Materials & Design最新文献_第10页

Innovations in theoretical modeling for vat photopolymerization 还原光聚合理论模型的创新

IF 7.9 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials & Design

Pub Date : 2025-12-26 DOI: 10.1016/j.matdes.2025.115384

Yue Wang , Yang Li , Hongzhao Zhou , Na Liu , Yancheng Wang , Kai Tao , Deqing Mei , Tao Yue

Vat photopolymerization (VPP) is a foundational additive manufacturing technology that fabricates objects layer by layer through photoinduced polymerization. Among its variants, mask projection vat photopolymerization (MP-VPP) has attracted considerable attention for combining high resolution and throughput with relatively low cost by utilizing dynamic masks. Despite these advantages, key process parameters such as exposure time and cure depth are often determined empirically, limiting reproducibility and scalability. To overcome this gap, we emphasize the importance of physics-based theoretical models that reveal the fundamental curing mechanisms, thereby supporting accurate process control and improved printing fidelity. This review introduces a unified spatiotemporal modeling framework for MP-VPP, grounded in first-principles physics and progressively incorporating temporal and spatial effects. Existing models are systematically categorized into two domains: (i) temporal-determination models, which describe curing kinetics, energy accumulation, and depth growth, and (ii) spatial-determination models, which address light propagation, optical interactions, and in-plane curing fidelity. For each category, recent advances are synthesized and their implications for optimization are discussed. The review concludes by outlining emerging challenges and research opportunities. By integrating temporal and spatial perspectives, this work strengthens the theoretical foundation of MP-VPP and facilitates its development toward more precise, reliable, and efficient manufacturing.

还原光聚合（VPP）是一种基础的增材制造技术，通过光诱导聚合逐层制造物体。在其变体中，掩膜投影还原光聚合（MP-VPP）因其利用动态掩膜将高分辨率和高通量与相对低成本相结合而受到广泛关注。尽管有这些优点，关键的工艺参数，如曝光时间和固化深度往往是经验确定的，限制了再现性和可扩展性。为了克服这一差距，我们强调了基于物理的理论模型的重要性，这些模型揭示了基本的固化机制，从而支持精确的过程控制和提高打印保真度。本文介绍了一种基于第一性物理原理并逐步纳入时空效应的MP-VPP统一时空建模框架。现有模型系统地分为两个领域：(i)时间决定模型，描述固化动力学，能量积累和深度增长；（ii）空间决定模型，解决光传播，光相互作用和平面内固化保真度。对于每个类别，综合了最近的进展，并讨论了它们对优化的影响。报告最后概述了新出现的挑战和研究机会。通过时空视角的整合，加强了MP-VPP的理论基础，促进了MP-VPP向更精确、可靠和高效的制造方向发展。

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引用次数: 0

In-situ interface characterization of mesophase pitch-based carbon fiber/epoxy composites 中间相沥青基碳纤维/环氧复合材料的原位界面表征

IF 7.9 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials & Design

Pub Date : 2025-12-24 DOI: 10.1016/j.matdes.2025.115398

Xiaoran Wei , Hongbin Zhang , Jianzheng Cui , Jun Liu , Jiajia Cheng , Huang Wu , Chong Ye , Jinshui Yang , Jianwei Zhang , Suli Xing , Yonglyu He , Ke Duan

Mesophase pitch-based carbon fibers (MPCF) are ideal reinforcements for composite materials used in spacecraft due to their extraordinary thermal conductivity and high stiffness. However, their practical applications are severely limited by a lack of understanding of fiber-matrix interfacial interactions. Here, through a joint study of fiber push-out testing and molecular dynamics simulations, we investigated the effect of fiber microstructure on the interfacial shear strength of MPCF-reinforced epoxy composites with the microstructure of MPCF being tailored by different spinneret geometries. Our results showed that the surface roughness and interfacial contact mode are two predominant factors determining the interfacial shear strength (IFSS), which contradicts the common intuition that carbon fibers with a higher degree of graphitization generally lead to worse interfacial properties. Owing to the enhanced surface roughness and full edge-plane contact mode, the skin-core structured MPCFs exhibit an IFSS of 17.83 MPa, which is nearly 3 times that of the split-radial structured MPCFs (5.14 MPa). The distinct interface behavior between epoxy and MPCFs with different microstructures, as revealed by molecular dynamics (MD) simulations, stems from more pronounced mechanical interlocking and enhanced intermolecular attraction at the interface. These findings offer significant guidelines for fabricating MPCFs with high thermal conductivity without sacrificing the interfacial load transfer ability through the modulation of surface roughness and interface contact modes.

中间相沥青基碳纤维（MPCF）具有优异的导热性和高刚度，是航天器复合材料的理想增强材料。然而，由于缺乏对纤维-基质界面相互作用的理解，它们的实际应用受到严重限制。在这里，通过纤维推出测试和分子动力学模拟的联合研究，我们研究了纤维微观结构对MPCF增强环氧复合材料界面剪切强度的影响，并根据不同的喷丝孔几何形状定制了MPCF的微观结构。我们的研究结果表明，表面粗糙度和界面接触模式是决定界面剪切强度（IFSS）的两个主要因素，这与石墨化程度越高的碳纤维通常导致界面性能越差的普遍直觉相矛盾。由于表面粗糙度的增强和全边面接触模式，皮核结构mpcf的IFSS为17.83 MPa，是裂径结构mpcf （5.14 MPa）的近3倍。分子动力学（MD）模拟表明，不同微观结构的环氧树脂和mpcf之间的不同界面行为源于界面上更明显的机械联锁和增强的分子间吸引力。这些发现为在不牺牲界面载荷传递能力的前提下，通过调节表面粗糙度和界面接触模式，制造具有高导热系数的mpcf提供了重要的指导。

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引用次数: 0

Targeted delivery of empagliflozin via glycyrrhetinic-acid-modified lipid nanoparticles for metabolic dysfunction–associated steatotic liver disease therapy 通过甘次酸修饰的脂质纳米颗粒靶向递送恩格列净用于代谢功能障碍相关的脂肪变性肝病治疗

IF 7.9 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials & Design

Pub Date : 2025-12-23 DOI: 10.1016/j.matdes.2025.115391

Ganxiang Yu , Huimin Deng , Chun Xu , Zhilan Huang, Yuanyuan Zhang, Cheng Luo, Lisha Chen, Huixin Chen

Metabolic dysfunction–associated steatotic liver disease (MASLD) is a common metabolic disorder characterized by excessive lipid accumulation in the liver, insulin resistance, and impaired glucose metabolism. Empagliflozin (EGZ) effectively reduces liver fat, enhances insulin sensitivity, and improves glucose metabolism in various metabolic conditions. To specifically target hepatocytes, glycyrrhetinic acid (GA) was incorporated into lipid nanoparticles (LNPs), creating a GA-targeted EGZ@LNP-GA drug delivery system designed to enhance the therapeutic effects of EGZ on MASLD. The EGZ@LNP-GA formulation was thoroughly characterized by evaluating particle size, encapsulation efficiency, and in vitro release kinetics. In vitro studies showed that EGZ@LNP-GA exhibited high specificity for LO2 cells compared to HeLa and HUVEC cells. Treating LO2 cells with EGZ@LNP-GA diminished lipid accumulation, as demonstrated by Oil Red O staining and triglyceride (TG) content assays. Western blot analysis revealed that EGZ@LNP-GA downregulated lipogenic factors SREBP1c and FAS, while upregulating the lipid oxidation regulator SIRT1, indicating its potential to enhance lipid metabolism. In an HFD-induced steatosis model, EGZ@LNP-GA reduced hepatic lipid accumulation, lowered inflammatory cytokines, improved insulin sensitivity, and enhanced glucose metabolism. These findings support the GA-targeted EGZ@LNP-GA system as a promising strategy for MASLD-related metabolic dysfunction.

代谢功能障碍相关脂肪变性肝病（MASLD）是一种常见的代谢性疾病，其特征是肝脏中脂肪积聚过多、胰岛素抵抗和葡萄糖代谢受损。恩格列净（EGZ）能有效降低肝脏脂肪，提高胰岛素敏感性，改善各种代谢条件下的葡萄糖代谢。为了特异性靶向肝细胞，将甘草次酸（GA）掺入脂质纳米颗粒（LNPs）中，创建了一个GA靶向EGZ@LNP-GA药物递送系统，旨在增强EGZ对MASLD的治疗效果。通过粒径、包封效率和体外释放动力学对EGZ@LNP-GA配方进行了全面表征。体外研究表明，与HeLa和HUVEC细胞相比，EGZ@LNP-GA对LO2细胞具有较高的特异性。通过油红O染色和甘油三酯（TG）含量测定，可以发现EGZ@LNP-GA降低了LO2细胞的脂质积累。Western blot分析显示，EGZ@LNP-GA下调脂质生成因子SREBP1c和FAS，上调脂质氧化调节因子SIRT1，表明其具有增强脂质代谢的潜力。在hfd诱导的脂肪变性模型中，EGZ@LNP-GA减少了肝脏脂质积累，降低了炎症细胞因子，改善了胰岛素敏感性，增强了葡萄糖代谢。这些发现支持ga靶向EGZ@LNP-GA系统作为masld相关代谢功能障碍的有希望的策略。

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引用次数: 0

Fundamental investigation on the impact of Cu powder oxidation states on processability by powder bed Fusion-Laser Beam/Metal (PBF-LB/M) 粉末床激光/金属熔合（PBF-LB/M）对Cu粉末氧化态影响的基础研究

IF 7.9 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials & Design

Pub Date : 2025-12-23 DOI: 10.1016/j.matdes.2025.115394

Arne Röttger , Jonas Hankel , Robert Ortmann , Eric Schneider , Fabienne Hellwig , Milli Suchita Kujur , Tobias Grimm , Christian Sternemann , Jan T. Sehrt

This study introduces targeted oxidation of Cu powders as a strategy to improve both laser power coupling and powder reusability for the PBF-LB/M process. Controlled surface oxidation at 200 °C and 300 °C reduces reactivity toward residual oxygen in the process atmosphere, stabilizes absorption, and eliminates the need for high baseplate preheating or increased laser power. Therefore, powder properties, oxide formation, and PBF-LB/M−produced samples were systematically characterized. X-ray photoelectron spectroscopy (XPS) and synchrotron X-ray diffraction (XRD) were employed to identify the surface phases. The fabricated samples were then analyzed with respect to their microstructure, hardness, and electrical conductivity. Results demonstrate that oxidation at 300 °C enhances energy absorption without significantly compromising powder flowability, thereby enabling the production of dense microstructures. Oxidation at 300 °C yielded a Cu matrix with ∼ 17 vol% Cu₂O, resulting in ∼ 60 % IACS electrical conductivity but increased hardness (∼160 HV0.1). The findings demonstrate that through targeted oxidation, dense copper structures can be manufactured even with the most widely used PBF-LB/M systems, which typically operate with infrared-emitting lasers that are often limited in terms of laser energy.

在PBF-LB/M工艺中，引入了铜粉的定向氧化策略，以改善激光功率耦合和粉末的可重用性。在200°C和300°C的受控表面氧化降低了对工艺气氛中残余氧的反应性，稳定了吸收，并且消除了对高底板预热或增加激光功率的需要。因此，粉末性能、氧化物形成和PBF-LB/M -生成的样品被系统地表征。采用x射线光电子能谱（XPS）和同步加速器x射线衍射（XRD）对其表面相进行了表征。然后对制备的样品进行微观结构、硬度和电导率分析。结果表明，在300°C下氧化增强了能量吸收，而不会显著影响粉末的流动性，从而能够产生致密的微观结构。在300°C下氧化得到Cu2O含量为~ 17 vol%的Cu基体，电导率为~ 60% IACS，但硬度增加（~ 160 HV0.1）。研究结果表明，通过定向氧化，即使使用最广泛使用的PBF-LB/M系统，也可以制造出致密的铜结构，而PBF-LB/M系统通常使用受激光能量限制的红外发射激光器。

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引用次数: 0

Precise-engineering of monodisperse magnetite nanoparticles with low-level of cobalt doping for enhanced MRI contrast performance 单分散磁铁矿纳米颗粒的精密工程与低水平的钴掺杂增强MRI对比性能

IF 7.9 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials & Design

Pub Date : 2025-12-23 DOI: 10.1016/j.matdes.2025.115386

Mirela Nistor , Vera Balan , Aurel Pui , Camelia Mihaela Zara-Danceanu , Paula Alexandra Postu , Marian Grigoras , Daniel Gherca , Valentin Toma , Cristina Mariana Uritu , Raluca M. Fratila , Rares-Ionut Stiufiuc , Brindusa Dragoi

Herein, we designed and synthesized cobalt-modified magnetite nanoparticles (MNPs) in an environmentally safe aqueous medium by using biocompatible Pluronic F127 as dispersant without altering the Fe³⁺/Fe²⁺ stoichiometric ratio of 2:1. Gradually increasing amounts of cobalt (1, 5, 10 mol %) were added to this formulation. The obtained MNPs were systematically characterized for their physico-chemical and magnetic properties by ICP-OES, XRD, TEM/EDX, FT-IR, RAMAN, XPS, DLS, Zeta potential, and VSM. Our method ensured that iron oxidation states and their stoichiometry remain unchanged while incorporation of Co was successfully achieved with Co²⁺ as the oxidation state, according to XPS. XRD confirmed the inverse spinel structure with cobalt ions mainly occupying the interstitial sites although RAMAN revealed a slight contribution of normal spinel. TEM revealed nanoparticles of ∼ 11.8 nm, displaying a mixed sphere- and cubic-like morphology while DLS and Zeta showed some Co-induced agglomeration and a shift toward positive values, respectively. In vitro cytotoxicity tests indicated good preliminary biocompatibility for all samples. Co-modified MNPs showed enhanced r₂ values in agarose phantoms on 1T MRI apparatus. These outcomes obviously indicate that cobalt-modified magnetite have promising practical implications, being suitable for cancer diagnosis and recommending further in vivo evaluation (e.g, toxicity, biodistribution, immune-response studies).

本研究以生物相容性Pluronic F127为分散剂，在不改变Fe3+/Fe2+ 2:1的化学计量比的情况下，在环境安全的水介质中设计并合成了钴修饰的磁铁矿纳米颗粒（MNPs）。逐渐增加钴的量（1,5,10摩尔%）加入到该配方中。采用ICP-OES、XRD、TEM/EDX、FT-IR、RAMAN、XPS、DLS、Zeta电位和VSM等方法对制备的MNPs进行了理化性质和磁性能表征。根据XPS的说法，我们的方法确保铁的氧化态及其化学计量保持不变，而Co的掺入成功地以Co2+作为氧化态。XRD证实了钴离子主要占据间隙位置的反尖晶石结构，而RAMAN显示正常尖晶石也有少量贡献。透射电镜显示纳米颗粒为~ 11.8 nm，呈现混合球形和立方状形貌，而DLS和Zeta分别表现出一些共诱导团聚和向正值偏移。体外细胞毒性试验表明所有样品具有良好的初步生物相容性。在1T MRI上，共修饰的MNPs在琼脂糖幻影中显示增强的r2值。这些结果明显表明钴修饰磁铁矿具有很好的实际意义，适合于癌症诊断，并推荐进一步的体内评估（例如毒性，生物分布，免疫反应研究）。

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引用次数: 0

Structure–property interplay in fully circular all-cellulose composites using structurally intact lignocellulosic fibers 使用结构完整的木质纤维素纤维的全圆形全纤维素复合材料的结构-性能相互作用

IF 7.9 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials & Design

Pub Date : 2025-12-22 DOI: 10.1016/j.matdes.2025.115385

Yahya Kara , Carlos A. Fuentes , Tim Huber

In this study, an innovative approach inspired by the all-cellulose composites (ACCs) concept was explored using regenerated cellulose as the matrix, reinforced with lignocellulosic fibers. Pulp cellulose was dissolved in two ionic liquids (ILs), EmimAc and BmimCI, and regenerated with two antisolvents, water and methanol, to form a cellulose matrix, while coir (CF) and bamboo (BF) fibers were employed as reinforcements. The relationship between these parameters on ACC's structure was comparatively investigated. The cellulose matrix regenerated by water exhibited higher crystallinity and thermal stability than the methanol-regenerated ones. The cellulose matrix dissolved in EmimAc enhanced the ACC’s tensile strength by up to 30 % to that of cellulose dissolved in BmimCI. The BF reinforcement translated to higher flexural strength and modulus, up to 45 % and 2-fold, respectively, than the CF ones. SEM and Micro-CT analyses revealed that the fibers were kept intact within the cellulose matrix, while ACCs had less than 2 v/v% porosity. The ILs employed to fabricate ACCs recovered from the antisolvent mixture showed no significant change in their properties. This approach bridges the gap between traditional ACCs and natural fiber-reinforced polymers, potentially opening new avenues for developing eco-friendly composites that leverage the inherent properties of lignocellulosic fibers.

在这项研究中，受全纤维素复合材料（ACCs）概念的启发，探索了一种创新的方法，使用再生纤维素作为基质，用木质纤维素纤维增强。将纸浆纤维素溶解于EmimAc和BmimCI两种离子液体中，再用水和甲醇两种反溶剂再生，形成纤维素基体，以椰子（CF）和竹（BF）纤维作为增强纤维。比较研究了这些参数对ACC结构的影响。水再生的纤维素基质结晶度和热稳定性高于甲醇再生的纤维素基质。在EmimAc中溶解的纤维素基质使ACC的抗拉强度比在BmimCI中溶解的纤维素基体提高了30%。与CF相比，BF加固的抗弯强度和模量分别提高了45%和2倍。SEM和Micro-CT分析显示，纤维在纤维素基质中保持完整，而acc的孔隙率小于2 v/v%。从抗溶剂混合物中回收的用于制造acc的ILs的性质没有明显变化。这种方法弥补了传统碳纤维和天然纤维增强聚合物之间的差距，为开发利用木质纤维素纤维固有特性的环保复合材料开辟了新的途径。

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引用次数: 0

Enhanced microstructure and toughness in narrow-gap oscillating laser-TIG hybrid welded Ti-6Al-4V plates via high-frequency pulsed current 高频脉冲电流增强窄间隙振荡激光- tig复合焊接Ti-6Al-4V板的显微组织和韧性

IF 7.9 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials & Design

Pub Date : 2025-12-22 DOI: 10.1016/j.matdes.2025.115388

Gang Ruan , Chen Shen , Lin Wang , Kanglong Wu , Danqi Zhang , Jiacheng Huang , Zihan Li , Li Wang , Fengcheng Song , Yuelong Zhang , Fang Li , Zhuguo Li , Xueming Hua

Welding of thick Ti-6Al-4V plates often produces coarse columnar grains and a wide heat-affected zone (HAZ), degrading joint strength and reliability. Recently, a tailored narrow-gap oscillating laser-TIG hybrid welding (NG-OL-TIG) technique has shown promise for high-performance thick Ti-6Al-4V welds. In this study, 100 Hz and 10 kHz pulsed currents were incorporated into NG-OL-TIG welding for 25 mm-thick Ti-6Al-4V plates to optimize microstructure and mechanical properties. Compared with direct-current (DC) welding, pulsed current improved microstructural uniformity and mechanical performance. At a high-frequency pulsed (HFP) current of 10 kHz, the HAZ width decreased by 26 % and the primary β-grain width by nearly 50 %. In the fusion zone (FZ), the HFP current promoted a columnar-to-equiaxed transition (CET) by intensifying thermal fluctuations, characterized by a temperature gradient of ∼370 K/mm, a cooling rate of ∼300 K/s, and a solidification rate of ∼2.6 mm/s. α’-martensite were refined by about 60 %, maintaining tensile ductility with only 3.7 % hardness increase. The −40 °C impact toughness at the fusion line (FL) reached 30 ± 2 J, exceeding that of the base metal (BM). This study proves HFP’s role in achieving high-quality thick Ti-6Al-4V welds during the NG-OL-TIG process.

Ti-6Al-4V厚板焊接时，柱状晶粒粗，热影响区宽，降低了接头强度和可靠性。最近，一种定制窄间隙振荡激光- tig混合焊接（NG-OL-TIG）技术显示出高性能Ti-6Al-4V厚焊缝的前景。采用100 Hz和10 kHz脉冲电流对25 mm厚Ti-6Al-4V板进行NG-OL-TIG焊接，优化其显微组织和力学性能。与直流（DC）焊接相比，脉冲电流改善了组织均匀性和力学性能。在10 kHz的高频脉冲电流下，HAZ宽度减小了26%，初级β晶粒宽度减小了近50%。在熔合区（FZ）， HFP电流通过强化热波动促进柱状到等轴转变（CET），其特征是温度梯度为~ 370 K/mm，冷却速率为~ 300 K/s，凝固速率为~ 2.6 mm/s。α′-马氏体细化约60%，保持拉伸延展性，硬度仅提高3.7%。熔合线上的- 40℃冲击韧性（FL）达到30±2 J，超过母材（BM）。本研究证明了在NG-OL-TIG工艺中，HFP对获得高质量的Ti-6Al-4V厚焊缝的作用。

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引用次数: 0

Freeze-thaw-induced microstructural damage in polyester fiber-reinforced cementitious composites revealed by X-ray microtomography 冻融致聚酯纤维增强胶凝复合材料微观结构损伤的x射线显微断层扫描研究

IF 7.9 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials & Design

Pub Date : 2025-12-22 DOI: 10.1016/j.matdes.2025.115256

Sophie Jung , Mahya Roustaei , Jordan Harvey , Hubert Taieb , Sam Bhat , Duane Froese , Nicolas Piche , Pooneh Maghoul

Fiber-reinforced cementitious composites are increasingly used in cold-region infrastructure because of their robustness, rapid installation, and sustainability. However, their long-term behavior under freeze-thaw cycles (FTCs) is still poorly understood at the microstructural scale. This study investigates frost-induced damage in a polyester fiber-reinforced cementitious composite using a fully saturated, closed-system protocol over 100 laboratory FTCs. High-resolution X-ray micro-computed tomography (11 µm voxel) performed at nine time points on a single specimen, combined with deep-learning segmentation, yields fiber-resolved pore and crack evolution and a mechanism-informed interpretation. The combined pore-plus-crack volume fraction rose from 10.0 % to 21.0 %, with local maxima up to 24.8 % in fiber-sparse zones. Thermomechanical modeling of a 185 µm cylindrical pore shows that differential thermal expansion between ice and matrix generates hoop stresses far exceeding those from crystallization pressure, identifying thermal-dilation mismatch as the dominant cracking mechanism under full saturation. Although polyester fibers usually toughen the composite under mechanical loading, freeze–thaw induces internal pore expansion that produces tensile hoop stresses in the matrix and concentrates them at fiber-matrix interfaces. These results provide new microstructural insight into durability limits and underscore the need to optimize pore structure and fiber-matrix interfaces to enhance freeze–thaw resistance.

纤维增强胶凝复合材料因其坚固性、快速安装和可持续性而越来越多地用于寒冷地区的基础设施。然而，它们在冻融循环（FTCs）下的长期行为在微观结构尺度上仍然知之甚少。本研究使用全饱和、封闭系统协议研究了超过100个实验室FTCs中聚酯纤维增强胶凝复合材料的霜冻损伤。在单个样品的9个时间点上进行高分辨率x射线微计算机断层扫描（11 μ m体素），结合深度学习分割，可以产生纤维分解的孔隙和裂纹演化以及机制信息解释。孔隙-裂纹复合体积分数由10.0%上升至21.0%，纤维稀疏区局部最大值为24.8%。对185µm圆柱孔的热力学模拟表明，冰与基质之间的热膨胀差产生的环向应力远远大于结晶压力产生的环向应力，表明热膨胀失配是全饱和条件下的主要开裂机制。虽然聚酯纤维通常在机械载荷下使复合材料增韧，但冻融会引起内部孔隙膨胀，从而在基体中产生拉伸环向应力，并将应力集中在纤维-基体界面上。这些结果为耐久性极限提供了新的微观结构见解，并强调了优化孔隙结构和纤维-基质界面以提高抗冻融性的必要性。

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引用次数: 0

Broadband transparent ultrasound transducer design via matching-free composite approach 基于无匹配复合方法的宽带透明超声换能器设计

IF 7.9 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials & Design

Pub Date : 2025-12-18 DOI: 10.1016/j.matdes.2025.115369

Zhang Jiaming , Lin Riqiang , Wang Xiatian , Bao Guocui , Yang Fan , Hou Shilin , Li Guo , Wang Yifei , Xiaojing Gong , Dai Jiyan , Kwok-Ho Lam

Photoacoustic imaging (PAI) combines the high optical contrast of light with the deep tissue penetration of ultrasound, making it a powerful modality for functional biomedical imaging. Transparent ultrasound transducers (TUTs) have been developed to facilitate co-axial illumination and detection in PAI systems by enabling light transmission directly through the transducer. However, the performance of TUTs has been limited by the significant acoustic impedance mismatch between conventional transparent piezoelectric single crystals/ceramics and biological tissues. In this study, a lithium niobate (LN) single crystal-based 1–3 composite piezoelectric material is employed for the first time in a practical biomedical imaging application as the active layer of a TUT. Leveraging its intrinsically high piezoelectric voltage constant (g₃₃) and electromechanical coupling coefficient (k_t), the 1–3 composite structure with a reduced volume fraction of LN possesses a lower acoustic impedance. This results in an improved acoustic transmission coefficient at the interface between TUT and biological tissues. Experimental results demonstrate that the LN 1–3 composite TUT achieves an ultra-wide bandwidth exceeding 100% without the use of a matching layer, enabling improved axial resolution that outperforms comparable reported TUTs. Additionally, the device exhibits superior receiving sensitivity when benchmarked against transducers fabricated using piezoelectric polymers. The imaging performance of the developed TUT was validated in a PAI system using phantom imaging, confirming its potential for high-performance biomedical imaging applications.

光声成像（PAI）将光的高光学对比度与超声的深层组织穿透性相结合，使其成为功能性生物医学成像的一种强大方式。透明超声换能器（TUTs）已经被开发出来，通过使光直接通过换能器来促进PAI系统中的同轴照明和检测。然而，传统的透明压电单晶/陶瓷与生物组织之间存在明显的声阻抗不匹配，限制了tut的性能。在本研究中，铌酸锂（LN）单晶1-3复合压电材料首次作为TUT的有源层应用于实际的生物医学成像应用中。利用其固有的高压电电压常数（g33）和机电耦合系数（kt），减少LN体积分数的1-3复合材料结构具有较低的声阻抗。这就提高了TUT与生物组织交界面处的声透射系数。实验结果表明，LN 1-3复合TUT在不使用匹配层的情况下实现了超过100%的超宽带带宽，从而提高了轴向分辨率，优于同类报道的TUT。此外，当与使用压电聚合物制造的换能器进行基准测试时，该器件表现出优越的接收灵敏度。开发的TUT的成像性能在PAI系统中使用幻影成像进行了验证，证实了其在高性能生物医学成像应用中的潜力。

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引用次数: 0

W and C co-segregation at dislocations in a γ-TiAl based alloy identified by correlative APT-TEM observations 通过相关的APT-TEM观察发现γ-TiAl基合金位错中W和C的共偏析

IF 7.9 2区材料科学 Q1 MATERIALS SCIENCE, MULTIDISCIPLINARY

Materials & Design

Pub Date : 2025-12-18 DOI: 10.1016/j.matdes.2025.115313

Michael Musi , Alain Couret , Petra Spoerk-Erdely , Helmut Clemens , Jean-Philippe Monchoux

In this work, a γ-TiAl based alloy has been designed for increased strength at high temperature using promising substitutional (W) and interstitial (C) solutes. Creep tests at 800 °C and 200 MPa show that the addition of C to a W-containing alloy leads to an increase by about two times of the creep lifetime of this alloy with a fine near lamellar microstructure. A correlative approach, combining 3D chemical reconstructions by atom probe tomography (APT), with specific dislocations characterizations by transmission electron microscopy (TEM), has therefore been developed to study the local chemical environment in the vicinity of dislocations. Because such advanced APT-TEM correlations are challenging, dislocations of marked edge character were first selected, because they seemed to exhibit higher tendency for segregation. In addition to the early stages of carbide precipitation, co-segregation effects of W and C were thus observed after creep. This effect is interpreted as resulting from the mutual chemical affinity between these two solutes. Therefore, selecting solutes of mutual chemical affinity appears as a promising dislocation engineering route suitable for the development of materials employed in high-temperature environments encountered in turbine blades of advanced aircraft engines.

在这项工作中，设计了一种γ-TiAl基合金，使用有前途的替代(W)和间隙(C)溶质来提高高温下的强度。在800℃和200 MPa下的蠕变试验表明，在含w合金中加入C可使该合金的蠕变寿命提高约2倍，并具有良好的近片层组织。因此，一种相关的方法，结合原子探针断层扫描（APT）的三维化学重建和透射电子显微镜（TEM）的特定位错特征，已经发展到研究位错附近的局部化学环境。由于这种先进的APT-TEM相关性具有挑战性，因此首先选择了具有显著边缘特征的位错，因为它们似乎表现出更高的偏析倾向。除了碳化物析出的早期阶段外，蠕变后还观察到W和C的共偏析效应。这种效应被解释为这两种溶质之间相互的化学亲和力。因此，选择具有相互化学亲和性的溶质是一种很有前途的位错工程路线，适用于先进航空发动机涡轮叶片高温环境材料的开发。

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引用次数: 0