Liquid Metal Phase Research Articles

Phase-Field Approach to Formation of Aluminum Oxyhydroxide Nanofibrils on a Liquid Aluminum Alloy Surface in Water-Containing Atmospheres

Formation of peculiar nanofibril structures on the surface of liquid aluminum alloys as a result of chemical reaction of aluminum with water vapors was well studied experimentally for various alloy components starting from mercury. However, the mechanism of nanofibril formation remains unclear to date, and the lack of an appropriate theoretical model does not allow evaluation of the structure parameters depending on the process conditions. We assume that the interface layer between the liquid metal phase and the atmosphere, containing the water vapor, develops certain inhomogeneities respect to the content of hydroxyl groups. That provides areas of suppressed and enhanced diffusion of the aluminum from the liquid phase toward the atmosphere contact. Phase-field modeling, taking into account their elastic interaction, demonstrates formation of the array of nano-islands, enriched with hydroxyl groups, which can be precursors for formation and growth of nanofibrils with elements of pre-boehmite structure.

Evaluation of Thermal and Mechanical Properties of Bi-In-Sn/WO3 Composites for Efficient Heat Dissipation.

Phase change materials (PCMs) offer promising solutions for efficient thermal management in electronic devices, energy storage systems, and renewable energy applications due to their capacity to store and release significant thermal energy during phase transitions. This study investigates the thermal and physical properties of Bi-In-Sn/WO3 composites, specifically for their use as phase change thermal interface materials (PCM-TIMs). The Bi-In-Sn/WO3 composite was synthesized through mechanochemical grinding, which enabled the uniform dispersion of WO3 particles within the Bi-In-Sn alloy matrix. The addition of WO3 particles markedly improved the composite's thermal conductivity and transformed its physical form into a putty-like consistency, addressing leakage issues typically associated with pure Bi-In-Sn alloys. Microstructural analyses demonstrated the existence of a continuous interface between the liquid metal and WO3 phases, with no gaps, ensuring structural stability. Thermal performance tests demonstrated that the Bi-In-Sn/WO3 composite achieved improved thermal conductivity, and reduced volumetric latent heat, and there was a slight increase in thermal contact resistance with higher WO3 content. These findings highlight the potential of Bi-In-Sn/WO3 composites for utilization as advanced PCM-TIMs, offering enhanced heat dissipation, stability, and physical integrity for high-performance electronic and energy systems.

Radiative heat transfer to enhance the performance of liquid metal-based phase change heat sink under natural convection condition

Liquid metal phase change materials have the advantages of high thermal conductivity and high volumetric latent heat, which are expected to address the growing challenges of thermal management of advanced electronics. In previous studies, the effect of radiative heat transfer from fins of a phase change heat sink on thermal management performance has rarely been considered. In this study, radiative coating materials with high emissivity were prepared and coated on the fins of the liquid metal phase change heat sink. The effect of radiative heat transfer on the performance of liquid metal phase change heat sink was investigated. The experimental results of continuous heating under natural convection conditions show that the introduction of the radiative coating with an emissivity of 0.9298 can extend the time for the surface temperature of the heat source to reach 100 °C by 9.4%, while shortening the recovery time of the phase change heat sink by 14.9%. The results of high-power cyclic heating indicate that the high emissivity coating can reduce the peak temperature by 16.6 °C in the tenth working cycle. A simplified numerical model was subsequently developed and validated to determine the specific effects of phase change and radiative heat transfer on the overall thermal control performance. The radiation-enhanced liquid metal phase change heat sink proposed in this study is simple and maintenance-free. It is expected to address the thermal management issues of electronic devices that cannot use active cooling or operate in thin-air environments.

Nanoporous Cu-based amorphous alloys prepared by selective dissolution in acidic media

Abstract Functional nanoporous materials are considered a significant category of nanostructured materials that exhibit distinct characteristics like high surface area, porosity, and improved mass transport properties. These qualities render them suitable for a wide range of applications including catalysis, energy storage, biomedical fields, and electrochemical sensors. Dealloying or laser-induced technologies are the primary methods employed to fabricate such nanoporous materials. Dealloying is a dependable top-down approach used to produce hierarchical, disordered nanoporous materials with customizable pore sizes in the range of a few nanometers. The process of dealloying involves the selective elimination or dissolution of one or more elements from an alloy through a corrosion mechanism, using various dealloying techniques, such as chemical, electrochemical, liquid metal, or vapor phase dealloying. In the present study, copper-based amorphous metallic ribbons (Cu75Ni6Sn5P10Ga4) were initially manufactured using the melt-spinning method. The Cu-based amorphous ribbons were structurally investigated by X-ray diffraction and thermal analysis. Subsequently, the ribbons were subjected to a dealloying treatment, using an acidic solution to selectively dissolve the nickel from their composition and to obtain a nanoporous structure. The microstructure and chemical composition of the ribbons before and after the dealloying process were investigated using scanning electron microscopy (SEM), combined with energy-dispersive X-ray spectroscopy. The dealloying process performed in 1 M H2SO4 solution at 25 °C for 60 minutes leads to a large number of nanopores, uniformly distributed onto the surface of the Cu-based ribbons.

Chemically Tailored Growth of 2D Semiconductors via Hybrid Metal-Organic Chemical Vapor Deposition.

Two-dimensional (2D) semiconducting transition-metal dichalcogenides (TMDCs) are an exciting platform for excitonic physics and next-generation electronics, creating a strong demand to understand their growth, doping, and heterostructures. Despite significant progress in solid-source (SS-) and metal-organic chemical vapor deposition (MOCVD), further optimization is necessary to grow highly crystalline 2D TMDCs with controlled doping. Here, we report a hybrid MOCVD growth method that combines liquid-phase metal precursor deposition and vapor-phase organo-chalcogen delivery to leverage the advantages of both MOCVD and SS-CVD. Using our hybrid approach, we demonstrate WS2 growth with tunable morphologies─from separated single-crystal domains to continuous monolayer films─on a variety of substrates, including sapphire, SiO2, and Au. These WS2 films exhibit narrow neutral exciton photoluminescence line widths down to 27-28 meV and room-temperature mobility up to 34-36 cm2 V-1 s-1. Through simple modifications to the liquid precursor composition, we demonstrate the growth of V-doped WS2, MoxW1-xS2 alloys, and in-plane WS2-MoS2 heterostructures. This work presents an efficient approach for addressing a variety of TMDC synthesis needs on a laboratory scale.

Analysis of magnesia-carbon bricks erosion in vanadium extraction converters: Insights from dynamic experiments and interface characterization

This paper uses a rotary furnace to simulate the dynamic erosion behavior of various magnesia-carbon bricks within a vanadium extraction converter, focusing on the effects of carbon content and antioxidants on erosion. The results indicate that vanadium-rich slag primarily consists of oxide solid solutions, iron vanadium spinel, and metallic Fe. Adding aluminum and silicon powders to the bricks reduces apparent porosity, increases body density, and improves slag erosion resistance. However, an increase in carbon content (12.54 wt% to 18.59 wt%) within magnesia-carbon bricks correlates with decreased high-temperature strength, exacerbating the reaction propensity with slag and consequent structural damage. Analysis of the interface phase between magnesia-carbon bricks and vanadium slag reveals a predominance of metal phase, spinel phase, and liquid slag phase. Thermodynamic calculations suggest an initial reaction between MgO and C on the brick surface, yielding Mg vapor and CO gas, while C reacts with slag to produce Cr and V elements, leading to surface structure degradation. Subsequent slag encasement and dissolution of remaining MgO via decarburization channels further erode magnesia-carbon bricks. Cumulative erosion iterations ultimately culmi nate in performance failure of magnesia-carbon bricks.

Observation of the liquid metal phase transition in optofluidic microcavities

Gallium (Ga) exhibits remarkable potential in flexible electronics, chemistry, and biomedicine due to its exceptional physical properties. The phase transition and supercooling characteristics of Ga have led to the emergence of numerous valuable applications. In this paper, we capitalize on this foundation by utilizing optofluidic microcavities supporting both high quality factor optical and optomechanical modes to investigate the phase transformation process and supercooling properties of Ga. Our study provides comprehensive insights into the dynamic behavior of Ga during the complete phase transition, such as measuring a hysteresis loop between the solid-to-liquid and liquid-to-solid transitions, revealing nonreciprocal resonance wavelength shift, and identifying a unique metastability state of Ga during melting. The linear thermal expansion coefficients of Ga were precisely measured to be 0.41 × 10−5 K−1 and −0.75 × 10−5 K−1 for solid and liquid Ga, respectively. Our research provides a comprehensive and versatile monitoring platform for newly fabricated liquid metal alloys, offering multidimensional insights into their phase transition behavior.

An In-Situ Analysis Method in EAF and BOF Steelmaking

An analysis was conducted to gage the feasibility of using a spectroscopic method to determine the chemical composition of the liquid metal phase in EAF and BOF steelmaking. The hypothesis that certain radiation intensities found in UV- and UV-near regions of an spectrum emitted from the hot-spot in the BOF or the impingement area of oxyfuel burners in EAF steelmaking can be used for analysing the chemical components present in the liquid metal is tested. Significant lab-scale experiment results and the conclusions regarding industrial scale implementation are presented.

Enhancement effects of FeCoNiCrMn high-entropy alloy doping on the Ti(C, N)-based cermets: Microstructure and mechanical properties

The enhancement effects of doping Ti(C, N)-based cermets with different contents of FeCoNiCrMn (HEA, high entropy alloy) on the mechanical properties, microstructure, cutting performance and high temperature bending strength of the Ti(C, N)-based cermets were investigated. Ti(C, N) particles had good wettability to the metal liquid phase of HEA, and with the increase of HEA content, the strength of the binder gradually improved. When the content of HEA was 12%, the cermets had the best comprehensive mechanical properties, with a relative density of 99.8%, Vickers hardness of 19.5 ± 0.2 GPa, fracture toughness of 8.2 ± 0.1 MPa·m1/2, and bending strength of 1229 ± 82 MPa. Compared with Co binders, HEA binders had better softening resistance at high temperatures. When the content of HEA exceeded 6%, the bending strength at 700 °C of the Ti(C, N)-based cermet tools were enhanced by 78%–96%, and the cutting life was increased by 35%–65%.

Preparation of a novel bio‐based aerogel with excellent hydrophobic flame‐retardancy and high thermal insulation performance

AbstractSodium‐alginate‐based aerogels possess wide prospects in the fields of packaging, aerospace, industrial construction and transportation because of their environmental compatibility and thermal insulation, but it is still a challenge to obtain a sodium alginate‐based aerogel with high flame retardancy and good thermal insulation. Herein, a sodium‐alginate‐based aerogel with high flame retardancy, thermal insulation and good hydrophobic properties was prepared by two‐step crosslinking strategy of phytic acid and metal ions and liquid phase deposition of trans‐cinnamic acid. As a result, the prepared SA/PA Mn+ aerogels obtained excellent flame retardancy (UL‐94 V‐0, LOI 50.1%) and rapid self‐extinguishing, and SA/PA Mn+ aerogels obtained good hydrophobic ability (CA = 134.2°). In addition, the mechanical properties of SA/PA Mn+ aerogels have also been improved, the compressive modulus increased from 0.66 to 6.37 MPa, and the specific modulus increased from 15.7 to 140.2 MPa cm −3 g−1. This research broadens the application of bio‐based flame‐retardant aerogels in the fields of packaging, aerospace, industrial construction and transportation.

Grain growth behavior in TaC-modified ultrafine Ti(C, N)-based cermets

Revealing the grain growth behavior during liquid phase sintering is of great significance for scientific application of grain growth inhibition strategies and the regulation of microstructure. In this study, the effects of both TaC addition and the particle size of starting materials on microstructure of Ti(C, N)-based cermets were investigated. Ultrafine Ti(C, N)-based cermets modified with TaC addition exhibit an obvious grain growth of grey phase during liquid phase sintering. The grain growth of grey phase is typically controlled by liquid-phase diffusion, with the grain growth index of 3 and activation energy of 48–66 kJ/mol. In particular, the increase in grain contiguity of grey phase caused by the evaporation of metal liquid phase at high temperatures, faceted transition of grey phase grains, and the loss of carbon and nitrogen are considered to be the main reasons for the decrease in the grain growth rate of grey phase at high temperatures.

Numerical modelling of heating and melting of metal in a mini industrial direct current electrical arc furnace

PurposeThe purpose of this paper is the study of the electro-vortex flow (EVF) as well as heating and melting processes for mini industrial direct current electric arc furnace (DC EAF).Design/methodology/approachA mini DC EAF was designed, manufactured and installed to study the industrial processes of heating and melting a small amount of melt, being 4.6 kg of steel in the case under study. Numerical modelling of metal melting was performed using the enthalpy and porosity approach at equal values and non-equal values of the solidus and liquidus temperatures of the metal. The EVF of the liquid phase of metal was computed using the large eddy simulation model of turbulence. Melt temperature measurements were made using an infrared camera and a probe with a thermocouple sensor. The melt speed was estimated by observing the movement of particles at the top surface of melt.FindingsThe thermal flux for metal heating and melting, which is supplied through an arc spot at the top surface of metal, is estimated using the thermal balance of the furnace at melting point. The melting time was estimated using numerical modelling of heating and melting of metal. The process started at room temperature and finished once whole volume of metal was molten. The evolution of the solid/melt phase boundary as well as evolution of EVF patterns of the melt was studied.Originality/valueNumerical studies of heating and melting processes in metal were performed in the case of intensive liquid phase turbulent circulation due to the Lorentz force in the melt, which results from the interaction of electrical current with a self-magnetic field.

Thermal and Viscous Irreversibilities Analysis in a Liquid Metal Phase Change Counter Flow Heat Exchanger

Sodium, a liquid metal, is utilized in a heat exchanger system coupled to a nuclear reactor to produce hydrogen. The subcooled liquid metal enters a counterflow heat exchanger, undergoes a phase change, and exits as superheated vapor. The sodium heating process occurs through heat exchange with superheated helium vapor in three phases: subcooled liquid, saturated vapor, and superheated vapor. This article analyzes the thermal and hydraulic performance of the three stages of the heat exchanger through thermal and viscous irreversibilities using analytical simulation. The solution obtained is based on applying the thermal efficiency method and the second law of thermodynamics. The thermodynamic Bejan number, the relationship between thermal irreversibility and total irreversibility, allows a cost-benefit analysis when determining thermal performance and viscous dissipation. The essential physical quantities used in the analysis are the lengths and internal diameters of the three segments of the heat exchanger. The results are analyzed and compared with previous analytical work published in the literature. Numerical and graphical results are obtained for temperature profiles, thermal effectiveness, heat transfer rate, thermal irreversibilities, pressure drops, viscous irreversibilities, entropy generation rate, and Bejan numbers. It is demonstrated that the cost-benefit is highly advantageous when the diameter used for the internal tubes of the three segments is equal to the diameter of the saturated sodium vapor section, corresponding to ¼ of the speed of sound in the tube.

Phase Equilibria and Thermodynamic Modelling of the PbO-ZnO-FeO-FeO1.5-SiO2 system and its subsystems in equilibrium with air/metallic lead/iron

The phase equilibria of the ZnO-“FeO1..5”, ZnO-“FeO1.5”-SiO2, PbO–ZnO-“FeO1.5” and PbO–ZnO-“FeO1.5”-SiO2 slag systems in equilibrium with air or metallic lead/iron were studied as part of the investigation of the 19-component PbO–ZnO–Cu2O–FeO–Fe2O3–CaO–SiO2–Al2O3–MgO–S-(As, Sn, Sb, Bi, Ag, Au, Ni, Cr, Co as minor elements) slag/matte/metal/speiss/gas system, supporting the operation/development of existing and emerging pyrometallurgical processes. In the experimental part of the study, samples underwent high temperature equilibration followed by quenching, and the direct measurement of the lead, zinc, iron and silicon concentrations in the liquid slag, solid oxide, and metal phases by electron probe microanalysis (EPMA). The a) massicot (PbO), b) spinel ((Zn, Fe)Fe2O4), c) zincite ((Zn,Fe)O1+x, 2 polymorphs), d) lead ferrite (Pb2+xFe2O5+x), e) plumboferrite (Pb4Fe22-xZnxO37), f) magnetoplumbite (Pb(Fe2O3,PbFeO2,PbZnO2)Fe10O16), and g) W-ferrite (PbZn2-xFe16+xO27) primary phase fields of the PbO–ZnO-“FeO1.5” system in equilibrium with air were studied between 780 and 1300 °C. The ZnO-“FeO1.5”, ZnO-“FeO1.5”-SiO2 and PbO–ZnO-“FeO1.5”-SiO2 systems in equilibrium with air were studied up to 1745 °C, significantly improving the availability of information on the composition range of the high- and low-Fe zincite ((Zn,Fe)O1+x) phases, and on the liquid slag composition at the boundaries of their primary phase fields. Lastly, the solubilities of iron in larsenite (Pb(Zn,Fe)SiO4) and melilite (Pb2(Zn,Fe)Si2O7) in equilibrium with air or metal were studied between 700 and 800 °C. The newly obtained and existing experimental data were used to develop a self-consistent set of thermodynamic parameters describing all phases in the system using the FactSage computer package.

Justification of obtaining fine-grained structure of welded joints at high-intensity impulse effect on welding circuit

An effective method of improving the reliability of operation of thermal and nuclear power facilities is to improve the quality of manufacture, installation and repair of their thermal and generating power equipment. One of the ways to improve the quality, technological and service properties of welded joints in the process of their implementation is to influence the structure of the crystallizing metal by thermal, electric high-intensity impulse effect for its grinding. This work proposes the results of an experimental study to substantiate the production of a fine-grained structure of welded joints obtained using manual arc welding with coated electrodes at a high-intensity impulse effect (QPS) with a fi.g.= 40×103 Gts frequency, voltage Ui.g.= 80.0 V, on the welding circuit. The energy characteristics of the process can be used to assess the effect of high-intensity impulse action on the welding circuit, including the arc plasma and the structure of the resulting weld. As the energy characteristics of the welding process, the welding current Iwd, the voltage on the arc discharge Ud, the power Rp. Oscillograms of the specified characteristics were obtained, as well as the values of the maximum (peak) and average power released in the welding circuit when QPS is exposed to it and without its use were determined. Energy evaluation of input of additional high-intensity pulse effect on welding circuit as ultrasonic energy for cavitations of surface layer of welding bath at QPS was performed. Direct current arc discharge at application of high-intensity pulse effect with frequency of fi.g.= 40×103Gts (QPS) is source of cavitations of liquid phase of metal of welding bath in limited surface layer of preset thickness. It can be assumed that the crystallization of the bath takes place in layers when the welding circuit is subjected to high-intensity pulse exposure with a frequency of fi.g.= 40×103 Gts (QPS). In this case, the growing crystals break when the liquid phase oscillates due to friction forces arising between the moving liquid phase and the growing crystal. At the site of crystal fracture, zones of dynamically super cooled metal are formed, which leads to the appearance of new crystallization centers, and a fine-grained structure of the weld appears.

Disordered GaSiP solid solution anodes with liquid metal phase for high-performance Li-ion batteries

Silicon (Si) has become the most promising next-generation anode to replace commercial graphite for Li-ion batteries (LIBs) profiting from its large reversible capacity of 4,200 mA h g−1. However, its sluggish reaction kinetics and large volume effect need to be resolved. Herein, we prepare a ternary GaSiP solid solution with a disordered lattice by a facile mechanochemistry method. As anodes of LIBs, the GaSiP provides a reversible capacity of 1,527 mA h g−1 at 100 mA g−1 with an initial Coulombic efficiency (ICE) of 90.8% based on the reversible Li-storage mechanism integrated intercalation and subsequent conversion processes as confirmed by crystallography characterization and electrochemical measurements. Importantly, the GaSiP carbon composite presents a long cycling stability of maintaining 1,362 mA h g−1 after 50 cycles at 0.1 A g−1, and 75% capacity retention rate after 1,200 cycles at 2 A g−1, and a high-rate performance of remaining 440 mA h g−1 at 20 A g−1. Broadly, this work opens the door to develop ternary phosphides with disordered lattice and liquid metallic phase using for electrochemical energy conversion and storage.

Experiment and thermodynamic modelling of phase equilibria in PbO−“CuO0.5” and PbO−“CuO0.5”−“FeO1.5” slag systems with metal

The phase equilibria of the PbO−“CuO0.5” and PbO−“CuO0.5”−“FeO1.5” slag systems in equilibrium with solid metallic copper and/or liquid metallic lead−copper alloy were studied as part of the investigation of the 19-element PbO−ZnO−Cu2O−FeO−Fe2O3−CaO−SiO2−Al2O3−MgO−S−(As, Sn, Sb, Bi, Ag, Au, Ni, Cr, Co as minor elements) multicomponent slag/matte/metal/speiss system, supporting the operation and development of the existing and emerging pyrometallurgical processes. In the experimental portion of this study, samples underwent high temperature equilibration followed by quenching, after which the compositions in the liquid slag, solid oxide and metallic phases were directly measured by electron probe microanalysis (EPMA). Phase equilibria data on the massicot (PbO), spinel ((Fe, Cu)Fe2O4), cuprite (Cu2O), lead ferrite (Pb2+xFe2O5+x), magnetoplumbite (Pb1+xFe12−xO19−x), copper plumbite (Cu2PbO2), and delafossite (CuFeO2) primary phase fields were obtained between 688 and 1000 °C. A key finding of the experimental study of the PbO−“CuO0.5” subsystem was that the copper plumbite (Cu2PbO2) phase melted incongruently, contradicting previous studies that suggested it apparently decomposed below the binary eutectic temperature to form massicot (PbO) and cuprite (Cu2O). Based on the results of past and present experimental studies, a self-consistent set of thermodynamic model parameters describing all phases in the system was derived using the FactSage software package.

Design and Scalable Fabrication of Liquid Metal and Nano-Sheet Graphene Hybrid Phase Change Materials for Thermal Management.

Here, a paraffin/liquid metal (LM)/graphene hybrid thermal composite material with a high thermal-conductivity as well as high latent heat is developed. The paraffin is encapsulated in calcium alginate, which produces leakage-free phase change material (PCM) capsules. LM is filled amongthe gaps of PCM capsules to enhance overall heat conduction. Graphene nano-sheets coating attains efficient heat dissipation because of its high spectral emissivity (>91%) in the spectrum of the mid-infrared region. The developed material is verified to have strong compatibility and durable stability. The composite is utilized as a thermal buffer (TB) for central processing unit thermal management to demonstrate the synergy of these superior thermal properties. In certain cases, active cooling normally used could be replaced by the developed TB without any energy consumption for thermal management, demonstrating a completely passive cooling strategy. Compared to traditional heat sink active cooling, general energy savings of 10.4-26.3% could thus be achieved by the developed composite in wider operating conditions, proving itspotential for more efficient and sustainable data center cooling alongside thermal management of other ground-based electrical/electronic equipment.

Single-Phase Ternary Compounds with a Disordered Lattice and Liquid Metal Phase for High-Performance Li-Ion Battery Anodes

HighlightsSingle-phase ternary GaSiP2with a disordered lattice and liquid metal was synthesized.GaSiP2 electrode achieved superior Li-storage performances in both half and full cells.Unique self-healing Li-storage mechanism of GaSiP2 was analyzed.

Phased Array Antenna System Enabled by Liquid Metal Phase Shifters

Phased Array Antenna System Enabled by Liquid Metal Phase Shifters