Multilayer Composites Research Articles

Fabrication of three-layered aluminium-copper laminated composites using friction stir additive manufacturing

Abstract The current study employed the friction stir additive manufacturing (FSAM) method to fabricate three-layered laminated composite by utilizing 3 mm thick sheets of AA6061-T6 alloy (top and bottom layers) and pure Cu (middle layer). The feasibility of FSAM in producing high-performance Al/Cu/Al laminated composites was evaluated by analyzing the influence of tool rotational speed on the microstructure and mechanical properties. The composites were fabricated at rotational speeds of 900 rpm, 1200 rpm, and 1500 rpm; maintaining a traverse speed of 90 mm min−1 throughout the experiments. Changes in the weld morphology, macrostructure, microstructure, and intermetallic formation were noted and analyzed. The findings indicated that achieving macro defect-free joints is possible with a rotational speed of 1200 rpm. Detailed examinations via electron dispersive spectrum and x-ray diffraction revealed the presence of AlCu, Al2Cu and Al2Cu3 intermetallic compounds within the nugget zone. Significantly varied microhardness levels ranging from 59.4 to 143.7 HV0.1 were observed, corresponding to distinct microstructural features within the processed zone. The Al/Cu laminated composite exhibited an excellent combination of strength and ductility; a UTS of 214.6 MPa and an elongation of 23.4%. The findings showcase that utilizing FSAM presents an exceptional opportunity to fabricate novel Al/Cu multilayered composites with distinctive mechanical properties.

Mechanical behaviour of 3D printed fiber-reinforced soft functional hydrogel composite: Opportunities for biomedical applications

Owing to the unique native properties of cellulose, such as biocompatibility, biodegradability, and excellent mechanical properties, it offers new strategies for designing environment-friendly, cost-effective, and high-mechanically robust hydrogel composites. Herein, we proposed the fabrication of 3D printed nature-inspired cellulose nanofibers (CNFs) reinforced anisotropic functional nanocomposite hydrogel structure.In this hypothetical study, we focuses on to develop nature-inspired 3D-printed Polyacrylamide PAM / Alginate (Alg) based single layered and multilayered laminate hydrogel composites reinforced with anisotropically oriented CNFs and performing finite element (FE) analysis study via implementing measured experimental material properties to explore the CNF reinforcement mechanism in the fiber-reinforced composite hydrogel. The FE modelling and simulation are based on an idealised anisotropic hyperelastic model used to analyse the anisotropic mechanical behaviour of the 3D printed hydrogel composite structure. The computational study of the nature-inspired printed helicoidally layup hydrogel composite construct exhibit enhanced mechanical properties, which offered appreciable stretchability, toughness and anisotropic mechanical behavior.It will assist the design of the more mechanically compliance composite hydrogel structure, making it suitable for load-bearing biomedical applications.

Research progress of bitumen bee structure based on atomic force microscopy: a literature review

ABSTRACT This review is focused on the bee structure observed by atomic force microscopy (AFM). For more than 20 years, the chemical origin and formation mechanism of the bee structure have been studied with the aid of AFM, resulting in numerous perspectives and controversies. Specifically, two dominant views dominate the debate on the chemical origin of bee structures. Some scholars tend to believe that the chemical composition of the bee structure is highly related to wax, while others consider that it is related to asphaltenes. In recent years, it has been acknowledged that the bee structure solely pertains to the microstructure on the surface of bitumen rather than its internal structure. The formation mechanism of the bee structure is elucidated by introducing the surface wrinkling theory of multilayer composites from the field of elastic-viscoelastic material. Based on the investigation of articles, this review concludes that the bee structure is more likely the wax crystallisation and surface wrinkling, and there exist certain specific correlations between the morphology of bee structures and macroscopic properties of bitumen. Furthermore, it is recommended that the bitumen research community adopt a standardised and simplified sample preparation procedure to enhance experimental comparability.

Wood‐like boards obtained from the recycling of rigid and flexible multilayer food packaging

AbstractNowadays, there is a growing concern about the damage caused by waste in the environment, which implies the generation of new processes and habits to contribute to a circular economy. This work explores a new alternative for the recycling of rigid and flexible containers without losing their structure of multilayer composites, which could be an advantage when used as boards or agglomerates. Then, the manufacturing process of recycled plates obtained from multilaminate containers is detailed. The idea lies in the combined use of two packaging with LDPE external layers, then being compatible without destroying the multilayer structure, to obtain wood‐like panels. Obtained composite boards are characterized in terms of moisture absorption, thermal conductivity and mechanical behavior, and properties compared with commercially available particleboards (LDF and MDF). The influence of the number of flexible containers in boards' performance was analyzed. The optimum processing temperature and pressure were also determined. Based on obtained results, it can be concluded that obtained boards have mechanical and moisture‐absorbing properties comparable to those of commercial particleboards, with greater resistance to environmental influences. Then, composite boards made from multilaminate containers are a promising and sustainable alternative for the construction and interior design industry. It is noticeable that this form of recycling has great advantages: it requires only a few steps, no solvents or water are used after washing and no sophisticated equipment is needed.Highlights Recycled multilaminate containers yield boards with competitive mechanical properties. Innovative process preserves multilayer structure for wood‐like panels. Optimized temperature and pressure parameters ensure board integrity. Superior moisture resistance compared with standard particleboards. Simple, solvent‐free method requires minimal equipment for production.

Carbon Fiber-Reinforced Thermoplastic Composite Coatings for Steel Pipelines.

Steel pipeline systems carry about three-quarters of the world's oil and gas. Such pipelines need to be coated to prevent corrosion and erosion. An alternative to the current epoxy-based coating, a multi-layered composite coating is developed in this research. The composite coatings were made from carbon fiber-reinforced thermoplastic polymer (CFRTP) material. Uniaxial carbon fiber CF/PPS prepreg tape was utilized, where the PPS (polyphenylene sulfide) is employed as a thermoplastic (TP) matrix. Compression molding was used to manufacture three flat panels, each consisting of seven plies: UD (Unidirectional), Biaxial, and Off-axis. Samples of carbon steel were coated with multi-layered composites. The physical, mechanical, and corrosion-resistant properties of steel-composite coated samples were evaluated. A better and more promising lap-shear strength of about 58 MPa was demonstrated. When compared to the Biaxial and Off-axis samples, the UD assembly had the maximum flexural strength (420 MPa); however, the Biaxial coating has the highest corrosion resistance (445 kΩ·cm2) when compared to the Off-axis and UD coatings.

Multiscale reinforcement of multi-layer ceramic composites with micrometer-scale carbon fibers and in-situ formed nanometer-scale SiC nanowires

Multiscale reinforcement of multi-layer ceramic composites with micrometer-scale carbon fibers and in-situ formed nanometer-scale SiC nanowires

Fazil Say’s «Shahmeran»: the metamodern paradigm of an Eastern myth in the music of a Turkish composer

The relevance of the study The relevance of this study stems from the insufficient scholarly exploration of Turkish academic music, particularly its contemporary manifestations, which integrate Eastern traditions with Western compositional techniques. The musical legacy of Fazıl Say, one of the most prominent representatives of 21st-century Turkish music, showcases a unique synthesis of national identity and global musical trends, reflecting Turkey's broader cultural context as a crossroads of civilizations. The main objective of the study is to examine the stylistic features of Fazıl Say’s symphonic poem «Shahmeran» as a realization of an Eastern myth in the context of global cultural trends of modernity, particularly metamodernism as a contemporary artistic paradigm. The methodologу includes the following approaches: the biographical method (to analyze the impact of the composer’s sociocultural environment on his creativity), the genre-stylistic method (to determine the genre characteristics of the composition and its connection with the traditions of Western instrumental music), the intonational-dramaturgical method (to explore the construction of the musical narrative), as well as cultural-historical and theoretical generalization methods (to define the place of the composition within the contemporary musical discourse). Results and conclusions. The symphonic poem «Shahmeran» by Fazıl Say is analyzed through the lens of the metamodern artistic paradigm as a multilayered composition that synthesizes elements of Eastern mythology, Turkish musical traditions, and contemporary compositional techniques. The central role of the myth of Shahmeran is identified as a tool for reinterpreting cultural heritage and generating new meanings within a globalized world. Emphasis is placed on the capacity of myth to function as a dynamic cultural code, adapting to modern challenges while maintaining its connection to archetypal structures, aligning with the key characteristics of metamodernism. The preconditions for the development of Turkish academic music are outlined, and the main factors that contributed to its rapid growth in the second half of the 20th century are determined. Fazıl Say’s creative method is examined, highlighting the influence of his active career as a pianist and his overseas education. Say’s compositional style is characterized as synthetic, seamlessly integrating Western compositional techniques with the distinctiveness of national musical traditions. The genre status of «Shahmeran» is identified as ambiguous, blending elements of a single-movement symphonic poem and a cello concerto under the framework of a programmatic title. The compositional features of the work are analyzed, including its fragmentary structure and non-linear form. The role of modalintonational and rhythmic specificities in shaping its distinct Eastern modality is emphasized. The significance of oriental instruments (kudüm, waterphone) and unique performance techniques (aleatory glissandi, the use of strings as percussion, and cello timbres approximating traditional instruments) is revealed, highlighting their contribution to the creation of a distinctive sonic landscape. It is demonstrated that the composer employs methods of «new simplicity», presented through the prism of oriental intonations.

Multilayer composites for improved mechanical performance of flexible rapier tape

Currently, laminated composites are used in the design and development of commercial rapier tapes employed in rapier weaving machines for weft insertion mechanisms. However, 3D woven reinforcements have the potential to enhance the mechanical performance of rapier tapes. This study focuses on comparing textile composites made from three different woven reinforcements i.e. plain 1/1, 2/2 twill, and a 3D woven orthogonal through the thickness and three different resins i.e. unsaturated polyester, epoxy, and acrylic. The developed composites underwent mechanical testing tailored for flexible rapier tapes. The results revealed that 3D-reinforced rapier tape composites (RTCs) exhibited higher tensile stress, strain at break, flexural force, flexural modulus, storage modulus, and stiffness compared to RTCs with 2D woven reinforcements. Among the resins, epoxy demonstrated superior mechanical performance across most properties, outperforming unsaturated polyester and thermoplastic acrylic resin. The developed single 3D multilayer reinforcement presents a feasible alternative for fabricating RTCs, with the potential to reduce energy.

Lithium Dendrite Deflection at Mixed Ionic–Electronic Conducting Interlayers in Solid Electrolytes

AbstractSolid state lithium metal batteries using garnet solid electrolytes such as LLZTO (Li6.4La3Zr1.5Ta0.5O12) promise substantial improvements in energy density and safety. However, practical implementation is hindered by lithium dendrite penetration at high current densities. Recent work shows that internal electrochemically induced mechanical stresses are large enough to propagate lithium dendrites and subsequently fracture solid electrolytes. This study builds on this understanding and demonstrates that stress‐driven dendrite propagation can be controlled via deflection at weakly bonded internal interfaces. This approach, based on a fracture‐mechanics analysis of multilayered composites, is investigated with a variety of interlayer materials that are embedded into LLZTO. The viability and effectiveness of dendrite deflection are most clearly evident with reduced graphene oxide where the critical current density increased from 0.6 to 3.8 mA cm−2. In this material, both the weak interface with LLZTO and the mixed ionic–electronic conducting nature of the interlayer appear to contribute to the improved performance. Additional insight into the mechanics of multilayered electrolytes is also obtained with finite element modeling. The overall results present a promising proof‐of‐concept demonstration along with important generalized design guidelines for creating multilayered solid electrolyte architectures that can enable high‐performance solid‐state batteries.

Deformation and fracture of lithosphere-inspired polymeric multi-layer composites

Inspired by the diversity of structures and patterns inherent in the earth's lithosphere, this study endeavors to enhance the interplay between stiffness and toughness through the introduction of a new class of polymeric multi-layer composite materials termed by the authors as "lithomers". Structured single-edge notched bending specimens were fabricated using a combination of additive manufacturing and casting, employing two different methacrylate-thiol resins. The outer layers exhibit a stiff and brittle characteristic, while the layer in between is compliant in nature. Three types of lithomers with wave-like structures and one with a rectilinear structure were investigated regarding their stiffness and toughness in a 3-point bending setup. The results were compared with those of a pure stiff matrix material. The findings revealed that fracture toughness increased regardless of the interlayer's shape compared to the pure matrix material. Correspondingly, this enhancement in fracture toughness correlated with a reduction in stiffness. The most balanced results in terms of stiffness and fracture toughness were achieved, with the lithomer having a wave-like structure in its initial stage. It exhibited a roughly 27 times improvement in fracture toughness with a moderate decrease in stiffness of approx. 1/5 compared to the pure matrix material.

Microstructural and tribological properties of multilayered coatings developed through heat treatment on the surface of CP-Ti

It is well known that applying NiTi intermetallic coatings on the surface of different alloys can improve their tribological behavior. In this paper, various intermetallic phases of Ni3Ti, NiTi, and NiTi2 and a Ti-rich pearlite-like eutectoid structure were in situ synthesized on the surface of commercially pure (CP) titanium grade 2. Nickel electroplating was performed on titanium samples followed by heat treatment at a temperature of 800 °C for various times up to 8 h. The formation of various phases and structures along the depth were studied using SEM, EDS and XRD. Heat treatment at a temperature of 800 °C for 4 h resulted in the formation of a multi-layered composite of Ni3Ti, NiTi, and NiTi2 intermetallic films with a thickness of 5, 9, and 2 μm, respectively. A nickel diffusion layer (NDL) with a pearlitic structure containing nanolayers of αTi-NiTi2 was also formed beneath the NiTi2 layer even after 30 min of heating. Among the different layers formed on the surface of CP-Ti, the titanium-rich NiTi (51–52 at.% Ti) showed the highest hardness of more than 400 HV. Sliding wear tests were performed under a normal load of 10 N and the surfaces of wear tracks were studied using SEM. The results showed higher wear resistance of all intermetallic layers and NDL than the titanium substrate, with the highest wear resistance for Ni3Ti top layer.

All-Polymer Composite Film with Outstanding Mechanical, Thermal Conductive, and EMI Shielding Performances.

Robust polymer-based composites with high thermal conductivity (TC) and electromagnetic interference shielding effectiveness (EMI SE) hold great promise for applications in rapidly developing electronics. Traditional composites containing inorganic fillers often suffer from increases in processing difficulty, density, and significant deterioration in mechanical properties. Herein, we report for the first time a flexible multilayered all-polymer composite of poly(p-phenyl-2,6-phenylene bisoxazole) (PBO) and poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), featuring excellent mechanical strength of 203.9 MPa, in-plane TC of 21.9 W/mK, EMI shielding effectiveness (SE) of 44.2 dB, high-temperature stability, and flame retardancy. The excellent TC, mechanical strength, and flame retardancy of PBO, the remarkable EMI shielding performance of PEDOT:PSS, and the π-π stacking interactions between adjacent layers contribute to the comprehensive properties, which outperform most of the traditional composites of polymers and inorganic fillers reported so far. This full-polymer design may pioneer a new strategy for the preparation of robust and lightweight multifunctional composites.

Multilayer architected polymer nanostructure for microwave absorber-based EMI shielding

Reflection-based electromagnetic interference shielding materials, though effectively stop the radiation, redirect the interference to nearby electronic devices, creating secondary pollution. In this sense, it is better to use absorption-dominant lightweight and flexible materials with high shielding effectiveness. This paper reports the fabrication of a multilayered polymer nanocomposite for enhancing electromagnetic interference shielding applications through absorption. By using a doctor-blade technique, three individual layers of poly(vinylidene fluoride) based polymer nanocomposite, each with different fillers, were prepared and stacked together to form a 3 mm thick multilayered (four-layer) composite. The fillers were 5% Ag-decorated graphene nanoplatelets, acid-functionalized MWCNT, and barium hexaferrite. Between 8 and 18 GHz, this multilayered composite absorbs a maximum of 90% of incident microwave radiation, resulting in a shielding in the range of 20–45 dB. This structure is very useful for developing flat and lightweight absorbers. For comparison, a homogeneously prepared nanocomposite comprising all these three fillers is found to give a shielding of around 53 dB with a reflection ranging between 78% and 89%.

Gigantic multilayered vesicle-like hydrogel-bilayer composites

Abstract Preparation of large vesicles with high stability is generally difficult. Here, we report the millimeter-scale multilayered vesicle-like hydrogel-bilayer composites with long-term stability through stabilization of the vesicular structure by polymerization of the lipid molecules and gelation of the inner solution. The well-oriented multilayered structure was examined by various methods. Reflecting the multilayered structure, the resulting vesicle-like composites exhibited extremely slow drug release behavior.

Simultaneously Enhanced Thermal Conductivity and Dielectric Breakdown Strength in Micro/Nano-BN/Epoxy/PC Multilayer Composites

Simultaneously Enhanced Thermal Conductivity and Dielectric Breakdown Strength in Micro/Nano-BN/Epoxy/PC Multilayer Composites

Weak interface-induced repeated kinking of a central crack in a brittle multilayered plate under remote shear loading

Understanding the repeated kinking pattern of cracks is essential for controlling the complex fracture trajectories in multilayered composites. While previous studies have explored many aspects of fractures in layered materials, the conditions governing the repeated kinking behavior under basic loading modes remain largely unrevealed. This research elucidates the continual kinking condition for a central crack in a brittle, multilayered plate with closely-parallel weak interfaces under remote shear stresses. Using the strain energy release rate (SERR) ratio criterion, we analytically derived a closed-form solution to the condition through the equivalent crack concept. The solution specifies a value domain for the intersection angle and fracture toughness ratio of weak interfaces, where the load-guided direction competes closely with the weak interface-guided direction to shape the crack trajectory into a repeated kinking pattern. Our theoretical results, validated by a series of finite element (FE) simulations, clarify how closely-parallel weak interfaces induce repeated crack kinking in multilayered materials under remote shear loading. This research paves the way for the deeper understanding of intricate crack trajectories under mixed loads in various practical applications.

Harmonizing lightweight and ablation resistance: Design and performance of multilayer composite insulation materials for solid rocket motors

AbstractThe realization of lightweight insulation materials is often accompanied by a decrease in ablation performance. Coordinating the contradiction between lightweight and ablation resistance is the key to the development of thermal protection technology. Addressing the need for high‐performance insulation materials within solid rocket motors (SRMs) combustion chambers, we designed three multilayer composite structural insulation materials and studied their properties. The results show that among these constructed multilayer composites, the bilayer structure exhibited the lowest density at a mere 0.72 g/cm3, marking a 27% reduction compared to the basic structure. Remarkably, the bilayer configuration demonstrated superior ablation resistance, showcasing a 25% decrease in the line ablation rate in contrast to the basic structure after oxygen‐acetylene test. This achievement embodies the successful harmonization of lightweight properties with ablation resistance. Furthermore, based on the performance and microstructure of the char layer, a further analysis revealed the enhancement mechanism of ablative performance by the multilayer composite structure. It was found that the synergistic effect of the compact/porous structure of the char layer grants the bilayer structure thermal insulation material optimal ablative performance. This work provides strong support for improving the performance of SRMs.Highlights Insulation materials with multilayer composite structures are designed. The materials exhibit both lightweight and superior ablation resistance. Compact/porous char layers enhance material ablation performance.

A Review of the Biomimetic Structural Design of Sandwich Composite Materials.

Sandwich composites are widely used in engineering due to their excellent mechanical properties. Accordingly, the problem of interface bonding between their panels and core layers has always been a hot research topic. The emergence of biomimetic technology has enabled the integration of the structure and function of biological materials from living organisms or nature into the design of sandwich composites, greatly improving the interface bonding and overall performance of heterogeneous materials. In this paper, we review the most commonly used biomimetic structures and the fusion design of multi-biomimetic structures in the engineering field. They are analyzed with respect to their mechanical properties, and several biomimetic structures derived from abstraction in plants and animals are highlighted. Their structural advantages are further discussed specifically. Regarding the optimization of different interface combinations of multilayer composites, this paper explores the optimization of simulations and the contributions of molecular dynamics, machine learning, and other techniques used for optimization. Additionally, the latest molding methods for sandwich composites based on biomimetic structural design are introduced, and the materials applicable to different processes, as well as their advantages and disadvantages, are briefly analyzed. Our research results can help improve the mechanical properties of sandwich composites and promote the application of biomimetic structures in engineering.

Progress on the Sound Absorption of Viscoelastic Damping Porous Polymer Composites.

Porous polymer composites (PPC) have developed rapidly recently, which are widely used in various industrial fields. Viscoelastic damping is an important behavior of porous polymer composites, and it can determine the sound absorption for noise reduction applications. This review has mainly covered the viscoelastic damping and sound absorption of porous polymer composites. Different fabrication approaches of porous polymer composites are gathered. The mechanism of viscoelastic damping behavior is described, and also the sound absorption properties. Followed by the introduction of enhanced sound absorption of viscoelastic damping porous polymer composites, including the incorporation of fillers, microstructures modification, combination with nanofibrous materials, and multilayer configuration, etc. The incorporated fillers can effectively adjust the interfacial area in composites, and obtain desired bonding conditions. Microstructures modification is an effective tool to improve the morphologies of both polymer matrix and fillers, which can be achieved by chemical treatment and surface coating. The combination with lightweight nanofibrous layer can increase the low frequency absorption. The configuration of multilayer composites can improve both acoustical and mechanical properties for engineering applications. It is hoped that this comprehensive review is benefit for the promising development of porous polymer composites in related fields.

EVOLUTION OF THE PRESS BONDING PROPERTIES OF Al/Cu BIMETAL BULK COMPOSITES (EXPERIMENTAL AND NUMERICAL INVESTIGATION)

Nowadays, the application of bimetallic laminates with special capabilities is increasing and has experienced high growth. These properties include high corrosion resistance, mechanical properties, thermal stability, and lightweight. In the midst of the technologies of multilayer composite materials, accumulative press bonding (APB) as a solid-phased method of welding is one of the most common techniques for the production of multilayer composites. One of the most important aims for this choice is the press pressure, which can generate a suitable mechanical connection and strong bonding between produced metal layer components. In this study, bimetal aluminum/copper bulk composites have been fabricated via the APB technique. Then, the effect of pressing parameters such as plastic strain and the number of layers on the stress distribution has been investigated. For samples with eight layers, the shear stress between the layers reached 3.1 MPa which is a suitable condition to generate a successful bonding. The stress applied on the layers has also increased with increasing the thickness reduction ratio. The interlayer shear stresses also increase with decreeing the thickness. With a higher reduction in thickness ratios, the amount of sinking layers was greater along the entire length of the sample, which led to the crushing of copper layers. During the APB process at higher pressing passes, increasing the volume of virgin material in the direction of the press led to increasing the compaction and better bonding of Al and Cu layers to each other.