Metallic Ribbons Research Articles

Electronic properties and topological phases of a two-dimensional allotrope of nitrogenated carbon

In this work we propose a two-dimensional carbon-nitrogen allotrope composed of pentagons and octagons in a structure of carbon chains bound by nitrogen dimers. Our first-principles calculations show the system behaves as a small-gap semiconductor which is thermodynamically stable at room temperature confirmed by molecular dynamic simulations. By cutting the sheet along different crystallographic directions, a variety of metallic or semiconductor one-dimensional ribbons can be obtained. We explore the topological properties of these nanoribbons finding that for a particular boundary geometry nontrivial topological phases can be obtained, depending on the ribbon termination. We investigate the emergence of symmetry protected interface topological states in heterojunctions and topological-induced edge states in finite ribbons.

Highly efficient and stable CuZr-based metallic glassy catalysts for azo dye degradation

Metallic glasses with the unique disordered atomic structure and metastable nature have been recently applied to degrade the azo dyes and other organic pollutants based on their superior catalytic performance. In this work, the functional properties of six CuZr-based metallic glassy ribbons with the different nominal components in degrading Acid Orange Ⅱ (AO Ⅱ) azo dyes were investigated. The Cu47.5Zr46Al6.5 metallic glassy ribbons could exhibit the more advanced catalytic performance for degradation process, which could completely degrade azo dye aqueous solution within 30 min. Additionally, the Cu47.5Zr46Al6.5 metallic glassy ribbons also showed the excellent cyclic stability along with approximately 97.68 % degradation efficiency after 10 cycles. These excellent catalytic performance and stability are closely related to the synergistic effect of exposed copper nanoparticles and produced copper oxides in the reaction, which contributes to accelerate the generation of more hydroxyl radicals (·OH) to react with dye molecules. Our findings can be able to develop a novel potential metallic glassy material for the functional application of wastewater treatment.

Enhanced electro-catalytic performance of Pd-based hierarchical nanoporous structures fabricated by micropatterning and dealloying of Pd–Ni–P metallic glass

Pd-based catalysts are of significance for their application in direct alcohol fuel cells, due to the superior electro-catalytic performance and CO poisoning resistance. In this work, using Pd32Ni48P20 metallic glassy ribbon as precursor, micro/nano hierarchical nanoporous structure was constructed by the hybrid approach of thermal plastic micropatterning and subsequently electrochemical dealloying at 0.88 V for 120 min in 0.5 M H2SO4 and 0.5 M H3PO4. This hierarchical structure was composed of the periodical micro-rods and nanoporous structure, where the chemical constituent was 80.33 at% Pd, 4.87 at% Ni, 4.96 at% P, and 9.84 at% O. The nanoporous structures showed an enhanced methanol electro-oxidation performance in alkaline medium, owing to their enlarged specific surface area. Compared to single nanoporous structure, the hierarchical nanoporous structure exhibited much better electro-catalysis, mainly attributed to the large surface area and high mass transfer efficiency, indicating a promising perspective for the application in alkaline direct alcohol fuel cells.

Spectroscopic and rheological investigation of candidates for the double-layered binder for amorphous metal ribbon

Sol-gel process is a well-known and useful chemical method used in many applications. Variety of reagents, synthesis parameters, and drying conditions allow to receive a final products in a different forms and with a desirable properties, in example as a film on the metal surfaces through the metal-oxane bond (M-O-Si). The presented paper contains results of investigation of the condensation process of sols based on tetraethoxysilane (TEOS) and 1,2-bis(triethoxysilyl)ethane (BTSE), where oxalic acid and acetic acid were used as the catalysts. Both of them were tested with attenuated total reflectance spectroscopy (ATR) and rheology measurements during drying procedure in order to determine a gel-point, temperature influence and changes in the structure. The received results show differences during the drying procedure of sols based on TEOS and BTSE and indicate 40 °C as the most crucial temperature for this process.

Fe-B-Nb-P Nanocrystalline Alloy With High Amorphous Forming Ability for Fabricating the Powder

The effect of B and P content on the amorphous forming ability (AFA), thermal stability, amorphous stability, and structural behavior was investigated in Fe-B-Nb-P alloys using metallic ribbons produced by a single-roller melt-spinning method. The maximum thickness, $t_{\mathbf {max}}$ , indicating AFA of Fe84-{x}B9Nb7Px ( ${x} =0$ –4), increased from 19.5 to $68.7~\mu \text{m}$ . The alloys exhibited two exothermic peaks to have resulted from the formation of bcc $\alpha $ -Fe and borides, respectively. The Fe84-{x}B9Nb7Px ( ${x} =0$ –3) alloys with the wide interval between two exothermic peaks exhibited the high thermal stability compared to the commercialized composition of Fe73.5Si13.5B9Nb3Cu1. The wide range between the glass transition temperature and crystallization temperature means the super-cooled liquid region, leading to obtain the high stable amorphous phase. The super-cooled liquid region was observed in Fe81-{y}B9+{y}Nb7P3 ( ${y} =0$ –2) alloys and the endothermic reaction of the super-cooled liquid region got larger by increasing B content. The $\alpha $ -Mn type structure was observed in Fe80B10Nb7P3 alloy annealed at 823 K, and it was considered to improve the amorphous stability. The Fe81B9Nb7P3 alloy with a high AFA of $68.7~\mu $ m exhibited excellent magnetic characteristics, $B_{s}$ of 1.51 T and $H_{c}$ of 4.7 A/m.

Versatile power and energy conversion of magnetoelectric composite materials with high efficiency via electromechanical resonance

A better understanding of magnetoelectric (ME) energy materials with superior properties stimulates exploration of next generation of versatile energy devices with a high efficiency. Although a number of investigations have focused on developing multiferroic composite materials because of their potential in cutting-edge multifunctional devices, advances in basic research have not yet been translated into benefits for practical applications. In the present investigation, we introduce a two-phase magnetoelectric composite made of nanocrystalline FeBSi metallic ribbons (Metglas) and Mn3+,2+ acceptor doped Pb(Mg1/3Nb2/3)O3–Pb(Zr,Ti)O3 (PMN-PZT) single crystal, and great enhancements in ME coupling coefficient (αME~12500 V/Oe cm) with a tunable resonance frequency, current-to-voltage (I–V) conversion ratio (~15090 V/I), as well as power conversion efficiency (η ~95%) are found at the fundamental electromechanical resonance, which represent the highest values ever reported. This study also provides a fundamental understanding of the role of a figure of merit (FOM), kij,eff× Qm,eff, on ME coupling performances in ferromagnetic and ferroelectric two-phase ME composite. The enhanced performances are attributed to the laser heat treatment induced Nano crystallization in Metglas, lower magnetic and dielectric loss (tan δ), and also higher mechanical quality factor (Qm,eff) in ME composite. This research opens up the possibilities of developing ME composite materials for next-generation versatile energy and power conversion devices.

FeBNbP nanocrystalline alloy powder with high amorphous forming ability and high B s for magnetic core

The influence of P content on amorphous forming ability and the magnetic characteristics were investigated in the FeBNbP nanocrystalline alloys using metallic ribbons. The Fe84-xB9Nb7Px(x=0-3) and Fe80B10Nb7P3 nanocrystalline alloy metallic ribbons prepared by a single-roller melt-spinning method. The Fe84-xB9Nb7Px (x=0-3) and Fe80B10Nb7P3 nanocrystalline alloys annealed at 873-923 K consist of stable α-Fe grain formed in a residual amorphous phase, and the nanocrystal α-Fe grain showed the average diameter from 6.3 to 7.7 nm. The critical thickness of ribbons indicating amorphous forming ability was increased from 20 μm to 68.7 μm with Fe81B9Nb7P3 by increasing P content. The Fe81B9Nb7P3 alloy also exhibited a high saturation magnetic flux density, Bs, of 1.51 T. In addition, Fe81B9Nb7P3 alloy indicated a good magnetic softness with a low coercivity, Hc, of 4.8 A/m. The Fe80B10Nb7P3 alloy increasing B content succeeded to obtain the powder with precursor of a stable amorphous phase by rapid quenching gas atomization method.

A robust self-stabilized electrode based on Al-based metallic glasses for a highly efficient hydrogen evolution reaction

Al-based metallic glass ribbon with a nanoporous layer of high-entropy alloy is a robust advanced self-stabilized free-standing electrode for hydrogen evolution reaction.

Crystallization Behavior and Resistivity of Al–Ni–Co–Nd(Sm) Amorphous Alloys

Aluminum-based metallic ribbons with the compositions Al86Ni4Co4Nd(Sm)6 and Al86Ni6Co2Nd(Sm)6 were produced by melt spinning. X-ray diffraction characterization showed that the ribbons had an amorphous structure. Their crystallization kinetics were studied by differential scanning calorimetry and their resistivity was measured by a standard four probe method. The Al–Ni–Co–REM ribbons were shown to have a broader temperature range of an amorphous state than do Al–Ni(Co)–REM ternary alloys. We found compositions with an enhanced glass-forming ability.

A model for the simulation of the chill block melt spinning (CBMS) process using OpenFOAM®

This work shows the results of a numerical model developed to simulate the CBMS technique for the production of the Fe78Si9B13 metallic magnetic ribbons for application in electronics. The model proposes a numerical approximation to a Vogel-Fulcher-Tammann (VFT) expression as a method in the solidification process. This approximation is introduced into the “compressibleInterFoam” routine, included in the OpenFOAM® suite, originally developed for the simulation of two immiscible, non-isothermal and compressible fluids. This routine solves, the phase fraction transport using the Volume of Fluids (VOF) approach. The boundary conditions imposed in the model were experimentally validated by digital image analysis with a high-speed camera at 5602 fps for the determination of the temperature profiles. The phase change is represented as a growth of several orders of magnitude of the alloy viscosity (μ) as the temperature (T) decreases, reaching solidification around the crystallization temperature (Tg). Also, we establish the condition of initial stability of CBMS process (R > 1.5) for Peclet numbers close to 400, and the validity up to limits of rotation in the wheel close to 40 m s−1. The proposed methodology is validated with previous work. Encouraging results show that the solution of the CBMS process can be adequately simulated with the proposed approach.

Lateral MoS2Heterostructure for Sensing Small Gas Molecules

The potential of a two-dimensional (2D) molybdenum-disulfide (MoS2) lateral het- erostructure in sensing small gas molecules is being assessed based on quantum mechan- ical calculations. This heterostructure combines two phases of MoS2, namely a metallic ribbon embedded within the semiconducting MoS2 phase. In this work the influence on the electronic structure of this 2D material due to the adsorption of gas molecules is investigated. Specifically, the adsorption of NO, NO2, O2, CO, and CO2 on the MoS2 heterostructure is studied. Overall, gas specific peaks in the electronic features of the 2D material could be clearly revealed, while differences were also found for a gas adsorption close to the interfaces of the material. The poisonous nitrogen oxide molecules showed a stronger adsorption on the material, but could very well be distinguished over the ’healthy’ molecular oxygen gas. The complexity of the heterostructure provides more rich gas adsorption characteristics over the single phase material and ...

Effect of Zener-Hollomon parameter on the flow behavior of Zr-based metallic glass

The constitutive behavior of Zr-based metallic glass ribbon around the glass transition temperature was investigated. The Zener-Hollomon equation was adopted to predict the flow stresses. The experimental results show that an exponent value of 0.75 and activation energy magnitude of 343 kJ/mol can be used in the hyperbolic sine model to predict the flow stress response of the steady-state stage. The activation energy is consistent with the free volume theory (335 kJ/mol). It is observed that the flow stress during steady-state is independent of the previously strain rate history and is only sensitivity to the current strain rate. A Z-parameter constitutive model to describe the hot deformation behavior of Zr-based metallic glass is developed.

Constitutive modelling of wavy elastic response of metallic glass ribbon

ABSTRACTA constitutive model is developed that incorporates the wavy elastic response of an arc-shaped metallic glass (MG) ribbon subjected to applied progressive normal load. This model is based on the evolution of the angle made between the buckled ribbon and the horizontal plane. It predicts the amount of elastic strain preventing the yielding of material when it is used as a flat spring or electromechanical switch for MEMS (Micro-Electro-Mechanical Systems) and NEMS (Nano-Electro-Mechanical Systems). The numerical solution of the constitutive equations resulting from the model is compared to experimental results and shows good agreement. This present result is useful for miniaturised ribbons since the estimation of the elastic strain in these was previously quite difficult.

The Role of Transition Metals in Crystallization of Amorphous Al–Ni–Co–Yb Alloys

Al86Ni4Co4Yb6 and Al86Ni6Co2Yb6 metallic ribbons have been obtained by a standard planar flow method. According to X-ray diffraction data, the ribbons are amorphous. Their crystallization kinetics at different heating rates and resistivity has been determined. These alloys remain amorphous in a wide range of compositions, and the crystallization process depends significantly on transition metal concentration.

Experiments on the Ultrasonic Bonding Additive Manufacturing of Metallic Glass and Crystalline Metal Composite.

Ultrasonic vibrations were applied to weld Ni-based metallic glass ribbons with Al and Cu ribbons to manufacture high-performance metallic glass and crystalline metal composites with accumulating formation characteristics. The effects of ultrasonic vibration energy on the interfaces of the composite samples were studied. The ultrasonic vibrations enabled solid-state bonding of metallic glass and crystalline metals. No intermetallic compound formed at the interfaces, and the metallic glass did not crystallize. The hardness and modulus of the composites were between the respective values of the metallic glass and the crystalline metals. The ultrasonic bonding additive manufacturing can combine the properties of metallic glass and crystalline metals and broaden the application fields of metallic materials.

Effects of refractory Nb on glass-forming ability and structure inhomogeneity of Cu50Zr50 binary metallic glass

This paper reports the effects of refractory Nb metal on the structural heterogeneity of a CuZr metallic glass. Cu50Zr50 metallic glass was taken as model material, and different quantities of Nb element (5 at% and 10 at%) was considered to comparatively study heterogeneity. The as-spun metallic glassy ribbons were examined with x-ray diffraction, differential scanning calorimetry and dynamic mechanical analysis. The results indicate that Nb element can decrease the glass-forming ability but enhance the glass transition temperature and thermal stability. For heterogeneity, the addition of 5 at% of Nb element will weaken the heterogeneity and the addition of 10 at% of Nb element will improve the heterogeneity. This work also disclosed that the time window from the onset temperature to the peak temperature of β relaxation for (Cu0.5Zr0.5)90Nb10 is larger than that for (Cu0.5Zr0.5)95Nb5, suggesting that Nb element may suppress the local motion from a smaller region to a larger region in the metallic glass.

Diffraction of Н-polarised photons on the infinite grating of metallic ribbons

Diffraction of Н-polarised photons on the infinite grating of metallic ribbons

Surface modification of Al by high-intensity low-energy Ti-ion implantation: Microstructure, mechanical and tribological properties

A high-intensity metal ribbon ion beam was generated using plasma immersion extraction and the acceleration of the metal ions with their subsequent ballistic focusing using a cylindrical grid electrode under a repetitively pulsed bias. To generate the dense metal plasma flow, two water-cooled vacuum arc evaporators with Ti cathodes were used. The ion current density reached 43 mA/cm2 at the arc discharge current of 130 A. High-intensity ion implantation (HIII) with a low ion energy ribbon beam was used for the surface modification of the aluminium. The irradiation fluence was changed from 1.5 × 1020 ion/cm2 to 4 × 1020 ion/cm2 with a corresponding increase in the implantation temperature from 623 to 823 K. The structure and composition of the Ti-implanted aluminium were studied using X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDX). The mechanical properties and wear resistance were measured using nanoindentation and “pin-on-disk” testing, respectively. It was shown that the HIII method can be used to form a deep intermetallic Al3Ti layer. It has been established that a thin (0.4 μm) modified layer with a hcp Ti(Al) structure is only formed on the surface at 623 K, while the formation of the ordered Al3Ti intermetallic phase occurs at the implantation temperatures of 723 and 823 K. Despite the significant ion sputtering of the surface, the thickness of the modified layer increases from ~1 μm to ~6 μm, and the implantation temperature rises from 723 to 823 K. It was found that the homogeneous intermetallic Al3Ti layer with a thickness of up to 5 μm was formed at 823 К. The mechanical and tribological properties of the aluminium were substantially improved after HIII. For the Ti-implanted aluminium, the hardness of the surface layer increases from 0.4 GPa (undoped Al) to 3.5–4 GPa, while the wear resistance increases by more than an order of magnitude.

Applications and Advances of Magnetoelastic Sensors in Biomedical Engineering: A Review.

We present a comprehensive investigation into magnetoelastic sensors (MES) technology applied to biomedical engineering. This includes the working principles, detection methods, and application fields of MES technology. MES are made of amorphous metallic glass ribbons and are wireless and passive, meaning that it is convenient to monitor or measure the parameters related to biomedical engineering. MES are based on the inverse magnetoelastic (Villari) effect. When MES are subjected to mechanical stress, their magnetic susceptibility will change accordingly. And the susceptibility of MES is directly related to their magnetic permeability. The varying permeability can positively reflect the applied stress. The various detection methods that have been developed for different field applications include measurement of force, stress, and strain, monitoring of various chemical indexes, and consideration of different biomedical parameters such as the degradation rate and force conditions of artificial bone, as well as various physiological indexes including ammonia level, glucose concentration, bacteria growth, and blood coagulation.

Analysis of solar cells interconnected by electrically conductive adhesives for high-density photovoltaic modules

Interconnection of solar cells by an electrically conductive adhesive (ECA) can replace the use of conventional metal ribbon connections for photovoltaic module fabrication. This technology increases the active area for photocurrent generation because the cells are connected in a busbar-less structure, and high-power, high-efficiency modules can be manufactured. In this study, we investigated the influence of the curing conditions on the characteristics of the ECA film and interconnected cell. In addition, this paper presents a new method for extracting the resistance contribution of the ECA to the interconnected cell. A low sheet resistance of <0.023 Ω/sq was observed when an ECA film on a slide glass substrate was cured for >60 s, regardless of the curing temperature. In addition, the sheet resistance was <0.02 Ω/sq at a curing temperature of 150 °C even for a short curing time of 5 s. At curing temperatures above 120 °C, the ECA resistance component of the interconnected cell was reduced to 0.2 mΩ or less, and the efficiency was increased by 0.4% or more. However, a curing time of >60 s was required for a similar efficiency improvement at lower temperatures. Notably, the characteristics of the interconnected cell simulated using the extracted ECA resistance values were similar to the measurement results.