Thickness Of Amorphous Layer Research Articles

Atomistic insights on the deformation mechanisms of amorphous/crystalline dual-phase high entropy alloys under nanoindentation

The amorphous/crystalline (A/C) dual-phase nanostructured model is an effective method to improve the mechanical properties of high entropy alloys (HEAs). However, the deformation mechanism of the dual-phase HEAs during nanoindentation is still unclear. Here, the effect of the amorphous layer position and thickness on the deformation behavior and mechanical properties of the A/C dual-phase CoCrFeMnNi HEAs under nanoindentation is investigated by molecular dynamics simulation. The results show that the amorphous phase has a significant impact on the mechanical behavior of the HEAs, and the amorphous layer plays a role in absorbing dislocations and hindering their continued movement. The embedding position of the amorphous layer has almost no effect on the elastic deformation of the HEAs. However, during the plastic deformation stage, as the insertion position of the amorphous layer in the HEAs moves downwards, the nanoindentation force of the HEAs shows an obvious increasing trend, which promotes deformation strengthening. The results also indicate that the amorphous layer thickness affects its ability to absorb dislocations, and the dislocation lengths in the HEA with smaller amorphous phase thickness are significantly higher than those in the models with larger amorphous phase thickness.

Non-Arrhenian hydrolysis of polyethylene terephthalate – A 5-year long aging study above and below the glass transition temperature

The hydrolysis of PET was studied over a wide range of temperatures from 25 to 105 °C for duration up to 5 years in water. It was demonstrated that independent of the aging temperature, a decrease in the molar mass was witnessed due to chain scissions that occur during hydrolysis of the ester group. Above Tg, it was shown that chain scissions induced an increase in degree of crystallinity and amorphous layer thickness. However, this phenomenon, chemi-crystallization, was not observed at low temperatures, i.e. below Tg. This change reflects a different behavior when the polymer is exposed to water in the glassy or rubbery state. This was highlighted by the quite different activation energies below and above Tg, respectively equal to 31 ± 12 and 134 ± 4 kJ/mol.

Improving the GeAsSe Ovonic Threshold Switching Characteristics by Carbon Buffer Layers for Ultralow Leakage Current (∼0.4 nA) and Low Drift Characteristics

Volatile Ovonic threshold switching (OTS) selectors have been regarded as the critical component of highly integrated three-dimensional (3D) cross-point array nonvolatile memory systems. However, relatively high leakage current hinders the further reduction of power consumption in the crossbar array. In addition, the threshold voltage drift phenomenon hinders the improvement of device reliability. Utilizing the buffer layer can effectively reduce the interaction between electrodes and the active layer in the cross-point architecture. Here, it manifests that leakage current can be reduced to ∼0.4 nA with a 5 nm thick amorphous carbon layer as a buffer layer in the GeAsSe-based OTS device, where the carbon layer stabilizes the composition of GeAsSe during the electrical switching cycles. It is also found that the carbon layer leads to a lower threshold voltage drift (35.6 mv/dec) and excellent endurance (>109 cycles with ∼0.4 nA ON-state current). The conduction mechanism analysis demonstrates that the inhibition of the carbon layer on drift originates from the high barrier height from delocalized states transformed into localized states. This work clearly demonstrates the role of the carbon layer and facilitates future 3D crossbar-storage technology applications.

2D and 3D TEM Characterisation of Benzene and Ethylene Soot

Flame-generated soot particles from two different fuels, benzene (B) and ethylene (E), at different ageing conditions, were analysed to assess their morphological and structural features. Samples were collected at 6, 10 and 14 mm from the nozzle location. Traditional 2D transmission electron microscopy (TEM) and a novel 3D TEM were used to investigate morphology variations. High-resolution TEM (HRTEM) was used to capture structural characteristics. Samples were then placed on lacey carbon microgrids. A field emission gun TEM was used to capture images of the agglomerates. Tilt series of ±60 degrees were acquired at 1-degree steps to perform the 3D reconstruction. IMOD software and backwards projection were used to reconstruct the tomogram from the tilt series. The 2D analysis revealed that soot particles’ agglomerations for both fuels change from a bundle to a chain-like structure as they “age”, i.e., extracted at a higher “flame height”. In B, the primary particle diameter increases as they get “older,” whereas in E, the opposite happens, and overall, E particles are bigger than B ones. The nanostructure presents ordered regions with parallel-stacked layers of carbon lamellae. This is more evident in the aged soot samples, with the difference that in E a thick amorphous layer is present at the edge of the particles, which is not observable for B. A nanostructure analysis suggests a trend of increasing fringes length as the soot ages, going from 1.04 nm of B6 to 1.22 nm of B10 to 1.05 nm of B14 and from 1.139 nm of E6 to 1.20 nm of E14 (±0.02 nm). The tortuosity does not vary greatly across all the samples, ranging between 1.132 and 1.149 (±0.004). Separation is also quite similar everywhere, with 0.404 nm of B6, 0.392 nm of B10, 0.399 nm of B14, 0.397 nm of E6 and 0.396 nm of E14 (±0.002 nm). Ring structures and particle overlaps, two examples of geometrical characteristics concealed in 2D, can be seen in the 3D reconstructions. Furthermore, the comparison between 3D and 2D volume and surface area raises questions about the reliability of those parameters as derived from 2D measurements. This study advances knowledge of how soot structure can be affected by the fuel type and emphasises the significance of how soot is investigated.

Insights into the Role of Defects in Fe2(MoO4)3 Catalysts

The catalytic activity and selectivity of Fe2(MoO4)3 obtained from solid-state synthesis protocols is investigated for the oxidative dehydrogenation (ODH) of ethanol to acetaldehyde. While Fe2(MoO4)3 annealed in a MoO3 atmosphere is found to be inactive, ball-milling of such solid-state synthesis precursors leads to an increase in activity, which cannot be attributed purely to the change in the specific surface area nor to a geometric effect of smaller particles. In a systematic study of the synthesis of Fe2O3-free Fe2(MoO4)3 samples, the correlation of ball-milling time, defect concentration, and catalytic activity is presented. In-depth X-ray diffraction studies, magnetic susceptibility, and 57Fe-Mössbauer spectroscopic measurements disclose characteristic signatures of the defect sites in the solid materials introduced by ball-milling and indicate: (i) MoO3-enriched amorphous layers of variable thickness (shell-like) and (ii) crystalline bulk defects corresponding to a reduction in the molar volume of the solid. The onset of recrystallization processes sets in around 300 °C and is accompanied by an enhanced MoO3 mobility in the particles, which adds to an increase in activity and a decreasing selectivity under catalytic conditions. Accordingly, the defects associated with the decreasing amorphous fraction are converted to crystalline bulk defects, which are monitored by the magnetic hyperfine field distribution of the respective Fe sites. Overall, this study shows the importance of the amorphous layer thickness with a sufficient defect concentration and of the bulk defects’ contribution to the chemical gradients, important for the MoO3 mobility and reduction of the MoO3 loss as a volatile species at the solid/gas phase boundary in ODH catalysis.

Large-Scale Fabrication of High-Performing Single-Crystal SiC Nanowire Sponges Using Natural Loofah

This study presents large-scale fabrication of single-crystal SiC nanowire (SiCnw) sponges through a carbothermal reduction approach using agricultural residue loofah, which is believed to be a perfect alternative to traditional petrochemical materials as the carbon source in industrial fabrication of SiC nanowires, without additional chemical C sources or catalysts. The single-crystal ultralong SiCnw are observed to have diverse morphologies with diameters of 50–400 nm, which possess a significant anisotropic and hierarchical microstructure with planar-aligned bamboo joints. A roughly 2 nm thick amorphous SiO2 layer is identified wrapping the crystalline 3C-SiC. The underlying vapor–solid mechanism is systematically investigated via thermodynamic calculations on the formation and interactions of SiO, CO, and SiC. Noteworthily, the fabricated loofah-based SiCnw sponge exhibits prominent high-temperature performance after thermal insulation tests of alcohol lamp flame and butane blowtorch flame, which is attributed to the stacking faults, SiO2 layer, SiC/SiO2 interface of the nanowires, and the overlength pathway in the porous aerogel–sponge domain synergetically acting as a phonon barrier to enhance phonon scattering, prolong phonon diffusion, and eventually reduce solid thermal conductivity in the sponge architecture. Our current work has great potential to be applied in the eco-friendly industrial preparation of high-performing SiCnw as thermal protection materials in harsh environments.

Effect of Amorphous Layer at the Heterogeneous Interface on the Device Performance of β-Ga2O3/Si Schottky Barrier Diodes

Heterogeneous integration of β-Ga2O3 with Si substrate is considered as an effective and low-cost technology for the thermal management of β-Ga2O3 electrical devices. In this work, an isotype heterojunction of n-Ga2O3/n+-Si (Ga2O3/Si) was fabricated by surface activated bonding in which an amorphous layer was induced by ion beam bombardment. The current density of Ga2O3/Si Schottky barrier diodes (SBDs) are about two orders of magnitude lower than that of Ga2O3 bulk SBDs at 2.8 V due to the influence of amorphous layer. The results are consistent with the simulation results when β-Ga2O3 Mole Fraction (MF=n(β-Ga2O3)/n(β-Ga2O3)+n(SiO2)) and thickness of amorphous layers (Tox) are set at 0.83 and 3 nm, respectively. Furthermore, devices with different MF and Tox were simulated based on the nonlocal tunneling model by Sentaurus TCAD. The decrease of β-Ga2O3 Mole Fraction and increase of amorphous layers thickness in the hetero-interface of Ga2O3/Si SBDs lead to a dramatic degeneration of current density and specific on-resistance in Ga2O3/Si SBDs. These results may provide some guidance for improvement of vertical heterogeneous integration β-Ga2O3 devices performance.

Influence of chlorotrifluoroethylene on crystal structure and polymer dynamics of poly(vinylidenefluoride-co-chlorotrifluoroethylene) antibacterial copolymers

<abstract> <p>The effect of chlorotrifluoroethylene (CTFE) on dynamic relaxations of poly(vinylidenefluoride-co-chlorotrifluoroethylene) films (P(VDF-CTFE)) containing 0, 10, 15 and 20% of CTFE was investigated via broadband dielectric spectroscopy (DRS) and dynamic mechanical analysis (DMA). The interpretation was accompanied by the crystal structure obtained from Fourier transform infrared spectroscopy, wide-angle X-ray diffraction, small-angle X-ray scattering and differential scanning calorimetry. Increment of CTFE contents caused reducing the degree of crystallinity but did not impact the long period, lamellar thickness, and amorphous layer thickness. Four dynamic processes were clearly observed in DRS spectra for the neat poly(vinylidene fluoride) and P(VDF-CTFE) which were attributed to the local motion of amorphous chains (<italic>β</italic>), the segmental relaxation of amorphous chains (<italic>α</italic><sub>1</sub>), the local conformational rearrangement of the TGTGʹ conformation (<italic>α</italic><sub>2</sub>) and the process associated with Maxwell–Wagner–Sillars interfacial polarization (α<sub>MWS</sub>). The extra relaxation was observed for P(VDF-CTFE), which was more likely associated to the molecular motion of CTFE chain segments (<italic>α</italic><sub>c</sub>), correspondent with DMA results. These PVDF and P(VDF-CTFE) conducted as self-antibacterial materials.</p> </abstract>

Orientation controlled microstructure and mechanical properties of TiN-Cu nanocomposite films

Adding soft metal phases into transition metal nitrides to generate nanocomposite structures can considerably tune the mechanical properties of films. We prepared TiN-Cu nanocomposite films with different orientations on MgO (100) and (110) substrates; the hardness of the film with 〈110〉 orientation was 40.4 GPa, while the 〈111〉-oriented film hardness was 28.1 GPa. This significant difference in hardness was attributed to orientation affecting Cu segregation at grain boundaries (GBs) to form different thicknesses of amorphous layers. This study opens a new avenue for tuning the mechanical properties of ceramic thin films.

On the deformation mechanism of 6H-SiC under the nanogrinding of multiple abrasive grains

This paper investigates effects of nanogrinding-induced defect on deformation of 6H‐SiC with the aid of molecular dynamic analyses. It was found that nanogrinding perfect 6H‐SiC will unavoidably bring about a damage layer containing amorphous phase transformation and discrete dislocations. The damage will significantly affect the subsequent deformation, surface morphology, grinding force and coefficient of friction. Under the interactions with the consecutive abrasives, the deformation mechanism of 6H‐SiC transits from plastic flow within the amorphous layer to the propagation of existing dislocations and finally to the nucleation of new dislocations. The remnant amorphous layer on the ground surface can be minimized when the grinding depth of the subsequent grains is to be less than the thickness of the first amorphous layer.

Thickness-dependent magnetooptical properties of ion beam sputtered polycrystalline Ce1Y2Fe5O12 films

Polycrystalline cerium-substituted yttrium iron garnet (Ce:YIG, Ce1Y2Fe5O12) films were deposited on synthetic fused silica substrates with various thicknesses using ion beam sputtering, and their roughness, transmissivity, optical constants, microstructure, and their magnetic and magnetooptical properties were measured. Thicker films exhibit cracking due to thermal mismatch stress. A ∼5 nm thick amorphous layer was observed at the interface between Ce:YIG and the substrates, resulting in a non-monotonic thickness dependence of the measured properties. A 338 nm thick Ce:YIG film showed the largest magnetooptical figure of merit defined as the ratio of Faraday rotation angle to absorption coefficient, 127°/dB at a wavelength of 1550 nm, more than three times larger than prior work.

Sub-surface alteration and related change in reflectance spectra of space-weathered materials

Context. Airless planetary bodies are studied mainly by remote sensing methods. Reflectance spectroscopy is often used to derive their compositions. One of the main complications for the interpretation of reflectance spectra is surface alteration by space weathering caused by irradiation by solar wind and micrometeoroid particles. Aims. We aim to evaluate the damage to the samples from H+ and laser irradiation and relate it to the observed alteration in the spectra. Methods. We used olivine (OL) and pyroxene (OPX) pellets irradiated by 5 keV H+ ions and individual femtosecond laser pulses and measured their visible (VIS) and near-infrared (NIR) spectra. We observed the pellets with scanning and transmission electron microscopy. We studied structural, mineralogical, and chemical modifications in the samples. Finally, we connected the material observations to changes in the reflectance spectra. Results. In both minerals, H+ irradiation induces partially amorphous sub-surface layers containing small vesicles. In OL pellets, these vesicles are more tightly packed than in OPX ones. Any related spectral change is mainly in the VIS spectral slope. Changes due to laser irradiation are mostly dependent on the material’s melting temperature. Of all the samples, only the laser-irradiated OL contains nanophase Fe particles, which induce detectable spectral slope change throughout the measured spectral range. Our results suggest that spectral changes at VIS-NIR wavelengths are mainly dependent on the thickness of (partially) amorphous sub-surface layers. Furthermore, amorphisation smooths micro-roughness, increasing the contribution of volume scattering and absorption over surface scattering. Conclusions. Soon after exposure to the space environment, the appearance of partially amorphous sub-surface layers results in rapid changes in the VIS spectral slope. In later stages (onset of micrometeoroid bombardment), we expect an emergence of nanoparticles to also mildly affect the NIR spectral slope. An increase in the dimensions of amorphous layers and vesicles in the more space-weathered material will only cause band-depth variation and darkening.

Hydrolytic degradation of biodegradable poly(butylene adipate-co-terephthalate) (PBAT) - Towards an understanding of microplastics fragmentation

The long-term behaviour of PBAT subjected to hydrolytic ageing is investigated in this paper. Samples were aged in water at several temperatures ranging from 80 to 100 °C for different durations. Changes in physico-chemical properties were investigated through NMR, GPC, DSC and X-Ray analyses and embrittlement was assessed by tensile tests. It is demonstrated that hydrolysis of PBAT occurs first on the ester group located between the terephthalate and adipate groups leading to a decrease in molar mass. For longer ageing durations, the ester situated within the adipate group undergoes hydrolysis. An increase in crystallinity ratio and a decrease in amorphous layer thickness was observed as consequences of the chain scission process. Finally, a clear change in mechanical behaviour is noted; for the early stages of ageing, the polymer exhibits a ductile behaviour while for longer ageing durations, the polymer is brittle due to a lack of chain entanglement. This transition takes place once the molar mass of PBAT falls below 11 kg/mol, i.e. when a critical molar mass M’c is reached.

Simulations of graphite boronization: A molecular dynamics study of amorphization resulting from bombardment

The molecular dynamics code LAMMPS was used to simulate the bombardment of a graphite structure by atomic boron with impact energies ranging from 50–250 eV. The transient structural evolution, penetration depth, and amorphous layer thickness were analyzed. Simulations show that larger impact energies lead to a greater volume of amorphization and penetration of boron, but that the growth rate of the amorphous layer decreases with increasing fluence. Furthermore, the change in surface chemistry of the amorphized structures was studied using the ReaxFF formalism, which found that the amorphization process introduces dangling bonds thus increasing reactivity in the amorphous region.

Brittle-ductile transition and nano-surface generation in diamond turning of single-crystal germanium

Single-crystal germanium (Ge) has been widely used in infrared optics and ultra-precision components, however, the appearance of alternating brittle and ductile fan-shaped patterns on machined surfaces seriously affects the machined surface quality. The present research focused on the brittle-ductile transition and its effect on the nano-surface generation in single-point diamond turning (SPDT) of (100), (110) and (111) crystal planes of Ge. Face cutting and plunge cutting experiments were performed, the surface anisotropy and brittle-ductile transition regime during cutting were analyzed, and the evolution of crystalline structure was discussed with molecular dynamics (MD) simulation. Theoretical and experimental results show: (1) The anisotropy of the machined surface is closely related to the atomic arrangement order and lattice structure. The anisotropy of the (111) crystal plane is stable while the (110) is unstable. (2) The critical length and depth of both the elastic-ductile and brittle-ductile transition are anisotropic; the depth and length of brittle regions are shallower and shorter than those of ductile regions and proportional to the tool edge radius. (3) The critical depth and thrust force of the elastic-ductile transition obtained in MD simulation can be employed to predict the changing trend of the brittle-ductile transition. (4) The thickness of amorphous layer produced on the machined surface is proportional to the ratio of cut depth to tool edge radius. The 1¯10 crystal orientation of the (111) crystal plane shows the best cutting performance. This paper provides deep insight into the brittle-ductile transition and nano-surface generation in SPDT of Ge.

Synthesis of transfer-free graphene films on dielectric substrates with controllable thickness via an in-situ co-deposition method for electrochromic devices

The solutions and polymer supported materials in graphene transfer process would introduce lots of containments, defects and wrinkles, which weakens the performance of graphene. Herein, an in-situ co-deposition method is carried out to obtain transfer-free graphene films with controllable thickness on several dielectric substrates. The amorphous carbon (carbon source) and copper (catalyst) are co-deposited on dielectric substrates. Followed by an in-situ annealing process, the amorphous carbon is transformed to few-layer graphene. High co-deposition temperature could promote the decomposition of Cu(acac)2 precursors, leading to the controllable thickness of amorphous carbon layer in Cu@C films. Finally, 3-, 5-, 8- and 10- layers graphene films with transmittance of up to 93.5% and square resistance of 0.8 kΩ·sq−1 are obtained and a high-performance electrochromic device is fabricated using 3 layers graphene films as electrodes. The “color” and “bleach” time of the electrochromic device is 16.6 s and 6.8 s with the transmittance of 26.8% and 79.7% separately. This method paves an alternative way for the batch production of transfer-free graphene film as electrode materials.

Diverse space weathering effects on asteroid surfaces as inferred via laser irradiation of meteorites

Context. Space weathering (SW) is crucial to improve the understanding of the evolution of optical characteristics on airless bodies. The classical view based on research of the Moon suggests that SW decreases albedo (darkening) and steepens spectral slope (reddening) in visible to near-infrared (VIS-NIR) wavelengths, producing nanophase iron (npFe0). However, this conclusion is not perfectly applicable to asteroids. Aims. In this study, we focus on investigating the space weathering spectral alteration effects (SWSAE) and the causes of spectral alteration on various types of asteroids after long-term continuous micrometeoroid bombardments. Methods. We used a pulsed laser to irradiate eight meteorites at the same energy, namely, of 28 mJ, in ten shots, including ordinary chondrites (OCs), aubrite (Aub), enstatite chondrites (ECs), CO, CV, and CM carbonaceous chondrites. Then we measured and compared the virgin and irradiated VIS-NIR reflectance spectra of these meteorites. We further surveyed the causes of spectral alteration through a scanning electron microscope and transmission electron microscope. Results. Three different SWSAE are shown: (1) darkening and reddening on OCs, Aub, CO, and CV chondrites; (2) brightening and reddening on ECs; (3) brightening and bluing on CM chondrite. After irradiation, npFe0 and nanophase iron-nickel particles were respectively found in CV and CO chondrites; thick amorphous layers without any nanophase particles were found in Aub; melting and sputtering of metal were observed in ECs; a great deal of vesicles or bubbles without any nanophase particles were found in CM chondrite. Conclusions. The long-term SW via micrometeoroid bombardments can spectrally remodel asteroid surfaces in different ways: darken and redden anhydrous silicate asteroids (e.g., S-, E-, and K-types); brighten and redden metal-rich M-type objects. The SWSAE of volatiles-rich carbonaceous asteroids (e.g., Ch-, Cgh-, and D-types) is related to SW degree: darkening and bluing at low degree then brightening and continue bluing as the SW degree increases. The various spectral units on Ryugu, Bennu, and Phobos can be created by the heterogeneity of the degree of SW.

Molecular dynamics investigation on mechanical behaviour and phase transition of nanocrystalline NiTi shape memory alloy containing amorphous surface

It is well known that surface severe plastic deformation will cause the surface amorphization of nickel-titanium shape memory alloy (NiTi SMA), so it is of significance to investigate the influence of amorphous phase on mechanical behaviour and phase transition of NiTi SMA. Nanocrystalline polycrystal (PC) models with the average grain size of 9, 12 and 15 nm, respectively, are established by molecular dynamics (MD) software. On the upper and lower surfaces of the aforementioned three PC models, the corresponding amorphous layers are formed to obtain the amorphous-nanocrystalline-amorphous (ANA) counterparts. MD simulation is used to investigate mechanical behaviour and phase transition of nanocrystalline NiTi SMA with amorphous surface. The phase transition stress, the maximum tensile stress and the irrecoverable strain increase with decreasing grain size. Furthermore, grain orientation has a great impact on phase transition of NiTi SMA. The existence of amorphous phase leads to superelastic degradation due to its plastic deformation, but it can greatly improve the tensile stress of NiTi SMA. The irrecoverable strain is reduced from 1.3% to 0.9% when the thickness of amorphous layer is decreased from 10 to 5 nm. The existence of amorphous phase results in reduction of martensite variants in the selected grains.

A comprehensive small angle X-ray scattering analysis on morphological structure of semicrystalline linear polymer in bulk state

In this study, we attempted to conduct a comprehensive small angle X-ray scattering (SAXS) analysis on the microstructure of a representative semicrystalline linear thermoplastic, polyethylene in bulk state using synchrotron radiation source. The scattering measurements and data analyses were performed by considering the range of scattering angle and its impacts, the proper correction of background scattering and its impacts, the merits and limitations of qualitative data analysis schemes, and the feasibilities of quantitative data analysis schemes in order to gain insights into the microstructure in a very complex nature associated with the structural dimension and orientation distributions. The SAXS scattering analysis is widely adopted with a limited angle range because of various reasons; but it was confirmed to cause overestimation and/or underestimation in the structural parameters because of the lack of scattering data in the Porod regime. Thereby, SAXS measurements should be essential with the range of scattering angle that fully covers the Porod regime as well as a part of the background scattering solely and then include background scattering correction. The paracrystal model scheme, as one of the quantitative methods, was found to be able to fit the experimental scattering profile in a more appropriate manner. But, the scattering profile part in the large angle region could yet be fitted; furthermore, the crystalline and amorphous layer thicknesses were overestimated due to ignoring the presence of transition layer. All other schemes could unsatisfactorily fit the experimental scattering data and, thereby, estimate only structural parameters. Even for such estimations, the quantitative model schemes were confirmed to provide structural parameters in less errors, compared to the qualitative analysis methods.

Investigation on the interfacial microstructure and mechanical properties of the W-Cu joints fabricated by hot explosive welding

The welding of thick W onto Cu, with good bonding, has been a big challenge due to the large differences in physical properties between W and Cu. Among various novel methods, explosive welding is the promising one to produce bimetals with large size and great thickness. However, the cracking of brittle W under high strain rate limits its application. In this work, hot-explosive welding technique was explored to overcome this problem. A 2 mm thick W plate was preheated to 500 ℃ and was successfully welded with pure Cu plate, without any cracks formed in W layer. The result suggests that preheating W to over its dynamic ductile-to-brittle transition temperature and decreasing the imported kinetic energy are two most important factors for the successful welding of thick W plate. The weldability window calculated using the parameters at 500 °C predicted the formation of a good wavy interface. The microstructures at W-Cu interface were characterized by optical microscope, SEM, EBSD and TEM. The mechanically mixed W-Cu phase and the 2∼6 nm thick amorphous layer along the interface created strong bonding between the immiscible W and Cu. The measured interfacial compressive shear strength reached 188 MPa, indicating a good bonding strength of the interface.