Scripta Materialia最新文献_第5页

Helium ion induced degradation of microstructure and thermal conductivity in MAX phase Ti3SiC2 氦离子诱导MAX相Ti3SiC2微观结构和导热性能的退化

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

Scripta Materialia

Pub Date : 2025-12-06 DOI: 10.1016/j.scriptamat.2025.117131

Yibo Zhang , Yaojun Li , Qian Liao , Yuexia Wang , Xianfeng Ma , Fei Zhu , Yuzhou Wang

Conventional nuclear ceramics suffer drastic thermal conductivity degradation under nuclear radiation. MAX phase materials, with their hybrid metallic-ceramic bond characteristics, represent promising fuel materials capable of mitigating irradiation-induced conductivity changes. Nonetheless, the critical property of post-irradiation thermal conductivity of MAX phase remains unexplored. In this study, we investigated the thermal conductivity of Ti₃SiC₂ following He ion irradiation. Multimodal microstructural characterization revealed irradiation-induced lattice disturbance and a high density of He bubbles. State-of-the-art spatial-domain thermoreflectance measurement demonstrated roughly 74% reduction in thermal conductivity, less severe than conventional ceramics but exceeding typical metals. This intermediate degradation stems from the electron-dominated thermal transport in Ti₃SiC₂, which is particularly sensitive to small-scale defects. First-principles calculation revealed the distinct impact of irradiation defects on electron transport, with Si and He related defects exhibiting the largest influence. The material’s retained thermal performance under irradiation suggests promising potential for enhancing thermal properties in advanced nuclear fuels.

传统的核陶瓷在核辐射下导热性能急剧下降。MAX相材料具有金属-陶瓷混合键特性，是一种很有前途的燃料材料，能够减轻辐射引起的电导率变化。然而，辐照后MAX相的热导率的临界性质仍未被探索。在这项研究中，我们研究了Ti3SiC2在He离子辐照下的热导率。多模态微观结构表征显示辐照引起的晶格扰动和高密度的He气泡。最先进的空间热反射测量表明，导热系数降低了约74%，比传统陶瓷轻，但超过了典型的金属。这种中间降解源于Ti3SiC2中的电子主导热输运，对小尺寸缺陷特别敏感。第一性原理计算揭示了辐照缺陷对电子输运的明显影响，其中Si和He相关缺陷的影响最大。这种材料在辐照下保持的热性能表明，它有潜力增强先进核燃料的热性能。

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引用次数: 0

FCC stacking fault energies from diffraction depend on orientation 衍射所得的FCC层错能与取向有关

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

Scripta Materialia

Pub Date : 2025-12-05 DOI: 10.1016/j.scriptamat.2025.117120

Runguang Li, Ziyu Ma, Jun Wang, Hossein Beladi, Matthew R. Barnett

Stacking fault energy (SFE) critically affects twinning and martensitic transformation in FCC metals. As an intrinsic parameter, it is expected to remain constant under various testing conditions at the same temperature. The widely used Reed-Schramm method estimates SFE from stacking fault probability (SFP) and root mean square (rms) microstrain in deformed metals. In this study, synchrotron high-energy X-ray diffraction was used to evaluate the SFP and rms microstrain in a tensile-deformed TWIP steel. The SFP showed a strong correlation with grain orientation, whereas rms microstrain was relatively orientation-insensitive. These parameters yielded orientation-sensitive measured SFE (mSFE) values ranging from 4 to 30 mJ/m², correlating with the developed [111]//LD (low mSFE) and [100]//LD (high mSFE) texture components. Transmission electron microscopy further revealed microstructural differences, with dense, highly extended stacking faults in [111]//LD grains but few in [100]//LD grains. These findings highlight the limitations of diffraction-based experimental strategies in determining the SFE.

层错能（SFE）对FCC金属的孪晶和马氏体相变有重要影响。作为一个本征参数，在相同温度下，在各种测试条件下都应保持恒定。目前广泛使用的Reed-Schramm方法是根据变形金属的层错概率（SFP）和均方根（rms）微应变来估计SFE。本研究采用同步高能x射线衍射对拉伸变形的TWIP钢的SFP和rms微应变进行了评价。SFP微应变与晶粒取向有较强的相关性，而rms微应变对取向不敏感。这些参数产生了取向敏感的测量SFE （mSFE）值，范围为4 ~ 30 mJ/m²，与发育的[111]//LD（低mSFE）和[100]//LD（高mSFE）纹理成分相关。透射电镜进一步揭示了微观结构上的差异，[111]//LD晶粒中存在密集且高度延伸的层错，而[100]//LD晶粒中很少存在层错。这些发现突出了基于衍射的实验策略在确定SFE方面的局限性。

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引用次数: 0

Rapid tempering to enhance dynamic performance of high and ultra-high strength steels 快速回火以提高高强度和超高强度钢的动态性能

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

Scripta Materialia

Pub Date : 2025-12-05 DOI: 10.1016/j.scriptamat.2025.117116

Lawrence Cho , Emily Pittman , Leslie Lamberson , Alec Williamson , David Ulrich , Garrison Hommer , Daniel M. Field , Krista R. Limmer , Kip O. Findley , John G. Speer

This study employed rapid, short-time duration (1 s) tempering to improve the dynamic performance of high-strength steel (HSS) and ultra-high-strength steel (UHSS), compared to quenched and conventionally (1800 s) tempered microstructures. Rapid tempering significantly improved the Charpy toughness of both steels compared to the conventionally tempered condition at an equivalent tempering parameter (TP) or hardness level. For conventionally tempered conditions, tempered martensite embrittlement was observed within the tempering temperature range of 200–400 °C, whereas rapid tempering exhibited increased Charpy toughness with increasing tempering temperature across all tempering conditions. Dynamic compression experiments indicated that rapid tempering led to improved ductility compared to the conventionally tempered condition at an equivalent TP. This work shows that the same rapid tempering strategy used for HSS is directly transferable to a higher-carbon UHSS and provides the first systematic evidence of improved strength-ductility combinations and cracking resistance under dynamic compression, supported by Kolsky bar experiments.

本研究采用快速、短时间（1 s）回火，与淬火和常规（1800 s）回火组织相比，提高了高强钢（HSS）和超高强钢（UHSS）的动态性能。与同等回火参数（TP）或硬度水平下的常规回火条件相比，快速回火显著提高了两种钢的夏比韧性。在常规回火条件下，在200-400°C回火温度范围内观察到回火马氏体脆化，而在所有回火条件下，随着回火温度的升高，快速回火表现出夏比韧性的增加。动态压缩实验表明，在同等TP条件下，与常规回火相比，快速回火可以提高塑性。这项工作表明，用于HSS的相同快速回火策略可直接转移到高碳超高压钢中，并提供了第一个系统的证据，证明在动态压缩下强度-塑性组合和抗裂性得到了科尔斯基棒实验的支持。

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引用次数: 0

Inclined TEDs with pairs of partial dislocations located away from the basal plane in 4H-SiC epilayers 在4H-SiC薄膜中，具有部分位错对的倾斜TEDs远离基面

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

Scripta Materialia

Pub Date : 2025-12-05 DOI: 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 (

11 \bar{2} 0

) 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 [

11 \bar{2} 0

] 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 (

11 \bar{2} (2 n)

) 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.

我们在4H-SiC脱毛层中发现了以前未报道的缺陷，这些缺陷不在[0001]方向或（112¯0）平面上。每个缺陷由一对由层错分隔的部分位错组成，而不是形成一个完美的位错。由于它们从[0001]方向向[112¯0]方向的倾角分别为52°和65°，因此我们将它们称为“伪螺纹边缘位错（ted）”。伪ted中部分位错间距也增加，在90°倾角下达到12 nm。根据观察到的晶体取向，伪ted沿（112¯（2n））面趋于稳定。此外，将完全位错形式的ted结构与基面位错形式的总能进行比较，发现随着倾角的增大，伪ted结构比完全位错形式更有利。

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引用次数: 0

Inhibiting dislocation recovery via yttrium-induced diffusion barriers: A novel strategy for creep resistance in Ni-based single crystal superalloys 通过钇诱导扩散屏障抑制位错恢复：镍基单晶高温合金抗蠕变的新策略

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

Scripta Materialia

Pub Date : 2025-12-04 DOI: 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.

微量钇(Y)的加入显著提高了第二代镍基单晶高温合金的耐高温蠕变性能。本研究通过阐明Y对1100℃/90 MPa蠕变过程中原子扩散和位错恢复的影响，揭示了其潜在机制。通过APT和TEM的耦合分析表明，Y优先向γ′相分配，分别改变了γ基体、γ′相和位错核中的界面化学性质，抑制了原子扩散率。这种扩散屏障减缓了位错网络的演化，同时延缓了它们的降解。最关键的是，它深刻地抑制了a<；100>；超级位错的爬升控制运动，这是主要的恢复机制。因此，Y掺杂保持了稳定的位错网络，抑制了恢复过程，导致了非常低的稳态应变率。这些发现揭示了微量Y通过抑制扩散介导的位错恢复来增强抗蠕变能力的新机制，为新的合金设计策略奠定了基础。

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引用次数: 0

Defect-driven polarization reconfiguration in Bi3.15Nd0.85Ti3O12 film Bi3.15Nd0.85Ti3O12薄膜中缺陷驱动的极化重构

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

Scripta Materialia

Pub Date : 2025-12-03 DOI: 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 Bi_3.15Nd_0.85Ti₃O₁₂ 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.

缺陷工程aurivillius相层状材料铁电性能控制的物理根源在于结构缺陷介导的局部极化演化。然而，广泛存在的非相边界（OPB）缺陷在极化配置中的作用尚不清楚。本研究以采用HfO2缓冲层优化的Bi3.15Nd0.85Ti3O12薄膜为模型体系，阐明OPB缺陷区域局部极化增强的内在机制。原子尺度的定量分析表明，OPB缺陷增强了b位阳离子的面内位移，并使它们在钙钛矿层内的面外极化方向重合。这种重构通过消除原始晶格中相邻伪钙钛矿块之间的面外偶极子的反平行排列而破坏了固有的反极性顺序。应变和空位再分配通过破坏电荷补偿进一步促进极化构型转变。这些发现提供了缺陷调制铁电的机理见解，并提出了通过应变和缺陷工程设计高性能器件的新方法。

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引用次数: 0

Two-step deep learning for decoding elastic constants of hexagonal-symmetry materials from resonant-spectrum image 共振光谱图像中六边形对称材料弹性常数的两步深度学习

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

Scripta Materialia

Pub Date : 2025-12-03 DOI: 10.1016/j.scriptamat.2025.117115

Kazuya Kohira , Shota Nakamura , Hiroki Fukuda , Kazuhiro Kyotani , Hirotsugu Ogi

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.

我们开发了一个基于卷积神经网络（cnn）的深度学习（DL）框架，利用cnn的高图像识别能力来预测六边形材料的弹性常数。将共振频率数据转换为三通道RGB图像，称为“弹性图像”，用于CNN训练。在没有模态识别的情况下，训练的模型可以准确地预测所有五个独立的弹性常数。我们揭示了平均杨氏模量是一个关键的分类六边形材料基于他们的弹性图像。此外，我们将最初为立方晶体开发的Blackman图扩展到六边形系统，从而大大减少了五维弹性常数空间。然后，我们建立了一个两步DL方案：首先，使用平均杨氏模量进行分类，然后在分类的平均杨氏模量类别中回归五个弹性常数。主弹性常数预测误差约为5%，平均杨氏模量预测误差约为1.5%。

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引用次数: 0

Investigation into the effect of adjacent crystallographic orientations on corrosion behavior in single-phase copper-nickel alloys by quasi-in-situ method 准原位法研究相邻晶向对单相铜镍合金腐蚀行为的影响

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

Scripta Materialia

Pub Date : 2025-12-02 DOI: 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.

采用准原位法研究了cu - 30% Ni合金在酸性NaCl溶液中的腐蚀过程。晶界和孪晶区是两个优先腐蚀的部位。优先腐蚀晶界的相邻晶粒一般形成非-Σ3高角度晶界。决定晶间腐蚀敏感性的不是表面取向，而是晶格错取向角。相比之下，优先腐蚀的孪晶区域是由孪晶和相邻基体的表面取向决定的。大的表面晶面偏差角导致了高的腐蚀敏感性。基于这些观察结果，用计算模型预测了多晶材料的腐蚀行为。结果表明：不同基体织构的晶间腐蚀敏感性相似，但含孪晶{100}晶的晶内腐蚀敏感性较高；因此，Cu-Ni合金中应避免主要的含孪晶{100}晶粒，以获得较高的耐蚀性。

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引用次数: 0

An alternative in-grain misorientation axes analysis for slip activity: A case study in a magnesium alloy 滑移活动的可选晶内取向轴分析：镁合金的案例研究

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

Scripta Materialia

Pub Date : 2025-12-02 DOI: 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.

基于电子背散射衍射（EBSD）的晶粒内错取向轴（IGMA）分析被广泛应用于形变材料的位错滑移活动研究。这项工作介绍了一种替代的，远程IGMA方法使用非连续对，而不是传统的短距离方法使用连续对。通过扩大两个像素之间的评估距离，允许存在更多的相反符号的晶粒尺度随机存储位错（ssd）及其相互抵消，远程方法增强了对晶粒尺度几何必要位错（GNDs）的检测，这些位错对于在变形时保持晶粒连续性至关重要，但可能被短程IGMA方法忽略。我们在沿两个方向压缩的高织构Mg-3Al-1 Zn （AZ31）合金上验证了这种方法，并确定了不同的滑移系统，说明了每种情况下的晶粒晶格曲率。这项工作强调了将空间和角度分离的非连续对集成到多晶体变形的IGMA分析中的互补价值。

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引用次数: 0

Interface-mediated softening and deformation mechanics in amorphous/amorphous nanolaminates 非晶/非晶纳米层合材料界面介导的软化和变形力学

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

Scripta Materialia

Pub Date : 2025-11-29 DOI: 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.

界面控制着非晶多层膜独特的力学响应。本文研究了双层厚度为2 ~ 334 nm的非晶/非晶Ta2O5/SiO2纳米层合材料的纳米压痕硬度和变形行为。单片SiO2表现出单一主导剪切带的灾难性破坏，而多层结构表现出不同的变形机制。硬度随双分子层厚度的减小而减小，从334 nm处的7.7 GPa降至2 nm处的5.5 GPa。横截面透射电镜显示，较细的双层厚度促进了紧密分布的垂直剪切带，并伴随双层压缩，而较粗的间距则导致较少分布的剪切带，并伴有化学混合。扫描进动电子衍射图显示凹痕下明显致密化。高界面密度有利于应变调节，防止脆性非晶材料典型的灾难性破坏。

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引用次数: 0