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
Composites Part A: Applied Science and Manufacturing
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.
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.
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.