今日更新:Composites Part A: Applied Science and Manufacturing 1 篇,Composites Part B: Engineering 1 篇,Composites Science and Technology 1 篇
Investigating the Impacts of Processing Variability on Tool-Part Interaction for Interply-toughened Aerospace Composites Using a Novel Shear Technique
Caleb Schoenholz, Navid Zobeiry
doi:10.1016/j.compositesa.2023.107973
使用新型剪切技术研究加工变异性对互层增韧航空航天复合材料工具-部件相互作用的影响
This study aims to investigate uncertainties in tool-part interaction during manufacturing of advanced aerospace composites. To achieve this goal, a custom-built shear test was developed using a Dynamic Mechanical Analyzer (DMA) to directly characterize tool-part interfacial stresses during composites processing. This novel method was used to quantify tool-part stresses during processing of interply-toughened Toray T800S/3900-2B on a steel tool with various conditions, accounting for variables such as the number of release coats on the tool, cure pressure and temperature, laminate layup, and strain rate. The observed trends in results were correlated with tool and part surface microstructures, investigated by laser scanning digital microscopy. This study’s findings underscored that the number of release coats, cure pressure, and temperature significantly influence tool-part interaction due to altered surface conditions and viscoelastic behaviors at the tool-part interface.
本研究旨在调查先进航空航天复合材料制造过程中工具-部件相互作用的不确定性。为实现这一目标,使用动态机械分析仪(DMA)开发了一种定制的剪切试验,以直接表征复合材料加工过程中的工具-部件界面应力。这种新方法用于量化钢制工具在不同条件下加工互层增韧东丽 T800S/3900-2B 时的工具部分应力,其中考虑了工具上脱模涂层的数量、固化压力和温度、层压板铺设和应变率等变量。观察到的结果趋势与激光扫描数码显微镜研究的工具和零件表面微观结构相关。这项研究的结果表明,脱模涂层的数量、固化压力和温度会显著影响工具与部件之间的相互作用,这是因为工具与部件界面的表面条件和粘弹性行为发生了改变。
Influence of surface integrity on the fatigue performance of TiB2/Al composite treated by ultrasonic deep rolling: Experiments and simulations
Yugang Li, Jiwei Geng, Zhiping Wang, Cunfeng Song, Chengcheng Zhang, Dong Chen, Haowei Wang
doi:10.1016/j.compositesb.2023.111160
表面完整性对经超声波深轧处理的 TiB2/Al 复合材料疲劳性能的影响:实验与模拟
The influences of surface integrity on the fatigue performance of in-situ 6 wt% TiB2/2024Al composite treated by ultrasonic deep rolling (UDR) were comprehensively investigated with both experiments and simulations. Results reveal that only a single pass of UDR treatment can impressively reduce the surface roughness of the fine-turned specimens by 94 %. Moreover, axial compressive residual stress (RSc) larger than −400 MPa and strain hardening (SH) higher than 50 % were obtained on the surface. The comprehensive effect of these surface integrity improvements has enhanced the fatigue limit by 22 %, extended the fatigue life by 10∼20 times, and expanded the safe region in the Goodman-Haigh graph by 14.6 %. More importantly, UDR significantly dispersed the TiB2-particle aggregates in the composite surface, which provided the possibility of improving the surface comprehensive mechanical properties of particles reinforced metal matrix composites (PRMMCs) through a simple and convenient mechanical way.
通过实验和模拟全面研究了经超声波深轧制(UDR)处理的原位 6 wt% TiB2/2024Al 复合材料的表面完整性对其疲劳性能的影响。结果表明,仅通过一次 UDR 处理就能将精车试样的表面粗糙度显著降低 94%。此外,表面的轴向压缩残余应力 (RSc) 大于 -400 MPa,应变硬化 (SH) 高于 50%。这些表面完整性改进的综合效果使疲劳极限提高了 22%,疲劳寿命延长了 10∼20 倍,Goodman-Haigh 曲线图中的安全区域扩大了 14.6%。更重要的是,UDR 能显著分散复合材料表面的 TiB2 颗粒聚集体,为通过简单便捷的机械方法改善颗粒增强金属基复合材料(PRMMC)的表面综合力学性能提供了可能。
Synergistic effect on dispersion, thermal conductivity and mechanical performance of pyrene modified boron nitride nanotubes with Al2O3/epoxy composites
Zahid Hanif, Dinh Duy Khoe, Ki-In Choi, Jung-Hwan Jung, Arni Gesselle M. Pornea, Numan Yanar, Cheolwoo Kwak, Jaewoo Kim
doi:10.1016/j.compscitech.2023.110419
芘改性氮化硼纳米管与 Al2O3/epoxy 复合材料在分散性、导热性和机械性能方面的协同效应
Due to the intrinsic attributes of boron nitride nanotubes (BNNT), its assimilation into composite materials displays an immense potential for thermal performance augmentation. However, the presence of Van der Waals forces and hydrophobicity of BNNT causing interfacial incompatibility with the polymeric matrix greatly hinders its practical applications. This instigates a dispersion dilemma and subsequent agglomeration of BNNT in the polymer matrix, which massively hampers the thermal performance of the polymer composites. In this respect, we here present a facile BNNT modification strategy; deposition of amine-attached pyrene (PAA) on the BNNT surface through a mild sonication process. The presence of amine in the pyrene molecules reduces the surface tension of PAA deposited BNNT (BNNT-PAA) allowing it to be readily dispersed in the various solvents even at the high concentrations. BNNT-PAA was added as a co-filler along with a primary filler (Al2O3) in the epoxy resin. The formed epoxy composites presented an improvement of as much as 33.1 % in tensile strain and 175.8 % in tensile stress with the addition of 1wt% of BNNT-PAA, while the thermal conductivity of vertical direction was enhanced as high as 62.3 %, possibly due to the constructed BNNT thermal conducting channels among alumina particles.
由于氮化硼纳米管(BNT)的固有特性,将其融入复合材料中显示出了提高热性能的巨大潜力。然而,由于 BNNT 存在范德华力和疏水性,导致其与聚合物基体的界面不相容,这极大地阻碍了其实际应用。这就造成了 BNNT 在聚合物基体中的分散困境和随后的团聚,严重影响了聚合物复合材料的热性能。为此,我们在此提出了一种简便的 BNNT 改性策略:通过温和的超声处理,在 BNNT 表面沉积胺附着的芘(PAA)。芘分子中胺的存在降低了 PAA 沉积的 BNNT(BNNT-PAA)的表面张力,使其即使在高浓度下也能很容易地分散在各种溶剂中。BNNT-PAA 作为辅助填料与主填料(Al2O3)一起添加到环氧树脂中。添加 1wt% 的 BNNT-PAA 后,所形成的环氧树脂复合材料的拉伸应变提高了 33.1%,拉伸应力提高了 175.8%,而垂直方向的热导率则提高了 62.3%,这可能是由于在氧化铝颗粒中构建了 BNNT 热导通道。