Scripta Materialia最新文献

英文中文

Iron as a microstructural architect in ATI 425 via DED-LB 铁作为一个微结构建筑师在ATI 425通过d - lb

IF 5.6 2区材料科学 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Scripta Materialia

Pub Date : 2026-04-15 Epub Date: 2026-02-02 DOI: 10.1016/j.scriptamat.2026.117199

Shenglu Lu, Tiantian Wang, Shudong Luo, Tingting Song, Milan Brandt, Ma Qian

Laser-based directed energy deposition (DED-LB) overcomes the long-standing barrier to iron alloying in titanium—β-fleck formation—unlocking new compositional space for alloy design. Here, we exploit this capability to engineer the α-β Ti alloy ATI 425 (≤1.8 wt.% Fe) with Fe additions up to 4.5 wt.%. Our findings reveal two previously unrecognised roles of Fe: (i) driving the development of a pronounced {

10 \bar{1} 2

} texture component with high Schmid factors across all primary slip systems, and (ii) promoting Type 2 α-variant misorientation (

[11 \bar{2} 0] / 60^{\circ}

) that favour transformation strain self-accommodation. At total Fe contents ≥4.5 wt.%, Fe additionally facilitates a columnar-to-equiaxed transition, notably without disrupting the [001]‖Z texture. Across the composition range, Fe progressively refines both prior-β grains and α–β lamellae. Based on ω-phase formation and tensile response, a new practical limit of ∼3.0 wt.% total Fe content is identified for DED-LB–processed ATI 425, which significantly enhances strength while preserving good ductility.

激光定向能沉积（d - lb）克服了钛β斑形成中铁合金化的长期障碍，为合金设计开辟了新的成分空间。在这里，我们利用这种能力来设计α-β钛合金ATI 425（铁含量≤1.8 wt.%），铁添加量高达4.5 wt.%。我们的研究结果揭示了铁的两个以前未被认识到的作用：(i)在所有主要滑移系统中驱动具有高施密德因子的明显{101¯2}织构成分的发展，以及（ii）促进有利于转变应变自适应的2型α变体取向错误（[112¯0]/60°）。当总铁含量≥4.5 wt.%时，铁还促进了柱状到等轴的转变，特别是在不破坏[001]‖Z织构的情况下。在整个组成范围内，铁逐渐细化了先前的-β晶粒和α -β片层。基于ω相形成和拉伸响应，确定了d - lb加工的ATI 425的总铁含量为~ 3.0 wt.%的新实用极限，在保持良好延展性的同时显著提高了强度。

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引用次数: 0

U1 Raman band as a signature of uranium interstitials in irradiated UO2 UO2辐照下铀间隙的U1拉曼谱带特征

IF 5.6 2区材料科学 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Scripta Materialia

Pub Date : 2026-04-15 Epub Date: 2026-02-04 DOI: 10.1016/j.scriptamat.2026.117213

A. Georgesco , C. Onofri , J.-P. Crocombette , F. Bruneval , D. Drouan , G. Gutierrez

The characterization of irradiated nuclear fuels is challenging because of their high radioactivity. Raman spectroscopy offers a rapid, non-destructive alternative well-suited for studying irradiated nuclear fuels, such as uranium dioxide (UO₂). In this study, Au-ion irradiations were performed and the nature of the U1 band was investigated through a combined approach involving Raman spectroscopy, Transmission Electron Microscopy (TEM), and Rate Theory (RT) modeling. Under irradiation, the U1 band area scales with the evolution of interstitial-type dislocation loop density observed by TEM. Under annealing, its decrease matches the reduction in uranium defect concentration predicted by the RT model, with a notable annealing step around 473 K, which we attribute to uranium interstitial-type defect mobility. These observations suggest that the U1 band reflects the presence of 3+ cations in an oxygen cubic cage, that would, in the case of irradiation, correspond to uranium interstitials in a 3+ charged state.

由于辐照核燃料的高放射性，对其特性的描述具有挑战性。拉曼光谱提供了一种快速、非破坏性的替代方法，非常适合研究辐照核燃料，如二氧化铀（UO2）。在这项研究中，通过拉曼光谱、透射电子显微镜（TEM）和速率理论（RT）模型的结合方法，进行了au离子辐照，并研究了U1波段的性质。辐照下，透射电镜观察到的U1波段面积随间隙型位错环密度的变化而增大。退火后，其下降与RT模型预测的铀缺陷浓度下降相匹配，在473 K左右有一个显著的退火步骤，我们将其归因于铀的间隙型缺陷迁移率。这些观察结果表明，U1波段反映了氧立方笼中3+阳离子的存在，在辐照的情况下，这将对应于3+带电状态的铀间隙。

引用次数: 0

Solute/interphase interaction and deviation from equilibrium during ferrite growth: Nanoscale diagnostics 铁氧体生长过程中溶质/相间相互作用和平衡偏差：纳米级诊断

IF 5.6 2区材料科学 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Scripta Materialia

Pub Date : 2026-04-15 Epub Date: 2026-01-28 DOI: 10.1016/j.scriptamat.2026.117195

Olha Nakonechna , Frédéric Danoix , Helena Zapolsky , Mohamed Gouné

A significant deviation in phase fractions from equilibrium is highlighted during γ-austenite to α-ferrite transformation at 625 °C of a Fe-C-Mn model alloy. To understand it, representative α/γ interfaces were analysed by atom probe tomography for different holding times, after selection assisted by electron backscattered diffraction (EBSD). Most of the interfaces exhibit strong Mn segregation within the interface, and some were found to be in paraequilibrium (PE) mode. Individual interface dynamics were revealed, and the observed growth sequence in PE mode, segregation at the α/γ interface, and partitioning of Mn into austenite are analyzed using the normalized interface velocity. This latter, rather than the intrinsic velocity of the interface, is shown to be the marker of solute/interface interaction. The original deviation of the ferrite phase fraction from equilibrium is associated with the velocity-dependent segregation effects. The proposed analysis provides clarification of the mechanisms and modes of ferrite growth in steels.

在625℃下，Fe-C-Mn模型合金的γ-奥氏体向α-铁素体转变过程中，相分数明显偏离平衡。为了理解这一点，在电子背散射衍射（EBSD）辅助选择后，用原子探针断层扫描分析了不同保温时间下具有代表性的α/γ界面。大多数界面在界面内表现出强烈的Mn偏析，有些界面处于副平衡态（PE）。利用归一化界面速度分析了在PE模式下观察到的生长顺序、α/γ界面的偏析以及Mn向奥氏体的划分。后者，而不是界面的固有速度，被证明是溶质/界面相互作用的标志。铁素体相分数与平衡相的原始偏差与速度相关的偏析效应有关。提出的分析澄清了钢中铁素体生长的机制和模式。

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引用次数: 0

Deformation induced kink band formation and ω-to-β phase reversion in a cold rolled metastable β Ti-10Mo alloy 冷轧亚稳态Ti-10Mo合金变形诱导扭结带形成和ω-to-β相逆转

IF 5.6 2区材料科学 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Scripta Materialia

Pub Date : 2026-04-15 Epub Date: 2026-01-31 DOI: 10.1016/j.scriptamat.2026.117194

Deepak V Pillai , Tirthesh Ingale , Fan Sun , Liang Qi , Rajarshi Banerjee , Yufeng Zheng

The deformation mechanism of a metastable β Ti-10Mo (wt.%) alloy during cold rolling was investigated using scanning electron microscopy, transmission electron microscopy, and aberration-corrected scanning transmission electron microscopy. While being typically considered a TRIP alloy, {332}_β<113>_β deformation twinning was identified as the dominant mechanism, accompanied by nanoscale stress-induced ω and αʺ martensite. Additionally, nanoscale <110>_β-type deformation induced kink bands formed via lattice rotation around <110>_β axis due to pileups of {112}_β<111>_β dislocations, effectively relaxing localized strain. Inside primary deformation kink bands, secondary <110>_β-type kink bands developed together with ω-free zones, wherein pre-formed athermal ω reverted to β phase. It is speculated that {112}_β<111>_β dislocation slip within primary kink bands promote secondary kink bands and facilitate the atomic shuffling along {112}_β planes leading to the ω-to-β phase reversion. These findings provide new insights into the role of kink band formation in strain accommodation and phase reversion in ductile metastable β titanium alloys.

采用扫描电镜、透射电镜和像差校正扫描电镜研究了亚稳态β Ti-10Mo （wt.%）合金在冷轧过程中的变形机理。虽然通常被认为是TRIP合金，但{332}β<；113>；β变形孪晶是主要机制，并伴有纳米级应力诱导的ω和α′′马氏体。此外，由于{112}β<；111>；β位错的堆积，纳米级的<；110>；β型变形诱导晶格围绕<；110>；β轴旋转形成扭结带，有效地松弛局部应变。在初级变形扭结带内，次级<；110>；β型扭结带与无ω区一起发育，其中预成型的非热ω向β相转变。推测{112}β<；111>；β位错滑移在初级扭结带内促进了次级扭结带，促进了原子沿{112}β平面的洗牌，导致了ω -β相的逆转。这些发现为研究扭结带形成在延展性亚稳β钛合金应变调节和相逆转中的作用提供了新的见解。

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引用次数: 0

Role of reinforcement-dominated strengthening and thermally activated accommodation/damage in the tensile performances of AlFeVSi-B2O3 composites 增强主导强化和热活化调节/损伤对AlFeVSi-B2O3复合材料拉伸性能的影响

IF 5.6 2区材料科学 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Scripta Materialia

Pub Date : 2026-04-15 Epub Date: 2026-02-09 DOI: 10.1016/j.scriptamat.2026.117215

Mengyu Li , Tong Gao , Guiliang Liu , Shushuai Liu , Xiangfa Liu

Two composites were prepared via in-situ reactions in AlFeVSi-B₂O₃ and Al-AlFeVSi-B₂O₃ systems followed by hot extrusion, forming micron-sized Al₈Fe₂Si together with nanometric VB₂ and γ-Al₂O₃. With the increase of temperature, the hardness, ultimate tensile strength and work hardening capacity decrease gradually. However, the fracture elongation increases when the temperature rises from 25 °C to 150 °C, and then decreases at 250 and 350 °C, exhibiting a "rise-then-fall" trend. Analysis of the temperature-dependent evolution in recrystallization fraction, dislocation density, and fracture morphology suggests that the non-monotonic trend arises from the interplay between reinforcement-dominated strengthening and thermally activated accommodation/damage mechanisms.

在AlFeVSi-B2O3和Al-AlFeVSi-B2O3体系中原位反应制备了两种复合材料，然后进行热挤压，与纳米级VB2和γ-Al2O3形成微米级Al8Fe2Si。随着温度的升高，合金的硬度、极限抗拉强度和加工硬化能力逐渐降低。断裂伸长率在25 ~ 150℃温度范围内呈先上升后下降的趋势，在250 ~ 350℃温度范围内呈先上升后下降的趋势。对再结晶分数、位错密度和断口形貌的温度依赖演化分析表明，这种非单调趋势是由增强主导的强化和热激活的调节/损伤机制相互作用产生的。

引用次数: 0

Improved strength-ductility with bimodal microstructure composed of kink-strengthening grains in a layer-structured Mg-Al-Y alloy 层状组织Mg-Al-Y合金中由扭结强化晶粒组成的双峰组织提高了强度-塑性

IF 5.6 2区材料科学 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Scripta Materialia

Pub Date : 2026-04-15 Epub Date: 2026-02-02 DOI: 10.1016/j.scriptamat.2026.117198

Han Chen , Kakeru Kubota , Daisuke Egusa , Yuto Ito , Michiaki Yamasaki , Eiji Abe

We report that a mille-feuille-type layer-structured Mg-Al-Y alloy shows a remarkably improved strength-ductility balance after applying a hot-extrusion process, which successfully generates a unique bimodal microstructure consisting of fine recrystallized grains and large kink-deformed grains. The strength originates primarily from the work-hardened large grains composed of a large number of kink boundaries (KBs), while the ductility is mainly due to the recrystallized grains that are almost free from defects. On the contrary to the significant solute-segregations at the KBs observed so far for the most kink-strengthened Mg-transition-metal-rare-earth alloys, the present Mg-Al-Y alloy exhibits notably weak solute-segregations, hence suggesting that the solute-segregation is not an essential factor to realize the KB strengthening effect. The solute-segregation behaviors as well as the layer-structure stability are discussed based on solute-pair interaction energy calculations and solute diffusion kinetics during the initial heat treatment and the hot-extrusion process.

本文报道了一种千叶型层状组织Mg-Al-Y合金在热挤压工艺后，其强度-塑性平衡得到了显著改善，成功地形成了由细小的再结晶晶粒和大的扭结变形晶粒组成的独特的双峰组织。强度主要来自由大量扭结边界（KBs）组成的加工硬化大晶粒，而延展性主要来自几乎没有缺陷的再结晶晶粒。与迄今为止观察到的大多数扭结强化mg -过渡金属-稀土合金在KB处存在明显的溶质偏析相反，Mg-Al-Y合金表现出明显的弱溶质偏析，因此表明溶质偏析不是实现KB强化效果的必要因素。基于溶质对相互作用能计算和溶质扩散动力学，讨论了初始热处理和热挤压过程中溶质偏析行为和层结构稳定性。

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引用次数: 0

High-resolution STEM/EDS characterization of defect cluster complexes in reactor pressure vessel steel model alloys 反应堆压力容器钢模型合金中缺陷团簇复合物的高分辨率STEM/EDS表征

IF 5.6 2区材料科学 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Scripta Materialia

Pub Date : 2026-04-15 Epub Date: 2026-01-29 DOI: 10.1016/j.scriptamat.2026.117197

Yusuke Noshi , Koki Onaka , Moe Ishiwaki , Manato Kakizawa , Ryoya Ishigami , Tomokazu Yamamoto , Kazuhiro Yasuda , Ken-ichi Fukumoto

Dislocation loop complexes with solute atoms were observed in this study using a high-resolution STEM/EDS analysis technique. In Fe-1.3Mn-0.6Ni alloy, Mn segregated along dislocation lines, and Ni segregated to the centers of dislocation loops. Mn, predominantly diffusing as mixed dumbbells with SIA, were driven to segregate toward tensile stress regions outside the dislocation edges, appearing near the dislocation lines. Conversely, when Ni diffused via the vacancy dragging mechanism, they were driven to segregate toward compressive stress regions inside the dislocation loop edges, manifesting as segregation at the centers of the loops. In contrast, in Fe-1.3Mn-0.6Ni-0.2Si alloy, Si addition inhibited this Ni segregation. This occurred because Si atoms preferentially interacted with point defects, thereby restricting the available diffusion pathways for Ni segregation. Furthermore, as Si is thermodynamically stable in solid solution, it did not undergo spontaneous segregation; instead, it indirectly inhibited Ni segregation by competing for point defect diffusion vehicles.

本研究使用高分辨率STEM/EDS分析技术观察了溶质原子的位错环配合物。在Fe-1.3Mn-0.6Ni合金中，Mn沿位错线偏析，Ni向位错环中心偏析。Mn主要像SIA混合哑铃一样扩散，被驱动向位错边缘外的拉应力区偏析，出现在位错线附近。相反，当Ni通过空位拖拽机制扩散时，它们被驱动向位错环边缘的压应力区偏析，表现为在环中心偏析。而在Fe-1.3Mn-0.6Ni-0.2Si合金中，Si的加入抑制了这种Ni偏析。这是因为Si原子优先与点缺陷相互作用，从而限制了Ni偏析的可用扩散途径。此外，由于Si在固溶体中热力学稳定，它不会发生自发偏析；相反，它通过竞争点缺陷扩散载体间接抑制了Ni偏析。

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引用次数: 0

Simultaneous boost in plasticity and thermoelectric performance of Ag2Te via Ag nanotwins induced by HPHT 高温高温诱导银纳米孪晶同时提高Ag2Te的塑性和热电性能

IF 5.6 2区材料科学 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Scripta Materialia

Pub Date : 2026-04-15 Epub Date: 2026-02-03 DOI: 10.1016/j.scriptamat.2026.117205

Erzhuo Jiang , Hongtao Wang , Kailiang Fang , Zhuoming Xia , Chenyang Xiao , Xiaobin Feng , Bo Duan , Guodong Li , Pengcheng Zhai , Qingjie Zhang

Ag₂Te is a promising thermoelectric material, owing to its complex crystal structure, high carrier mobility, and tunable mechanical properties. In this work, dense Ag nanotwins were in situ formed within the Ag₂Te matrix via high-pressure and high-temperature (HPHT) sintering. These nanotwins enhanced the plasticity of the material, resulting in a fracture strain of 14.6 %, approximately 300 % higher than that of the twin-free Ag₂Te-473 sample. The nanotwins also improved the thermoelectric performance by boosting the Seebeck coefficient and suppressing the lattice thermal conductivity. As a result, the Ag₂Te-773 sample achieved a peak ZT of 0.78 at 570 K. These findings demonstrate that HPHT offers a viable route to co-optimize the mechanical and thermoelectric performance in brittle fast-ion semiconductors through microstructural design.

由于其复杂的晶体结构、高载流子迁移率和可调的力学性能，Ag2Te是一种很有前途的热电材料。在这项工作中，通过高压高温烧结（HPHT）在Ag2Te基体中原位形成致密的银纳米孪晶。这些纳米孪晶提高了材料的塑性，导致断裂应变为14.6%，比不含孪晶的Ag2Te-473样品高约300%。纳米孪晶还通过提高塞贝克系数和抑制晶格热导率来改善热电性能。结果表明，Ag2Te-773样品在570 K时ZT峰值为0.78。这些发现表明，HPHT通过微结构设计为脆性快离子半导体的机械和热电性能共同优化提供了一条可行的途径。

引用次数: 0

Origin of strain localization near prior austenite grain boundary in martensitic steel: Role of chemical and dislocation structures 马氏体钢在奥氏体晶界附近应变局部化的起源：化学和位错组织的作用

IF 5.6 2区材料科学 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Scripta Materialia

Pub Date : 2026-04-15 Epub Date: 2026-01-31 DOI: 10.1016/j.scriptamat.2026.117201

Wujun Yin , Fabien Briffod , Jiyun Kang , Haoyu Hu , Kazuhiko Yamazaki , Takayuki Shiraiwa , Manabu Enoki

Premature failure near prior austenite grain boundaries (PAGBs) limits the ductility of lath-martensitic steels, yet the mechanistic origin of this vulnerability remains unclear due to their complex hierarchical microstructure. This study integrates atom probe tomography, electron channeling contrast imaging, and high-resolution digital image correlation to directly correlate atomic-scale chemical segregation with local dislocation activity and strain evolution near PAGBs. The results reveal that habit-plane in-lath dislocations dominate deformation in fine-lath martensite adjacent to PAGBs, preferentially activated according to the Schmid law and facilitated by their long mean free path. Intense carbon segregation at PAGBs, together with nanoscale carbide precipitates in their vicinity, forms a strong barrier to dislocation motion, producing substantial dislocation accumulation near the boundary. This interaction drives severe strain localization, providing direct nanoscale evidence linking chemical heterogeneity to localized mechanical response near the PAGBs.

在先前奥氏体晶界（pagb）附近的过早破坏限制了板条马氏体钢的延展性，但由于其复杂的分层微观结构，这种脆弱性的机制起源尚不清楚。该研究结合了原子探针断层扫描、电子通道对比成像和高分辨率数字图像相关，直接将原子尺度的化学偏析与pagb附近的局部位错活动和应变演化联系起来。结果表明，在与pagb相邻的细板条马氏体中，习惯面位错主导变形，优先根据施密德定律激活，并由其较长的平均自由程促进。pagb处强烈的碳偏析以及其附近的纳米级碳化物沉淀形成了位错运动的强大屏障，在边界附近产生了大量的位错积累。这种相互作用驱动了严重的应变局部化，提供了直接的纳米尺度证据，将化学异质性与pagb附近的局部机械响应联系起来。

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引用次数: 0

Solid -state dewetting in Pd/a-Ge bilayers Pd/a-Ge双分子层的固态脱湿

IF 5.6 2区材料科学 Q2 MATERIALS SCIENCE, MULTIDISCIPLINARY

Scripta Materialia

Pub Date : 2026-04-15 Epub Date: 2026-01-29 DOI: 10.1016/j.scriptamat.2026.117188

Bärbel Krause , Gregory Abadias , David Babonneau

The post-growth morphology and the chemical composition of sputter-deposited Pd/a-Ge films were studied by in situ atomic force microscopy and X-ray photoelectron spectroscopy under UHV conditions. The polycrystalline films consist of locally epitaxial Pd/Pd₂Ge grains on an amorphous germanium buffer layer. We found that the films show a thickness-dependent tendency for solid-state dewetting, which occurs at the interface between the Pd and Pd₂Ge layers and for Pd thicknesses below 6 nm. The post-growth dewetting is correlated with the real-time stress evolution during deposition. Real-time x-ray reflectivity measurements confirm that the dewetting is kinetically hindered during deposition, while individual grains dissolve after deposition, leaving deep holes. The room-temperature dewetting of Pd/a-Ge combines characteristic features of epitaxial and polycrystalline dewetting mechanisms. We propose that it is driven by the misfit strain between Pd and Pd₂Ge, while the stability of individual grains is determined by the local grain boundary configuration.

采用原位原子力显微镜和x射线光电子能谱技术研究了溅射沉积Pd/a-Ge薄膜在超高压条件下的生长后形貌和化学成分。该多晶薄膜由局部外延的Pd/Pd2Ge晶粒组成，外延在非晶锗缓冲层上。我们发现，在Pd和Pd2Ge层之间的界面以及Pd厚度低于6 nm时，薄膜表现出与厚度相关的固态脱湿趋势。生长后的脱湿与沉积过程中的实时应力演化有关。实时x射线反射率测量证实，在沉积过程中，脱湿受到动力学阻碍，而单个颗粒在沉积后溶解，留下深孔。Pd/a-Ge的室温脱湿结合了外延和多晶脱湿机制的特点。我们认为这是由Pd和Pd2Ge之间的失配应变驱动的，而单个晶粒的稳定性是由局部晶界配置决定的。

引用次数: 0

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