【新文速递】2024年3月14日复合材料SCI期刊最新文章

   

今日更新：Composite Structures 4 篇，Composites Part A: Applied Science and Manufacturing 4 篇，Composites Part B: Engineering 4 篇

Composite Structures

Spectral collocation method for free vibration of sandwich plates containing a viscoelastic core

Ming Ji, Chao Kang, Yu Sekiguchi, Masanobu Naito, Chiaki Sato

doi:10.1016/j.compstruct.2024.118024

包含粘弹性核心的夹层板自由振动的光谱配位法

Viscoelastic constrained layer damping is a simple and efficient method for reducing noise, vibration, and fatigue in metal structures. In this work, a spectral collocation method utilizing a layer-wise plate theory was established to inspect the vibration characteristics of a sandwich plate with a viscoelastic core. The displacements of each layer satisfied the Mindlin plate theory. The core's transverse shear stress remained constant. The three layers’ transverse displacements were assumed to be identical. The displacement fields were reduced to nine variables by utilizing the interfaces’ continuity of the displacements. The equations of motion were obtained by utilizing Hamilton’s principle. The viscoelastic core’s material properties were considered as frequency-dependent. To address the complex eigenvalue problem, an iterative algorithm was used. The theoretical results were compared with published theoretical and experimental data for fully clamped rectangular sandwich plates to validate the proposed method. The modified Oberst beam method was applied by fitting the impulse response function to obtain the adhesive’s frequency-dependent storage modulus and loss factor. The natural frequencies and corresponding loss factors of three sandwich plates with different adhesives were measured by conducting impact tests. The numerical results from the present theoretical method agreed well with the measured results.

粘弹性约束层阻尼是减少金属结构噪音、振动和疲劳的一种简单而有效的方法。在这项研究中，利用层向板理论建立了一种频谱配位方法，用于检测带有粘弹性核心的夹层板的振动特性。各层的位移符合明德林板理论。夹芯的横向剪应力保持不变。假设三层的横向位移相同。利用位移的界面连续性，将位移场简化为九个变量。利用汉密尔顿原理得到了运动方程。粘弹性磁芯的材料特性被认为与频率有关。为了解决复杂的特征值问题，采用了迭代算法。将理论结果与已发表的全夹紧矩形夹层板的理论和实验数据进行了比较，以验证所提出的方法。通过拟合脉冲响应函数，应用改进的奥伯斯特梁法获得了粘合剂随频率变化的存储模量和损耗因子。通过进行冲击试验，测量了使用不同粘合剂的三种夹层板的固有频率和相应的损耗因子。本理论方法得出的数值结果与测量结果吻合良好。

Explainable machine learning accelerated density functional theory prediction for diffusive transport behavior of elements in aluminum matrix and graphene/aluminum interface

Jingtao Huang, Jingteng Xue, Mingwei Li, Yuan Cheng, Zhonghong Lai, Jin Hu, Fei Zhou, Nan Qu, Yong Liu, Jingchuan Zhu

doi:10.1016/j.compstruct.2024.118025

可解释的机器学习加速密度泛函理论对铝基体和石墨烯/铝界面中元素扩散传输行为的预测

In this paper, the diffusive migration behavior of alloy atoms in aluminum matrix and different types of graphene/aluminum interfaces is systematically investigated by using a machine learning accelerated density functional theory. A small sample dataset is established by first principles calculation, the types of input and output eigenvalues are determined by feature engineering, and the number of input features for perfect interfaces, defective interfaces, and aluminium matrix are finally determined to be 6, 5, and 4 by taking into account the effects of model complexity and prediction accuracy. With a five-fold crossover and by comparing more than a dozen machine learning models, the CatBoost algorithm possesses the lowest error as well as a better coefficient of determination. We further optimized the CatBoost algorithm with further parameters and adjusted the regularization term coefficients to avoid the risk of overfitting. The impact of each feature on the model prediction results was quantitatively described by constructing a matrix of SHAP values. The best performing Catboost model was used to predict the full periodic table data, which in turn was used to screen out the elemental species that are easy to move towards the graphene/aluminum composite interface. Those alloying elements are beneficial for modifying the defective graphene in the composite by comparing the results of elemental diffusive migration in the aluminum matrix as well as at different graphene/aluminum interfaces. The results of machine learning accelerated first principles calculations can provide a theoretical basis for further development of new aluminum alloy composite.

本文利用机器学习加速密度泛函理论，系统研究了合金原子在铝基体和不同类型石墨烯/铝界面中的扩散迁移行为。通过第一性原理计算建立小样本数据集，通过特征工程确定输入和输出特征值的类型，考虑模型复杂度和预测精度的影响，最终确定完美界面、缺陷界面和铝基体的输入特征数分别为 6、5 和 4。通过五次交叉和对十多个机器学习模型的比较，CatBoost 算法的误差最小，判定系数也较高。我们进一步优化了 CatBoost 算法的参数，并调整了正则化项系数，以避免过拟合风险。通过构建 SHAP 值矩阵，定量描述了每个特征对模型预测结果的影响。性能最好的 Catboost 模型被用来预测整个元素周期表数据，进而筛选出容易向石墨烯/铝复合材料界面移动的元素种类。通过比较铝基体以及不同石墨烯/铝界面的元素扩散迁移结果，这些合金元素有利于改变复合材料中的缺陷石墨烯。机器学习加速第一原理计算的结果可为进一步开发新型铝合金复合材料提供理论依据。

Improving mechanical behavior of adhesively bonded composite joints by incorporating reduced graphene oxide added polyamide 6,6 electrospun nanofibers

Melisa Yeke, Murat Barisik, Metin Tanoğlu, M Erdal Ulaşlı, Kaan Nuhoğlu, Gözde Esenoğlu, Seçkin Martin, Ceren Türkdoğan, Hande İplikçi, Engin Aktaş, Serkan Dehneliler, M Erdem İriş

doi:10.1016/j.compstruct.2024.118026

 

加入还原氧化石墨烯的聚酰胺 6,6 电纺纳米纤维，改善粘接复合材料接头的机械性能

Adhesive joining of fiber-reinforced polymer (FRP) composites requires adequate interface tailoring and careful surface preparation to obtain a strong bond between components. This study aimed to improve the mechanical performance of adhesively bonded unidirectional carbon fiber-based (CFRP) composite parts by modifying joint surfaces with graphene-added electrospun Polyamide 6,6 (PA66) nanofibers. Reduced graphene oxide (rGO) was dispersed at 10 % wt/v PA66 solution at three different concentrations below rGO saturation limits. Bead-free nanofibers with homogenous graphene distribution were obtained on a prepreg by electrospinning. Addition of up to 2 % rGO yielded complete dispersion through the nanofiber network while the higher values created local agglomerations. Surface wetting experiments showed conversion of slightly hydrophobic surfaces to complete hydrophilic with electrospun nanofiber coating and the lowest contact angle was obtained at 2 % wt/v rGO addition (26.18°±2.03°). Composite plates were produced in a hot press keeping the modified prepregs on top. Plates with different surface treatments joined by secondary bonding using 3 plies of FM 300 K film adhesive. Mechanical properties of adhesively bonded composites were tested by Single lap joint and Charpy impact tests. We achieved an 18 % increase in shear strength and 31 % increase in impact strength by adding 2 % wt/v ratio rGO into PA66 electrospun nanofiber.

纤维增强聚合物 (FRP) 复合材料的粘接需要适当的界面调整和仔细的表面处理，以获得部件之间的牢固粘接。本研究旨在通过使用添加了石墨烯的电纺聚酰胺 6.6 (PA66) 纳米纤维对接合面进行改性，从而提高粘接单向碳纤维基 (CFRP) 复合材料部件的机械性能。还原氧化石墨烯（rGO）以低于 rGO 饱和极限的三种不同浓度分散在 10 % wt/v 的 PA66 溶液中。通过电纺丝技术在预浸料上获得了石墨烯分布均匀的无珠纳米纤维。在纳米纤维网络中加入不超过 2% 的 rGO 可使石墨烯完全分散，而更高的浓度则会产生局部团聚。表面润湿实验表明，电纺纳米纤维涂层可将轻微疏水表面转化为完全亲水表面，添加 2% wt/v rGO 时接触角最小（26.18°±2.03°）。复合材料板是在热压机中生产的，上面保留了改性预浸料。使用 3 层 FM 300 K 薄膜粘合剂对经过不同表面处理的板材进行二次粘合。通过单搭接和夏比冲击试验测试了粘合复合材料的机械性能。通过在 PA66 电纺纳米纤维中添加 2% wt/v 比率的 rGO，我们发现剪切强度提高了 18%，冲击强度提高了 31%。

Shell-infill composite structure design based on a hybrid explicit- implicit topology optimization method

Yilin Guo, Chang Liu, Xu Guo

doi:10.1016/j.compstruct.2024.118029

基于显隐混合拓扑优化法的壳体填充复合结构设计

The present paper introduces a hybrid explicit–implicit topology optimization method for shell-infill composite structure design. The proposed approach effectively combines the advantages of the explicit Moving Morphable Component (MMC) method, which describes structural topology only using a set of geometric parameters, and the implicit Solid Isotropic Material with Penalization (SIMP) method, which offers greater design freedom for characterizing the structural features. Compared to the existing methods for shell-infill structure design, the proposed approach can obtain optimized shell-infill structures with complex infill topology without resorting to complex filtering/projection operations. Numerical examples demonstrate the effectiveness of the proposed approach.

本文介绍了一种用于壳填充复合材料结构设计的显式-隐式混合拓扑优化方法。所提出的方法有效地结合了显式移动可变形分量（MMC）方法和隐式各向同性材料（SIMP）方法的优点，前者仅使用一组几何参数来描述结构拓扑，而后者则为表征结构特征提供了更大的设计自由度。与现有的壳体填充结构设计方法相比，所提出的方法无需进行复杂的过滤/投影操作，即可获得具有复杂填充拓扑结构的优化壳体填充结构。数值实例证明了所提方法的有效性。

Composites Part A: Applied Science and Manufacturing

Direct electrospinning of short polymer Fibers: Factors affecting size and quality

Daniel P. Ura, Urszula Stachewicz

doi:10.1016/j.compositesa.2024.108138

 

直接电纺短聚合物纤维：影响尺寸和质量的因素

The growing demand for lightweight and robust materials drives the development of polymer-based and fiber-reinforced composites. Here, using short fibers offers several advantages; however, currently employed methods for producing short fibers, such as homogenization, result in a wide dispersion of dimensions in the produced fibers, which is an undesirable effect in composite materials. In this study, electrospinning is used to produce polymer short fibers directly. This research highlights, for the first time, the differences in the electrospinning process dynamics between short and continuous fibers. By adjusting parameters: voltage and distance, we control dimensions of short fibers below 1 µm in diameter and around 4 µm in length to a few microns in diameter and approximately 14 µm in length. Direct electrospinning of short fibers offers significant advantages, including a narrow size distribution and reproducibility compared to chopped continuous fibers with homogenization.

对轻质坚固材料的需求日益增长，推动了聚合物基纤维增强复合材料的发展。然而，目前使用的生产短纤维的方法（如均质化）会导致生产的纤维尺寸分散，这在复合材料中是不可取的。本研究采用电纺丝技术直接生产聚合物短纤维。这项研究首次强调了短纤维和连续纤维在电纺丝过程动力学上的差异。通过调整电压和距离等参数，我们控制了直径低于 1 微米、长度约为 4 微米的短纤维尺寸，以及直径为几微米、长度约为 14 微米的短纤维尺寸。与均匀化切碎的连续纤维相比，直接电纺短纤维具有显著的优势，包括尺寸分布窄和可重复性好。

A full-scale composite tidal blade fatigue test using single and multiple actuators

Sergio Lopez Dubon, Fergus Cuthill, Christopher Vogel, Conchur Ó Brádaigh, Edward D. McCarthy

doi:10.1016/j.compositesa.2024.108140

使用单个和多个致动器的全尺寸复合材料潮汐叶片疲劳试验

In order to perform fatigue testing on tidal turbine blades, it is necessary to apply cyclic loads that do not match the blade’s natural frequency. This is due to the high stiffness of the blades and the thermal challenges associated with testing composite materials at frequencies typically around 18–20 Hz. To overcome this challenge, auxiliary systems are used to load the blades. However, conventional hydraulic systems commonly used for this purpose are known to be energy-intensive and inefficient. In this work, we present results obtained at the FastBlade fatigue testing facility, which utilises a regenerative digital displacement hydraulic pump system to address these issues. This innovative system has proven to be highly efficient, resulting in up to 75% energy savings compared to standard hydraulic systems. To perform these tests, we first performed a series of Reynolds-Averaged Navier–Stokes (RANS) simulations using on-site water velocity data to determine equivalent target hydrodynamic loads. These target loads are applied to the blades using initially a single contact point and, later, three load contact points. The FastBlade facility showcases an effective approach to fatigue testing during these tests. Throughout the testing process, comprehensive measurements are taken to evaluate the response of the blades and the FastBlade test structure itself. These measurements provide valuable insights into the mechanical behaviour of the blades when a single or multi-actuator setup is used to match the root bending moment and contribute to the refinement of testing practices. Notably, the blades successfully endured the equivalent of 20 years of tides in an accelerated fatigue loading test without experiencing catastrophic failure. The data obtained from these tests will enable the identification of improvements in testing procedures, including control strategies, load introduction methods, instrumentation layout, instrument calibration, and test design. This knowledge will lead to enhanced performance and reliability of the FastBlade facility, further advancing the field of tidal turbine blade testing.

为了对潮汐涡轮机叶片进行疲劳测试，有必要施加与叶片固有频率不匹配的循环载荷。这是由于叶片具有很高的刚度，而且在通常约为 18-20 Hz 的频率下测试复合材料会面临热挑战。为了克服这一挑战，需要使用辅助系统对叶片进行加载。然而，众所周知，通常用于此目的的传统液压系统能耗高、效率低。在这项工作中，我们介绍了在 FastBlade 疲劳测试设备上获得的结果，该设备利用再生式数字排量液压泵系统来解决这些问题。事实证明，这种创新系统具有很高的效率，与标准液压系统相比，最多可节省 75% 的能源。为了进行这些测试，我们首先利用现场水速数据进行了一系列雷诺平均纳维-斯托克斯（RANS）模拟，以确定等效目标流体动力负载。这些目标载荷最初使用单个接触点施加到叶片上，后来使用三个载荷接触点施加到叶片上。在这些测试过程中，FastBlade 设备展示了一种有效的疲劳测试方法。在整个测试过程中，都会进行全面测量，以评估叶片和 FastBlade 测试结构本身的响应。这些测量结果为了解叶片在使用单个或多个执行器设置以匹配根弯曲力矩时的机械性能提供了宝贵的信息，并有助于改进测试方法。值得注意的是，叶片在加速疲劳加载试验中成功承受了相当于 20 年的潮汐，而没有出现灾难性故障。从这些测试中获得的数据将有助于确定测试程序的改进措施，包括控制策略、载荷引入方法、仪器布局、仪器校准和测试设计。这些知识将提高 FastBlade 设备的性能和可靠性，进一步推动潮汐涡轮机叶片测试领域的发展。

Platelet critical length for Prepreg Platelet Molded Composites

Sai S. Aranke, R. Byron Pipes

doi:10.1016/j.compositesa.2024.108142

预浸料血小板模塑复合材料的血小板临界长度

This work presents a comprehensive evaluation of platelet critical length in Prepreg Platelet Molded Composites (PPMCs), addressing the complex failure mechanisms in these material systems. An array of overlaid platelets is loaded under uniaxial tension while evaluating the failure mechanism as a function of platelet length. The research identifies two primary failure mechanisms: interface failure and platelet failure, which are distinctly dependent on platelet length. The transition between the dominant failure modes occurs at a critical platelet length, marking a critical juncture in the PPMC performance. This study offers insights into the stress transfer mechanisms within an array of platelets leading to failure. To evaluate the critical length, a continuum-based damage model for the platelets and a cohesive zone-based damage model for the platelet interfaces was implemented in a Finite Element Analysis (FEA) framework. The cohesive based interface allows for mode-I and mode-II failure types, with the approach being validated through benchmark studies of Double Cantilever Beam (DCB) and End-Noted Flexure (ENF) simulations. The central idea of the paper posits that the length of platelets impacts the mechanical properties and performance of PPMCs. It details the complex stress transfer mechanisms in PPMCs and their relation to the dominant failure mechanisms.

这项研究全面评估了预浸料小板模塑复合材料（PPMC）中的小板临界长度，解决了这些材料系统中复杂的失效机制问题。在单轴拉力下加载叠层血小板阵列，同时评估作为血小板长度函数的失效机制。研究确定了两种主要的失效机制：界面失效和血小板失效，这两种失效机制明显取决于血小板的长度。主要失效模式之间的过渡发生在临界血小板长度上，这标志着 PPMC 性能的关键时刻。这项研究有助于深入了解导致失效的血小板阵列内部的应力传递机制。为了评估临界长度，我们在有限元分析（FEA）框架中对血小板实施了基于连续体的损伤模型，对血小板界面实施了基于内聚区的损伤模型。基于内聚区的界面允许模式 I 和模式 II 失效类型，通过双悬臂梁 (DCB) 和端面挠曲 (ENF) 模拟的基准研究对该方法进行了验证。论文的中心思想认为，血小板的长度会影响 PPMC 的机械性能和性能。论文详细阐述了 PPMC 中复杂的应力传递机制及其与主要失效机制的关系。

Bottom-up stochastic multiscale model for the mechanical behavior of multidirectional composite laminates with microvoids

Mengze Li, Shuran Li, Yu Tian, Haowei Zhang, Weidong Zhu, Yinglin Ke

doi:10.1016/j.compositesa.2024.108144

带有微空洞的多向复合材料层压板力学行为的自下而上随机多尺度模型

This study for the first time develops a coherent and efficient bottom-up stochastic multiscale modeling approach, which aims at revealing the impact of microvoids on the mechanical properties and damage mechanisms of multidirectional (MD) carbon fiber-reinforced polymer (CFRP) composites. To this end, void defects within the composites are characterized using X-ray micro-computed tomography to construct a high-fidelity representative defective volume (RDV). Subsequently, the influence of voids on the microscale failure modes and macroscopic mechanical properties are analyzed by using micromechanics-based finite element (FE) method. Finally, a stochastic multiscale analysis method is developed to predict the mechanical response of MD CFRP laminates and validated by tensile and three-point bending experiments. The results indicate that the proposed framework can accurately predict the mechanical behavior and damage mechanisms of MD CFRP composites. This framework is believed to be a promising method to provide valuable guidance for reliability design and optimization of CFRP composites.

本研究首次开发了一种连贯高效的自下而上随机多尺度建模方法，旨在揭示微空洞对多向 (MD) 碳纤维增强聚合物 (CFRP) 复合材料的机械性能和损伤机制的影响。为此，利用 X 射线显微计算机断层扫描技术对复合材料内部的空洞缺陷进行表征，以构建高保真的代表性缺陷体积（RDV）。随后，利用基于微观力学的有限元（FE）方法分析了空隙对微观失效模式和宏观力学性能的影响。最后，开发了一种随机多尺度分析方法来预测 MD CFRP 层压板的力学响应，并通过拉伸和三点弯曲实验进行了验证。结果表明，所提出的框架可以准确预测 MD CFRP 复合材料的力学行为和损伤机制。该框架有望为 CFRP 复合材料的可靠性设计和优化提供有价值的指导。

Composites Part B: Engineering

Functional AlF3 modification over 5.3 V spinel LiCoMnO4 cathode for Li-ion batteries

Sreekumar Sreedeep, Yun-Sung Lee, Vanchiappan Aravindan

doi:10.1016/j.compositesb.2024.111365

 

在 5.3 V 尖晶石钴锰酸锂正极上进行功能性 AlF3 修饰，用于锂离子电池

We report the improved electrochemical activity of the 5.3 V LiCoMnO4 (LCMO) cathode with the functionalization of AlF3 coating. LCMO@AlF3 is prepared by adopting the co-precipitation technique followed by a wet coating by altering the concentration of AlF3 by 1–3 wt%. LCMO@AlF3 exhibits improvement in the electrochemical performance compared to pristine LCMO. In addition, LCMO@AlF3 exhibits superior electrochemical performance with specific capacities of 107, 102, and 95 mAh g−1 and retentions of 68, 77, and 74 % after 100 cycles for 1, 2, and 3 wt% AlF3 coating. However, pristine LCMO shows a specific capacity of 105 mAh g−1 with a retention of 48 % after 100 cycles. Also, LCMO@AlF3 exhibits a decrement in the irreversible capacity loss (ICL) compared to pristine LCMO, which enhances the coulombic efficiency of the former compared to the latter. Further, the AlF3 coating of 2 and 3 wt% has been optimized to exhibit excellent electrochemical performance. The diffusion coefficients are calculated from cyclic voltammetric and electrochemical impedance spectroscopic techniques and are in the order of ∼10−12 cm2 s−1. Further, in-operando and in-situ impedance studies are conducted to authenticate the electrochemical activity observed in half-cell studies. In full-cell assembly with Li4Ti5O12 (LTO) anode, the LCMO@AlF3: 2–3 wt%/exhibits better electrochemical performance compared to its bare configuration. In addition, the electrochemical activity at various temperature (−10 to 25 °C) conditions is performed and reported.

我们报告了通过 AlF3 涂层功能化提高 5.3 V 锂钴锰氧化物（LCMO）阴极电化学活性的情况。LCMO@AlF3 采用共沉淀技术制备，然后通过改变 AlF3 的浓度 1-3 wt% 进行湿涂层。与原始 LCMO 相比，LCMO@AlF3 的电化学性能有所提高。此外，LCMO@AlF3 还具有优异的电化学性能，在涂覆 1、2 和 3 wt% AlF3 的 100 个循环后，比容量分别为 107、102 和 95 mAh g-1，保持率分别为 68、77 和 74%。然而，原始 LCMO 的比容量为 105 mAh g-1，100 次循环后的保持率为 48%。此外，与原始 LCMO 相比，LCMO@AlF3 的不可逆容量损失（ICL）有所减少，从而提高了前者的库仑效率。此外，2 和 3 wt% 的 AlF3 涂层经过优化，表现出优异的电化学性能。通过循环伏安法和电化学阻抗谱技术计算得出的扩散系数在 10-12 cm2 s-1 左右。此外，还进行了操作中和原位阻抗研究，以验证半电池研究中观察到的电化学活性。在与 Li4Ti5O12（LTO）阳极进行全电池组装时，LCMO@AlF3：2-3 wt%/与其裸配置相比表现出更好的电化学性能。此外，还报告了在不同温度（-10 至 25 °C）条件下的电化学活性。

Viable route to the manufacture of short carbon fiber-rich UHTC complex shapes with enhanced toughness

Davide Gardini, Lavina Backman, Peter Kaczmarek, Claudio Capiani, Alex Sangiorgi, Cesare Melandri, Laura Silvestroni

doi:10.1016/j.compositesb.2024.111373

 

制造富含碳纤维的超高强韧性短型复杂形状的可行途径

ZrB2 - based pasted, containing 5, 20, 45, 60 vol% short carbon fibers (Cf), were prepared in order to obtain complex shapes via direct ink writing, which were then sintered by hot pressing. The rheological behavior of the pastes indicated that at low Cf concentrations, the fibers act as a lubricant decreasing the paste viscosity. Above 20 vol% Cf, they act also as a binder creating an interconnected network that dominates over the on the lubrication effect, resulting in a viscosity increase. Complex shapes in the form of a hollow cylinder and a winglet with a functionally graded composition were then extruded and hot pressed, using a versatile powder bed method that enabled full densification with no need to use ad-hoc machined graphite inserts. Bars obtained from the direct ink writing process resulted in high alignment of the short fiber and displayed fracture toughness increase of 54% over that of the unreinforced matrix, while demonstrating a 42% increase with respect to conventionally hot pressed dry mixtures. This work shows the great potential of manufacturing complex shapes in ultra-high temperature ceramics matrices reinforced with short fibers for a plethora of design possibilities, including functional grading with control over layer composition, thickness and even short fiber alignment.

为了通过直接墨水书写获得复杂的形状，制备了含有 5、20、45 和 60 Vol% 短碳纤维 (Cf) 的 ZrB2 基浆料，然后通过热压进行烧结。浆料的流变行为表明，在碳纤维浓度较低时，纤维可作为润滑剂降低浆料粘度。当 Cf 含量超过 20 Vol% 时，纤维还能起到粘合剂的作用，形成一个相互连接的网络，在润滑效果上占据主导地位，从而导致粘度增加。然后，使用多功能粉末床方法挤压和热压出具有功能分级成分的空心圆柱体和翼片等复杂形状，该方法可实现完全致密化，无需使用临时加工的石墨插入件。通过直接油墨书写工艺获得的棒材短纤维排列整齐，断裂韧性比未增强基体提高了 54%，比传统热压干燥混合物提高了 42%。这项工作表明，用短纤维增强的超高温陶瓷基体制造复杂形状的产品具有巨大的潜力，可实现多种设计可能性，包括控制层组成、厚度甚至短纤维排列的功能分级。

Impact of ettringite seeding on hydration, strength and shrinkage of Na2SO4 activated slag

Xiufeng Deng, Maogao Li, Yifan Wang, Jintang Wang, Junjie Zhang, Zhuowen Yang, Xingyang He, Jin Yang, Hongbo Tan

doi:10.1016/j.compositesb.2024.111374

添加乙曲矿对 Na2SO4 活性渣水化、强度和收缩的影响

Na2SO4 activated slag (NSAS) is accepted as one of the most promising low carbon cementitious materials, while its slow strength development seemed the most prominent defect. In this study, nanoscale ettringite (NE) was prepared, and used as nucleation seed to stimulate the hydration of NSAS, thereby promoting the strength development. Compressive strength, hydration process, pore structure, and shrinkage were studied, and the underlying mechanism was revealed. Results indicated that 5% NE enhanced the compressive strength of NSAS paste by 74% at 7 d and by 98% at 28 d, and the reason was that NE significantly facilitated the hydration of slag and the formation of hydrates, including ettringite and C-(A)-S-H gel, especially in the early stage. Furthermore, the presence of NE hastened the dissolution of aluminum phases, and these aluminum phases were inclined to precipitate as ettringite rather than C-(A)-S-H gel. Meanwhile, NE caused the size miniaturization of ettringite crystal formed in hydration. The reason might be that NE provided more nucleation sites, which led to the dispersed growth of ettringite. The small ettringite was harmless to pore structure, and compensated for autogenous shrinkage. In the presence of 1% NE, the porosity and autogenous shrinkage at 28 d decreased from 9.62% and 5209 μm/m to 8.24% and 3992 μm/m, respectively. In addition, NE-NSAS showed great potential in low-carbon cementitious materials.

Na2SO4 活性矿渣（NSAS）被认为是最有前途的低碳水泥基材料之一，但其最突出的缺陷似乎是强度发展缓慢。本研究制备了纳米级乙丁睛石（NE），并将其作为成核种子来刺 激 NSAS 的水化，从而促进其强度发展。研究了抗压强度、水化过程、孔结构和收缩率，并揭示了其内在机理。结果表明，5% 的 NE 可使 NSAS 浆料的抗压强度在 7 d 和 28 d 分别提高 74% 和 98%，其原因是 NE 显著促进了矿渣的水化和水合物的形成，包括埃特林岩和 C-(A)-S-H 凝胶，尤其是在早期阶段。此外，NE 的存在加速了铝相的溶解，这些铝相倾向于沉淀为乙长石而非 C-(A)-S-H 凝胶。同时，NE 使水合过程中形成的乙长石晶体尺寸变小。原因可能是 NE 提供了更多的成核位点，从而导致了埃曲沸石的分散生长。小的埃曲石对孔隙结构无害，并能补偿自生收缩。在 1%的 NE 存在下，28 d 时的孔隙率和自生收缩率分别从 9.62% 和 5209 μm/m 降至 8.24% 和 3992 μm/m。此外，NE-NSAS 在低碳水泥基材料方面显示出巨大潜力。