关键词： 石墨烯基复合材料   化学工程   催化剂载体   膜分离  

摘要： 本文深入探讨了石墨烯基复合材料在化学工程中的应用。石墨烯作为一种具有独特二维结构的碳材料,因其优异的性能而在化学工程中展现出广泛的应用前景。文章首先概述了石墨烯基复合材料的制备方法和优势性能,然后详细分析了其在催化剂载体、膜分离材料、防腐涂料、传感器和能源存储材料等化学工程领域的应用。同时,文章也指出了石墨烯基复合材料在制备技术和性能优化方面存在的挑战,并对其未来的发展趋势进行了展望。本文旨在为石墨烯基复合材料在化学工程中的进一步应用提供有益的参考和指导。

关键词： 锂离子电池   水系粘结剂   硅基负极   复合材料   电化学性能  

摘要： 以羧甲基纤维素钠(CMC)/丁苯橡胶(SBR)、聚丙烯酸(PAA)、丙烯酸衍生物多元共聚物（LA136D）为粘结剂，多孔硅/石墨复合材料作为负极分别组装了锂离子半电池，研究了不同结构粘结剂对复合材料电化学性能的影响。结果表明，以PAA作为粘结剂的复合材料首次放电比容量为564.98 mAh/g，初始库伦效率为84.6%，经过120次循环后放电比容量为453 mAh/g，相较于第二圈（507.97mAh/g）容量保持率为86.2%。相比其他粘结剂，PAA的三维交联网络结构赋予复合材料材料更强的机械强度和结构稳定性，能够有效缓解硅在充放电过程中因体积膨胀引起的结构破坏。

关键词： 碳纤维增强树脂复合材料   孔加工   缺陷   工艺研究   开孔拉伸   数值模拟  

摘要： 碳纤维增强树脂复合材料是以碳纤维为增强体、树脂为基体的复合材料,因其质量轻、耐腐蚀、抗疲劳等优良特性,逐渐替代了许多传统金属材料,广泛应用于航空航天、车辆制造、船舶运输等领域。碳纤维增强树脂复合材料的各向异性及非均质特性给加工带来了极大挑战和困难,尤其是大型复合材料的连接装配避免不了小孔结构的加工,但是孔周围产生的应力集中会显著降低连接件的抗疲劳性能。基于此,该文系统综述了碳纤维增强树脂复合材料的制孔方法及其特点。首先,阐述了不同加工工艺下碳纤维增强树脂复合材料制孔的研究进展,并分析了不同工艺下产生的主要缺陷,包括孔的表面形貌特征(如边沿毛刺、撕裂、热影响区、表面粗糙度等)和孔的侧壁形貌特征(如纤维分层、孔锥度、侧壁粗糙度等)。其次,针对复材层板的强度和破坏模式,综述了孔加工对复材层板性能的影响。最后,总结和讨论了碳纤维增强树脂复合材料制孔技术的发展趋势和前景。

关键词： Stress-strain curves  

摘要： Longitudinal tensile tests were carried out on SiCf/TC17 composites at room/high temperature to investigate the tensile behaviors. The damage evolution and failure mechanisms were revealed based on microscopic fracture morphology analysis. Afterwards， a constitutive model was developed to describe the tensile behaviors of SiCf/TC17 composites. The results showed that the ultimate tensile strength of SiCf/TC17 composites decreased with the increasing temperature， while the nonlinear segment of the stress-strain curve increased. The major failure mechanisms at room temperature lied in multiple fractures of the interfacial reaction layer and random breakage of weak fibers，whereas large-scale interface debonding and fiber pullout， matrix cracking and fiber breakage were more common at high temperatures. The results of different strength-predicted models demonstrated that the failure mode of SiCf/TC17 composites at room temperature was controlled by local loading sharing， while the high-temperature ultimate tensile strength was more consistent with the global loading sharing model. The stress-strain curve of SiCf/TC17 composites was simulated by the proposed constitutive model with coupling fiber cumulative damage. The simulation results exhibited a trend similar to that of the experimental data at 25 ℃ and 450 ℃. Finally， based on the tensile properties obtained from the tests， finite element stress-strain analysis and static strength calibration of the TMCs blade-ring structure were carried out. The result indicated that the blade-ring structure exhibited a significantly elevated strength reserve factor at the typical service temperature. © 2025 Beijing University of Aeronautics and Astronautics (BUAA). All rights reserved.

关键词： Strain rate  

摘要： Three-dimensional and five-directional (3D5D) glass fiber/epoxy resin braided composite circular tubes were fabricated by 3D braiding molding technology and resin transfer molding (RTM). Axial impact compression performance tests were conducted on the 3D5D braided composite circular tubes using the split Hopkinson pressure bar (SHPB) at low temperatures (−100℃, −50℃) and room temperature (20℃). The effects of temperature and strain rate on the axial impact compression performance of 3D5D braided composite circular tubes were studied using the stereomicroscope and SEM. The results show that temperature and strain rate have a significant effect on the axial impact compression performance of 3D5D glass fiber/epoxy resin braided composite circular tubes. Under the low-temperature field, the axial impact compression mechanical properties of 3D5D braided composite circular tubes are better than those at room temperature. With the increase of strain rate and the decrease of temperature, the peak stress, the compression modulus and the specific absorption energy of 3D5D braided composite circular tubes increase to varying degrees. In the low-temperature field, the axial impact compression failure characteristic of the material is brittle fracture and the fracture of the fiber bundle is relatively neat. The degrees of specimens' failure and deformation become more severe with the increase of strain rate and the decrease of temperature. However, the 3D5D braided composite circular tubes maintain good structural integrity even at high strain rates and low temperatures. © 2025 Beijing University of Aeronautics and Astronautics (BUAA). All rights reserved.

关键词： Aspect ratio  

摘要： The processing of small holes with large aspect ratio in SiC fiber reinforced SiC ceramic matrix composites (SiCf/SiC composites) are characterized by anisotropy, high hardness, and low electrical conductivity, which makes it difficult. Femtosecond laser processing and water-guided laser processing belong to the advanced laser processing methods, which have the advantages of controllable processing quality, automated processing, and low processing cost, and are the preferred technological solutions to solve the large aspect ratio of small holes in SiCf/SiC composites. Small holes with an aspect ratio of 10 are processed in SiCf/SiC composites by using femtosecond laser rotary drilling (FLRD) and water jet guided laser drilling (WJGLD). The morphology and physical phases of the entrance, exit, and wall of the small holes were analyzed, and the hole diameter, hole wall roughness, and processing efficiency of the small holes were compared. The results show that the exit quality of the holes processed by laser is better than the entrance quality, and the small holes processed by femtosecond laser have the advantages of sharp orifice, good roundness, and small taper, while the water guide laser processing has the advantages of clean orifices and hole walls, and high processing efficiency. To address the demand for small holes with large aspect ratios in heat-resistant components of SiCf/SiC composites, suitable drilling technology should be selected by considering factors such as processing quality, processing efficiency, and processing conditions. © 2025 Beijing University of Aeronautics and Astronautics (BUAA). All rights reserved.

关键词： 纳米TiO2   光催化   汽车尾气   过滤降解   复合材料  

摘要： 针对目前的汽车尾气过滤降解技术存在净化效果不佳、整体系统的复杂性和维护难度较高的问题,研究选择将纳米TiO2与玻璃微珠结合应用于汽车尾气降解中,通过光催化作用将汽车尾气中的有害气体氧化分解,从而降低其浓度。结果 表明,在30min时,研究模型对CO和NO的降解率分别为44.92%和47.68%,氧化铝对NO的降解率仅仅为11.41%,纳米TiO2模型对CO的降解率为15.87%。在MEIC数据集中,研究模型在60min时的即时降解率达到了49.64%,此时氧化铝模型的汽车尾气即时降解率显示最低,仅仅为36.78%。结果 说明,研究所提出的模型能够提高汽车尾气降解的效果,为保护生态环境提供了有效的数据支持。

关键词： 颗粒增强铝基复合材料   电弧增材制造   金属型模具   拉拔  

摘要： 颗粒增强铝基复合材料因其优异的高比强度和高比刚度，被广泛应用于交通、航空航天、船舶等领域。对于结构复杂的筒体、箱体等薄壁结构件，其成型难度大，机械加工余量大，生产周期长。而采用WAAM技术可以快速打印成形此类结构件。开展颗粒增强铝基复合材料制备、焊丝制备、电弧增材制造（WAAM）试验等，分析了T6热处理后颗粒增强铝基复合材料WAAM试样的力学性能。结果表明：采用金属型模具浇注颗粒增强铝基复合材料，提高了冷却速率，从而细化晶粒，使成分偏析程度减小，保证了组织的均匀性。通过控制单道次粗拉伸和精拉伸的变形比，辅以中间退火处理（410℃±10℃，保温1.5 h），可制备出满足WAAM要求的焊丝。采用制备的焊丝在合适的工艺参数下获得了成形良好、无孔隙的墙体增材制造样品。WAAM样品经T6热处理后，抗拉强度为370～390 MPa、屈服强度为320～335MPa、伸长率为2.5%～4.5%，满足使用要求。

关键词： C   /SiC-ZrC   RMI-PIP   力学性能   微观结构   抗烧蚀  

摘要： 高速飞行器的快速发展对抗烧蚀和高承载超高温陶瓷基复合材料提出了迫切需求，Cf/C-SiC-ZrC复合材料具有较好的承载能力和优异的抗氧化烧蚀性能，表现出巨大的应用潜力。先驱体浸渍裂解（PIP）与反应熔渗（RMI）复合工艺是提高Cf/C-SiC-ZrC复合材料制备效率、降低成本以及改善性能的有效途径。但在PIP-RMI工艺中，先PIP生成的陶瓷阻碍后续液态金属的浸渗与反应，降低复合材料的力学性能和抗烧蚀性能。本研究提出了先RMI（Si-Zr合金）再PIP（SiC先驱体）制备Cf/SiC-ZrC复合材料的新工艺，研究了其微观结构、组分分布、力学性能和抗氧化烧蚀性能。结果表明，随着PIP次数的增加，Cf/SiC-ZrC复合材料的力学性能显著提高，经3次PIP处理后拉伸强度达到197.0 MPa，压缩强度为228.3 MPa，弯曲强度为301.3 MPa，经2400 °C氧乙炔火焰烧蚀100 s后，线烧蚀率和质量烧蚀率分别低至-3.04×10-3mm·s-1和1.51×10-3g·s-1，满足抗烧蚀和高承载的要求，展现出了广阔的应用前景。