Interfacial Mechanical Properties Research Articles

Interfacial Microstructure Evolution and Mechanical Properties of TC4/MgAl2O4 Joints Brazed with Ti–Zr–Cu–Ni Filler Metal

Interfacial Microstructure Evolution and Mechanical Properties of TC4/MgAl2O4 Joints Brazed with Ti–Zr–Cu–Ni Filler Metal

Effect of surface roughness on interface characteristics and mechanical properties of dissimilar diffusion bonded 45 steel/additive manufactured 316L steel joints

Effect of surface roughness on interface characteristics and mechanical properties of dissimilar diffusion bonded 45 steel/additive manufactured 316L steel joints

A novel high entropy composite interlayer for diffusion bonding of TC4 titanium alloy to 316 L stainless steel

Titanium/steel hybrid structure exhibit broad prospects in the nuclear industry and aerospace applications. Achieving high-performance titanium/steel bonding is crucial. Herein, the novel AlCoCrNiCuAg/Cu high entropy composite interlayer was designed for vacuum diffusion bonding of TC4 alloy to 316L stainless steel. The effects of bonding temperature, holding time and assembly sequence on the interfacial microstructure and mechanical properties were investigated, and the fracture behaviors were researched. Typical microstructure of the joint bonded at 1010 °C for 90min via AlCoCrNiCuAg/Cu sequence was TC4/β-Ti/β-Ti+TiFe/TiFe2+χ+σ/α-Fe+χ+σ/316L. With bonding temperature increased, due to the dispersed distribution of the Cuss phase in the Ti-Fe phases, the highest shear strength of 222.8MPa was achieved at 1010oC/90min. The cleavage characteristics were confirmed in the fracture surfaces, suggesting the brittle fracture. The main cracks were located at the junction of the TiFe2+χ+σ and the β-Ti+TiFe layers, further confirmed that the interface appeared immense strain, accelerating the joint fracture.

Effect of thickness ratio on microstructure evolution and coordinated behavior of Mg/Al composite plates in one-pass asymmetric rolling with differential temperature rolls

To explore how varying matrix thicknesses influence interfacial morphology, microstructure, and mechanical properties of Mg/Al composite plates, this study prepared composite plates with distinct thickness ratios using an asymmetric rolling process featuring differential temperature rolls. The findings indicate that the Mg alloy largely exhibits significant recrystallization and sub-grained, while the Al alloy largely demonstrates a sub-grained characteristic. Notably, there exists a strong positive correlation between bonding strength at the interface and thickness ratio. As the thickness ratio increases, enhanced shear deformation at the interface triggers more slip system initiation, resulting in a gradual reduction of texture intensity in both the Mg and Al layers. Specifically, when the AZ31B/Al6061 thickness ratio reaches 5, the recrystallization level of the Mg layer is relatively elevated, accompanied by a fine and uniform grain size in the Al layer. This situation decreases the likelihood of stress concentration at the interface, which results in exhibiting relatively optimal elongation and bonding strength.

Interface mechanical properties of CFRP-seawater sea sand concrete under simulated seawater immersion

In this study, the interfacial mechanical properties of carbon fiber-reinforced polymer (CFRP) sheet reinforced seawater sea sand concrete (SSSC) in simulated seawater immersion environment were studied. The results present that the interface bearing capacity of CFRP-SSSC decreases significantly after seawater immersion. The decreasing rate increases greatly with the extending of immersion periods. Seawater immersion also affects the failure mode of interface between CFRP and SSSC, which leads to the damaged surface expanding from the base layer of concrete to the junction section of resin and aggregate. The distribution of strain and stress along the bonding direction presents the load transfer from the loading end to the free end. The shear stress peak locates near the loading end and decreased about 15-20% due to seawater immersion as a result of the deterioration of the interfacial property. The analysis on the microstructure of CFRP-SSSC interface proves that the chemical ions in seawater causes the hydrolyzation of epoxy resin adhesive layer. The CFRP-SSSC interface presents a lower interfacial bonding properties than CFRP reinforced normal concrete (NC). The improvement of strength grade of concrete from C30 to C50 increases the bonding properties of the CFRP about 9-12% and mitigates the influence of seawater immersion. The obtained bond-slip curve indicates that the seawater immersion decreases the interface ductility. A modified Popovics model is applied to predict the bond-slip curve and presents a high fitting degree.

Interface needle structure induced high-performance aluminum alloy/PPS hybrids

Direct joining molding of metals and polymers has received increasing attention in the field of lightweight fabrication. The aluminum alloy (Al) surface was modified by secondary anodizing and a special needle-like structure was formed on the Al surface. Then, the glass fiber-filling polyphenylene sulfide (PPS) was directly joined with Al by the hot pressing technique. The relationship between the interfacial structure and mechanical properties of Al/PPS hybrids was systematically investigated and discussed. The results showed that the generation of needle-like structures could improve the surface roughness and wettability, thus effectively improving the mechanical interlocking ability of the interface and forming the Al-O-C chemical bond with PPS. The maximum tensile strength of Al/PPS hybrids was 28.34 MPa, and their impact toughness (ak) reached 9.69 J/cm2. Even though the hybrids were exposed to a salt spray environment or 200 °C, the strength could still reach 25 MPa. This study has prepared a high-performance metal/plastic hybrid by secondary anodizing method, which can be applied in harsh environments.

Upcycling of polyethylene/polypropylene mixtures promoted by well-controlled multiblock olefin copolymers

Polyethylene (PE) and isotactic polypropylene (iPP) are two of the most widely used polymer materials, whose huge consumptions urge people to tackle their recycling problem. The incompatibility of PEs and PPs has resulted in their waste streams being recycled into low-value products with poor mechanical properties. Herein, a series of iPP-based olefin block copolymers (OBC) with up to five alternating hard/soft blocks were prepared via coordinative chain transfer polymerization. The facile synthetic strategy of multiblock OBCs not only overcame the inefficiency and diseconomy of living coordination polymerization, but also avoided the critical requirements of complex dual-catalyst systems for chain shuttling polymerization, making it suitable for low-cost and large-scale production of OBCs. These well-designed OBCs provided excellent elastomeric properties combining high strength, high elongation, and high elastic recovery. More importantly, they also demonstrated a strong ability in the upcycling of PE/PP mixtures, transforming brittle blends into tough materials. The PE/PP blends compatibilized with OBCs exhibited greatly improved interfacial adhesion and mechanical properties, with up to 25 times higher elongation at break compared to uncompatibilized blends. It was further demonstrated by the extruding-blow-molded bottles prepared using post-consumer PE/PP products, where recycled bottles containing OBCs exhibited much better mechanical properties than those without OBC. The synthetic strategy of OBCs and the upcycling route of PE/PP blends in this work are not only of great academic value, but also of substantial economic and environmental significance, providing insights into the sustainable development of plastics.

Improving interfacial microstructure and mechanical properties of ODS-W/Cu joints via anodization treatment and spark plasma sintering

The bonding properties at the interface between the first wall oxide dispersion strengthened tungsten (ODS-W) and the heat sink copper (Cu) are vital for their application in future nuclear fusion reactors. However, the immiscibility and significant differences in the coefficient of thermal expansion between ODS-W and Cu pose considerable challenges for bonding these two materials. This study utilizes anodization and hydrogen reduction processes to form a nanoporous structure on the surface of ODS-W, thereby achieving effective bonding between ODS-W and Cu by spark plasma sintering (SPS). The effects of the anodization parameters on the surface characteristics of ODS-W, and the influence of the bonding temperature on the interfacial microstructure and mechanical properties of the ODS-W/Cu joints were investigated. The results demonstrate that under an anodization condition of 50 V for 40 min, a nanoporous structure with an average pore size of about 90 nm can forms on the surfaces of ODS-W. This significantly increases the surface roughness, thereby enhancing the interfacial bonding of ODS-W with Cu during SPS. As the bonding temperature increases, the interfacial microstructure changes from linear to serrated shape, effectively suppressing crack propagation and forming a stronger mechanical interlock between ODS-W and Cu. This significantly enhances the mechanical properties of the joints. Typically, at a bonding temperature of 1000 °C, the tensile strength of the anodized ODS-W/Cu joints reaches 245.2 MPa, which is 157.9 % higher than that of directly bonded joints. Additionally, the tensile fracture primarily occurs within the Cu substrate, transitioning from brittle to ductile fracture modes.

Interfacial microstructure and mechanical property of dissimilar resistance spot welded joint of TC4 titanium alloy and 316L stainless steel with nickel interlayer

Dissimilar materials of TC4 titanium alloy and 316L stainless steel were joined by means of resistance spot welding with nickel interlayer in different thicknesses. A significant enhancement in terms of nugget morphology quality with less defects was achieved for the welded joints with nickel interlayer compared with that without interlayer. With increasing the nickel interlayer thickness from 50 μm to 300 μm, the effective nugget diameter increased gradually from ∼4.8 mm to ∼5.2 mm, which was lower than that of the interlayer-free welded joint being ∼5.9 mm. A thinner intermetallic compound layer with dual-layered structure features with thickness of ∼11 μm was formed at the nugget/titanium interface in the welded joint with nickel interlayer compared with that of the interlayer-free welded joint, meanwhile an intermetallic compound layer with thickness of ∼3 μm was formed at the nugget/stainless steel interface, which exhibited serrated structure features. The introduction of nickel interlayer in the welded joint could suppress the formation of the brittle Ti–Fe intermetallics such as Fe2Ti, and facilitate the formation of TiNi, Ti2Ni and TiNi3. A more homogeneous current density distribution and a lower peak temperature (1809 °C) during welding were achieved via employing nickel interlayer. With increasing nickel interlayer thickness from 0 μm to 300 μm, the tensile shear load of welded joints experienced an increased tendency first and then decreased, meanwhile the maximum tensile shear load of 3.7 kN was obtained with the interlayer thickness of 200 μm, which was 61% higher than that of the interlayer-free welded joint.

Development of High-Performance Bipolar Membranes with Optimal Junction Properties for Efficient Electro-Membrane Processes

A bipolar membrane (BPM) is a special type of ion-exchange membrane in which an anion-exchange layer (AEL) and a cation-exchange layer (CEL) are combined. Water molecules can be easily dissociated at the interface of the BPM by the strong electric field generated when a reverse bias voltage is applied through the membrane. Such dissociation leads to the generation of proton and hydroxide ions, which are then transported through the CEL and AEL, respectively, resulting in the production of acid and base solutions. Under a forward bias, these ions are drawn back to the bipolar interface, where they neutralize each other. The energy derived from this neutralization process, represented as a junction potential (JP) value, is a key factor in the BPM's efficiency. BPMs with ideal JP values are critical for achieving high separation and energy efficiencies in electro-membrane processes. Furthermore, for the prolonged operation of these processes, BPMs must possess a highly adhesive bipolar junction. Our work includes the development of a novel BPM with an ideal JP and a highly adhesive bipolar junction. This BPM has been applied to various electro-membrane processes, including an acid-base flow battery and direct seawater electrolysis. The BPMs are fabricated using poly(phenylene oxide) (PPO)-based ionomers, and incorporates an iron-based catalyst and a reinforcing material. These additions enhance the water-splitting performance and the durability of the interface between the ion-exchange layers. The prepared BPMs not only demonstrated excellent interfacial adhesiveness and mechanical properties but also achieved a water-splitting efficiency of 98% or higher. In comparison to commercial BPM, the electro-membrane processes utilizing the prepared BPM exhibited superior performance. This work was supported by the National Research Foundation of Korea (NRF) grants funded by the Korean government (MEST) (NRF-2022M3C1A3081178 & NRF-2022M3H4A4097521).

Development of high impact toughness Cu/ODS-Cu joints using HIP bonding process for the preparation of W/Cu/ODS-Cu monoblock divertor

Compared to CuCrZr, oxide dispersion strengthened copper alloy (ODS-Cu) exhibits higher stability of properties under irradiation and exposure to elevated temperatures, demonstrating broad application prospects in divertor components. Oxygen-free high thermal conductivity copper (Cu-OFHC) has been frequently employed as an interlayer between W and Cu-based alloy in the fabrication of W/Cu divertor components. This study investigates the effect of joining temperature together with the addition of a Ni interlayer on the interface microstructure and mechanical properties of the Cu-OFHC/ODS-Cu joints. As the joining temperature increased from 680 ℃ to 900 ℃, the interface bonding ratio of the Cu-OFHC/ODS-Cu joints improved from 40.4% to 95.8%, and the impact toughness increased from 23.4 J/cm2 to 133.1 J/cm2. With the addition of a Ni interlayer, the interface bonding ratio increased from 40.4% to 90.3%, and the impact toughness improved from 23.4 J/cm2 to 122.5 J/cm2. Increasing the joining temperature or adding a Ni interlayer effectively reduced interfacial voids, enhanced the interface bonding ratio, and consequently improved the impact toughness of Cu-OFHC/ODS-Cu joints. Then, the W/Cu/ODS-Cu monoblock mock-ups with good interfacial bonding were successfully fabricated under two conditions: at a joining temperature of 900 ℃ without an interlayer and at 680 ℃ with a Ni interlayer. These results provide a fundamental understanding for achieving high-quality Cu-OFHC/ODS-Cu joints and offer technical support for the engineering preparation of W/Cu/ODS-Cu components in future fusion devices.

Molecular dynamics study of Gr(GO)/C-A-S-H composites at different temperatures: optimization of structural, dynamic and mechanical properties of civil engineering materials

In recent years, composites have been widely used in engineering fields, where nanomaterials such as graphene (Gr) and graphene oxide (GO) have potential advantages as interfacial modifiers in enhancing the properties of composites. However, the relationship between the interfacial structure and the mechanical properties of the nanocomposites is not clear, and the behavior of the composites may differ significantly at different temperatures. This study aims to investigate in depth the interfacial structure, dynamics, and mechanical properties of Gr, epoxy group-containing (-O) and hydroxyl group-containing (-OH) graphene oxide and calcium aluminosilicate hydrate (C-A-S-H) composites at different temperatures using molecular dynamics. The effect of nanomaterial composition on the interfacial chemical bonding network is revealed. The local chemical structures of bridging aluminum [Al(Q2b)] and interlayer aluminum (Alw) show different changes at different temperatures. Elevated temperature promotes the hydrolysis of interlayer water molecules to form hydroxyl groups, which affects the formation of chemical bonding networks.Al(Q2b) favors Gr and C-A-S-H linkages, whereas Alw favors GO and C-A-S-H bonding. Temperature changes lead to different chemical bonding connections and altered atomic motions. At the interface, Al atoms form a more stable chemical bonding network, which improves the interaction strength at the interface. Different composite models exhibited different mechanical properties at high temperatures and introducing epoxy and hydroxyl groups enhanced the plastic deformation of the composites. Structural analyses showed that temperature changes affected the molecular structure and interfacial bonding effects of the composites, which in turn affected the mechanical properties of the materials. At different temperatures, GO-O/C-A-S-H has higher tensile strength and Young's modulus, which can resist the degradation of performance caused by thermal expansion to a certain extent, and ensure the stability and safety of the structure, so it is more practical. These findings provide important insights to deepen the understanding of composite properties and have positive implications for future composite design and applications.

Interfacial microstructure and mechanical properties of CBN brazed in a continuous tunnel furnace with low-temperature Sn-Cu-Ti filler alloy

Currently, the most common process for manufacturing brazed cubic boron nitride (CBN) tools is vacuum brazing using Cu-based active filler alloys. However, the high brazing temperature of Cu-based alloys and the long heating time in a vacuum furnace inevitably cause severe thermal damage, thereby compromising the mechanical properties of the brazed CBN abrasives. In this study, CBN abrasives were brazed using low-temperature Sn-Cu-Ti filler alloys in a continuous tunnel furnace. The final contact angles of the Sn-Cu-Ti filler alloys on the surfaces of the brazed CBN abrasives were determined at 650 °C. When the Ti content in the alloy was 4 %, the final contact angle was 37.2° and the CBN maintained a good exposure height and achieved a firm holding force. The interfacial microstructure was analysed using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD). It was found that a layer of needle-like compounds, primarily comprising TiB2 and TiN, with an approximate thickness of 5 μm, was formed at the interface, indicating the formation of a chemical–metallurgical bond between the Sn-Cu-Ti alloy and CBN abrasive. The residual stresses and mechanical properties of brazed CBN abrasives with Sn-Cu-Ti and traditional Cu-based alloys were measured and compared. The results showed that compared to the brazed CBN with the Cu-based alloy, the average residual stress of the brazed CBN with the Sn-Cu-Ti alloy was reduced by 25.2 %, while the compressive strength and impact toughness increased by 25.3 % and 13.8 %, respectively. The experimental results provide new insights into reducing thermal damage to CBN for improving the processing performance of brazed CBN tools.

Study on interfacial mechanical properties of bonded pipe joint under dynamic load

This study analyses the interfacial mechanical behaviour of adhesive-bonded pipe joints under dynamic loading conditions. First, a mechanical model of the bonding interface of a pipe joint was established. Next, computational formula for the interfacial slip and shear stress in the pipe joints were obtained using variable separation, eigenfunction expansion, and Laplace transform methodologies. Further, the effects of various parameters, including the loading duration, bond length, adhesive layer thickness, stress rate, adhesive shear modulus, elastic moduli of the main pipe and coupler pipe, and adhesive-layer thickness, on the mechanical response of the pipe joints were assessed. The goal is to study the impact of these parameters on the maximum shear stress, interfacial slip, and normal stress in the main and coupler pipes, their effects on the pipe joint strength can be determined, thereby providing a theoretical basis for the design of practical pipe–joint configurations. The innovation of this study is as follows: it considers high-stress-rate dynamic loads for formulating complete mathematical equations. Further, it employs theoretical methods to calculate the relative slip and shear stress in pipe joints, through which theoretical formulas for engineering applications of adhesive-bonded pipe joints were derived. Additionally, the study analyses the impact of various parameters on the dynamic mechanical behaviour of the adhesive layer at the pipe joint interface, leading to a deeper understanding of the interface mechanical behaviour characteristics and key parameters to be considered while receiving dynamic loads in pipe joints.

Extremely Stable, Multidirectional, All‐in‐One Piezoelectric Bending Sensor with Cycle up to Million Level

AbstractFlexible bending sensors are crucial components of flexible/wearable electronics. However, their broad application is restricted by their difficulty in sensing different bending directions and, more importantly, their significant output attenuation after long cycles. Herein, a new design of an All‐in‐One piezoelectric bending sensor is proposed, in which double‐deck, cross‐over 3D interdigital microelectrodes (silver nanowires (Ag NWs)) are embedded in a piezoelectric polymer film (poly(vinylidene fluoride‐trifluoroethylene (P(VDF‐TrFE))). The piezoelectric film with the embedded 3D microelectrodes exhibits a high anisotropy coefficient ( > 1) based on dual piezoelectric modes (d31 and d33), which renders it more sensitive to different bending directions. More importantly, the homogeneous interconnected interface and heterogeneous microinterlocked interface formed inside the sensor significantly enhance its interface mechanical properties, with at least a tensile strength of 51 MPa, a shear strength of 28 MPa, and an interfacial toughness of 300 J m−2, which are nearly two orders of magnitude greater than those of conventional sandwich architectures. The prepared All‐in‐One sensor shows an extremely stable piezoelectric output over as many as 16 00 000 bending cycles, which represents a remarkable breakthrough. Furthermore, a single sensor can be used to remotely control the multidirectional motion of a smart car, demonstrating enormous potential in practical applications.

Interfacial microstructure and mechanical property of the discontinuous short tungsten fiber-reinforced tungsten matrix composites

For tungsten fiber-reinforced tungsten matrix (Wf/W) composites, the interface between W matrix and W fiber has a dominant effect on the mechanical properties. In this study, the interfacial microstructure in the Wf/W composites with or without Y2O3 coating deposited on W fiber is investigated. The crystal structure of the Y2O3 coating composed of nano-sized columnar grains on the W fibers is cubic. And the crystal structure of Y2O3 coating changes to be face centered cubic after sintering in the Wf/W composites. Two kinds of interfaces, including the interface between W matrix and Y2O3 coating, the interface between W fiber and Y2O3 coating, are present in the Wf/W composites. Different orientation relationships are observed in these two kinds of interface. The stable orientation relationship with 111Y2O3 // 01¯1W have the lowest interfacial energy. The Y2O3 interface is essential for improving the toughening behavior of Wf/W composites and impeding the abnormal grain growth on the surface of W fiber sintering at low temperature. The recrystallization nucleus is developed by the bonding between W powder and W fiber during sintering, and then grow fast into W fiber. The apparent activation energy of abnormal grain growth of W fibers is about 242.7 KJ/mol sintering at temperature between 1500 and 1800 °C. The abnormal large grains usually show intergranular brittle fracture and make the W fiber be brittle.

High-performance polybenzimidazole composite membranes doped with nitrogen-rich porous nanosheets for high-temperature fuel cells

Traditional phosphoric acid (PA) doped polybenzimidazole (PBI) membranes encounter many issues when used in high-temperature proton exchange membrane fuel cell (HT-PEMFC), including the loss of PA within the membrane and limitations on conductivity. The mixed matrix membranes (MMMs) synergistically combine the advantages of pore fillers and polymer matrix, making them promising candidates for HT-PEMs. Interface compatibility is the main factor affecting the further development of MMMs. This research presented OPBI composite membranes filled with porous nanosheets, featuring average pore diameters of 2.83 nm, 3.38 nm, and 2.60 nm, respectively. The high aspect ratio and plentiful nitrogen components of the nanosheets increase the π-π and hydrogen bonding interactions with the polymer matrix, resulting in outstanding interface compatibility and mechanical properties of MMMs. The results of theoretical calculations indicate that there is a stronger interaction energy between the nanosheets and PA molecules, and the abundant pore structure within the nanosheets facilitates the absorption of PA molecules, leading to the formation of a continuous PA network. Consequently, MMMs exhibited enhanced proton conductivity, as well as improved PA absorption and retention. Furthermore, the effect of pore size distribution of nanofillers on the performance of MMMs were investigated. Membranes composed of nanosheets with large pore size showed a higher conductivity of 176.7 mS cm−1 at 200 °C, leading to excellent performance and stability in assembled H2/O2 fuel cells. This work offers valuable insights into the design of MMMs and high-performance HT-PEMs.

Interfacial strength and its regulation in the carbon monofiber/epoxy binder system

The strength of polymer composite materials (CMs) is largely determined by the strength of interfacial interactions at a fiber/matrix interface. In this work the strength in a unit cell of CM carbon monofiber/cured epoxy matrix is investigated. The relevance of the work is due to direct measurements of strength at the monofiber/matrix interface, excluding defects of micro-droplet and technological errors associated with impregnation in a traditional assessment of polymer composite materials strength. Changes of surface morphology and energy characteristics of fibers in plasma chemical treatment process is shown. The study of fiber surface energy and formation of carbon monofiber/epoxy matrix interface of carbon fiber reinforced composite unit cell was carried out on the specially developed original device Drop-Sting test. Micro pull-out test was used to investigate the shear mechanical properties of interface and to determine the strength of carbon fiber reinforced composite unit cells before and after treatment in oxygen discharge plasma. It is shown that the increase in the strength of the monofiber/matrix interfacial interface after the treatment of carbon fiber in plasma occurs due to the increase in the surface energy and wettability of monofibers.

Characterization and mechanism analysis of interfacial shear strength between individual aramid fiber and epoxy by oxygen plasma treatment at elevated temperatures: Experiment and simulation

The weak adhesion between aramid fibers Ⅲ and the resin matrix, due to its smooth surface and high inertness of the fibers. This property restricts the mechanical properties of the composites in high temperatures environments. This work describes the treatment of aramid fibers Ⅲ with oxygen plasma to introduce reactive oxygen-containing functional groups onto fiber surface. The analysis focused on the impact of interfacial friction and interfacial wettability on the transfer of load across composites at various temperatures. According to the X-ray photoelectron spectroscopy (XPS) analysis, the fiber surface showed an increase in the number of active groups after plasma treatment. In addition, two new oxygen-containing functional groups -C-O- and -O-CO appeared. The use of Scanning Electron Microscopy (SEM) and atomic Force Microscopy (AFM) showed that the plasma treatment has an etching effect on the fiber surface and increases the roughness of the fiber surface. Furthermore, after plasma treatment, the fibers adhered to the resin matrix through hydrogen bonding and π-π bonding. The utilization of this technique led to a significant enhancement in the interfacial properties of monofilament composites across various temperature ranges. The IFSS of plasma-treated aramid fiber Ⅲ/EP exhibited increases of 38 % at the test temperature of 25℃. Surprisingly, the IFSS of plasma-treated aramid fiber III/EP exhibited a significant increase of 52 % at the test temperature of 120℃. In this paper, COMSOL software was utilized to simulate the IFSS before and after plasma treatment at different temperatures. Mechanistically explains the effect of temperature on the interfacial mechanical properties of composites.

Study on mechanical properties of ZnO/Si interface under thermal shock

Influence of thermal shock on ZnO/Si interfacial mechanical properties was studied through experiments, molecular dynamics simulations and machine learning prediction. ZnO films were deposited onto silicon wafers by radio frequency magnetron sputtering and then suffered different times of thermal shock. The experimental results show the adhesion strength of ZnO/Si interface is relatively stable under thermal shock. XRD and simulation illustrate the interfacial reactions of Si based films could experience strong interaction through Si, Zn and O atoms located at ZnO/Si interface during thermal shock, which could explain the stability of the interface. The machine learning prediction indicates the mechanical properties of ZnO/Si interface are still relatively stable after more thermal shocks. The obtained conclusions are hoped to be helpful for the understanding of ZnO/Si properties under thermal load and to guide the design of related devices in energy field.