Solid Metal Research Articles

Graph neural networks predict energetic and mechanical properties for models of solid solution metal alloy phases

We developed a PyTorch-based architecture called HydraGNN that implements graph convolutional neural networks (GCNNs) to predict the formation energy and the bulk modulus for models of solid solution alloys for various atomic crystal structures and relaxed volumes. We trained the GCNN surrogate model on a dataset for nickel–niobium (NiNb) generated by the embedded atom model (EAM) empirical interatomic potential for demonstration purposes. The dataset was generated by calculating the formation energy and the bulk modulus as a prototypical elastic property for optimized geometries starting from initial body-centered cubic (BCC), face-centered cubic (FCC), and hexagonal compact packed (HCP) crystal structures, with configurations spanning the possible compositional range for each of the three types of initial crystal structures. Numerical results show that the GCNN model effectively predicts both the formation energy and the bulk modulus as function of the optimized crystal structure, relaxed volume, and configurational entropy of the model structures for solid solution alloys.

Computational Heat transfer analysis of capsulated liquid metal fins

Fins are extended surfaces to increase convection heat transfer. Conventional fins are made of solid metals and alloys. Liquid metals such as sodium have melting points below atmospheric temperature. Liquid metals have lower specific heats and higher thermal diffusivity when compared to solid metals. These properties can be used in enhancing heat transfer. In the present work, a numerical model is developed for analyzing the effect of capsulating liquid metal in a solid pin fin. COMSOL Multiphysics package is used to determine heat transfer characteristics under varying geometric and flow conditions. The enhancement of heat transfer due to capsulating Mercury in the Aluminium pin fin when compared to solid Aluminium pin fin is detailed.

Development of materials with a multilayer structure of the gradient type based on liquid compositions for the shielding of electromagnetic fields

Nowadays, for shielding and absorption of electromagnetic fields of a wide frequency range, composite materials or solid metal structures are offered and widely used. The article deals with research and development of multilayer protective liquid materials for shielding electric, magnetic and electromagnetic fields of a wide frequency range. A series of liquid shielding mixtures based on standard certified paints and finely dispersed magnetite was produced. Testing of the protective properties of these mixtures was carried out by sequentially applying 2–3 layers of mixtures to the surface, each of which had a certain concentration of the shielding substance. The shielding and reflection coefficients for these multilayer structures are given. It is shown that the advantage of the developed multilayer protective liquid materials lies in obtaining a gradient of electrophysical and magnetic properties of the protective structure with the possibility of calculating dielectric and magnetic permeabilities, taking into account the morphology of the shielding particles. A method of obtaining protective materials of the gradient type, which reduce the influence of electromagnetic fields, is proposed, which is possible for the treatment of surfaces of large areas and complex configurations.

Effect of intragastric administration on the morphology of laboratory rats’ gastrointestinal tract

BACKGROUND: In preclinical studies on laboratory animals, oral administration with special probe for test substances is very in demand. Most studies are devoted to the psychophysiological and clinical-biochemical reaction of the animals body to this effect, but extremely few studies consider the effect of the manipulation itself on the development of pathology in the tissues of the gastrointestinal tract associated with the inevitable mechanical impact of the probe on the mucous membranes.
 AIM: To identify pathological changes in the organs of the gastrointestinal tract of laboratory rats that are associated with the effects of intragastric administration of the tested substances, and compare the data obtained with the frequency of spontaneous diseases.
 MATERIALS AND METHODS: The data of pathomorphological observations obtained from Wistar rats involved in the course of scientific work carried out at NPO Dom Pharmacy in the period from 2018 to 2021 were used. 1400 sentinel animals were analyzed, and the same number of intact rats. Intact animals were gavaged with a control substance (distilled water) for 14 days.
 RESULTS: In less than 5% of clinically healthy animals, inflammatory diseases of insignificant intensity and prevalence in all parts of the intestine can be detected. As a result of the anipulation of intragastric administration, an almost twofold increase in the number of cases of catarrhal esophagitis and gastritis, erosive and ulcerative lesions of the mucous membrane of the esophagus and stomach in its glandular part and hyperkeratosis in its non-glandular part was noted.
 CONCLUSIONS: The type and frequency of occurrence of the background pathology of the gastrointestinal tract of laboratory rats were determined. It has been proven that repeated traumatization of the mucous membrane associated with mechanical contact of a solid metal probe with the epithelium provokes the development of inflammatory diseases of the esophagus and stomach, without affecting the underlying parts of the intestine.

In-depth Li+ transportation in three-dimensionalized nanodiamond network for improved liquid and solid lithium metal batteries

Confining lithium (Li) deposition in three-dimensional scaffold is commonly employed to suppress Li dendrite and enhance the cycling stability of next generation Li metal batteries (LMBs). However, the efficiency of this strategy is often degraded under lean-Li conditions, due to the serious precipitation of deposited Li on the top surface of the electronic conducting scaffold such as carbon or metal matrix. Here it is found that building an insulating interlayer on the scaffold but with a high Li+ transfer dynamism, can be a promising strategy to address the above challenge. We successfully three-dimensionalize an insulating and robust nanodiamond (ND) network on carbon paper (CP) via chemical vapor deposition, which not only retards the electron transfer to avoid the top Li precipitation, but also exhibits impressive Li affinity and mobility to undergo an in-depth Li+ transportation throughout the scaffold. Based on this advanced three-dimensionalized ND network, the Li anode performance in CP@ND significantly exceeds that in the traditional carbon fiber matrix, particularly under lean-Li conditions. Furthermore, the application of CP@ND leads to a sharply improved cyclability of all-solid-state LMBs, establishing a novel guideline of protecting Li anode in the electrolyte-mobility-limited environment.

A reconfigurable and automatic platform for the on-demand production of stretchable conductive composites

Stretchable conductive composites (SCCs) have been widely used as interconnects and sensors in stretchable electronic devices due to their tunable electromechanical properties and intrinsically high stretchability compared to solid metals. SCCs can be readily made by mixing (or breaking bulk) conductive fillers within an elastomeric polymer, which are subsequently cured. Despite the simplicity of this, most fabrication methods follow customized protocols and lack precise automatic control. These methods also require bulky and costly equipment (e.g. stirrers, mixers, ovens, and vacuuming machines). Also, variations in the production process make it challenging to maintain the consistency of SCC’s electrical and mechanical properties produced in different batches. To solve this problem, this work develops an automatic SCC production platform (ASPP) that can be programmed to produce SCCs with high consistency in properties. The versatility of ASPP is demonstrated by fabricating SCCs with single and hybrid fillers, and porous structures. The consistency of SCCs’ electromechanical properties is examined using samples fabricated in different batches following the same protocol. We further utilize the fabricated SCCs to realize various intelligent tactile sensing and heating platforms. The capability demonstrated for the ASPP shows its potential in fabricating SCCs for applications in soft robotics and wearable devices.

Wideband Characterization of Microstrip Technology with Borofloat 33 and Some Classic Transparent Glasses

In this work, we made the technical qualification of borofloat 33 glass and also other much cheaper conventional glasses, associated with solid metallization by a broadband characterization method of microstrip technology based on the S-parameters. This made it possible to extract the electromagnetic parameters (dielectric permittivity, tangent loss) necessary for the design and construction of low visual impact antennas. The values of S11, S33, S12, and S34 are then extracted on vector network analyzer (VNA). The data of these measurement results are processed and the values of the loss tangent and the dielectric constant are thus measured with ADS software. We have obtained for the classical glass εr = 6.5 and tanδ = 0.0206; for the microscope glass εr = 6.15 and tanδ = 0.021 and at the end for the borofloat 33 glass εr = 4.5 and tanδ = 0.012.

Dissimilar Joining of Immiscible Fe–Mg using Solid Metal Dealloying

Joining of Mg alloy to steel has received wide attention for design of multi-materials. This letter describes joining of immiscible pure iron and pure magnesium (Fe–Mg), as a simplified model, performed by solid metal dealloying (SMD) between Mg and Fe100−xNix interlayers that were preliminary joined to the Fe part by diffusion bonding. SMD formed an Fe–Mg bicontinuous composite with interconnected morphology at the Fe–Mg weld interface. The effect of Ni composition x in the interlayer on the weld strength was examined. Strong joints were obtained when 30 < x < 50 at.%, which caused Mg base-metal fracture due to a well-interconnected Fe–Mg structure. When too little (x < 30 at.%) or too much (x > 60 at.%) Ni was added, interfacial fracture occurred due to limited dealloying reaction and formation of an isolated Fe product surrounded by a large amount of brittle Mg2Ni.

The interface microstructure and phase constitution of Nb/316L composite plates fabricated by explosive welding

ABSTRACT Niobium has a reputation for its superior superconducting, high strength and corrosion resistance at elevated temperatures. In this work, the explosive welding technique was successfully performed to join Nb/316L dissimilar metals. To reveal the phase constitution and texture distribution at the joining interface, the EBSD test was carried out. It was concluded that an irregular large wavy structure of fine crystal, sub-grains and twin structures was formed. In addition, the recrystallised structures, substructures, deformed structures and local internal stress at the joining interface were attributed to severe plastic deformation and rapid solidification of liquid metal. Furthermore, six different deformation textures and recrystallisation textures were confirmed at the joining interface due to severe plastic deformation and dynamic recrystallisation.

Partial discharge induced decomposition and by-products generation properties of HFO-1234ze(E)/CO2: a new eco-friendly gas insulating medium

HFO-1234ze(E) is introduced as a new eco-friendly insulating gas for medium-voltage gas-insulated equipment (MV-GIE). However, there are few reports on the partial discharge (PD) induced decomposition and gaseous, solid by-product generation characteristics of HFO-1234ze(E)/CO2. Herein, the PD decomposition characteristics of HFO-1234ze(E)/CO2 were explored based on a needle-plate electrode that simulates the metal protrusion defect in MV-GIE. The partial discharge inception voltage, and phase-resolved partial discharge of HFO-1234ze(E)/CO2 under different mixing ratios, PD intensity and duration time at 0.15 MPa were obtained. Meanwhile, the PD-induced decomposition and generation of gaseous, solid by-products of HFO-1234ze(E)/CO2 were analyzed. A three-zone pattern that describes the gas–solid metal interface interaction was proposed for the first time. It is found that the increase of HFO-1234ze(E) content brings superior insulation performance, while the precipitation of gaseous (CF4, C2F6, CHF3, C3HF7) and solid by-products gradually aggravated. In order to avoid the negative impact of PD-induced decomposition on the insulation and service life of MV-GIE, the optimal HFO-1234ze(E) content of 30% is recommended. Based on the optimal mixing ratio (30% HFO-1234ze(E)/70% CO2), the effect of gas pressure and electrode materials on solid precipitation, breakdown voltage was also explored. This work guides the development of HFO-1234ze(E) based MV-GIE and understanding the solid by-products precipitation mechanism of eco-friendly insulating gas.

Codependent failure mechanisms between cathode and anode in solid state lithium metal batteries: mediated by uneven ion flux

An in-depth understanding of the degradation mechanisms is a prerequisite for developing the next-generation all solid-state lithium metal battery (ASSLMB) technology. Herein, synchrotron X-ray computed tomography (SXCT) together with other probing tools and simulation method were employed to rediscover the decaying mechanisms of LiNi0.8Co0.1Mn0.1O2 (NCM)|Li6PS5Cl (LPSCl)|Li ASSLMB. It reveals that the detachment and isolation of NCM particles cause the current focusing on the remaining active regions of cathode. The extent of Li stripping and the likelihood of Li+ plating into LPSCl facing the active NCM particles becomes higher. Besides, the homogeneity of Li stripping/plating is improved by homogenizing the electrochemical reactions at the cathode side by LiZr2(PO4)3 (LZP) coating. These results suggest a codependent failure mechanism between cathode and anode that is mediated by uneven Li ion flux. This work contributes to a holistic understanding of the degradation mechanisms in ASSLMBs and opens new opportunities for their further optimization and development.

The Effect of Cr Additive on the Mechanical Properties of Ti-Al Intermetallics by First-Principles Calculations

The structure, elastic properties and electronic structure of Ti-Al intermetallics including Ti3Al (space group P63/mmc), TiAl (space group I4/mmm) and TiAl3 (space group P4/mmm) are systematically studied by first-principles calculations. The results show that Ti-Al intermetallics can exist stably whether Cr replaces Ti or Al. The ductility of the alloy cannot be improved when Ti is replaced in Cr-doped TiAl and TiAl3. However, when it replaces Al, the alloy has better ductility. In Ti3Al, the ductility can be improved regardless of whether Cr replaces Ti or Al, and the effect is better when it replaces Al. The bond in Ti-Al intermetallics is mainly a Ti-Ti metal bond. The metal bond between Ti-Ti is strengthened and a solid metal bond is formed between Cr and Ti, inducing a better ductility of the material, after Cr replaces Al in Ti-Al intermetallics.

Effect of Humus on the Solidification and Stabilization of Heavy Metal Contaminated River Sediment

To better reutilize heavy metal contaminated river sediment containing organic matter, the sediments in a river located in Chongming District, Shanghai were collected and Portland cement was used as a curing agent along with commercial organic matter to conduct the solidification/stabilization experiment. The unconfined compressive strength and heavy metal leaching concentrations of solidified blocks with different water content, organic matter content, and cement content were tested and analyzed to determine the optimal ratio. The effects of fulvic acid (FA), humic acid (HA), and an HA/FA ratio on the solidification and stabilization, as well as the speciation of heavy metals in sediment before and after solidification and stabilization, were studied. The results showed that when the organic content of the sediment is 6.16%, the water content is 65% and the cement content is greater than 38%, so the curing effect proves to be satisfactory. Fulvic acid has a stronger inhibiting effect on cement hydration than humic acid, and its consumption in the curing process is more significant. The addition of humic acid contributes to the stabilization of heavy metals, while the increase in fulvic acid greatly weakens the stability of heavy metals. The exchangeable state of heavy metals in the sediment has been reduced to varying degrees after solidification and stabilization. The research results can provide a basis for the reclamation and utilization of heavy metal contaminated river sediment with organic matter.

Shaping a Soft Future: Patterning Liquid Metals.

This review highlights the unique techniques for patterning liquid metals containing gallium (e.g., eutectic gallium indium, EGaIn). These techniques are enabled by two unique attributes of these liquids relative to solid metals: 1) The fluidity of the metal allows it to be injected, sprayed, and generally dispensed. 2) The solid native oxide shell allows the metal to adhere to surfaces and be shaped in ways that would normally be prohibited due to surface tension. The ability to shape liquid metals into non-spherical structures such as wires, antennas, and electrodes can enable fluidic metallic conductors for stretchable electronics, soft robotics, e-skins, and wearables. The key properties of these metals with a focus on methods to pattern liquid metals into soft or stretchable devices are summari.

An efficient Mn1-yCeyOx composite oxide mesoporous catalysts for catalytic combustion of aromatic hydrocarbon

A simple and effective method, pyrolytic melt polymerization using solid metal salts, was successfully synthesized catalysts with a mesoporous structure. A series of high-performance composite oxide catalysts made from the manganese oxide was prepared. The characteristics of these materials were evaluated using various technologies, such as XRD, BET, H2-TPR, and in-situ DRIFTS. The catalytic combustion performance of catalysts for typical aromatic hydrocarbon (toluene and CB) was investigated. And we speculated the catalytic reaction path of toluene by in-situ infrared analysis. Based on T90%, the catalytic activity ranking was: Mn0.8Ce0.2Ox＞MnOx＞Mn0.5Ce0.5Ox＞Mn0.2Ce0.8Ox＞CeOx. Furthermore, Mn0.8Ce0.2Ox exhibited excellent catalytic stability in the CB and toluene for 20 h. The increase of oxygen vacancies was attributed to the doping of Ce which increased the amount of Mn3+ and Ce3+. The active oxygen and abundant oxygen vacancies on the Mn0.8Ce0.2Ox promote the good catalytic performance for aromatic hydrocarbons.

Building K-C Anode with Ultrahigh Self-Diffusion Coefficient for Solid State Potassium Metal Batteries Operating at -20 to 120°C.

Solid state potassium (K) metal batteries are intriguing in grid-scale energy storage, benefiting from the low cost, safety, and high energy density. However, their practical applications are impeded by poor K/solid electrolyte (SE) interfacial contact and limited capacity caused by the low K self-diffusion coefficient, dendrite growth, and intrinsically low melting point/soft features of metallic K. Herein, a fused-modeling strategy using potassiophilic carbon allotropes molted with K is demonstrated that can enhance the electrochemical performance/stability of the system via promoting K diffusion kinetics (2.37 × 10-8 cm2 s-1 ), creating a low interfacial resistance (≈1.3 Ω cm2 ), suppressing dendrite growth, and maintaining mechanical/thermal stability at 200°C. A homogeneous/stable K stripping/plating is consequently implemented with a high current density of 2.8mA cm-2 (at 25°C) and a record-high areal capacity of 11.86 mAh cm-2 (at 0.2mA cm-2 ). The enhanced K diffusion kinetics contribute to sustaining intimate interfacial contact, stabilizing the stripping/plating at high current densities. Full cells coupling ultrathin K-C composite anodes (≈50µm) with Prussian blue cathodes and β/β″-Al2 O3 SEs deliver a high energy density of 389Wh kg-1 with a retention of 94.4% after 150 cycles and fantastic performances at -20 to 120°C.

Retention Behaviour of Heavy Metals from Industrial Sludge Amended with Admixtures to Use Them as Liners for Landfill Facilities

The solidification of contaminants within the soil/waste has proved to be a versatile technique to de-contaminate them and make them usable for several applications. In this method, the development of binder provisions leads to the conversion of the environmentally unstable condition of waste materials into a nearly stable material. Further, these materials pose a minimum threat that can be absorbed into the environment. Normally lime/cement and other pozzolanic materials are used as binder materials. In this work, it is proposed to use the efficiency of binding fly ash to improve the unconfined compressive strength (UCC) of soils, particularly during the curing period. This is because improvement in strength is a reflection of the improvement of bonding soil particles. Fly ash as the main source material, in addition to a minor proportion of cement and lime, is used to determine the strength. UCC test results revealed that as the percentage of fly ash increases there is an increase in compressive strength. It is also observed that with an increase in lime content and an increase in cement content, the UCC strength also increases. The strength in cement-stabilized compacted specimens is more compared to lime-stabilized mixtures. To confirm that the improvement in strength is related to the solidification of contaminated metals, particularly for soils containing copper and chromium, the stabilized mixture is tested for the leaching of these metals. Leaching tests were conducted on various stabilized mixtures at different curing periods. The leachate was examined for metal ion concentration using Atomic Absorption Spectrophotometer. The leaching behavior of heavy metals from different proportions of soil matrix revealed that with an increase in lime or cement percentage, a decrease in leachability is observed. It is found that the leaching of heavy metals from cement-stabilized soils was lower than in lime mixture combinations. However, minimum strength improves the solidification and retention of heavy metals effectively.

Crosslinked polymer electrolyte constructed by metal-oxo clusters for solid lithium metal batteries

By using structurally well-defined metal-oxo clusters as crosslinkable nanofillers, the authors develop a hybrid inorganic/organic crosslinked polymer electrolyte. With the favorable electrochemical and mechanical properties, as well as the enhanced lithium dendrite-suppressing capability, the metal-oxo cluster crosslinked polymer electrolyte can significantly improve the capacities, rate capabilities, and cycling stabilities of solid lithium metal batteries. Download : Download high-res image (175KB)Download : Download full-size image

Improving transmission through honeycomb panels through modal considerations

Recent efforts centered at Sandia National Laboratories have demonstrated transmission of power and data through continuous metal media using vibration in connection with piezoelectric tiles; however, solid metal construction may be disadvantageous in structural contexts due to the greater mass needed to achieve given stiffness characteristics. Other common structural materials, on the other hand, such as aluminum honeycomb panels, may offer poor transmission possibilities when their characteristics are not appropriated accounted for in the selection of transducers. In this study, COMSOL simulations of the aluminum honeycomb panel materials were used to select transducers with resonance frequencies in proximity to the natural modes of the panel's honeycomb cells. This enabled improved transmission through the honeycomb panels in comparison to less targeted approaches. [SNL is managed and operated by NTESS under DOE NNSA Contract No. DE-NA0003525.]

KINETICS OF OXIDATION OF Ca–Ge SYSTEM MELTS BY AIR OXYGEN

With the introduction of complex alloys and metals – reoxidizers into liquid steel, their waste is observed, or more precisely, oxidation by the gas phase of the furnace. To select the optimal composition of complex deoxidizers, it is necessary to know the physicochemical laws of this process, which are little studied. To study the kinetics of oxidation of metal melts, the method of continuous sample weighing is used, which is usually used in the study of high-temperature corrosion of solid metals. The mechanism of interaction of liquid metals with oxygen is similar in nature to high-temperature gas corrosion of solid metals. In both cases, adsorption of gas molecules on the metal surface, nucleation, and then growth of an oxide film take place. In this work, the kinetics of oxidation of Ca-Ge melts with atmospheric oxygen was studied using thermogravimetry, IR spectroscopy, and X-ray phase analysis. It is shown that germanium additions up to 33.3 at % increase the resistance of melts to oxidation. An increase in temperature contributes to an increase in the rate of oxidation of melts of the Ca–Ge system. The process of oxidation of the investigated melts obeys the parabolic law. The true rate of oxidation is on the order of 10–4 kg · m–2 · s–1. The apparent activation energy of oxidation, depending on the composition of the alloys, is 39.8–526.7 kJ/mol. The products of melt oxidation are СaGe4О9 and GeО2. The mechanism of the influence of germanium on the kinetics of oxidation of Ca-Ge melts has been established. The CaGe4O9 oxide plays a dominant role in the formation of a protective oxide film.