今日更新:Composite Structures 1 篇,Composites Part A: Applied Science and Manufacturing 1 篇,Composites Part B: Engineering 7 篇,Composites Science and Technology 2 篇
Thermoelastic contact of layer-substrate system: Effects of force-like interface and Kapitza thermal resistance models
Yibin Jiang, Pengyang Zhao, Wenwang Wu
doi:10.1016/j.compstruct.2024.118675
层-衬底系统的热弹性接触:类力界面和Kapitza热阻模型的影响
Heterogenous materials composed of multiple layers with different material properties are commonly used for multi-functional engineering applications. Due to the existences of inevitable interfacial defects, discontinuities in displacement, stress, or thermal transmission often occur across the interfaces. This paper focus on the problem of layer-substrate system under three-dimensional sliding thermoelastic contact, and force-like imperfect interface and Kapitza thermal resistance interface defects are specially treated. By employing Fourier transforms, closed-form analytical expressions for the three-dimensional thermoelastic field of layer-substrate system with imperfect interface within Fourier spectral space are derived. The temperature and stress fields are computed using discrete convolution fast Fourier transform (DC-FFT) and the conjugate gradient method (CGM). Based on this model, the impact of defects on in-plane and out-of-plane stresses, von Mises stress, and the temperature field is investigated, and it is found that the force-like and Kapitza thermal resistance defects will result in discontinuities in stress and temperature field across the interface plane, and parametric analysis is performed for understanding the physical laws and key factors influencing the interface elastic fields discontinuities.
多相材料是由具有不同材料性能的多层材料组成的,通常用于多功能工程应用。由于不可避免的界面缺陷的存在,在界面上经常出现位移、应力或热传递的不连续。本文重点研究了三维滑动热弹性接触下的层-基体系问题,重点研究了类力缺陷界面和Kapitza热阻界面缺陷。利用傅里叶变换,导出了具有不完全界面的层-衬底体系三维热弹性场的傅里叶谱空间封闭解析表达式。采用离散卷积快速傅里叶变换(DC-FFT)和共轭梯度法(CGM)计算了温度场和应力场。基于该模型,研究了缺陷对面内、面外应力、von Mises应力和温度场的影响,发现类力缺陷和Kapitza热阻缺陷会导致界面平面上的应力场和温度场不连续,并进行了参数化分析,以了解影响界面弹性场不连续的物理规律和关键因素。
Preparation of biconnected carbon fiber/Cu composites with excellent thermal and mechanical properties
Hongda Guan, Xinbo He, Pengfei Zhu, Zijian Zhang, Junchen Huang, Xuanhui Qu
doi:10.1016/j.compositesa.2024.108564
具有优异热力学性能的双连接碳纤维/Cu复合材料的制备
A continuous three-dimensional CF network was constructed to fabricate biconnected CF/Cu composites. The effects of two-step electrodeposition and CF volume fraction on the thermal and mechanical properties of the composites were investigated. The results indicate that the two-step electrodeposition effectively fills the contact pores between CFs, reducing the porosity of the composites by 50 % compared to one-step electrodeposition. Moreover, the thermal conductivity of the composites prepared by two-step electrodeposition is enhanced by about 20 W m−1 K−1 relative to one-step electrodeposition, accompanied by a 25 % increase in bending strength. By controlling electrodeposition time, varying CF content on Cu foam can be obtained, enabling production of CF/Cu composites with different CF volume fractions. The 50 vol% CF/Cu composite exhibits excellent thermal conductivity, appropriate coefficient of thermal expansion, and outstanding bending strength.
构建了连续三维CF网络,制备了双连接CF/Cu复合材料。研究了两步电沉积工艺和CF体积分数对复合材料热性能和力学性能的影响。结果表明,两步电沉积有效地填充了碳纤维之间的接触孔,与一步电沉积相比,复合材料的孔隙率降低了50% %。此外,与一步电沉积相比,两步电沉积制备的复合材料的导热系数提高了约20 W m−1 K−1,同时抗弯强度提高了25 %。通过控制电沉积时间,可以获得不同CF含量的Cu泡沫,从而制备出不同CF体积分数的CF/Cu复合材料。50 vol%的CF/Cu复合材料具有优良的导热性、适宜的热膨胀系数和优异的抗弯强度。
COMPRESSIVE RESISTANCE OF THIN-WALLED PULTRUDED GFRP PROFILES: THE ROLE OF DELAMINATION EXAMINED THROUGH EXPERIMENTS AND FE SIMULATIONS
José Gonilha, João Alfredo de Lazzari, João Ramôa Correia, Nuno Silvestre
doi:10.1016/j.compositesb.2024.111929
薄壁拉挤GFRP型材的抗压性能:通过实验和有限元模拟研究分层的作用
Significant efforts have been made in the last decades to develop design rules and guidelines for composite structures, meeting the increasing interest in pultruded glass fibre reinforced profiles (GFRP) by the construction industry. One aspect that has been difficult to address is the crushing resistance of these profiles, with previous research indicating that the design equations are not conservative, predicting much higher resistances than those obtained in experimental tests. This paper explores the possibility that crushing resistance is governed by tensile failure in the through-thickness direction of the laminates, by Poisson effect, and proposes modifications to a previously presented material damage model to account for this in finite element (FE) simulations. Compressive experimental tests were conducted in stub-column specimens, with 5 different open-section configurations, obtained from three different producers. The test results were compared to analytical and FE simulations, confirming that the former grossly overestimate the resistance, while the latter, with the proposed damage model, compare well with experimental results.
在过去的几十年里,为了满足建筑行业对挤压玻璃纤维增强型材(GFRP)日益增长的兴趣,已经做出了重大的努力来制定复合结构的设计规则和指导方针。一个难以解决的方面是这些型材的抗压性,先前的研究表明,设计方程不是保守的,预测的阻力比实验测试中获得的阻力高得多。本文探讨了压碎阻力是由层压板在整个厚度方向上的拉伸破坏所控制的可能性,通过泊松效应,并提出了对先前提出的材料损伤模型的修改,以在有限元(FE)模拟中考虑到这一点。压缩实验测试在短柱试件中进行,从三个不同的生产商获得5种不同的开截面配置。将试验结果与分析和有限元模拟结果进行了比较,证实了前者严重高估了阻力,而后者采用所提出的损伤模型与试验结果比较吻合。
Temperature-controlled in-situ construction of composition-tunable nanoparticle-decorated SOFC cathodes with enhanced oxygen reduction kinetics and CO2 tolerance
Chuangang Yao, Baixi Xia, Haixia Zhang, Haocong Wang, Wenwen Zhang, Xiaoshi Lang, Kedi Cai
doi:10.1016/j.compositesb.2024.111917
具有增强氧还原动力学和二氧化碳耐受性的成分可调纳米颗粒装饰SOFC阴极的温控原位构建
High oxygen reduction reaction (ORR) catalytic activity and CO2 resistance of the cathode are fundamental to the commercial application of solid oxide fuel cells (SOFCs). Therefore, we develop a temperature-driven reduction-reoxidation strategy to in-situ construct heterostructured perovskite cathodes decorated with different nanoparticles by controlling the reduction temperature. For (Pr0.4Sr0.6)0.95Co0.2Fe0.8-xNixO3-δ(PSCFN, x = 0.05, 0.1), reduction (@700 °C)-reoxidation results in the exsolution of a ComFenNi3-m-nO4 spinel phase on the perovskite scaffold surface, while reduction (@750 °C)-reoxidation leads to the formation of both ComFenNi3-m-nO4 spinel phase and NiO nanoparticles. The exsolution of these highly active species increases the quantity of oxygen reduction active sites and effectively suppresses Sr segregation. The simultaneous formation of ComFenNi3-m-nO4 spinel phase and NiO nanoparticles induces B-site ion vacancies in the main phase, therefore facilitates the formation of oxygen vacancies. Additionally, the presence of ComFenNi3-m-nO4/NiO/PSCFN heterointerfaces promotes oxygen adsorption and transfer. The strong interactions among ComFenNi3-m-nO4, NiO, and PSCFN significantly enhance the structural stability. At 800 °C, Reo2-PSCFN0.1 achieves an output performance of 1.12 W cm−2, representing a 36.6 % enhancement compared to PSCFN0.1. Moreover, the Rp of Reo2-PSCFN0.1 is merely 0.0186 Ω cm2, marking a 40.4 % decrease relative to PSCFN0.1. This temperature-driven reduction-reoxidation strategy shows great promise as a novel approach for creating high-performance IT-SOFC cathodes.
我们开发了一种基于温度驱动的还原-氧化策略,通过控制还原温度来原位构建不同纳米粒子修饰的钙钛矿型阴极。对于(Pr0.4Sr0.6)0.95Co0.2Fe0.8-xNixO3-δ(PSCFN,x=0.05, 0.1),在700°C还原-氧化后,在钙钛矿骨架表面析出ComFenNi3-m-nO4尖晶石相;在750°C还原-氧化后,形成ComFenNi3-m-nO4尖晶石相和NiO纳米粒子。这些高度活性物种的析出增加了氧还原活性位点的数量,有效抑制了Sr的偏析。同时形成ComFenNi3-m-nO4尖晶石相和NiO纳米粒子会诱导主相中的B位离子空位,从而促进氧空位的形成。此外,ComFenNi3-m-nO4/NiO/PSCFN异质界面促进了氧的吸附和转移。复合物FenNi3-m-nO4、NiO和PSCFN之间的强相互作用显著提高了结构稳定性。在800°C时,Reo2-PSCFN0.1实现了1.12 W cm-2的输出性能,比PSCFN0.1提高了36.6%。此外,Reo2-PSCFN0.1的Rp仅为0.0186 Ω cm2,比PSCFN0.1降低了40.4%。这种由温度驱动的还原-氧化策略作为一种创建高性能IT-SOFC阴极的新型方法,具有巨大的潜力。
The nitriding treatment of ternary nanofibers toward outstanding electromagnetic wave absorption performance
Xiangwei Meng, Shuting Zhang, Meijie Yu, Chengguo Wang
doi:10.1016/j.compositesb.2024.111922
氮化处理使三元纳米纤维具有优异的电磁波吸收性能
Beneficial from the high electrical conductivity and remarkable chemical stability, transition metal nitrides have attracted widespread attention in the employment of electromagnetic wave absorption. Toward this end, Fe4N/zirconium dioxide/carbon nanofibers composited absorber was triumphantly prepared by the combination of electrospinning, carbonization, and subsequent nitridation. After undergoing the nitriding treatment, the emergency of Fe4N with superior electromagnetic properties, the introduction of more defects and functional groups, and the synergistic effect between each component would dramatically intensify multiple loss mechanisms, optimize the impedance matching, and improve the wave absorbing properties. Ultimately, the ternary fibrous nanocomposite realized the minimum reflection loss of −63.7 dB at 12.5 GHz with corresponding matching thickness of 2.2 mm, and an ultrabroad bandwidth up to 7.0 GHz. Therefore, this work substantiated the promising potential of Fe4N in the practical application of microwave absorption, and shed light on the exploitation of a new generation metal nitrides-based wave absorbents.
过渡金属氮化物由于具有较高的导电性和优异的化学稳定性,在电磁波吸收方面受到了广泛的关注。为此,通过静电纺丝、碳化、氮化等工艺,成功制备了Fe4N/二氧化锆/碳纳米纤维复合吸收剂。经过渗氮处理后,电磁性能优越的Fe4N的出现,引入更多的缺陷和官能团,以及各组分之间的协同作用,会极大地强化多种损耗机制,优化阻抗匹配,提高吸波性能。最终,该三元纤维纳米复合材料在12.5 GHz时实现了最小反射损耗- 63.7 dB,对应的匹配厚度为2.2 mm,超宽带高达7.0 GHz。因此,本研究证实了Fe4N在微波吸收实际应用中的巨大潜力,并为新一代金属氮基吸波剂的开发提供了思路。
Damage mechanisms of SiC fibers and BN interphase in SiCf/SiC composites during NITE process
Yu Zhang, Xu Shen, Qin Ma, Shuang Mu, Shaoming Dong, Jinshan Yang
doi:10.1016/j.compositesb.2024.111923
NITE过程中SiCf/SiC复合材料中SiC纤维和BN界面相损伤机理
In this work, the mechanical behavior of NITE-SiCf/SiC composites, accompanied by the damage mechanisms of SiC fibers and BN interphase during NITE process, are investigated. The results show that the fracture characteristic of NITE-SiCf/SiC composite is transformed from quasi-ductile mode to brittle mode with the elevating temperature, as well as severe damage of SiC fiber and BN interphase. The damage of SiC fibers is originated from high temperature, sintering aids corrosion and matrix compression. High temperature and sintering aids diffusion lead to the grain growth and strength degradation of SiC fibers. The damage of BN interphase is caused by the sintering aids corrosion, mainly the reaction of Al2O3, and matrix compression. The stress distribution is simulated via finite element analysis proving that up to 17.5 GPa and 17.0 GPa stress originated from matrix shrinkage during sintering process is applied to the fiber and interphase respectively, making the fiber deformation and interphase fragmentation. The degraded fiber strength and destroyed interphase structure weaken the load-bearing capacity and crack deflection ability, causing degradation of mechanical properties and reliability of composites. This work helps to comprehensively understand and optimize the properties of SiCf/SiC composites prepared by NITE process.
本文研究了NITE- sicf /SiC复合材料在NITE过程中的力学行为,以及SiC纤维和BN界面相的损伤机制。结果表明:随着温度的升高,NITE-SiCf/SiC复合材料的断裂特征由准韧性模式转变为脆性模式,SiC纤维和BN界面相损伤严重;SiC纤维的损伤主要来源于高温、烧结助剂腐蚀和基体压缩。高温和烧结助剂扩散导致SiC纤维晶粒长大和强度下降。BN界面相的破坏主要是由助烧剂腐蚀(主要是Al2O3的反应)和基体压缩引起的。通过有限元分析模拟应力分布,结果表明,在烧结过程中,纤维和界面分别受到17.5 GPa和17.0 GPa的应力,导致纤维变形和界面碎裂。纤维强度的退化和相间结构的破坏使复合材料的承载能力和裂纹挠曲能力减弱,导致复合材料的力学性能和可靠性下降。这项工作有助于全面了解和优化NITE工艺制备的SiCf/SiC复合材料的性能。
Achieving Excellent Thermal Transport in Diamond/Cu Composites by Breaking Bonding Strength-Heat Transfer Trade-off Dilemma at the Interface
Guo Chang, Shuang Zhang, Kaiyun Chen, Wei Zhang, Liang Li, Yongjian Zhang, Haoran Peng, Dongxiao Kan, Luhua Wang, Hailong Zhang, Wangtu Huo
doi:10.1016/j.compositesb.2024.111925
打破界面结合强度-传热权衡困境,实现金刚石/Cu复合材料的优异热传递
The heat transport enhancement of diamond/Cu composites, a new generation of thermal management materials, is trapped in the bonding strength-heat transfer trade-off dilemma at the interface due to the noticeable difference in physical and chemical properties between Cu and diamond. Herein, we propose a new strategy combining ultrathin interface modification and low-temperature high-pressure (LTHP) sintering process to prepare the diamond/Cu composites. With a suitable coefficient of thermal expansion (CTE) of < 10 ppm/K, the obtained diamond/Cu composites exhibit an outstanding thermal conductivity (k) value of 763 W/m K, over 90% of the theoretical prediction of the differential effective medium (DEM) model. Meanwhile, using a lower diamond volume fraction (45% vs. 50%–70%), the k value is higher than those by conventional powder metallurgy, meaning a substantial reduction in the cost by reducing diamond filler content. For such a highly mismatched diamond/Cu interface, we maintain a high bonding strength by lowering the thermal stress damage while achieve a high thermal conductance (G) of 93.5 MW/m2 K by minimizing the heat transfer obstacles. The prepared interface structure is a diamond/TiC/CuTi2/Cu configuration, where the two possible heat transfer bottlenecks (the diamond/TiC interface and the TiC/CuTi2 interlayer) are no longer limiting factors on the overall interface. The successful resolution to the interfacial heat transfer problem is responsible for the superior thermal transport performance of the composites. This work deals with the critical challenge for the diamond/Cu composites and offers deep insight into the improvement mechanisms of thermal transfer. The proposed strategy can be generalized to the integration of highly mismatched interfaces widely present in other composites or thermal management systems.
金刚石/Cu复合材料是新一代热管理材料,由于Cu与金刚石在物理和化学性质上的显著差异,其热传递增强在界面处陷入了结合强度-传热的权衡困境。在此,我们提出了一种结合超薄界面改性和低温高压烧结工艺制备金刚石/Cu复合材料的新策略。在合适的热膨胀系数(CTE) < 10 ppm/K时,金刚石/Cu复合材料的导热系数(K)为763 W/m K,超过微分有效介质(DEM)模型理论预测值的90%。同时,使用较低的金刚石体积分数(45% vs. 50%-70%), k值高于传统粉末冶金的k值,这意味着通过减少金刚石填料含量,可以大幅降低成本。对于这种高度不匹配的金刚石/Cu界面,我们通过降低热应力损伤来保持高结合强度,同时通过最小化传热障碍获得93.5 MW/m2 K的高导热系数(G)。制备的界面结构为金刚石/TiC/CuTi2/Cu结构,其中两个可能的传热瓶颈(金刚石/TiC界面和TiC/CuTi2夹层)不再是整个界面的限制因素。界面传热问题的成功解决是复合材料具有优良传热性能的重要原因。这项工作解决了金刚石/Cu复合材料面临的关键挑战,并为改善热传递机制提供了深入的见解。所提出的策略可以推广到广泛存在于其他复合材料或热管理系统中的高度不匹配界面的集成。
Modeling and measurements of creep deformation in a ceramic fiber reinforced metal matrix composite
Xu Kong, Yumin Wang, Qing Yang, Rui Yang
doi:10.1016/j.compositesb.2024.111926
陶瓷纤维增强金属基复合材料蠕变的建模与测量
This study proposes a novel analytical model for creep deformation in long brittle fiber-reinforced metal matrix composites. Unlike traditional creep models based on the steady-state creep expression of the creep behavior for the matrix in the composite, this model addresses the unsteady-state creep behavior. It also highlights the similarity between the governing equations for creep testing of the composite and stress relaxation testing of the unreinforced matrix. Owing to load transfer from the creeping matrix to the rigid fiber during the creep process, the matrix experiences decreasing stress and theoretically never reaches a steady state. Creep tests are conducted on a SiC fiber-reinforced Ti-6Al-2Sn-4Zr-2Mo-0.1Si alloy composite, within a stress range of 1100∼1350 MPa at 500 °C, with strain variation measured by an extensometer. Experimental results reveal significant discrepancies between the observed data and predictions based on steady-state creep assumptions. The differences between previous models and the proposed model are discussed using the experimental data.
本文提出了一种新的长脆纤维增强金属基复合材料蠕变分析模型。与传统的基于复合材料中基体蠕变行为稳态蠕变表达式的蠕变模型不同,该模型处理的是非稳态蠕变行为。这也突出了复合材料蠕变试验的控制方程与未加筋基体应力松弛试验的相似之处。在蠕变过程中,由于载荷从蠕变基体转移到刚性纤维,使得基体应力逐渐减小,理论上不会达到稳定状态。对SiC纤维增强Ti-6Al-2Sn-4Zr-2Mo-0.1Si合金复合材料进行了蠕变试验,在500℃、1100 ~ 1350 MPa的应力范围内,用伸长计测量应变变化。实验结果显示观测数据与基于稳态蠕变假设的预测之间存在显著差异。利用实验数据讨论了该模型与以往模型的差异。
Drug-free extracellular vesicles: A spatiotemporally controlled release engineering strategy for osteogenesis and anti-inflammatory niches in rotator cuff regeneration
Guoyang Zhang, Dingyi Shi, Yiyao Wei, Mingqi Wang, Haohan Wang, Zhiqi Lin, Haihan Gao, Weixuan Lin, Hanyi Wang, Yonglin Guo, Yingyu Ge, Yi Lin, Yiwen Jiang, Xiaoyu Yan, Yuhao Kang, Liren Wang, Jinzhong Zhao, Weiyang Ying
doi:10.1016/j.compositesb.2024.111928
无药物细胞外囊泡:一种时空控制释放工程策略,用于肌腱套再生中的成骨和抗炎小生境
Natural small-molecule drugs have promising potential to promote tissue regeneration in various fields. Therefore, maximizing drug efficiency while minimizing potential side effects is imperative. Peiminine, a natural product extracted from natural Fritillaria, is one of small-molecule drugs in the field of bone regeneration due to its good bone-promoting and anti-inflammatory abilities. However, its application is limited by a lack of biological activity, poor biocompatibility at high concentrations, and difficulty in achieving long-term slow-release and therapeutic effects. Extracellular vesicles (EVs) produced by preconditioned cells are considered to have special biological functions, and their potential to further retain, buffer, and transmit drug effects and expand the therapeutic effect has been widely studied. Thus, our study provides a drug-free bioengineering strategy by preconditioning bone marrow mesenchymal stem cells (BMSC) with Peiminine, then EVs, secreted as Peim-EVs, were extracted and combined with a decellularized extracellular matrix (dECM). The final EVs-dECM system with a spatiotemporally controlled release system was formed. In vitro studies demonstrated that Peim-EVs solved the problem of Peiminine biocompatibility and exhibited osteogenic and anti-inflammatory effects, which may be related to PI3K/AKT, MAPK/NF-κB, and Hippo signaling pathways. An in vivo model of rotator cuff injury in rats also showed that EVs-dECM had a good effect on rotator cuff repair. Combined with engineering strategy, this study provides verification and scenario expansion for drug application, especially for drug-free strategies that retain the biological effects of drugs, and has broad significance.
天然小分子药物在促进组织再生方面具有广阔的应用前景。因此,最大限度地提高药物效率,同时尽量减少潜在的副作用是势在必行的。贝母碱是从天然贝母中提取的天然产物,具有良好的促骨和抗炎作用,是骨再生领域的小分子药物之一。然而,由于缺乏生物活性,高浓度时生物相容性差,难以达到长期缓释和治疗效果,限制了其应用。细胞外囊泡(EVs)被认为具有特殊的生物学功能,其进一步保留、缓冲、传递药物效应和扩大治疗效果的潜力已被广泛研究。因此,我们的研究提供了一种无药物的生物工程策略,通过用Peiminine预处理骨髓间充质干细胞(BMSC),然后提取以peim - ev形式分泌的ev,并将其与脱细胞细胞外基质(dECM)结合。最终形成具有时空控制释放系统的ev - decm系统。体外研究表明,peim - ev解决了peim的生物相容性问题,并具有成骨和抗炎作用,这可能与PI3K/AKT、MAPK/NF-κB和Hippo信号通路有关。大鼠肩袖损伤的体内模型也显示ev - decm对肩袖修复有良好的效果。本研究结合工程策略,为药物应用特别是保留药物生物效应的无药策略提供了验证和场景拓展,具有广泛意义。
Experimental Study on the Influence of Optimised Automated Fibre Placement Processing Parameters on the Impact Response and Residual Flexural Strength of AS4/APC-2 Laminates
Shafaq Shafaq, Matthew J. Donough, Binayak Bhandari, Andrew W. Phillips, Nigel A. St John, B. Gangadhara Prusty
doi:10.1016/j.compscitech.2024.110945
优化自动铺放纤维工艺参数对AS4/APC-2层压板冲击响应及残余抗弯强度影响的实验研究
This study explores automated fibre placement (AFP) for manufacturing impact-resistant carbon fibre (AS4) /PEEK (APC-2) laminates by modifying the in-situ consolidation parameters. However, manufacturing these laminates without compromising their mechanical properties is challenging owing to the synergistic effect of parameters. The results indicate that a fast deposition rate and high consolidation force are associated with improved impact resistance and a higher threshold energy for damage. Improvements in flexural strength (27.4%) and modulus (22.6%), are achieved in non-impacted specimens. Acoustic emission monitoring was conducted during flexural-after-impact test to correlate the internal damage with the mechanical performance of AS4/APC-2 composites. The experimental results indicated that a fast deposition rate combined with high consolidation force can withstand higher impact loads. The FAI test showed the highest residual flexural strength and stiffness under these parameters, as it effectively resisted low-velocity impact (LVI) damage. However, the slight trade-off observed in post-impact strength suggested the presence of resin-rich areas, which may affect the damage tolerance of the laminates.
本研究通过修改原位固合参数,探索了用于制造抗冲击碳纤维(AS4) /PEEK (APC-2)层压板的自动化纤维放置(AFP)技术。然而,由于参数的协同效应,制造这些层压板而不损害其机械性能是具有挑战性的。结果表明,快速的沉积速率和高固结力与提高的抗冲击性能和更高的损伤阈值能有关。在非冲击样本中,抗弯强度(27.4%)和模量(22.6%)均有改善。通过对AS4/APC-2复合材料弯曲后冲击试验过程中的声发射监测,将AS4/APC-2复合材料的内部损伤与力学性能联系起来。实验结果表明,快速的沉积速率和较高的固结力可以承受较高的冲击载荷。在这些参数下,FAI测试显示出最高的残余抗弯强度和刚度,因为它有效地抵抗了低速冲击(LVI)损伤。然而,在冲击后强度中观察到的轻微权衡表明存在富含树脂的区域,这可能会影响层压板的损伤容限。
Electromagnetic wave absorption and enhanced mechanical properties of magnetic self-healing metal shell microcapsules filled polymer
Qian Ren, Xiaoyu Zhang, Yiran Wu, Dawei Sun, Xin Zhang
doi:10.1016/j.compscitech.2024.110944
磁性自愈金属壳微胶囊填充聚合物的电磁波吸收及增强力学性能
In this work, PUF/PU@IPDI (PPI) polymer shell microcapsules were synthesized through interfacial polymerization and in situ polymerization. Subsequently, a layer of metal Ni was plated on the surface of microcapsules to fabricate Ni/PUF/PU@IPDI (NPPI) composites. The results revealed that NPPI microcapsules exhibited superior thermal stability and mechanical properties, and NPPI-60 obtained the greatest strength (102.8 MPa). The minimum reflection loss (RL) value of the NPPI-20 composite was up to -32.8 dB at 5.5 mm and the corresponding effective absorption bandwidth (EAB) was 2.4 GHz. Additionally, the NPPI-10 composite displayed the highest healing efficiency (78.6% and 86.6% for the scratch depth and width, respectively), and the mechanical strength and fracture toughness of epoxy resin were enhanced by the addition of metal microcapsules. The core-shell structure established by electroless plating can endow self-healing microcapsules with outstanding mechanical characteristics as well as good wave absorption capability, indicating that NPPI composites have promising applications in the field of electromagnetic wave absorption and function and structure integration design of composites.
本文通过界面聚合和原位聚合制备了PUF/PU@IPDI (PPI)聚合物壳微胶囊。随后,在微胶囊表面镀一层金属Ni,制备Ni/PUF/PU@IPDI (NPPI)复合材料。结果表明,NPPI微胶囊具有优异的热稳定性和力学性能,其中NPPI-60的强度最高(102.8 MPa)。在5.5 mm处,NPPI-20复合材料的最小反射损耗(RL)值高达-32.8 dB,相应的有效吸收带宽(EAB)为2.4 GHz。此外,NPPI-10复合材料的修复效率最高(划痕深度和宽度分别为78.6%和86.6%),金属微胶囊的加入提高了环氧树脂的机械强度和断裂韧性。通过化学镀建立的核壳结构可以使自愈微胶囊具有优异的力学特性和良好的吸波能力,这表明NPPI复合材料在电磁波吸收和复合材料功能结构一体化设计领域具有广阔的应用前景。