今日更新:Composites Part A: Applied Science and Manufacturing 2 篇,Composites Part B: Engineering 3 篇,Composites Science and Technology 1 篇Composites Part A: Applied Science and ManufacturingA low-density polymer/CrMnFeCoNi composite with high strength and high damping capacityZhaohan Jiang, Gongli Tan, Xiangyi Huang, Teng Li, Hanyu Cai, Xiaojun Li, Qiru Wang, Xinxin Lv, Shen Gongdoi:10.1016/j.compositesa.2024.108130具有高强度和高阻尼能力的低密度聚合物/铬锰铁钴镍复合材料A novel damping composite was successfully prepared by taking a porous CrMnFeCoNi high-entropy shape memory alloy as the skeleton and filling its pores with the composite composed of carbon nanotubes and polyurethane/epoxy interpenetrating polymer networks. When the porosity, pore size and CNT loading are 80 %, 1.2 mm and 2 wt%, respectively, the compressive strength, elastic modulus and energy absorption capacity of the composite are 35.7 MPa, 1.31 GPa and 23.1 MJ/m3 (ε = 65 %), respectively. Furthermore, it has a mere density of 2.525 g/cm3. Its loss factor is greater than 0.093 and can reach a maximum of 0.145 within the temperature and frequency range of 20 ∼ 150 ℃ and 0.1 ∼ 200 Hz. A triple-phase micromechanical model was utilized to explore the damping mechanism of composites. Results indicate the coupling of multiple damping mechanisms is the reason for the high ground-state damping of composites, and interface damping is the primary damping mechanism. The superposition of the ε → γ reverse martensite transformation peak of the CrMnFeCoNi HESMA skeleton and the glass transition peak of the CNTs/polymer composite matrix realizes the wide damping temperature range of the composite.以多孔铬锰铁钴镍高熵形状记忆合金为骨架,在其孔隙中填充碳纳米管和聚氨酯/环氧互穿聚合物网络组成的复合材料,成功制备了一种新型阻尼复合材料。当孔隙率、孔径和碳纳米管含量分别为 80%、1.2 mm 和 2 wt% 时,复合材料的抗压强度、弹性模量和能量吸收能力分别为 35.7 MPa、1.31 GPa 和 23.1 MJ/m3 (ε = 65 %)。此外,它的密度仅为 2.525 g/cm3。在 20 ∼ 150 ℃ 和 0.1 ∼ 200 Hz 的温度和频率范围内,其损耗因子大于 0.093,最大可达 0.145。利用三相微机械模型探索了复合材料的阻尼机制。结果表明,多种阻尼机制的耦合是复合材料高基态阻尼的原因,而界面阻尼是主要的阻尼机制。CrMnFeCoNi HESMA 骨架的ε → γ反向马氏体转变峰与 CNTs/聚合物复合基体的玻璃化转变峰的叠加实现了复合材料较宽的阻尼温度范围。Self-healing thermally conductive polymer composites based on polyvinyl alcohol with dynamic borate ester and hydrogen bondsXing Xie, Dan Yangdoi:10.1016/j.compositesa.2024.108131 基于具有动态硼酸酯和氢键的聚乙烯醇的自愈合导热聚合物复合材料Traditional thermally conductive polymer materials exhibit a propensity for damage when applied in dynamic environments, which leads to shortened service life and suboptimal utilization of resources. Herein, polyvinyl alcohol (PVA)-based thermally conductive composites with a self-healing capability are prepared based on dynamic borate ester bonds and hydrogen bonds. Poly(dopamine) functionalized graphene oxide (denoted as PGO) is used as a thermally conductive filler to achieve a high thermal conductivity (TC) of 0.79 W/(m·K) for the PGO/PVA composites, which is 527 % of pure PVA (0.15 W/(m·K)). The improved TC of PGO/PVA composites is mainly attributed to the reduction in interface thermal resistance and the construction of heat conduction channels. Additionally, the PGO/PVA composites display a self-healing efficiency higher than 60 % at room temperature without external simulation. Furthermore, the as-prepared PGO/PVA composites exhibit excellent mechanical properties, with a tensile strength of 409 kPa and an elongation at break of 479 %, respectively. This work provides a promising strategy for fabricating thermally conductive polymer composites, which can be deployed as thermal interface materials for long-term applications.传统的导热聚合物材料在动态环境中使用时容易发生损坏,从而导致使用寿命缩短和资源利用率降低。本文基于动态硼酸酯键和氢键,制备了具有自修复能力的聚乙烯醇(PVA)基导热复合材料。使用聚(多巴胺)功能化氧化石墨烯(简称 PGO)作为导热填料,PGO/PVA 复合材料的导热系数(TC)高达 0.79 W/(m-K),是纯 PVA(0.15 W/(m-K))的 527%。PGO/PVA 复合材料 TC 值的提高主要归功于界面热阻的降低和热传导通道的构建。此外,PGO/PVA 复合材料在室温下的自愈效率高于 60%,无需外部模拟。此外,制备的 PGO/PVA 复合材料还具有优异的机械性能,拉伸强度和断裂伸长率分别达到 409 kPa 和 479 %。这项工作为制造导热聚合物复合材料提供了一种前景广阔的策略,这种复合材料可作为热界面材料长期应用。Composites Part B: EngineeringSynthesis mechanism of pelleted heterostructure Ti64–TiB composites via an interdiffusion and self-organization strategy based on powder metallurgyLei Liu, Shufeng Li, Xin Zhang, Shaolong Li, Shaodi Wang, Bo Li, Lina Gao, Huiying Liu, Dongxu Hui, Deng Pan, Shota Kariya, Junko Umeda, Katsuyoshi Kondohdoi:10.1016/j.compositesb.2024.111366通过基于粉末冶金的相互扩散和自组织策略合成颗粒状异质结构 Ti64-TiB 复合材料的机理Titanium matrix composites (TMCs) are the most attractive next-generation structural materials for lightweight design due to their high specific modulus and specific strength. Designing heterogeneous grain structures has been a widespread strategy for overcoming the strength-ductility trade-off in powder metallurgical TMCs. However, achieving a customizable heterogeneous grain structure in TMCs remains a formidable challenge. Here, we propose a novel interdiffusion and self-organization strategy based on the powder metallurgy method to fabricate a pelleted heterostructure Ti6Al4V(Ti64)–TiB composites, which integrates a heterogeneous distribution of reinforcements and heterogeneous grain structures of the matrix. The study reveals that the formation of the pelleted heterostructures is primarily governed by the interdiffusion reaction process between Ti and Al, and V elements, coupled with the growth and distribution changes of TiB induced by the interdiffusion reaction. Moreover, the pellet size is tailored by the spherical Ti–TiB composite powder, allowing precise control over the heterogeneous grain regions. This research contributes valuable insights into the manufacturing process of pelleted heterostructure Ti64–TiB composites and provides a conceptual framework applicable to the design of similar structures in various metal matrix composite systems.钛基复合材料(TMC)具有很高的比模量和比强度,是最有吸引力的新一代轻质结构材料。在粉末冶金钛基复合材料中,设计异质晶粒结构一直是克服强度-电导率权衡的普遍策略。然而,在 TMC 中实现可定制的异质晶粒结构仍然是一项艰巨的挑战。在此,我们提出了一种基于粉末冶金方法的新型相互扩散和自组织策略,用于制造球团异质结构 Ti6Al4V(Ti64)-TiB 复合材料,该复合材料整合了增强体的异质分布和基体的异质晶粒结构。研究表明,球团异质结构的形成主要受制于 Ti 与 Al 和 V 元素之间的相互扩散反应过程,以及由相互扩散反应引起的 TiB 的生长和分布变化。此外,球形 Ti-TiB 复合粉末可定制颗粒尺寸,从而实现对异质晶粒区域的精确控制。这项研究为粒状异质结构 Ti64-TiB 复合材料的制造工艺提供了宝贵的见解,并为各种金属基复合材料体系中类似结构的设计提供了概念框架。Exploring the development and applications of sustainable natural fiber composites: A review from a nanoscale perspectiveYuqi Feng, Huali Hao, Haibao Lu, Cheuk Lun Chow, Denvid Laudoi:10.1016/j.compositesb.2024.111369 探索可持续天然纤维复合材料的开发和应用:纳米视角综述As a result of global sustainable development, natural fiber composites (NFCs) have become increasingly attractive due to their remarkable performance, novel functionality, and eco-friendliness. Natural fibers are biodegradable, affordable, and low-density, which makes them potential materials for use in developing alternatives to traditional petroleum-based synthetic fiber composites. However, challenges such as inadequate compatibility between natural fibers and matrix limit the further development of NFCs. Studies have shown that molecular dynamics (MD) simulations can offer valuable insights into the fundamental properties and deformation mechanisms governing the macroscopic performances of NFCs, including mechanical properties, thermal stability, and interfacial interactions. Based on the underlying understanding of the nanostructure of natural fibers, these fibers can be modified at nanoscale to improve the performance of NFCs. This paper first reviews the hierarchical structures of natural fibers, mainly wood and bamboo fibers, highlighting their relationship with mechanical and thermal properties. Treatments to improve natural fiber-matrix compatibilities are then presented. The fundamental factors behind the functionalized properties of modified NFCs are emphasized from the nanoscale. Additionally, applications of NFCs as structural and functional materials in the construction, automotive, and aerospace industries are reviewed. Finally, this paper identifies the growing use of machine learning-assisted MD simulation techniques to facilitate the design of NFCs. Literature and data sources for this study were obtained through a combination of online academic databases, citation chaining, government databases, and industry reports.在全球可持续发展的大背景下,天然纤维复合材料(NFC)因其卓越的性能、新颖的功能和生态友好性而变得越来越有吸引力。天然纤维可生物降解、价格低廉、密度低,是开发传统石油基合成纤维复合材料替代品的潜在材料。然而,天然纤维与基体之间的兼容性不足等挑战限制了 NFC 的进一步发展。研究表明,分子动力学(MD)模拟可以为了解支配 NFC 宏观性能的基本特性和变形机制(包括机械性能、热稳定性和界面相互作用)提供有价值的见解。基于对天然纤维纳米结构的基本了解,可以在纳米尺度上对这些纤维进行改性,从而提高 NFC 的性能。本文首先回顾了天然纤维(主要是木纤维和竹纤维)的分层结构,重点介绍了它们与机械性能和热性能的关系。然后介绍了改善天然纤维与基质相容性的处理方法。从纳米尺度强调了改性 NFC 功能化特性背后的基本因素。此外,还回顾了 NFC 作为结构和功能材料在建筑、汽车和航空航天工业中的应用。最后,本文指出了机器学习辅助 MD 仿真技术在促进 NFC 设计方面日益广泛的应用。本研究的文献和数据来源综合了在线学术数据库、引文链、政府数据库和行业报告。Assessing the stress-transfer capability of mineral impregnated PBO yarns in a limestone calcined clay cement-based (LC3) matrixCesare Signorini, Andrea Nobili, Marco Liebscher, Jitong Zhao, Ameer H. Ahmed, Thomas Köberle, Viktor Mechtcherinedoi:10.1016/j.compositesb.2024.111364评估石灰石煅烧粘土水泥基(LC3)中矿物浸渍 PBO 纱线的应力传递能力Technical textiles made of poly(p-phenylene-2,6-benzobisoxazole) (PBO) represent attractive candidates for strengthening and repairing damaged concrete and masonry structures, due to the outstanding durability and mechanical performance of PBO fibres. Similar to their aramid counterpart, PBO fibres have proven to be very effective against dynamic and impact loading. In this contribution, the pull-out behaviour of PBO multifilament yarns embedded into a blended cement-based matrix is investigated, with particular reference to its stress-transfer capacity. In addition to the as-received PBO yarns, impregnation with a cement-based suspension, which can fully preserve the inorganic nature of the composite system, is also evaluated. Experimental results are presented and interpreted using a one-dimensional mechanical model. The findings indicate that mineral impregnation of the yarns provides a 40% increase in the stress-transfer capacity with the matrix, corresponding to a halving of the anchoring length. These performance gains are also supported by a transition in the failure mechanism which shifts from friction-based pull-out to fibre rupture.聚(对苯二甲酰-2,6-苯并异噁唑)(PBO)纤维具有出色的耐久性和机械性能,因此在加固和修复受损的混凝土和砖石结构方面,PBO 技术纺织品是极具吸引力的候选材料。与芳纶纤维类似,PBO 纤维已被证明对动态和冲击载荷非常有效。本文研究了嵌入混合水泥基质中的 PBO 多纤丝的拉出行为,特别是其应力传递能力。除了原始 PBO 纱线外,还评估了水泥基悬浮液的浸渍情况,该悬浮液可完全保持复合材料系统的无机性质。实验结果通过一维机械模型进行了展示和解释。研究结果表明,对纱线进行矿物浸渍后,纱线与基体之间的应力传递能力提高了 40%,相当于锚固长度缩短了一半。这些性能的提高还得益于失效机制的转变,即从摩擦拉断转变为纤维断裂。Composites Science and TechnologyA controllable foaming approach for the fabrication of “rattan-like” graphene-based composite aerogel with desirable microwave absorption capacityXiaoxiao Zhang, Qitan Zheng, Yujie Chen, Qunfu Fan, Hua Li, Hezhou Liu, Zhixin Chen, Yao Li, Hui Pan, Xueliang Jiang, Shenmin Zhudoi:10.1016/j.compscitech.2024.110532 可控发泡法制造具有理想微波吸收能力的 "藤状 "石墨烯基复合气凝胶As a common environmental pollutant, microwave can cause great harms to human health. The development of high-performance microwave absorber with lightweight is indeed necessary. Herein, “rattan-like” graphene-based composite aerogels, having macroscopic pores surrounded by plenty of small pores, were designed and fabricated via an in-situ foaming then carbonized approach. Firstly, graphene oxide (GO), nanocellulose and ferrous ions were integrated into an aerogel with uniform large pores via a freeze-casting method. Then, the aerogel was immersed into a H2O2 solution, during which bubble clusters generated in situ. These bubbles were driven into the stacked GO sheets and formed small pores. With the increase of the H2O2 concentration from 0.5 to 10 wt%, the count percentage of the small pores in the aerogel increased from 81.5 to 95.2%. After the final carbonization, the graphene sheets were dually interconnected with magnetic nanoparticles and carbonized nanocellulose. The unique porous structure and dual-connected networks endowed the aerogel with enhanced conductive loss and optimized impedance matching capacity, and thus an excellent microwave absorption performance, whose maximum reflection loss achieves −68.5 dB. Further, the aerogel also exhibited superior sound absorption performance (noise reduction coefficient up to 0.91 in 1000–6300 Hz), and good mechanical stability.微波作为一种常见的环境污染物,会对人体健康造成极大危害。因此,开发高性能、轻质的微波吸收剂十分必要。本文设计并通过原位发泡然后碳化的方法制造了 "藤条状 "石墨烯基复合气凝胶,其宏观孔隙被大量小孔包围。首先,通过冷冻铸造法将氧化石墨烯(GO)、纳米纤维素和亚铁离子集成到具有均匀大孔的气凝胶中。然后,将气凝胶浸入 H2O2 溶液中,在此过程中会在原位产生气泡团。这些气泡被驱赶到堆叠的 GO 片材中,形成了小孔。随着 H2O2 浓度从 0.5 wt% 增加到 10 wt%,气凝胶中小孔的计数百分比从 81.5% 增加到 95.2%。最终碳化后,石墨烯薄片与磁性纳米颗粒和碳化纳米纤维素实现了双重互连。独特的多孔结构和双连接网络使气凝胶具有更强的传导损耗和更佳的阻抗匹配能力,因而具有优异的微波吸收性能,其最大反射损耗达到-68.5 dB。此外,气凝胶还具有优异的吸音性能(1000-6300 Hz 的降噪系数高达 0.91)和良好的机械稳定性。来源:复合材料力学仿真Composites FEM