Interfacial Adhesion Strength Research Articles

Tailoring the Holocellulose Fiber/Acrylic Resin Composite Interface with Hydrophobic Carboxymethyl Cellulose to Enhance Optical and Mechanical Properties.

Interface engineering is essential for cellulosic fiber-reinforced polymer composites to achieve high strength and toughness. In this study, carboxymethyl cellulose (CMC) functionalized with hydrophobic quaternary ammonium ions (QAs) were utilized to modify the interface between holocellulose fibers (HF) and acrylic resin. The wet HF/CMC papers were prepared by vacuum filtration, akin to papermaking, followed by cationic ion exchange with different hydrophobic QAs. Subsequently, the modified papers were dried, impregnated with an acrylic resin monomer, and cured to produce transparent composite films. The effect of the hydrophobic QA moieties on the structure and optical and mechanical properties of the HF/CMC/acrylic resin composites were investigated. The composite film with cetyltrimethylammonium (CTA)-functionalized CMC showed high optical transmittance (87%) with low haze (43%), while the composite film with phenyltrimethylammonium (PTMA)-functionalized CMC demonstrated high Young's modulus of 7.6 GPa and high tensile strength of 180 MPa. These properties are higher than those of the composites prepared through covalent interfacial modification strategies. The results highlighted the crucial role of hydrophobic functionalized CMCs in facilitating homogeneous resin impregnation in the HF fiber network, producing a composite with enhanced interfacial adhesion strength, increased optical transparency, and mechanical strength. This facile use of hydrophobic CMCs as interfacial compatibilizers provides an energy-efficient route for preparing transparent, thin, and flexible composite films favorable in optoelectronic applications.

Bias voltage-induced structural change in PECVD-deposited diamond-like carbon coatings for optimizing the tribological performance

To improve the adhesion strength and enhance the wear resistance of diamond-like carbon (DLC) coatings, different negative bias voltages were utilized to deposit a-Si:C:H/H-DLC/DLC composite coatings on the 45 steel substrates using direct current plasma enhanced chemical vapor deposition technology. Influences of negative bias voltages on the surface morphology, microstructure, mechanical properties, and tribological performance were investigated. The results showed that as the bias voltages increased from −400 V to −600 V, the surface roughness and thickness of the coatings increased, reaching a maximum roughness of 0.426 μm and a maximum total thickness of 9.9 μm. Raman data illustrated the decrease of hydrogen contents and the increase in sp3 bonds content, matching well with the increasing hardness and elastic modulus. The residual stress tended to increase as the bias voltages, while the adhesion strength reached the maximum value of 62.45 ± 2.65 N at −550 V. Under the synergistic effects of surface roughness, interfacial adhesion strength, hardness and elastic modulus, the average friction coefficient and wear rate of the coatings initially decreased and then increased, reaching the best tribological performance at −550 V.

Nickel–silicon interfacial adhesion strength measured by laser spallation

Thin films of amorphous silicon (a-Si) coated on metals such as nickel (Ni) are one of the most promising anode architectures for high-energy-density lithium-ion (Li-ion) batteries. The performance and longevity of batteries with this type of electrode depend on the integrity of the Ni/a–Si interface. The integrity of the a-Si /Ni bonded interface during cycling is critical, but the experimental characterization of interfacial failure of this material system is highly challenging and there is a sparsity of interface strength data in the literature. Here, we describe a laser spallation (LS) technique to characterize the interfacial adhesion strength of Ni/a–Si multilayer films created by chemical vapor deposition (CVD). The LS technique enables the non-contact measurement of the tensile interfacial strength with high precision when compared to conventional methods for characterizing adhesion. Interferometric measurement combined with finite element analysis shows that the Ni/a–Si interface, created via the CVD of a-Si on Ni surfaces can withstand ≈46–72 MPa in tension before failure initiation. To ensure successful and precise characterization of interfacial adhesion strength using LS, we further develop a design criterion for multi-layer samples by analyzing the thin-film mechanics. Our study provides insights into the strength of the Ni/a–Si interface that governs the performance and durability of high-energy-density anodes and offers design guidelines for improving thin-film electrode integrity.

Reversibly stable and highly stretchable transparent polymer nanocomposite adhesives using hierarchical spring-like molecular nanobridges

For the development of stretchable optoelectronic devices, optically transparent composite adhesives should afford reversible stretchability and high optical transmittance as well as strong interfacial adhesion. However, simultaneous achievement of these essential prerequisites for advanced stretchable optical composite adhesives remains challenging. Herein, we offer an unprecedented approach for the fabrication of reversibly stretchable and optically transparent polymer nanocomposite adhesives based on the construction of hierarchical elastic molecular nanobridges between rigid-flexible hybrid nanoparticles and matrix resin. Photoreactive flexible poly(propylene glycol) (meth)acrylate chains were chemically combined with a rigid nano-silica core to form rigid and flexible hybrid nanoparticles. Subsequently, multiple elastic molecular nanobridges between the embedded hybrid nanoparticles and acrylate resin matrix were constructed inside the polymer composite through UV curing, which results in a stretchable interconnection that allows efficient repeated stretching and recovery of stretchable polymer nanocomposite adhesives. The newly fabricated nanocomposite adhesive film with a low content of rigid-flexible hybrid nanoparticles afforded an excellent reversible stretchability and outstanding cyclic elastic durability, and simultaneously maintained high optical transparency (95.1%) and interfacial adhesion strength (21.5 N/25 mm) of the film compared to those of conventional optical adhesive film.

Improved Plating Adhesion of Polyarylate Fibers via Supercritical CO2 and Impregnation of Slightly Soluble Oil on the Fiber Surface

There is a growing demand for conductive fibers with high bending resistance, particularly for applications, such as smart textiles and robot arms. The amount of fiber for such applications can be reduced using high-performance fibers with high tensile properties, such as polyaramid and polyarylate Vectran®). However, because such fibers are crystalline with rigid molecular structures, they poorly adhere to plated films; thus, the plated fibers exhibit poor bending fatigue resistance. To solve this problem, in this study, we expanded polyarylate fiber using supercritical CO2 (ScCO2) and impregnated it with a metal complex (palladium acetate), which acts as a catalyst for electroless plating to induce an anchoring effect. However, because polyarylate fiber has an extremely low polarity, it is difficult to uniformly impregnate it with many metal complexes, even with ScCO2. Generally, an organic solvent is added to tune the polarity of supercritical CO2; however, the metal complex penetrates the fiber, thereby reducing the amount of metal complex near the fiber surface. Therefore, we tuned the polarity of the surface by applying various oils to the fiber surface. The sample electroplated in ScCO2 with oil applied to its surface showed the highest bending fatigue resistance, followed by that treated in ScCO2 without oil, and the sample treated in an aqueous solution showed the lowest. Furthermore, we measured the interfacial adhesion strength of the samples using the microdroplet method, and the same trend was observed.

Synergistic interactions of citric acid grafted β-cyclodextrin and polyethyleneimine for improving interfacial properties of basalt fiber/epoxy composites

Basalt fiber responds well to the global concept of environmental protection due to its attractive superiorities of green and excellent mechanical performance. However, the ultra-low interfacial adhesion strength of fiber-to-matrix deeply restricts its wide application. Moreover, attempts to utilize natural- or bio-materials on basalt fiber towards growth in interfacial adhesion remains in its infancy, if feasible, it would make green materials shine brilliantly. Herein, we install citric acid modified β-cyclodextrin (β-CD) and polyethyleneimine (PEI) on basalt fiber via dipping approach for the first time, which results in 76.9% increment in fiber-to-epoxy adhesion over control fiber. Unique inner hydrophobic and outer hydrophilic conical cavity architecture of β-CD endows interphase with dense ring hydrogen bond band “core”- covalent/ionic bonding “shell” multiple interactions that balance stress transfer and energy dissipation. Additionally, “rigid” β-CD and “flexible” PEI function as crack deflection and stress distribution for gaining stronger interphase of basalt fiber composites. This paper serves to provide a new exploitation for advancing green and high-performance composites.

Study on the interfacial adhesion mechanism between polydopamine and coal: Experimental demonstration and molecular simulation

Understanding the adhesion mechanism between polydopamine (PDA) and coal surface is crucial for implementing the mussel strategy in self-adhesive gel for fire suppression. In this study, a combination of experiments and molecular simulations was utilized to explore the interfacial adhesion mechanism between PDA and coal. Initially, the adhesion potential of varying concentrations of PDA solutions was evaluated using a UV–Vis spectrophotometer, and in conjunction with contact angle/surface tension measurements, it was observed that adhesion strength did not show a direct correlation with PDA concentration. Subsequently, the adhesion sites of PDA on the coal surface were identified through spectroscopic analysis and confirmed using Dmol3 simulations. The study revealed that the amino and phenolic hydroxyl groups in the PDA structure could establish hydrogen bonds with oxygen-containing functional groups on the coal surface (e.g., COOH, OH, R-O-R'), while the aromatic rings in the molecules engaged in π-π stacking interactions. These non-covalent forces collectively facilitated the adhesion process. Molecular dynamics (MD) simulations were then employed to validate the relationship between PDA solution concentration and adhesion strength, which aligned with the experimental findings. Furthermore, the MD simulations elucidated how the concentration of PDA solution influenced its interfacial adhesion strength with coal by considering water molecule diffusion. Overall, this research offers a theoretical foundation for designing self-adhesive gel for fire suppression.

Constructing coral-like PDA layer on glass fiber to enhance the erosion resistance of epoxy coating

Glass fiber (GF) reinforced epoxy resin composite materials are widely used in wind power, automobiles, and ships, etc. The failure of glass fiber reinforced epoxy resin composites (GF/EP) is mainly attributed to the smooth surface and chemical inertness of GF. Dopamine, extracted from the adhesive protein secreted by mussels, exhibits excellent adhesion performance especially in wet environments. Thence, we constructed a coral-like layer of dopamine nanoparticles on the surface of glass fiber (PDA@GF) by self-surface polymerization deposition, which could simultaneously improve the chemical activity and roughness of the fiber surface, and form mechanical meshing and chemical bonding with the epoxy resin, thereby enhancing the interfacial adhesion strength between GF and EP. PDA layer with different surface morphologies were constructed on the GF surface by finely adjusting the reaction parameters, and the influences of surface morphologies on the mechanical performance of GF/EP coatings were explored. Based on the results obtained from tensile test, friction test, and erosion test, it was evident that the PDA@GF/EP composite material exhibited superior mechanical properties when the PDA layer exhibited a coral-like morphology, in comparison to the other two kinds of surface morphologies. Meanwhile, the dispersion of the fiber within the epoxy resin was examined using X-ray computed tomography (X-ray CT). On this basis, we investigated the anti-wear performance and erosion resistance of composite coatings with different fiber contents, furthermore, we revealed the anti-wear and anti-erosion mechanism.

Effect of Spheroidizing Annealing Process on Microstructure and Properties of Quenching and Tempering 60Cr16MoMA Martensitic Stainless Steel

The effect of spheroidizing annealing on carbide characteristic parameters, mechanical properties and wear resistance of the quenching and tempering (Q&T) high carbon martensitic stainless steel is investigated. The microstructure of the steel is characterized and analyzed through various techniques, including scanning electron microscope (SEM), X‐ray diffraction (XRD), electron backscattering diffraction (EBSD), and transmission electron microscope (TEM). Results show that the microstructure of the annealing steel is mainly composed of ferrite and M23C6 carbide. With the rise of austenitizing temperature, the average diameter of carbide of the annealed steel increases. The average diameter of carbides in the Q&T steel changes in the same way as that observed in the annealed steel. The steel has the lowest annealing hardness, highest Q&T toughness, and wear resistance at an annealed soaking temperature of 860 °C. The influence factor of the toughness and wear resistance can be identified that small‐sized carbides and low angle grain boundaries exhibit strong interface adhesive strength. This reduces the probability of cracking in the particle or at the interface.

Direct‐Current Triboelectric Nanogenerators Based on Contact–Separation Mode and Conductive–Adhesive Interface

AbstractDirect‐current triboelectric nanogenerators (DC‐TENGs), which are used in smart electronics and energy storage, have attracted tremendous scientific interest owing to their rectification‐free and high energy utilization efficiency. In this study, the authors propose a new type of DC‐TENG that operates in the contact–separation mode with a unique adhesive–conductive interface for the first time. The results demonstrate that the TENG output increases with increasing interfacial adhesion strength; both the adhesive polymer and conductive tribomaterial are essential factors for the DC output. The proposed mechanism is based on mechanoion generation via covalent bond cleavage during material transfer and the charge leakage effect. Specifically, the DC‐TENG exhibits unique frequency‐decreasing and force‐enhancing output characteristics. It can directly drive LEDs or charge commercial capacitors. By integrating a stretchable electrode, an adhesive‐based single‐electrode TENG can be used as a strain sensor or material detector. This work presents a new type of DC‐TENG with a conventional two‐electrode configuration and provides new perspectives on the fundamental research and applications of DC‐TENGs.

Comparative study on the influence of additives on interfacial adhesion strength between fibres and extruded polymer core via peel-off test

Various peel-off experiments can be used to determine the adhesion strength of various fibres. Among them was the ‘T’ type peel-off test, which measures the adhesions between fibres. The use of organic and inorganic fillers in flake or powder form will alter the adhesive properties of the binders as well as the adhesive strength between the fibres. In this study, the adhesion strength between three different varieties of glass fibres (C-Glass, E-Glass, and S-Glass fibres) with a PLA core has been investigated. As a binder, an epoxy resin was used, and the resin was modified with inorganic additives such as alumina, bentonite, and silicon carbide. Peel-off testing was used to examine the effect of additives on the bonding strength between a thermoplastic core and a synthetic fibre. The addition of inorganic compounds was found to reduce the adhesion strength between the fibres and the core. In order to evaluate the initial adhesion between the filaments and the core, nine specimens were fabricated without the addition of any additives and their strengths were determined. Maximum adhesion strength of 71.8 MPa was recorded for the neat resin. The adhesive strength after inclusion of additives was observed to decrease by 18.14%, and recorded maximum peel-off strength of 58.2 MPa. Also, the inclusion percentages of the additives were found to be the most influential factor in determining the composites’ adhesive properties. Validation tests were also conducted with the optimized results which demonstrated that the predicted and experimental results were in excellent agreement. Macro and micro approaches were employed to analyze the deformation mechanisms in order to gain a comprehensive understanding of how the additives affected the adhesion strength.

Role of Fly Ash in the Repair Interface between Magnesium Phosphate Cement and Cement Concrete

This paper examines a rapid repair material for cement concrete pavement based on magnesium phosphate cement (MPC) blended with fly ash (FA). Three kinds of stress forms for rapid repair of Portland cement concrete pavement (PCCP) were evaluated and the role of FA in the repair interface was studied. The optimal mixture ratio of FA-MPC mortar was determined, and the compressive and flexural strength tested. The composite specimens were then designed to test the interfacial bonding, tensile, and plain shear strength. Finally, the multi-scale mechanism of FA in the interface was analyzed by a pull-off adhesion test, nanoindentation test, scanning electron microscope (SEM)/energy dispersive spectrometer (EDS), Raman spectrum, and molecular dynamics simulation. The optimal content of FA in MPC mortar was 20%. The laminated beam structure had the maximum strength, and the interface load bearing capacity was the lowest. For further multi-scale analysis, the results of the pull-off adhesion test showed the adhesion strength of interface was increased by the curing age and loading rate. Adhesion capacity of basalt aggregate and FA-MPC was stronger than that of Portland cement mortar and FA-MPC. The elastic modulus of MPC-aggregate interface was more than that of MPC-OPC mortar. SEM/EDS and Raman spectrum results showed that the MPC blended with FA had cracks and defects at the interface formed with cement mortar. Less FA formed near the interface. The good adhesion ability of FA and basalt aggregate was verified by molecular dynamics simulation. By contrast, poor adhesion strength with cement mortar was confirmed.

The effect of photooxidation aging on the cohesion and interfacial adhesion behavior of epoxy asphalt with a composite acidic curing system based on molecular simulation

AbstractThis paper investigated the cross‐linking network structure of epoxy asphalt (EA) with the different ratio of composite curing agents, and further determined the effect of photooxidation aging on the tensile and interfacial adhesion behavior of EA with different cross‐linking network structures through molecular simulation. Based on the molecular models of EA and the interface model between EA and aggregate, the crosslinking network structural characteristics and tensile mechanical behavior were determined. The interfacial adhesion behavior and the mechanization were further studied. The results indicate that 20‐EA and 6‐EA have an epoxy resin cross‐linked network with uniform pore structure and phase distribution. 2‐EA showed a denser cross‐linking network and uneven aggregation phenomenon. Photooxidative aging alleviated the aggregation phenomenon. A dense cross‐linking network improved the tensile strength and the ability of tensile performance to resist photooxidation aging. The interface of EA‐quartz exhibited higher adhesion strength than EA‐calcite due to the closer distance and stronger nonbonding interactions between EA and quartz. The low anhydride content and photooxidation aging made EA approach to the aggregate interface, increasing nonbonding interaction and interfacial adhesion strength. In addition, quartz aggregates were more suitable for application in EA mixtures due to the higher interfacial adhesion strength and lower water sensitivity.

Experimental Investigation on Ice–Aluminum Interface Adhesion Strength under Heating Conditions

Ice accumulation on airfoils and engines seriously endangers fight safety. The design of anti-icing/de-icing systems calls for an accurate measurement of the adhesion strength between ice and substrates. In this research, a test bench for adhesion strength measurement is designed and built. Its reliability and accuracy are verified by the calibration. The adhesion strength is first measured at different loading speeds and freezing times, and the most suitable values are determined based on the results. Then, the variation in adhesion strength with heating temperatures at different initial substrate temperatures and different heating powers is investigated. Parameter AW is defined to evaluate the heating power from the point of view of energy consumption and adhesion strength. As a result, the loading speed and the freezing time are determined to be 0.5 mm/s and 90 min, respectively. The adhesion strength degrades as the heating temperature increases. As the initial temperature drops, the adhesion strength decreases more slowly. Furthermore, the temperature of WAS (Weak Adhesion State) under heating varies with the initial temperature. Heating with a high power will yield more reduction in adhesion strength for the same temperature increase. The values of AW illustrate that a medium power heating is more favorable to reduce the adhesion strength with a low energy consumption.

High bonding strength of polyphenylene sulfide-aluminum alloy composite structure achieved by constant current anodizing in tartaric acid

The high-strength and facile direct joining of metal to polymer has attracted increasing attention in adhesion. The aluminum alloy (Al) specimen was fabricated by constant current anodization and enlarging treatment. The influences of surface energy, porosity, and anodization time on the interface bonding strength of the injection molding polyphenylene sulfide (PPS)–Al composite structures were quantitatively discussed. Results showed that the bonding strength of the joints was significantly affected by the wettability, porosity, thickness, and pore diameter of the anodized aluminum oxide (AAO) films. When the current density and anodization time were 120 A/m2 and 30 min, the Al surface energy and the bonding strength reached the maximum of 74.8 mN/m and 11.7 MPa. With the enlargement treatment of the AAO film, when the etching duration was 45 min, the bonding strength increased to 25.0 MPa. In general, these results are of great importance to the further design and optimization of the polymer-metal hybrid with reliable interface adhesive strength.

Experimental Study and Mechanism Analysis on Compression–Shear Behavior of Hydraulic Asphalt Concrete at Different Temperatures

Abstract Hydraulic asphalt concrete (HAC), typically employed as an impermeable structure in embankment dams, is increasingly recognized for its widespread engineering applications. However, investigations of the mechanical performance of HAC under combined compressive–shear stress remain limited, particularly given its temperature sensitivity. Therefore, this study investigates the mechanical behaviors of HAC under combined compressive–shear stress at diverse temperatures and normal compressive stresses. Specifically, the failure modes, stress–strain curves, peak shear stress, and strain of HAC under various temperatures and normal compressive stresses are obtained for analysis. Experimental results demonstrate that the combination of normal compressive stress and temperature induces changes in peak shear stress and correlated shear strain. Increased normal compressive stress results in vertical restriction and the emergence of horizontal cracks, with deformation amplifying at elevated temperatures. All failure modes of HAC under these conditions are absent of spalled fines and debris. It is observed that as the normal compressive stress increases, the peak shear stress progressively increases, whereas an increase in temperature yields a clear decrease in peak shear stress. The shear strength of HAC comprises the cohesion strength of the asphalt matrix and the interfacial adhesion strength between aggregates and asphalt. Finally, three modified compressive–shear failure criteria that exhibit good prediction accuracy are established for HAC at diverse temperatures. This research offers a theoretical reference for the future investigation and engineering application of HAC.

New insight into the interaction between maleic anhydride grafted polypropylene and aluminum foil converted with trivalent chromate: An experimental and DFT study

The good adhesion between layers of aluminum (Al)/polymer composite is necessary for the safety of lithium-ion batteries. The Al foil was converted with environmentally friendly trivalent chromate [Cr(III)] to enhance its adhesive strength with the inner adhesive layer. The morphology, composition and adhesive strength with maleic anhydride grafted polypropylene (mPP) of different Cr-converted Al foils were studied. The Cr conversion coating mainly consists of metal oxides and hydroxides and the interfacial adhesion strength is enhanced by 93 % through Cr(III) conversion treatment. The effect of Cr conversion on the acid-base characteristics on the Al was determined through contact angle measurement. The results reveal that Cr conversion increases the acidity of the Al surface. The bonding mechanism at the interface was further studied fundamentally. To study the reaction at the interface mPP/Al foils, a coating-evaporation technique was utilized to fabricate a nano-thick mPP layer on the Al foils. The morphology and thickness of the mPP coating on the substrate were analyzed using atomic force microscopy and the interfacial reaction was characterized through attenuated total reflection-Fourier Transform Infrared Spectroscopy. The bonding mechanism at the molecular level was further investigated by quantum chemical calculations based on density function theory. The results of theoretical calculations further indicate that the strength of the interfacial interaction between mPP and Cr oxides and hydroxides is stronger than that between mPP and Al oxides and hydroxides.

A unified treatment of axisymmetric adhesive contact for piezoelectric materials

Nanoindentation technique has been widely applied to characterize the electromechanical properties of piezoelectric materials, where the adhesion effect induced by different surface forces becomes very prominent. The indenter tip should have more general profile rather than just three common simple shapes (flat, cone and sphere) in practical testing. In this study, the classical Johnson-Kendall-Roberts (JKR) and Maugis-Dugdale (M-D) models are extended to investigate the adhesion behaviors of a piezoelectric half-space indented by the power-law shaped punches with different electric properties, whose shape index is denoted as n. The JKR-n and M-D-n adhesion models for both the electrically conducting and electrically insulating punches are set up by means of Griffith energy balance. The Derjaguin-Muller-Toporov-n (DMT-n) adhesion solutions are derived from the corresponding M-D-n adhesion models as the limiting cases. The generalized Tabor parameter and interfacial adhesion strength applicable to piezoelectric materials are defined for the first time, with the former being used to describe the transition behavior from JKR-n model to DMT-n model. The impacts of the electric loading and the shape index on adhesion behaviors are discussed in detail. It is found that the pull-off force increases with the electric potential, which reveals the adhesion strengthening effect caused by electric loading. The shape index has a prominent influence on the pull-off force, interfacial adhesion strength, contact radius at pull-off moment, indentation depth and contact radius at self-equilibrium state, and the transition behavior from JKR-n model to DMT-n model. The results derived from this work not only are helpful to understand the contact behaviors of piezoelectric materials at micro/nano scale, but also provide a theoretical basis for nanoindentation technique in evaluating material properties of piezoelectric mediums.

A Noncontact Method for Estimating Thin Metal Film Adhesion Strength Through Current-Induced Void Growth

Abstract Studies have reported that the electromigration-induced void growth velocity in metal thin films is inversely related to the adhesion strength of the metal thin film with the base and passivation layers. It was also observed that the contribution of interface adhesion strength to electromigration resistance decreases with an increase in temperature. In this study, an expression is derived for the diffusive void growth velocity induced by electromigration from a generalized thermodynamically consistent continuum-based theory for reaction–diffusion driven solid-state interface evolution. This relation captures the effect of adhesion with the base and passivation layers on electromigration resistance of thin metal films. Electromigration experiments were carried out at elevated temperatures and high current density to induce voiding in thin Cu metal film deposited on a base layer of TiN and passivated with TiN or SiNx. The degradation of interface adhesion strength with temperature is modeled using an Andrade-type of relationship. The void growth rates characterized in these experiments are combined with the expression for void growth rate to estimate the interface adhesion strength for the Cu–TiN and Cu–SiNx interfaces. The methodology for estimating the adhesion strength of the metal-passivation layer interface is validated through comparison with interface adhesion strengths from mechanical de-adhesion tests reported in the literature.

Effects of active elements (Si, Cu, Zn, Mg) on the interfacial properties of Fe/Fe2Al5: A first-principles study

Active elements play a crucial role in enhancing the interfacial bonding between matrix and intermetallic in Fe-based materials. In this paper, alloying elements (Si, Cu, Zn, Mg) were innovatively added to study the influence on the strength of Fe/Al alloy with the help of first-principles calculation. The first-principles calculation was used to understand the interface strengthening mechanism at the electronic level. The results show that Al(Fe-Fe)-TOP Fe2Al5(0−20)/Fe(110) is an ideal interface configuration for the following studies. The doping atoms are more inclined to replace the Al atoms at the interface. When replacing Al atom, alloying element Cu, Mg and Zn can significantly improve the bonding strength of Fe2Al5(0−20)/Fe(110) interface, and the effect of Si is weak that can be neglected. Furthermore, the analyses of electronic structure show that the Fe-Al and Fe-Mg bonds are metallic bonds with covalency. The Fe-Si bonds are mainly ionic bonds. There are obvious charge transfer between Cu, Zn and Fe atoms, and the Fe-Cu and Fe-Zn bonds are strong metal bonds. The bonding strength between atoms may be linked to the number of valence electrons they possess. These results provide important insights into enhancing the interfacial adhesion strength of the Fe/Fe2Al5 system in Fe/Al alloys by adding active elements.