Pub Date : 2026-01-07DOI: 10.1016/j.scriptamat.2026.117166
R. Kevorkyants , D.S. Shtarev
DFT study on the crystal structure and optoelectronic properties of hypothetical quasi 0D perovskites ABX3 (A=BeBH3, MgBH3; B=Sb, Bi; X = I) is presented. They are predicted to be dynamically stable species with P1 spatial symmetry and electronic bandgaps in the range [1.77–1.95] eV. Electronic transitions shall occur between VBs (I-) and CBs (Sb3+ or Bi3+) formed from p-electron orbitals. The computed charge density indicates a formation of donor-acceptor bond between vacant 2p-orbital of boron and valence s2 lone electron pairs of the pnictogen cations. Atoms of the alkaline earth metals are not involved in chemical bonding and resemble noble gas atoms encapsulated in minerals. Thus, during a fictitious perovskite formation from the pnictogen iodides and BeBH3 or MgBH3 complexes the BH3 molecule must recoordinate. This study demonstrates unusual donor-acceptor interactions in perovskites broadening our knowledge of their physico-chemical properties and paving the way to their prospective applications.
{"title":"Boron-pnictogen donor-acceptor bonding as a perovskite design principle: DFT case study of quasi 0D A(BX3)2 (A=BeBH3, MgBH3; B=Sb, Bi; X=I)","authors":"R. Kevorkyants , D.S. Shtarev","doi":"10.1016/j.scriptamat.2026.117166","DOIUrl":"10.1016/j.scriptamat.2026.117166","url":null,"abstract":"<div><div>DFT study on the crystal structure and optoelectronic properties of hypothetical quasi 0D perovskites ABX<sub>3</sub> (<em>A</em>=BeBH<sub>3</sub>, MgBH<sub>3</sub>; <em>B</em>=Sb, Bi; <em>X</em> = <em>I</em>) is presented. They are predicted to be dynamically stable species with P1 spatial symmetry and electronic bandgaps in the range [1.77–1.95] eV. Electronic transitions shall occur between VBs (I<sup>-</sup>) and CBs (Sb<sup>3+</sup> or Bi<sup>3+</sup>) formed from <em>p</em>-electron orbitals. The computed charge density indicates a formation of donor-acceptor bond between vacant 2<em>p</em>-orbital of boron and valence s<sup>2</sup> lone electron pairs of the pnictogen cations. Atoms of the alkaline earth metals are not involved in chemical bonding and resemble noble gas atoms encapsulated in minerals. Thus, during a fictitious perovskite formation from the pnictogen iodides and BeBH<sub>3</sub> or MgBH<sub>3</sub> complexes the BH<sub>3</sub> molecule must recoordinate. This study demonstrates unusual donor-acceptor interactions in perovskites broadening our knowledge of their physico-chemical properties and paving the way to their prospective applications.</div></div>","PeriodicalId":423,"journal":{"name":"Scripta Materialia","volume":"275 ","pages":"Article 117166"},"PeriodicalIF":5.6,"publicationDate":"2026-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145940423","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 : 2026-01-03DOI: 10.1016/j.scriptamat.2025.117159
Yangchao Deng , Lu Yang , Fan Wu , Jianfeng Wen , Wajira Mirihanage , Kun Yan , Wenyou Zhang , Rocco Lupoi
The strength-ductility trade-off remains a critical challenge in additively manufactured stainless steels due to their process-induced microstructures. In this study, type 316 stainless steel (SS316) was fabricated via a novel metal additive manufacturing technique employing powder sheets (MAPS), demonstrating exceptional strength with considerable ductility. To elucidate the mechanisms underlying this performance, quasi-in-situ electron backscatter diffraction (EBSD) was employed to monitor the microstructural evolution and deformation behaviour of SS316 produced by MAPS in comparison with laser powder bed fusion (LPBF). LPBF exhibits extensive deformation twinning that facilitates broad strain accommodation with sustained hardening, whereas MAPS shows dense dislocation storage within cellular substructures, leading to pronounced strain hardening and superior strength. The limited twinning activation in MAPS constrains strain redistribution, localising plasticity along cellular subgrain boundaries. The interplay between dislocation-dominated hardening and twinning-limited plasticity provides MAPS-processed SS316 with enhanced mechanical performance and highlights the importance of processing strategy in tailoring deformation pathways.
{"title":"Process-induced micromechanics variations in additively manufactured 316 stainless steel characterised by quasi-in-situ EBSD","authors":"Yangchao Deng , Lu Yang , Fan Wu , Jianfeng Wen , Wajira Mirihanage , Kun Yan , Wenyou Zhang , Rocco Lupoi","doi":"10.1016/j.scriptamat.2025.117159","DOIUrl":"10.1016/j.scriptamat.2025.117159","url":null,"abstract":"<div><div>The strength-ductility trade-off remains a critical challenge in additively manufactured stainless steels due to their process-induced microstructures. In this study, type 316 stainless steel (SS316) was fabricated via a novel metal additive manufacturing technique employing powder sheets (MAPS), demonstrating exceptional strength with considerable ductility. To elucidate the mechanisms underlying this performance, quasi-in-situ electron backscatter diffraction (EBSD) was employed to monitor the microstructural evolution and deformation behaviour of SS316 produced by MAPS in comparison with laser powder bed fusion (LPBF). LPBF exhibits extensive deformation twinning that facilitates broad strain accommodation with sustained hardening, whereas MAPS shows dense dislocation storage within cellular substructures, leading to pronounced strain hardening and superior strength. The limited twinning activation in MAPS constrains strain redistribution, localising plasticity along cellular subgrain boundaries. The interplay between dislocation-dominated hardening and twinning-limited plasticity provides MAPS-processed SS316 with enhanced mechanical performance and highlights the importance of processing strategy in tailoring deformation pathways.</div></div>","PeriodicalId":423,"journal":{"name":"Scripta Materialia","volume":"275 ","pages":"Article 117159"},"PeriodicalIF":5.6,"publicationDate":"2026-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145883758","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 : 2026-01-03DOI: 10.1016/j.scriptamat.2025.117163
Yipeng Li , Dewang Cui , Danmin Peng , Yifan Ding , Yiwei Wang , Zhipeng Sun , Yuanming Li , Chi Chen , Xi Qiu , Guang Ran
Dislocation structures are critical for mechanical properties. While dislocations can act as sinks for point defects, their irradiation-induced instability remains a significant challenge. Using in-situ 800 keV Kr2+ irradiation of Mo-14Re alloys, we systematically compared the evolution of random dislocations and ordered dislocation arrays, the latter being the fundamental building blocks of subgrain boundaries. We find that complex arrays—particularly triple arrays—form stable sessile junctions, including binary <100> junctions and ternary 1/2<111> junctions, that topologically lock the network. These cooperative multi-junction interactions strongly restrict irradiation-induced dislocation motion, preserving microstructural integrity up to 3.0 dpa while simultaneously sustaining a denuded zone free of dislocation loops. This work reveals that increasing topological complexity in dislocation arrays, and thus in the subgrain boundaries they comprise, markedly enhances their microstructural stability under irradiation.
{"title":"Stable dislocation junctions empower superior radiation stability of dislocation arrays and subgrain boundaries","authors":"Yipeng Li , Dewang Cui , Danmin Peng , Yifan Ding , Yiwei Wang , Zhipeng Sun , Yuanming Li , Chi Chen , Xi Qiu , Guang Ran","doi":"10.1016/j.scriptamat.2025.117163","DOIUrl":"10.1016/j.scriptamat.2025.117163","url":null,"abstract":"<div><div>Dislocation structures are critical for mechanical properties. While dislocations can act as sinks for point defects, their irradiation-induced instability remains a significant challenge. Using in-situ 800 keV Kr<sup>2+</sup> irradiation of Mo-14Re alloys, we systematically compared the evolution of random dislocations and ordered dislocation arrays, the latter being the fundamental building blocks of subgrain boundaries. We find that complex arrays—particularly triple arrays—form stable sessile junctions, including binary <100> junctions and ternary 1/2<111> junctions, that topologically lock the network. These cooperative multi-junction interactions strongly restrict irradiation-induced dislocation motion, preserving microstructural integrity up to 3.0 dpa while simultaneously sustaining a denuded zone free of dislocation loops. This work reveals that increasing topological complexity in dislocation arrays, and thus in the subgrain boundaries they comprise, markedly enhances their microstructural stability under irradiation.</div></div>","PeriodicalId":423,"journal":{"name":"Scripta Materialia","volume":"275 ","pages":"Article 117163"},"PeriodicalIF":5.6,"publicationDate":"2026-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145883757","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 : 2026-01-02DOI: 10.1016/j.scriptamat.2025.117158
Meiqian Huang , Zijian Zhou , Shuhua Tian , Chen Wang , Xinguang Wang , Xiang-Xi Ye , Rui Zhang , Weihong Zhang , Xipeng Tao , Yizhou Zhou , Xiaofeng Sun , Chuanyong Cui
The crystallographic orientation relationship (OR) between the distinctive plate-shaped M6C carbide and the γ matrix in a Ni-W-Cr superalloy designed for thorium-based molten salt reactors (TMSRs) was investigated. Multi-scale characterization indicates that these carbides, in contrast to conventional granular M6C, display a plate-shaped morphology and a novel twin OR with the γ matrix: [111]M6C//[111]γ, [01]M6C//[01]γ and [11]M6C//[2]γ. This OR forms low-energy semi-coherent interfaces on {111}γ habit planes, effectively reducing the nucleation barrier. This study clarifies the precipitation mechanism of plate-shaped M6C and offers insights for microstructural optimization in refractory-rich superalloys.
{"title":"A novel plate-shaped M6C carbide with a twin orientation relationship to the matrix in a Ni-W-Cr superalloy","authors":"Meiqian Huang , Zijian Zhou , Shuhua Tian , Chen Wang , Xinguang Wang , Xiang-Xi Ye , Rui Zhang , Weihong Zhang , Xipeng Tao , Yizhou Zhou , Xiaofeng Sun , Chuanyong Cui","doi":"10.1016/j.scriptamat.2025.117158","DOIUrl":"10.1016/j.scriptamat.2025.117158","url":null,"abstract":"<div><div>The crystallographic orientation relationship (OR) between the distinctive plate-shaped M<sub>6</sub>C carbide and the γ matrix in a Ni-W-Cr superalloy designed for thorium-based molten salt reactors (TMSRs) was investigated. Multi-scale characterization indicates that these carbides, in contrast to conventional granular M<sub>6</sub>C, display a plate-shaped morphology and a novel twin OR with the γ matrix: [111]<sub>M6C</sub>//[111]<sub>γ</sub>, [<span><math><mover><mn>1</mn><mo>¯</mo></mover></math></span>01]<sub>M6C</sub>//[0<span><math><mover><mn>1</mn><mo>¯</mo></mover></math></span>1]<sub>γ</sub> and [<span><math><mover><mn>2</mn><mo>¯</mo></mover></math></span>11]<sub>M6C</sub>//[<span><math><mrow><mover><mn>1</mn><mo>¯</mo></mover><mover><mn>1</mn><mo>¯</mo></mover></mrow></math></span>2]<sub>γ</sub>. This OR forms low-energy semi-coherent interfaces on {111}<sub>γ</sub> habit planes, effectively reducing the nucleation barrier. This study clarifies the precipitation mechanism of plate-shaped M<sub>6</sub>C and offers insights for microstructural optimization in refractory-rich superalloys.</div></div>","PeriodicalId":423,"journal":{"name":"Scripta Materialia","volume":"274 ","pages":"Article 117158"},"PeriodicalIF":5.6,"publicationDate":"2026-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145881020","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 : 2025-12-30DOI: 10.1016/j.scriptamat.2025.117155
Yong Chen , Haiying Yang , Jinfa Ma , Ping Yang
We investigate the impact of vacancy defects in the near-interface region of diamond on the interface thermal conductance (ITC) of diamond/MoS2 heterostructures by nonequilibrium molecular dynamics simulations. The results show that when the density of random vacancy defects in the near-interface region of the diamond reaches 5 %, ITC increases by 37 % compared to defect-free interfaces. In addition, increasing the radius and number of vacancies can also enhance the ITC. The vacancies scatter high-frequency phonons and excite low-frequency phonons, thereby improving the degree of phonon spectrum coupling between diamond and MoS2. However, the enhancement effect of ITC weakens as vacancies move away from the interface because the scattered phonons are attenuated by phonon-phonon scattering in the defect-free region during transmission, thereby reducing the thermal transport efficiency. This study provides an effective measure for optimizing the thermal management of diamond/MoS2 heterointerfaces.
{"title":"Vacancy defects drive efficient interfacial thermal transport of diamond/MoS2 heterostructure","authors":"Yong Chen , Haiying Yang , Jinfa Ma , Ping Yang","doi":"10.1016/j.scriptamat.2025.117155","DOIUrl":"10.1016/j.scriptamat.2025.117155","url":null,"abstract":"<div><div>We investigate the impact of vacancy defects in the near-interface region of diamond on the interface thermal conductance (ITC) of diamond/MoS<sub>2</sub> heterostructures by nonequilibrium molecular dynamics simulations. The results show that when the density of random vacancy defects in the near-interface region of the diamond reaches 5 %, ITC increases by 37 % compared to defect-free interfaces. In addition, increasing the radius and number of vacancies can also enhance the ITC. The vacancies scatter high-frequency phonons and excite low-frequency phonons, thereby improving the degree of phonon spectrum coupling between diamond and MoS<sub>2</sub>. However, the enhancement effect of ITC weakens as vacancies move away from the interface because the scattered phonons are attenuated by phonon-phonon scattering in the defect-free region during transmission, thereby reducing the thermal transport efficiency. This study provides an effective measure for optimizing the thermal management of diamond/MoS<sub>2</sub> heterointerfaces.</div></div>","PeriodicalId":423,"journal":{"name":"Scripta Materialia","volume":"274 ","pages":"Article 117155"},"PeriodicalIF":5.6,"publicationDate":"2025-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145880949","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}
This study presents a thermomechanical processing strategy to improve the resistance to hydrogen embrittlement (HE) in martensitic steels through controlling variant selection at prior austenite grain boundaries (PAGBs), while retaining ultrahigh tensile strength (>1.5 GPa). Under identical hydrogen-charging conditions, the 10% hot-compressed specimen exhibited the highest HE resistance, correlating with its largest fraction of low-angle PAGB segments. Misorientation-distribution analysis and tensile tests revealed a non-monotonic dependence of compressive strain: an optimal compressive level maximized the beneficial stress-assisted variant selection at PAGBs, whereas excessive strains promoted self-accommodation of transformation strain in the work-hardened austenite, diminishing the beneficial effect. The improved HE resistance stems from reduced hydrogen trapping, enhanced strain-dissipating slip transfer, and increased cohesive energy at PAGBs. Tailoring variant selection at PAGBs through this simple process thus provides an industry-feasible route to hydrogen-resistant high-strength martensitic steels.
{"title":"Enhancing hydrogen embrittlement resistance in high-strength martensitic steels via tailoring variant selection at prior austenite grain boundaries","authors":"Xiaodong Lan, Kazuho Okada, Rintaro Ueji, Akinobu Shibata","doi":"10.1016/j.scriptamat.2025.117157","DOIUrl":"10.1016/j.scriptamat.2025.117157","url":null,"abstract":"<div><div>This study presents a thermomechanical processing strategy to improve the resistance to hydrogen embrittlement (HE) in martensitic steels through controlling variant selection at prior austenite grain boundaries (PAGBs), while retaining ultrahigh tensile strength (>1.5 GPa). Under identical hydrogen-charging conditions, the 10% hot-compressed specimen exhibited the highest HE resistance, correlating with its largest fraction of low-angle PAGB segments. Misorientation-distribution analysis and tensile tests revealed a non-monotonic dependence of compressive strain: an optimal compressive level maximized the beneficial stress-assisted variant selection at PAGBs, whereas excessive strains promoted self-accommodation of transformation strain in the work-hardened austenite, diminishing the beneficial effect. The improved HE resistance stems from reduced hydrogen trapping, enhanced strain-dissipating slip transfer, and increased cohesive energy at PAGBs. Tailoring variant selection at PAGBs through this simple process thus provides an industry-feasible route to hydrogen-resistant high-strength martensitic steels.</div></div>","PeriodicalId":423,"journal":{"name":"Scripta Materialia","volume":"274 ","pages":"Article 117157"},"PeriodicalIF":5.6,"publicationDate":"2025-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145880948","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 : 2025-12-29DOI: 10.1016/j.scriptamat.2025.117156
Hanlin Che , Hailong Xu , Xu Xu , Zhigang Yang , Hao Chen , Chi Zhang , Jugan Zhang
Carburized steels are widely used in gears and bearings components but exhibit different fatigue failure mechanism. After rotating bending fatigue (RBF) test, broadened distribution of crack initiation sites arose relative to homogeneous materials because of the interaction between residual stress and hardness gradients within the carburized layer. A predictive method was developed to evaluate the fatigue behavior of carburized steels under RBF testing. A parameter with decent linear correlation to fatigue life was established, integrating ideal crack initiation location, non-metallic inclusion size, local Vickers hardness and applied stress. The overall fatigue performance is further controlled by inclusion size, carburized layer depth, and matrix hardness. This work introduces a novel framework that explicitly incorporates both carburized layer gradients and inclusion distribution, enabling reliable prediction of fatigue strength at 107 cycles.
{"title":"Predictive method for rotating bending fatigue performance of carburized steel considering layer gradients and inclusions","authors":"Hanlin Che , Hailong Xu , Xu Xu , Zhigang Yang , Hao Chen , Chi Zhang , Jugan Zhang","doi":"10.1016/j.scriptamat.2025.117156","DOIUrl":"10.1016/j.scriptamat.2025.117156","url":null,"abstract":"<div><div>Carburized steels are widely used in gears and bearings components but exhibit different fatigue failure mechanism. After rotating bending fatigue (RBF) test, broadened distribution of crack initiation sites arose relative to homogeneous materials because of the interaction between residual stress and hardness gradients within the carburized layer. A predictive method was developed to evaluate the fatigue behavior of carburized steels under RBF testing. A parameter with decent linear correlation to fatigue life was established, integrating ideal crack initiation location, non-metallic inclusion size, local Vickers hardness and applied stress. The overall fatigue performance is further controlled by inclusion size, carburized layer depth, and matrix hardness. This work introduces a novel framework that explicitly incorporates both carburized layer gradients and inclusion distribution, enabling reliable prediction of fatigue strength at 10<sup>7</sup> cycles.</div></div>","PeriodicalId":423,"journal":{"name":"Scripta Materialia","volume":"274 ","pages":"Article 117156"},"PeriodicalIF":5.6,"publicationDate":"2025-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145880947","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 : 2025-12-26DOI: 10.1016/j.scriptamat.2025.117145
Xavier Quintana , Mackenzie Warwick , Muhammad Jahangir Khan Lodhi , Kevin Field , Julie Tucker , Fei Teng , Trishelle Copeland-Johnson
Ni-Cr-Mo alloys are widely used in the nuclear industry as structural materials due to their high temperature strength and corrosion resistance. Ni-based alloys containing around 33 at.% (Cr+Mo) developed a long-range ordered Ni2(Cr,Mo) phase after thermal aging and/or irradiation. The ordering mechanism for thermally-aged Ni2(Cr,Mo) phase is well-understood, characterized to be sluggish, homogeneous, and isotropic. The ordering mechanism for irradiation-induced Ni2(Cr,Mo) phase is not fully understood, characterized as having rapid formation and demonstrating anisotropic precipitation. This work elucidates the anisotropic precipitation and anisotropic precipitation mechanism of Ni2(Cr,Mo) after proton irradiation in Ni-Cr-Mo alloys. Selected area electron diffraction and bright-field scanning transmission electron microscopy imaging are used to image superlattice reflections from the ordered phase and irradiation-induced defects, respectively. A higher degree of anisotropic precipitation is observed with increasing dislocation loop and void size; a phenomenon not observed in thermally aged samples.
{"title":"Anisotropic growth of Ni2(Cr,Mo) ordered phase in proton irradiated Ni-Cr-Mo alloys","authors":"Xavier Quintana , Mackenzie Warwick , Muhammad Jahangir Khan Lodhi , Kevin Field , Julie Tucker , Fei Teng , Trishelle Copeland-Johnson","doi":"10.1016/j.scriptamat.2025.117145","DOIUrl":"10.1016/j.scriptamat.2025.117145","url":null,"abstract":"<div><div>Ni-Cr-Mo alloys are widely used in the nuclear industry as structural materials due to their high temperature strength and corrosion resistance. Ni-based alloys containing around 33 at.% (Cr+Mo) developed a long-range ordered Ni<sub>2</sub>(Cr,Mo) phase after thermal aging and/or irradiation. The ordering mechanism for thermally-aged Ni<sub>2</sub>(Cr,Mo) phase is well-understood, characterized to be sluggish, homogeneous, and isotropic. The ordering mechanism for irradiation-induced Ni<sub>2</sub>(Cr,Mo) phase is not fully understood, characterized as having rapid formation and demonstrating anisotropic precipitation. This work elucidates the anisotropic precipitation and anisotropic precipitation mechanism of Ni<sub>2</sub>(Cr,Mo) after proton irradiation in Ni-Cr-Mo alloys. Selected area electron diffraction and bright-field scanning transmission electron microscopy imaging are used to image superlattice reflections from the ordered phase and irradiation-induced defects, respectively. A higher degree of anisotropic precipitation is observed with increasing dislocation loop and void size; a phenomenon not observed in thermally aged samples.</div></div>","PeriodicalId":423,"journal":{"name":"Scripta Materialia","volume":"274 ","pages":"Article 117145"},"PeriodicalIF":5.6,"publicationDate":"2025-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145837427","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 : 2025-12-26DOI: 10.1016/j.scriptamat.2025.117153
M. Sun , W.B. Jiang , J.F. Peng , Q.F. Fang , X.B. Wu
The detrimental effect of the ordered D03 structure on the magnetostriction of Fe-Ga alloys has been extensively recognized over the past two decades, yet its role in governing magnetic domain behavior and damping characteristics remains poorly understood. In this study, a series of Fe-Ga alloys with systematically varied D03 phase fractions were designed to elucidate the influence of nano-scaled D03 precipitates on defect relaxation, damping performance, and magnetic domain morphology. With increasing Ga content, the D03 phase fraction increases progressively, accompanied by a morphological evolution from spherical to near-rectangular shapes due to spatial confinement. Unexpectedly, the widespread precipitation of D03 does not eliminate magnetic damping, and instead it shifts the onset of magnetic damping to higher strain amplitudes. Moreover, the presence of enlarged D03 precipitates raises the critical amplitude required to initiate magnetic domain motion, below which the domain activity becomes effectively frozen. This work closes a key knowledge gap in the low-amplitude magnetic mechanical hysteresis damping regime and demonstrates that tailoring the size of the second-phase precipitates offers a viable strategy to modulate the amplitude range for achieving high damping.
{"title":"Strain-dependent magnetic domain freezing and unfreezing governed by D03 phase evolution in Fe-Ga alloys","authors":"M. Sun , W.B. Jiang , J.F. Peng , Q.F. Fang , X.B. Wu","doi":"10.1016/j.scriptamat.2025.117153","DOIUrl":"10.1016/j.scriptamat.2025.117153","url":null,"abstract":"<div><div>The detrimental effect of the ordered D0<sub>3</sub> structure on the magnetostriction of Fe-Ga alloys has been extensively recognized over the past two decades, yet its role in governing magnetic domain behavior and damping characteristics remains poorly understood. In this study, a series of Fe-Ga alloys with systematically varied D0<sub>3</sub> phase fractions were designed to elucidate the influence of nano-scaled D0<sub>3</sub> precipitates on defect relaxation, damping performance, and magnetic domain morphology. With increasing Ga content, the D0<sub>3</sub> phase fraction increases progressively, accompanied by a morphological evolution from spherical to near-rectangular shapes due to spatial confinement. Unexpectedly, the widespread precipitation of D0<sub>3</sub> does not eliminate magnetic damping, and instead it shifts the onset of magnetic damping to higher strain amplitudes. Moreover, the presence of enlarged D0<sub>3</sub> precipitates raises the critical amplitude required to initiate magnetic domain motion, below which the domain activity becomes effectively frozen. This work closes a key knowledge gap in the low-amplitude magnetic mechanical hysteresis damping regime and demonstrates that tailoring the size of the second-phase precipitates offers a viable strategy to modulate the amplitude range for achieving high damping.</div></div>","PeriodicalId":423,"journal":{"name":"Scripta Materialia","volume":"274 ","pages":"Article 117153"},"PeriodicalIF":5.6,"publicationDate":"2025-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145837429","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 : 2025-12-26DOI: 10.1016/j.scriptamat.2025.117149
Jingxian Zhang, Qianglong Liang, Xiangdong Ding
NiTi-based shape memory alloys are promising candidates for solid-state refrigeration owing to the latent heat associated with stress-induced martensitic transformations. However, the conventional B2→B19′ pathway is constrained by a fundamental trade-off between elastocaloric performance and cyclic stability. In this work, we demonstrate that activating the R→B19′ transformation pathway effectively circumvents this limitation. Differential scanning calorimetry confirms stable and reversible R→B19′ transformations in binary NiTi alloys. The reduced energy barrier between the R-phase and B19′ martensite facilitates a more continuous and efficient transformation, thereby suppressing the accumulation of irreversible defects. Through integrated thermomechanical processing and microstructural characterization, we show that NiTi alloys undergoing reversible R↔B19′ transformations exhibit a large adiabatic temperature change (18.59 K), high recoverable strain (4.86%), and exceptional cycling stability, retaining over 99% of performance after 200 tensile cycles. These findings establish a robust design strategy for high-performance shape memory alloys.
{"title":"Cyclic stable superelasticity and elastocaloric effect via the R→B19′ transformation in NiTi","authors":"Jingxian Zhang, Qianglong Liang, Xiangdong Ding","doi":"10.1016/j.scriptamat.2025.117149","DOIUrl":"10.1016/j.scriptamat.2025.117149","url":null,"abstract":"<div><div>NiTi-based shape memory alloys are promising candidates for solid-state refrigeration owing to the latent heat associated with stress-induced martensitic transformations. However, the conventional B2→B19′ pathway is constrained by a fundamental trade-off between elastocaloric performance and cyclic stability. In this work, we demonstrate that activating the R→B19′ transformation pathway effectively circumvents this limitation. Differential scanning calorimetry confirms stable and reversible R→B19′ transformations in binary NiTi alloys. The reduced energy barrier between the R-phase and B19′ martensite facilitates a more continuous and efficient transformation, thereby suppressing the accumulation of irreversible defects. Through integrated thermomechanical processing and microstructural characterization, we show that NiTi alloys undergoing reversible R↔B19′ transformations exhibit a large adiabatic temperature change (18.59 K), high recoverable strain (4.86%), and exceptional cycling stability, retaining over 99% of performance after 200 tensile cycles. These findings establish a robust design strategy for high-performance shape memory alloys.</div></div>","PeriodicalId":423,"journal":{"name":"Scripta Materialia","volume":"274 ","pages":"Article 117149"},"PeriodicalIF":5.6,"publicationDate":"2025-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145837428","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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