes more favorable compared with a perfect dislocation.
{"title":"Inclined TEDs with pairs of partial dislocations located away from the basal plane in 4H-SiC epilayers","authors":"Chiharu Ota, Johji Nishio, Ryosuke Iijima","doi":"10.1016/j.scriptamat.2025.117123","DOIUrl":"10.1016/j.scriptamat.2025.117123","url":null,"abstract":"<div><div>We discovered previously unreported defects in the 4H-SiC epilayers that do not lie along the [0001] direction or on the (<span><math><mrow><mn>11</mn><mover><mn>2</mn><mo>¯</mo></mover><mn>0</mn></mrow></math></span>) plane. Each defect consists of a pair of partial dislocations separated by a stacking fault rather than forming a perfect dislocation. Because they have inclination angles of 52° and 65° from the [0001] direction toward the [<span><math><mrow><mn>11</mn><mover><mn>2</mn><mo>¯</mo></mover><mn>0</mn></mrow></math></span>] direction, we refer to them as “pseudo- threading edge dislocations (TEDs).” The spacing between partial dislocations in the pseudo-TEDs also increases, reaching up to 12 nm at an inclination angle of 90° Based on the observed crystallographic orientation, the pseudo-TEDs appear to stabilize along the (<span><math><mrow><mn>11</mn><mover><mn>2</mn><mo>¯</mo></mover><mrow><mo>(</mo><mrow><mn>2</mn><mi>n</mi></mrow><mo>)</mo></mrow></mrow></math></span>) planes. Furthermore, comparison of the elastic strain energy between TEDs in the form of perfect dislocations and the total energy of basal plane dislocations suggests that as the inclination angle increases, the pseudo-TED structure becomes more favorable compared with a perfect dislocation.</div></div>","PeriodicalId":423,"journal":{"name":"Scripta Materialia","volume":"274 ","pages":"Article 117123"},"PeriodicalIF":5.6,"publicationDate":"2025-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145683454","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2025-12-04DOI: 10.1016/j.scriptamat.2025.117122
Nan Wang , Jide Liu , Xinli Wang , Wei Xu , Jinguo Li
Trace addition of yttrium (Y) significantly enhances the high-temperature creep resistance of a second-generation nickel-based single crystal superalloy. This study reveals the underlying mechanism by elucidating the influence of Y on atomic diffusion and dislocation recovery during creep at 1100°C/90 MPa. Through coupled APT and TEM, it demonstrates that Y preferentially partitions to the γ′ phase, altering interfacial chemistry and suppressing atomic diffusivity in the γ matrix, γ′ phase and dislocation cores, respectively. This diffusion barrier decelerates the evolution of dislocation networks, while retarding their degradation. Most critically, it profoundly inhibits the climb-controlled motion of a<100> super-dislocations, which is the primary recovery mechanism. Consequently, Y doping preserves a stable dislocation network and suppresses recovery processes, resulting in an exceptionally low steady-state strain rate. These findings uncover a novel mechanism whereby trace Y enhances creep resistance by inhibiting diffusion-mediated dislocation recovery, establishing a foundation for a new alloy design strategy.
{"title":"Inhibiting dislocation recovery via yttrium-induced diffusion barriers: A novel strategy for creep resistance in Ni-based single crystal superalloys","authors":"Nan Wang , Jide Liu , Xinli Wang , Wei Xu , Jinguo Li","doi":"10.1016/j.scriptamat.2025.117122","DOIUrl":"10.1016/j.scriptamat.2025.117122","url":null,"abstract":"<div><div>Trace addition of yttrium (Y) significantly enhances the high-temperature creep resistance of a second-generation nickel-based single crystal superalloy. This study reveals the underlying mechanism by elucidating the influence of Y on atomic diffusion and dislocation recovery during creep at 1100°C/90 MPa. Through coupled APT and TEM, it demonstrates that Y preferentially partitions to the γ′ phase, altering interfacial chemistry and suppressing atomic diffusivity in the γ matrix, γ′ phase and dislocation cores, respectively. This diffusion barrier decelerates the evolution of dislocation networks, while retarding their degradation. Most critically, it profoundly inhibits the climb-controlled motion of a<100> super-dislocations, which is the primary recovery mechanism. Consequently, Y doping preserves a stable dislocation network and suppresses recovery processes, resulting in an exceptionally low steady-state strain rate. These findings uncover a novel mechanism whereby trace Y enhances creep resistance by inhibiting diffusion-mediated dislocation recovery, establishing a foundation for a new alloy design strategy.</div></div>","PeriodicalId":423,"journal":{"name":"Scripta Materialia","volume":"274 ","pages":"Article 117122"},"PeriodicalIF":5.6,"publicationDate":"2025-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145684057","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2025-12-03DOI: 10.1016/j.scriptamat.2025.117121
Xiaobo Yu , Zhenyou Li , Yang Bai , Qinghua Zhang , Peng Chen , Hong Zhao , Lin Gu , Qian Zhan
The physical origin of controlling ferroelectric properties in defect-engineered Aurivillius-phase layered materials lies in the local polarization evolution mediated by structural defects. Nevertheless, the role of widely prevalent out-of-phase boundary (OPB) defects in configuring polarization remains unclear. This study uses Bi3.15Nd0.85Ti3O12 film, optimized with a HfO2 buffer layer, as a model system to elucidate the intrinsic mechanism behind the enhanced local polarization within the OPB defect regions. Atomic-scale quantitative analysis reveals that OPB defects enhance the in-plane displacement of B-site cations and co-align their out-of-plane polarization directions within the perovskite layers. This reconfiguration disrupts the intrinsic antipolar ordering by eliminating the antiparallel alignment of out-of-plane dipoles between adjacent pseudo-perovskite blocks in the pristine lattice. Strain and vacancy redistribution further promote the polarization configuration transition by disrupting charge compensation. These findings provide mechanistic insights into defect-modulated ferroelectricity and suggest a new approach for designing high-performance devices through strain and defect engineering.
{"title":"Defect-driven polarization reconfiguration in Bi3.15Nd0.85Ti3O12 film","authors":"Xiaobo Yu , Zhenyou Li , Yang Bai , Qinghua Zhang , Peng Chen , Hong Zhao , Lin Gu , Qian Zhan","doi":"10.1016/j.scriptamat.2025.117121","DOIUrl":"10.1016/j.scriptamat.2025.117121","url":null,"abstract":"<div><div>The physical origin of controlling ferroelectric properties in defect-engineered Aurivillius-phase layered materials lies in the local polarization evolution mediated by structural defects. Nevertheless, the role of widely prevalent out-of-phase boundary (OPB) defects in configuring polarization remains unclear. This study uses Bi<sub>3.15</sub>Nd<sub>0.85</sub>Ti<sub>3</sub>O<sub>12</sub> film, optimized with a HfO<sub>2</sub> buffer layer, as a model system to elucidate the intrinsic mechanism behind the enhanced local polarization within the OPB defect regions. Atomic-scale quantitative analysis reveals that OPB defects enhance the in-plane displacement of B-site cations and co-align their out-of-plane polarization directions within the perovskite layers. This reconfiguration disrupts the intrinsic antipolar ordering by eliminating the antiparallel alignment of out-of-plane dipoles between adjacent pseudo-perovskite blocks in the pristine lattice. Strain and vacancy redistribution further promote the polarization configuration transition by disrupting charge compensation. These findings provide mechanistic insights into defect-modulated ferroelectricity and suggest a new approach for designing high-performance devices through strain and defect engineering.</div></div>","PeriodicalId":423,"journal":{"name":"Scripta Materialia","volume":"274 ","pages":"Article 117121"},"PeriodicalIF":5.6,"publicationDate":"2025-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145684055","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We developed a deep learning (DL) framework based on convolutional neural networks (CNNs) to predict elastic constants of hexagonal materials by leveraging high image-recognition capability of CNNs. Resonant frequency data were converted into three-channel RGB images, referred to as ”elasticity images” for CNN training. Without mode identification, the trained models accurately predicted all five independent elastic constants. We reveal that the average Young modulus is a critical for classification of hexagonal materials based on their elasticity images. Furthermore, we extended the Blackman diagram, originally developed for cubic crystals, to hexagonal systems, enabling a substantial reduction of five-dimensional elastic-constant space. We then established a two-step DL scheme: first, classification using the average Young modulus, followed by regression of the five elastic constants in the classified average-Young-modulus class. The prediction error was approximately 5 % for the principal elastic constants and 1.5 % for the average Young modulus.
{"title":"Two-step deep learning for decoding elastic constants of hexagonal-symmetry materials from resonant-spectrum image","authors":"Kazuya Kohira , Shota Nakamura , Hiroki Fukuda , Kazuhiro Kyotani , Hirotsugu Ogi","doi":"10.1016/j.scriptamat.2025.117115","DOIUrl":"10.1016/j.scriptamat.2025.117115","url":null,"abstract":"<div><div>We developed a deep learning (DL) framework based on convolutional neural networks (CNNs) to predict elastic constants of hexagonal materials by leveraging high image-recognition capability of CNNs. Resonant frequency data were converted into three-channel RGB images, referred to as ”elasticity images” for CNN training. Without mode identification, the trained models accurately predicted all five independent elastic constants. We reveal that the average Young modulus is a critical for classification of hexagonal materials based on their elasticity images. Furthermore, we extended the Blackman diagram, originally developed for cubic crystals, to hexagonal systems, enabling a substantial reduction of five-dimensional elastic-constant space. We then established a two-step DL scheme: first, classification using the average Young modulus, followed by regression of the five elastic constants in the classified average-Young-modulus class. The prediction error was approximately 5 % for the principal elastic constants and 1.5 % for the average Young modulus.</div></div>","PeriodicalId":423,"journal":{"name":"Scripta Materialia","volume":"274 ","pages":"Article 117115"},"PeriodicalIF":5.6,"publicationDate":"2025-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145684056","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2025-12-02DOI: 10.1016/j.scriptamat.2025.117117
Xiang Lu , Wenlong Wang , Pingping Zhao , Qingke Zhang , Cheng Xu , Yuanxiang Zhang , Qiangfei Hu , Lijing Yang , Zhenlun Song
In this study, the corrosion process of Cu-30 %Ni alloys in acidic NaCl solution was investigated by a quasi-in-situ method. The grain boundaries and twinned regions were two preferentially corroded sites. The adjacent grains of the preferentially corroded grain boundaries generally formed non-Σ3 high-angle grain boundaries. Their lattice misorientation angle rather than the surface orientation determined the intergranular corrosion susceptibility. By comparison, the preferentially corroded twinned regions were governed by the surface orientation of the twin and adjacent matrix. The large surface crystal planes deviation angle resulted in high corrosion susceptibility. Based on these observations, the corrosion behavior of polycrystalline material is predicted by computational models. The results showed that the intergranular corrosion susceptibility is similar for different matrix textures, but a high intragranular corrosion susceptibility is found in the twin-containing {100} grains. Thus, dominant twin-containing {100} grains should be avoided in Cu-Ni alloys in order to obtain high corrosion resistance.
{"title":"Investigation into the effect of adjacent crystallographic orientations on corrosion behavior in single-phase copper-nickel alloys by quasi-in-situ method","authors":"Xiang Lu , Wenlong Wang , Pingping Zhao , Qingke Zhang , Cheng Xu , Yuanxiang Zhang , Qiangfei Hu , Lijing Yang , Zhenlun Song","doi":"10.1016/j.scriptamat.2025.117117","DOIUrl":"10.1016/j.scriptamat.2025.117117","url":null,"abstract":"<div><div>In this study, the corrosion process of Cu-30 %Ni alloys in acidic NaCl solution was investigated by a quasi-in-situ method. The grain boundaries and twinned regions were two preferentially corroded sites. The adjacent grains of the preferentially corroded grain boundaries generally formed non-Σ3 high-angle grain boundaries. Their lattice misorientation angle rather than the surface orientation determined the intergranular corrosion susceptibility. By comparison, the preferentially corroded twinned regions were governed by the surface orientation of the twin and adjacent matrix. The large surface crystal planes deviation angle resulted in high corrosion susceptibility. Based on these observations, the corrosion behavior of polycrystalline material is predicted by computational models. The results showed that the intergranular corrosion susceptibility is similar for different matrix textures, but a high intragranular corrosion susceptibility is found in the twin-containing {100} grains. Thus, dominant twin-containing {100} grains should be avoided in Cu-Ni alloys in order to obtain high corrosion resistance.</div></div>","PeriodicalId":423,"journal":{"name":"Scripta Materialia","volume":"274 ","pages":"Article 117117"},"PeriodicalIF":5.6,"publicationDate":"2025-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145652003","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2025-12-02DOI: 10.1016/j.scriptamat.2025.117119
Jing Yang , Kunyu Xiao , Dexin Zhao , Yanfei Wang , Chongxiang Huang , Xiaolong Ma
Electron backscatter diffraction (EBSD)-based in-grain misorientation axes (IGMA) analysis is widely employed to elucidate dislocation slip activity in deformed materials. This work introduces an alternative, long-range IGMA method using non-consecutive pairs, in contrast to the conventional short-range method using consecutive pairs. By expanding the evaluation distance between two pixels to allow for the presence of more grain-scale stochastically stored dislocations (SSDs) of opposite sign and their mutual cancellation, the long-range method enhances the detection of grain-scale geometrically necessary dislocations (GNDs) that are essential for maintaining grain continuity upon deformation but may be overlooked by the short-range IGMA method. We validate this approach on a highly textured Mg-3Al-1 Zn (AZ31) alloy compressed along two directions and identified different slip systems accounting for grain-scale lattice curvature of each case. The work underscores the complementary value of integrating spatially and angularly separated non-consecutive pairs into IGMA analyses for deformation of polycrystals.
{"title":"An alternative in-grain misorientation axes analysis for slip activity: A case study in a magnesium alloy","authors":"Jing Yang , Kunyu Xiao , Dexin Zhao , Yanfei Wang , Chongxiang Huang , Xiaolong Ma","doi":"10.1016/j.scriptamat.2025.117119","DOIUrl":"10.1016/j.scriptamat.2025.117119","url":null,"abstract":"<div><div>Electron backscatter diffraction (EBSD)-based in-grain misorientation axes (IGMA) analysis is widely employed to elucidate dislocation slip activity in deformed materials. This work introduces an alternative, long-range IGMA method using non-consecutive pairs, in contrast to the conventional short-range method using consecutive pairs. By expanding the evaluation distance between two pixels to allow for the presence of more grain-scale stochastically stored dislocations (SSDs) of opposite sign and their mutual cancellation, the long-range method enhances the detection of grain-scale geometrically necessary dislocations (GNDs) that are essential for maintaining grain continuity upon deformation but may be overlooked by the short-range IGMA method. We validate this approach on a highly textured Mg-3Al-1 Zn (AZ31) alloy compressed along two directions and identified different slip systems accounting for grain-scale lattice curvature of each case. The work underscores the complementary value of integrating spatially and angularly separated non-consecutive pairs into IGMA analyses for deformation of polycrystals.</div></div>","PeriodicalId":423,"journal":{"name":"Scripta Materialia","volume":"274 ","pages":"Article 117119"},"PeriodicalIF":5.6,"publicationDate":"2025-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145652004","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2025-11-29DOI: 10.1016/j.scriptamat.2025.117118
Vivek Devulapalli , Fedor F. Klimashin , Manuel Bärtschi , Stephan Waldner , Silvia Schwyn Thöny , Johann Michler , Xavier Maeder
Interfaces govern the unique mechanical response of amorphous multilayers. Here, we examine nanoindentation hardness and deformation behaviour of amorphous/amorphous Ta2O5/SiO2 nanolaminates with bilayer thickness ranging from 2 nm to 334 nm. While monolithic SiO2 exhibits catastrophic failure through a single dominant shear band, multilayer architectures demonstrate varied deformation mechanisms. Hardness decreases with reduced bilayer thickness, from 7.7 GPa at 334 nm to 5.5 GPa at 2 nm spacing, contrasting with crystalline systems, which strengthen with decreasing spacing. Cross-sectional transmission electron microscopy reveals that fine bilayer thickness promotes closely spaced vertical shear bands accompanied by bilayer compression, while coarser spacings show fewer, widely spaced shear bands with chemical intermixing. Scanning precession electron diffraction mapping demonstrates significant densification beneath indents. The high interface density facilitates strain accommodation that prevents catastrophic failure typical of brittle amorphous materials.
{"title":"Interface-mediated softening and deformation mechanics in amorphous/amorphous nanolaminates","authors":"Vivek Devulapalli , Fedor F. Klimashin , Manuel Bärtschi , Stephan Waldner , Silvia Schwyn Thöny , Johann Michler , Xavier Maeder","doi":"10.1016/j.scriptamat.2025.117118","DOIUrl":"10.1016/j.scriptamat.2025.117118","url":null,"abstract":"<div><div>Interfaces govern the unique mechanical response of amorphous multilayers. Here, we examine nanoindentation hardness and deformation behaviour of amorphous/amorphous Ta<sub>2</sub>O<sub>5</sub>/SiO<sub>2</sub> nanolaminates with bilayer thickness ranging from 2 nm to 334 nm. While monolithic SiO<sub>2</sub> exhibits catastrophic failure through a single dominant shear band, multilayer architectures demonstrate varied deformation mechanisms. Hardness decreases with reduced bilayer thickness, from 7.7 GPa at 334 nm to 5.5 GPa at 2 nm spacing, contrasting with crystalline systems, which strengthen with decreasing spacing. Cross-sectional transmission electron microscopy reveals that fine bilayer thickness promotes closely spaced vertical shear bands accompanied by bilayer compression, while coarser spacings show fewer, widely spaced shear bands with chemical intermixing. Scanning precession electron diffraction mapping demonstrates significant densification beneath indents. The high interface density facilitates strain accommodation that prevents catastrophic failure typical of brittle amorphous materials.</div></div>","PeriodicalId":423,"journal":{"name":"Scripta Materialia","volume":"273 ","pages":"Article 117118"},"PeriodicalIF":5.6,"publicationDate":"2025-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145690472","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2025-11-25DOI: 10.1016/j.scriptamat.2025.117114
Ya Li , Robert Kahlenberg , Philipp Retzl , Ernst Kozeschnik
The interplay between thermal and athermal nucleation of MgSi co-clusters during quenching of solution-heat-treated Al-Mg-Si alloys is investigated through computer simulations. Thermal nucleation is typically described by classical nucleation theory, which refers to the formation of supercritical nuclei via the diffusion-controlled attachment of solute atoms to clusters of critical size. In the process of athermal nucleation, pre-existing subcritical nuclei become supercritical due to a decrease in critical size, for instance, as a result of increased undercooling during quenching. In this study, we develop a comprehensive nucleation model that integrates thermal and athermal contributions, offering new insights into the MgSi co-cluster formation in Al-Mg-Si alloys during continuous cooling. The results reveal that athermal nucleation is the predominant nucleation mechanism for MgSi co-clusters during quenching. Furthermore, the dependencies of thermal and athermal nucleation on cooling rate, temperature, and alloy composition are elucidated.
{"title":"Thermal and athermal nucleation of MgSi co-clusters in Al-Mg-Si alloys","authors":"Ya Li , Robert Kahlenberg , Philipp Retzl , Ernst Kozeschnik","doi":"10.1016/j.scriptamat.2025.117114","DOIUrl":"10.1016/j.scriptamat.2025.117114","url":null,"abstract":"<div><div>The interplay between thermal and athermal nucleation of MgSi co-clusters during quenching of solution-heat-treated Al-Mg-Si alloys is investigated through computer simulations. Thermal nucleation is typically described by classical nucleation theory, which refers to the formation of supercritical nuclei via the diffusion-controlled attachment of solute atoms to clusters of critical size. In the process of athermal nucleation, pre-existing subcritical nuclei become supercritical due to a decrease in critical size, for instance, as a result of increased undercooling during quenching. In this study, we develop a comprehensive nucleation model that integrates thermal and athermal contributions, offering new insights into the MgSi co-cluster formation in Al-Mg-Si alloys during continuous cooling. The results reveal that athermal nucleation is the predominant nucleation mechanism for MgSi co-clusters during quenching. Furthermore, the dependencies of thermal and athermal nucleation on cooling rate, temperature, and alloy composition are elucidated.</div></div>","PeriodicalId":423,"journal":{"name":"Scripta Materialia","volume":"273 ","pages":"Article 117114"},"PeriodicalIF":5.6,"publicationDate":"2025-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145621008","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2025-11-24DOI: 10.1016/j.scriptamat.2025.117112
Xiaoliang Ji , Yiping Xia , Jian Lin , Longxiao Huang , Yishu Wang , Fu Guo
The low-temperature embrittlement of β-Sn poses a critical reliability challenge for Sn-based solders in cryogenic electronics. In this work, a comparative investigation was conducted by quasi-in-situ EBSD at 77 K and 293 K to elucidate the deformation mechanisms accounting for the ductile-to-brittle transition of β-Sn. It is found that the deformation mechanisms shift from dislocation-dominated to twinning-dominated as the temperature decreases. Dynamic recovery and continuous dynamic recrystallization were suppressed at 77 K, while discontinuous dynamic recrystallization occurred around the crack propagation path. The intergranular fracture at cryogenic temperature could be attributed to the failure of twin-twin transmission across grain boundaries. Molecular dynamics simulations further verified that the twin-twin transmission could accommodate the local strain, correlating its failure with the intergranular cracking. These findings offer new insights into the cryogenic brittleness of β-Sn, helping design Sn-based solders with enhanced cryogenic reliability.
{"title":"Temperature-dependent deformation mechanisms and transition of fracture behaviors in polycrystalline Sn","authors":"Xiaoliang Ji , Yiping Xia , Jian Lin , Longxiao Huang , Yishu Wang , Fu Guo","doi":"10.1016/j.scriptamat.2025.117112","DOIUrl":"10.1016/j.scriptamat.2025.117112","url":null,"abstract":"<div><div>The low-temperature embrittlement of β-Sn poses a critical reliability challenge for Sn-based solders in cryogenic electronics. In this work, a comparative investigation was conducted by quasi-in-situ EBSD at 77 K and 293 K to elucidate the deformation mechanisms accounting for the ductile-to-brittle transition of β-Sn. It is found that the deformation mechanisms shift from dislocation-dominated to twinning-dominated as the temperature decreases. Dynamic recovery and continuous dynamic recrystallization were suppressed at 77 K, while discontinuous dynamic recrystallization occurred around the crack propagation path. The intergranular fracture at cryogenic temperature could be attributed to the failure of twin-twin transmission across grain boundaries. Molecular dynamics simulations further verified that the twin-twin transmission could accommodate the local strain, correlating its failure with the intergranular cracking. These findings offer new insights into the cryogenic brittleness of β-Sn, helping design Sn-based solders with enhanced cryogenic reliability.</div></div>","PeriodicalId":423,"journal":{"name":"Scripta Materialia","volume":"273 ","pages":"Article 117112"},"PeriodicalIF":5.6,"publicationDate":"2025-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145621340","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2025-11-22DOI: 10.1016/j.scriptamat.2025.117111
Haruki Nishida , Yuhei Ogawa , Akinobu Shibata
Plastic flow behavior and strain rate sensitivity, S, of Fe-15Cr-15Ni (mass%) austenitic steel, alloyed with either hydrogen or carbon, were evaluated by tensile and stress relaxation tests at ambient temperature. The effects of these two interstitial elements on solid solution-hardening and thermally activated dislocation motion were compared in terms of Haasen plot—S versus flow stress. Both hydrogen and carbon exhibited solid solution-hardening of the same order of magnitude, increasing S proportionally with their concentrations. However, their ability to increase S was distinct. Hydrogen caused a much steeper increase in S, acting as extremely localized obstacles resisting dislocation motion. In contrast, despite exhibiting comparable solid solution-hardening, carbon led to an order of magnitude smaller increase in S than hydrogen. This result demonstrates a relatively long-range and less rate-sensitive nature of carbon, which is totally different from hydrogen in its obstacle character.
{"title":"Distinct impacts of hydrogen and carbon on thermally activated dislocation motion in Fe-Cr-Ni austenitic steel","authors":"Haruki Nishida , Yuhei Ogawa , Akinobu Shibata","doi":"10.1016/j.scriptamat.2025.117111","DOIUrl":"10.1016/j.scriptamat.2025.117111","url":null,"abstract":"<div><div>Plastic flow behavior and strain rate sensitivity, <em>S</em>, of Fe-15Cr-15Ni (mass%) austenitic steel, alloyed with either hydrogen or carbon, were evaluated by tensile and stress relaxation tests at ambient temperature. The effects of these two interstitial elements on solid solution-hardening and thermally activated dislocation motion were compared in terms of <em>Haasen plot</em>—<em>S</em> versus flow stress. Both hydrogen and carbon exhibited solid solution-hardening of the same order of magnitude, increasing <em>S</em> proportionally with their concentrations. However, their ability to increase <em>S</em> was distinct. Hydrogen caused a much steeper increase in <em>S</em>, acting as extremely localized obstacles resisting dislocation motion. In contrast, despite exhibiting comparable solid solution-hardening, carbon led to an order of magnitude smaller increase in <em>S</em> than hydrogen. This result demonstrates a relatively long-range and less rate-sensitive nature of carbon, which is totally different from hydrogen in its obstacle character.</div></div>","PeriodicalId":423,"journal":{"name":"Scripta Materialia","volume":"273 ","pages":"Article 117111"},"PeriodicalIF":5.6,"publicationDate":"2025-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145621339","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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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