Showing papers on "Epoxy published in 2010"

Fracture and fatigue in graphene nanocomposites

Abstract: Graphene, a single-atom-thick sheet of sp-bonded carbon atoms, has generatedmuch interest due to its high specific area and novel mechanical, electrical, and thermal properties. Recent advances in the production of bulk quantities of exfoliated graphene sheets from graphite have enabled the fabrication of graphene–polymer composites. Such composites show tremendous potential for mechanical-property enhancement due to their combination of high specific surface area, strong nanofiller–matrix adhesion and the outstanding mechanical properties of the sp carbon bonding network in graphene. Graphene fillers have been successfully dispersed in poly(styrene), poly(acrylonitrile) and poly(methyl methacrylate) matrices and the responses of their Young’s modulus, ultimate tensile strength, andglass-transition temperaturehave been characterized. However, to the best of our knowledge there is no report on the fracture toughness and fatigue properties of graphene–polymer composites. Fracture toughness describes the ability of a material containing a crack to resist fracture and it is a critically important material property for design applications. Fatigue involves dynamic propagation of cracks under cyclic loading and it is one of the primary causes of catastrophic failure in structural materials. Consequently, the material’s resistance to fracture and fatigue crack propagation are of paramount importance to prevent failure. Herein we report the fracture toughness, fracture energy, and fatigue properties of an epoxy polymer reinforced with various weight fractions of functionalized graphene sheets. Remarkably, only 0.125% weight of functionalized graphene sheets was observed to increase the fracture toughness of the pristine (unfilled) epoxy by 65% and the fracture energy by 115%.Toachievecomparableenhancement,carbonnanotube (CNT) and nanoparticle epoxy composites require one to two orders of magnitude larger weight fraction of nanofillers. Under fatigue conditions, incorporation of 0.125% weight of functionalized graphene sheets drastically reduced the rate of crack propagation in the epoxy 25-fold. Fractography analysis

The toughness of epoxy polymers and fibre composites modified with rubber microparticles and silica nanoparticles

Abstract: The present paper investigates the effect of adding silica nanoparticles to an anhydride-cured epoxy polymer in bulk and when used as the matrix of carbon- and glass-fibre reinforced composites. The formation of ‘hybrid’ epoxy polymers, containing both silica nanoparticles and carboxyl-terminated butadiene-acrylonitrile (CTBN) rubber microparticles, is also discussed. The structure/property relationships are considered, with an emphasis on the toughness and the toughening mechanisms. The fracture energy of the bulk epoxy polymer was increased from 77 to 212 J/m2 by the presence of 20 wt% of silica nanoparticles. The observed toughening mechanisms that were operative were (a) plastic shear-yield bands, and (b) debonding of the matrix from the silica nanoparticles, followed by plastic void-growth of the epoxy. The largest increases in toughness observed were for the ‘hybrid’ materials. Here a maximum fracture energy of 965 J/m2 was measured for a ‘hybrid’ epoxy polymer containing 9 wt% and 15 wt% of the rubber microparticles and silica nanoparticles, respectively. Most noteworthy was the observation that these increases in the toughness of the bulk polymers were found to be transferred to the fibre composites. Indeed, the interlaminar fracture energies for the fibre-composite materials were increased even further by a fibre-bridging toughening mechanism. The present work also extends an existing model to predict the toughening effect of the nanoparticles in a thermoset polymer. There was excellent agreement between the predictions and the experimental data for the epoxy containing the silica nanoparticles, and for epoxy polymers containing micrometre-sized glass particles. The latter, relatively large, glass particles were investigated to establish whether a ‘nano-effect’, with respect to increasing the toughness of the epoxy bulk polymers, did indeed exist.

EPOXY POLYMERS : New materials and innovations

Abstract: Preface . List of Contributors . 1 General Concepts about Epoxy Polymers ( Jean-Pierre Pascault and Roberto J.J. Williams). 1.1 Polymerization Chemistry of Epoxy Monomers . 1.2 Transformations During the Formation of an Epoxy Network . 1.3 General Properties of Epoxy Networks . References . Part One New Polymers/Materials . 2 Thermoplastic Epoxy Polymers ( Jerry E. White). 2.1 Introduction . 2.2 Synthesis and Characterization of Epoxy Thermoplastics . 2.3 Fundamental Properties of Epoxy Thermoplastics . 2.4 Conclusions . Acknowledgments . References . 3 Epoxy Functional Acrylic Polymers for High Performance Coating Applications ( Carmen Flosbach and Roger Fugier). 3.1 Introduction . 3.2 Epoxy Functional Acrylic Polymers (Epoxy Acrylates) . 3.3 Synthesis of Epoxy Acrylates . 3.4 Design of Epoxy Acrylates as Film-forming Components in Coatings . 3.5 Cross-linking Reactions in Coating Systems . 3.6 Conclusions . References . 4 Epoxy Polymers Based on Renewable Resources ( Alessandro Gandini). 4.1 Introduction . 4.2 Synthesis and Polymerization of Monomers and Macromonomers Bearing Multiple Epoxy Functions . 4.3 Synthesis and Polymerization of Monomers Bearing a Single Epoxy Group . 4.4 Conclusions . References . Part Two (Nano)Structured Epoxy Networks . 5 Nanostructured Epoxies by the Use of Block Copolymers ( Sixun Zheng). 5.1 Introduction . 5.2 Formation Mechanisms of Nanostructures in Thermosets . 5.3 Morphologies of Epoxy Thermosets Modified With Block Copolymers . 5.4 Thermomechanical Properties of Nanostructured Thermosets . 5.5 Conclusions . References . 6 Self-Assembly of Epoxy-Based Polymers ( Cristina E. Hoppe and Roberto J.J. Williams). 6.1 Introduction . 6.2 Linear Nanostructured Epoxies . 6.3 Crosslinked Nanostructured Epoxies . 6.4 Possible Applications of Nanostructured Epoxies . References . 7 Polymer Dispersed Liquid Crystal, Thermotropic and Other Responsive Epoxy Polymers ( Agnieszka Tercjak and Inaki Mondragon). 7.1 Epoxy-Based Polymer Dispersed Liquid Crystal . 7.2 Polymer Dispersed Liquid Crystal Prepared by PIPS . 7.3 Block Copolymers Used as a Polymer Dispersing Agent for Liquid Crystal . 7.4 Epoxy Polymers Based on Azo-Benzene Organic Molecules . 7.5 Conclusions and Perspectives . References . 8 POSS and Other Hybrid Epoxy Polymers ( Libor Matejka). 8.1 Introduction . 8.2 Epoxy-Silica Hybrids . 8.3 Epoxy - POSS Hybrids . 8.4 Conclusions . Acknowledgment . References . 9 Lamellar Silicate-Modified Epoxies ( Jannick Duchet-Rumeau and Henry Sautereau). 9.1 Introduction . 9.2 Structure and Properties of Lamellar (Phyllo) Silicates . 9.3 Morphologies of Lamellar Silicates-Polymer Nanocomposites . 9.4 Chemical Modification of Lamellar Silicates for Epoxy Networks . 9.5 Dispersion and Structuration of Lamellar Silicates in the Initial Formulation . 9.6 Structuration of Lamellar Silicates in a Reactive Medium . 9.7 Mechanical Properties of Lamellar Silicates-Modified Epoxies . 9.8 Ternary Blends Based on Epoxy/Layered Silicates . 9.9 Barrier Properties of Nanoclay-Modified Epoxies . 9.10 Conclusions . References . 10 Epoxy/Carbon Nanotube Nanocomposites ( Luyi Sun and Hung-Jue Sue). 10.1 Introduction . 10.2 Preparation of Epoxy/CNT Nanocomposites . 10.3 Properties of Epoxy/CNT Nanocomposites . 10.4 Summary and Outlook . References . Part Three Innovative Formulations and Processing . 11 Epoxy Adhesives: A View of the Present and the Future ( Senen Paz Abuin). 11.1 Introduction . 11.2 Requirements and Conditions for the Design of an Epoxy Formulation . 11.3 Criteria for Selecting Adhesive Formulations . 11.4 Conclusions and Perspectives . Acknowledgments . References . 12 UV-Cured Nanostructured Epoxy Coatings ( Marco Sangermano). 12.1 Introduction . 12.2 Organic-Organic Nanocomposite Epoxy Coatings . 12.3 Organic-Inorganic Nanocomposite Epoxy Coatings . 12.4 Conclusions . Acknowledgments . References . 13 Electron Beam Curing of Epoxy Composites ( Felipe Wolff-Fabris and Volker Altstadt). 13.1 Introduction to Electron Beam Curing . 13.2 Material's Features . 13.3 Manufacturing Process . 13.4 Perspectives . References . 14 Composite Processing: State of the Art and Future Trends ( Stephan Costantino and Urs Waldvogel). 14.1 Introduction . 14.2 Infusion . 14.3 Resin Transfer Molding . 14.4 Prepreg . 14.5 Alternative Mold Heating Methods . 14.6 Sheet Molding Compound (SMC)/Bulk Molding Compound (BMC) . 14.7 Filament Winding . 14.8 Pultrusion . 14.9 Expandable Epoxy Systems . 14.10 Conclusions and Trends for the Future . References. 15 Thermoplastic Curable Formulations ( Thomas Fine, Raber Inoubli, Pierre Gerard, and Jean-Pierre Pascault). 15.1 Introduction . 15.2 Typical Preparation of Thermoplastic Curable Formulations . 15.3 Rheological Behavior of Blends of Block Copolymer and Thermoset Precursors . 15.4 Choice of the Hardener . 15.5 Processing and Properties . 15.6 Conclusions . Acknowledgments . References . 16 Structural Epoxy Foams ( Lisa A. Mondy, Rekha R. Rao, Harry Moffat, Doug Adolf, and Mathew Celina). 16.1 Background . 16.2 Continuum-Level Model for Foaming Materials . 16.3 Material Models and Experiments to Populate Numerical Model . 16.4 Numerical Method . 16.5 Model Validation . 16.6 Discussion and Suggested Improvements to the Model . 16.7 New Foaming Strategies to Minimize Gravity-Induced Density Gradients . 16.8 Summary . Acknowledgments . References . 17 Self-Healing Epoxy Composites ( Michael W. Keller). 17.1 Introduction . 17.2 Sequestered Healing-Agent Systems . 17.3 Intrinsically Healing Materials . 17.4 Potential Applications of Self-Healing Materials in a Bio-Engineering Setting . 17.5 Outlook for Self-Healing Materials . References . Part Four Conclusions and Perspectives . 18 Conclusions and Perspectives ( Jean-Pierre Pascault and Roberto J.J. Williams). 18.1 Definitions of Epoxy Polymers . 18.2 New Monomers and Formulations . 18.3 Nanostructured Epoxies . 18.4 Engineering Properties . 18.5 Functional Properties . 18.6 Health-Related Issues . 18.7 Life-Cycle Assessment . References . Index .

Fast Fourier Transform IR Characterization of Epoxy GY Systems Crosslinked with Aliphatic and Cycloaliphatic EH Polyamine Adducts

Abstract: The use of fast FT-IR spectroscopy as a sensitive method to estimate a change of the crosslinking kinetics of epoxy resin with polyamine adducts is described in this study. A new epoxy formulation based on the use of polyamine adducts as the hardeners was analyzed. Crosslinking reactions of the different stoichiometric mixtures of the unmodified GY250 epoxy resin with the aliphatic EH606 and the cycloaliphatic EH637 polyamine adducts were studied using mid FT-IR spectroscopic techniques. As the crosslinking proceeded, the primary amine groups in polyamine adduct are converted to secondary and the tertiary amines. The decrease in the IR band intensity of epoxy groups at about 915 cm-1, as well as at about 3,056 cm-1, was observed due to process. Mid IR spectral analysis was used to calculate the content of the epoxy groups as a function of crosslinking time and the crosslinking degree of resin. The amount of all the epoxy species was estimated from IR spectra to changes during the crosslinking kinetics of epichlorhydrin.

In situ stabilized carbon nanofiber (CNF) reinforced epoxy nanocomposites

Abstract: Carbon nanofibers (CNFs) suspended epoxy resin nanocomposites and the corresponding polymer nanocomposites are fabricated. The surface of CNFs is introduced a functional amine terminated groups via silanization, which in situ react with epoxy monomers. This in situ reaction favors the CNFs dispersion and improves the interfacial interaction between CNFs and monomers. Effects of particle loading, surface treatment and operating temperatures of rheological tests on the complex viscosity, storage modulus and loss modulus are systematically studied. Unique rheological phenomena “a decreased viscosity with a better dispersion” are observed and explained in terms of the improved filler dispersion quality. Meanwhile, significant increase in the tensile property and storage modulus is observed and related to the better dispersion and the introduced strong interfacial interaction as revealed by SEM imaging. Finally, electrical conductivity is investigated and an unusual deficiency of surface treatment to improve the electrical conductivity is explained by an insulating coating layer.

Graphene Nanoribbon Composites

Abstract: It is well established that pristine multiwalled carbon nanotubes offer poor structural reinforcement in epoxy-based composites. There are several reasons for this which include reduced interfacial contact area since the outermost nanotube shields the internal tubes from the matrix, poor wetting and interfacial adhesion with the heavily cross-linked epoxy chains, and intertube slip within the concentric nanotube cylinders leading to a sword-in-sheath type failure. Here we demonstrate that unzipping such multiwalled carbon nanotubes into graphene nanoribbons results in a significant improvement in load transfer effectiveness. For example, at ∼0.3% weight fraction of nanofillers, the Young’s modulus of the epoxy composite with graphene nanoribbons shows ∼30% increase compared to its multiwalled carbon nanotube counterpart. Similarly the ultimate tensile strength for graphene nanoribbons at ∼0.3% weight fraction showed ∼22% improvement compared to multiwalled carbon nanotubes at the same weight fraction of n...

Constructing hierarchically structured interphases for strong and tough epoxy nanocomposites by amine-rich graphene surfaces

Abstract: The exquisite structure of natural materials manifests the importance of particle mobility and load transfer in developing advanced polymer nanocomposites; however, it is difficult to concurrently meet these two mutually exclusive requirements. To address this issue, we demonstrate an approach that constructs a hierarchical, flexible interphase structure in epoxy nanocomposites through a local amine-rich environment around graphene sheets (GNs) and volume exclusion effect of grafting chains. Long-chain aromatic amines, which are chemically similar to the curing agent, are covalently bonded on the surface of GNs by diazonium addition. They play multifold roles in the structure formation of epoxy composites, (1) promoting the exfoliation and molecular level dispersion of GNs in the matrix, (2) serving as a linker between GNs and epoxy networks for improved load transfer, (3) modulating the stoichiometric ratio around GNs to construct a hierarchical structure that can dissipate more strain energy during fracture. With the addition of 0.6 wt% amine-functionalized GNs, the resulting composite exhibits significant mechanical improvements, 93.8 and 91.5% increases in fracture toughness and flexural strength, respectively. This approach affords a novel design strategy for developing high-performance structural composites.

Polymer Composites: From Nano- to Macro-Scale

Abstract: Nano-Composites: Structure and Properties. Carbon nanotube reinforced polymers: a state of the art review.- Application of non-layered nanoparticles in polymer modification.- Reinforcement of thermosetting polymers by the incorporation of micro- and nanoparticles.- Polyimides reinforced with the sol-gel derived organosilicon nanophase: synthesis and structure-property relationships.- Layered silicate/rubber nanocomposites via latex and solution intercalations.- Property improvements of an epoxy resin by nanosilica particle reinforcement.- Special Characterization Methods and Modelling. Micro-scratch testing and FE contact and debonding analysis of polymer composites.- Determination of interface strength of polymer-polymer joints by a curved interface tensile test.- Manufacturing and characterization of microfibrillar reinforced composites from different polymer blends.- Tribological characteristics of micro- and nanoparticle reinforced polymer composites.- Macro-Composites: Processing and Application. Production of thermoplastic towpregs and towpreg-based composites.- Manufacturing of tailored reinforcements for LCM processes.- De-consolidation and re-consolidation of thermoplastic composites during processing.- LFT composites in automotive applications.- Mechanical Performance of Macro-Composites. Deformation mechanisms of knitted fabric composites.- Impact damage in composite laminates.- Discontinuous basalt fiber reinforced hybrid composites.- Accelerated testing methodology for durability of polymer composites.- Author index.- Subject index.

A facile route for irreversible bonding of plastic-PDMS hybrid microdevices at room temperature

Abstract: Plastic materials do not generally form irreversible bonds with poly(dimethylsiloxane) (PDMS) regardless of oxygen plasma treatment and a subsequent thermal process. In this paper, we perform plastic-PDMS bonding at room temperature, mediated by the formation of a chemically robust amine–epoxy bond at the interfaces. Various plastic materials, such as poly(methylmethacrylate) (PMMA), polycarbonate (PC), polyimide (PI), and poly(ethylene terephthalate) (PET) were adopted as choices for plastic materials. Irrespective of the plastic materials used, the surfaces were successfully modified with amine and epoxy functionalities, confirmed by the surface characterizations such as water contact angle measurements and X-ray photoelectron spectroscopy (XPS), and chemically robust and irreversible bonding was successfully achieved within 1 h at room temperature. The bonding strengths of PDMS with PMMA and PC sheets were measured to be 180 and 178 kPa, respectively, and their assemblies containing microchannel structures endured up to 74 and 84 psi (510 and 579 kPa) of introduced compressed air, respectively, without destroying the microdevices, representing a robust and highly stable interfacial bonding. In addition to microchannel-molded PDMS bonded with flat plastic substrates, microchannel-embossed plastics were also bonded with a flat PDMS sheet, and both types of bonded assemblies displayed sufficiently robust bonding, tolerating an intense influx of liquid whose per-minute injection volume was nearly 1000 to 2000 times higher than the total internal volume of the microchannel used. In addition to observing the bonding performance, we also investigated the potential of surface amine and epoxy functionalities as durable chemical adhesives by observing their storage-time-dependent bonding performances.

Comparison of tensile and compressive characteristics of vinyl ester/glass microballoon syntactic foams

Abstract: The present study is focused on the synthesis and characterization of vinyl ester/glass microballoon syntactic foams. Tensile and compressive properties of vinyl ester matrix syntactic foams are characterized. Results show that the compressive strength and moduli of several syntactic foam compositions are comparable to those of the neat matrix resin. Due to the lower density of syntactic foams, the specific compressive properties of all compositions are higher than those of the neat resin. Similar trends are observed in the tensile properties. Mechanical properties of vinyl ester matrix syntactic foams are compared to well-documented mechanical properties of epoxy matrix systems. The comparison shows that low cost vinyl ester resins, which are extensively used in marine applications, can result in syntactic foams with comparable performance to epoxy matrix systems. In addition, tensile modulus is found to be 15–30% higher than the compressive modulus for all syntactic foam compositions. This difference is related to the possibility of particle fracture in the stress range where modulus is calculated in the compressive stress–strain curves.

Cellulose Whisker/Epoxy Resin Nanocomposites

Abstract: New nanocomposites composed of cellulose nanofibers or “whiskers” and an epoxy resin were prepared. Cellulose whiskers with aspect ratios of ∼10 and ∼84 were isolated from cotton and sea animals called tunicates, respectively. Suspensions of these whiskers in dimethylformamide were combined with an oligomeric difunctional diglycidyl ether of bisphenol A with an epoxide equivalent weight of 185−192 and a diethyl toluenediamine-based curing agent. Thin films were produced by casting these mixtures and subsequent curing. The whisker content was systematically varied between 4 and 24% v/v. Electron microscopy studies suggest that the whiskers are evenly dispersed within the epoxy matrix. Dynamic mechanical thermoanalysis revealed that the glass transition temperature (Tg) of the materials was not significantly influenced by the incorporation of the cellulose filler. Between room temperature and 150 °C, i.e., below Tg, the tensile storage moduli (E′) of the nanocomposites increased modestly, for example from 1...

Epoxy resin composition for fiber-reinforced composite material, prepreg, and fiber-reinforced composite material

Abstract: Provided are a fiber-reinforced composite material excellent in heat resistance and strength properties, an epoxy resin composition to obtain the fiber-reinforced composite material, and a prepreg obtained by using the epoxy resin composition. Further provided are a fiber-reinforced composite material having less volatile matters during the curing time, and having excellent heat resistance and strength properties, an epoxy resin composition to obtain the fiber-reinforced composite material, and a prepreg obtained by using the epoxy resin composition. Provided are: an epoxy resin composition for a fiber-reinforced composite material, comprising an amine type epoxy resin [A], an aromatic amine curing agent [B], and a block copolymer [C] having a reactive group capable of reacting with an epoxy resin; a prepreg obtained by impregnating a reinforced fiber with the epoxy resin composition; and a fiber-reinforced composite material obtained by curing the prepreg. Further provided are: an epoxy resin composition comprising an epoxy resin [A] having two or more of four- or more-membered ring structures, and having either one of a glycidyl amino group directly bonded to the ring structure or a glycidyl ether group directly bonded to the ring structure, epoxy resin [B] having three or more of functional groups, a curing agent [C], and an elastomer component [D]; a prepreg obtained by impregnating a reinforced fiber with the epoxy resin composition; and a fiber-reinforced composite material obtained by curing the prepreg.

Dramatic Increase in Fatigue Life in Hierarchical Graphene Composites

Abstract: We report the synthesis and fatigue characterization of fiberglass/epoxy composites with various weight fractions of graphene platelets infiltrated into the epoxy resin as well as directly spray-coated on to the glass microfibers. Remarkably only ∼0.2% (with respect to the epoxy resin weight and ∼0.02% with respect to the entire laminate weight) of graphene additives enhanced the fatigue life of the composite in the flexural bending mode by up to 1200-fold. By contrast, under uniaxial tensile fatigue conditions, the graphene fillers resulted in ∼3−5-fold increase in fatigue life. The fatigue life increase (in the flexural bending mode) with graphene additives was ∼1−2 orders of magnitude superior to those obtained using carbon nanotubes. In situ ultrasound analysis of the nanocomposite during the cyclic fatigue test suggests that the graphene network toughens the fiberglass/epoxy-matrix interface and prevents the delamination/buckling of the glass microfibers under compressive stress. Such fatigue-resista...

The effect of adding carbon nanotubes to glass/epoxy composites in the fibre sizing and/or the matrix

Abstract: Carbon nanotubes (CNTs) were integrated in glass fibres epoxy composites by either including CNTs in the fibre sizing formulation, in the matrix, or both. The effects of such controlled placement of CNTs on the thermophysical properties (glass transition temperature and coefficient of thermal expansion) and the Mode I interlaminar fracture toughness of the composites were studied. The present method of CNT-sizing of the glass fibres produces an increase of almost +10% in the glass transition temperature and a significant reduction of −31% in the coefficient of thermal expansion of the composites. Additionally, the presence of CNTs in the sizing resulted in an increased resistance of crack initiation fracture toughness by +10%, but a lowered crack propagation toughness of −53%. Similar trends were observed for both instances when CNTs were introduced only in the matrix and in combination of both matrix and sizing.

Toughening of Epoxies with Block Copolymer Micelles of Wormlike Morphology

Abstract: An amphiphilic poly(ethylene-alt-propylene)-b-poly(ethylene oxide) (PEP-PEO) block copolymer (BCP) was blended with a bisphenol A-based epoxy resin formulation and self-assembled into a wormlike micelle structure. With an incorporation of 5 wt % of the BCP material, the fracture toughness was improved by >100% over the neat epoxy. The morphology and mechanical properties of this BCP-modified epoxy were investigated using transmission electron microscopy, dynamic mechanical analysis, tensile tests, and fracture toughness measurements. Toughening mechanisms from the wormlike micelle-modified material were investigated using the double-notch four-point-bending technique, and the results are compared with data obtained from the same epoxy thermoset formulation containing a BCP that self-assembled into spherical micelles. Elongated cylindrical micelles produce improved toughness, which is interpreted on the basis of a combination of mechanisms including crack tip blunting, cavitation, particle debonding, limit...

Enhanced thermal conductivity of epoxy nanocomposites filled with hybrid filler system of triethylenetetramine-functionalized multi-walled carbon nanotube/silane-modified nano-sized silicon carbide

Abstract: Multi-walled carbon nanotubes (MWCNTs) were first treated by a 3:1 (v/v) mixture of concentrated H 2 SO 4 /HNO 3 , and then triethylenetetramine (TETA) grafting was carried out. Nano-sized silicon carbide particles (SiC np ) were modified by the silane coupling agent. Epoxy nanocomposites filled with hybrid filler system containing TETA-functionalized MWCNTs and silane-modified SiC np were prepared. The investigation on the thermal conductivity of epoxy nanocomposites filled with single filler system and hybrid filler system was performed. Chemical surface treatment is conducive to the enhancement of thermal conductivity of epoxy composites. The thermal conductivity of epoxy composites with hybrid filler system is higher than that of epoxy composites with any single filler system (functionalized MWCNTs or modified SiC np ), which is due to the effective combination of MWCNT-to-MWCNT and SiC np -to-SiC np conductive networks. Hybrid filler system could provide synergistic effect and cost reduction simultaneously.

Experimental investigation of a novel hybrid metal–composite joining technology

Abstract: An integrative joining technology between steel and carbon fibre-reinforced plastics (CFRP) is presented for lightweight design applications in aviation industries. Small spikes are welded onto metal surfaces via “cold-metal transfer” which then build up a fibre-friendly fixation through form-closure with co-cured composites. Manufacture of such reinforced hybrid specimens and results of static tensile testings are discussed. Video-extensometry is applied to characterize the hybrid joints in terms of strength and failure history. Comparisons with epoxy bonded references show improvements in ultimate load, maximum deformation and energy absorption capacity.