Metals In Samples Research Articles

Noble Dome: A Novel Air-Free Transfer System For Battery Research with Electron Microscopy

"Noble Dome: A Novel Air-Free Transfer System" introduces an innovative solution for loading air-sensitive samples into SEM/FIB instruments. Traditional loading methods expose samples to atmosphere during transfer, hindering investigations of reactive materials. The presented prototype, Noble Dome, directly attaches to the SEM/FIB, enabling sample transfer in an oxygen-free environment. The device's design and operational process are outlined, including airtight chambers, gas introduction, and modified venting systems. Experimental results demonstrate Noble Dome's effectiveness in preserving sample integrity. Compared to existing solutions, which often pose limitations, Noble Dome offers a practical approach for various research needs.Imaging and micromanipulation techniques such as Scanning Electron Microscopy (SEM) and Focused Ion Beam (FIB) can reveal critical information about the microstructure and composition of materials. To utilize these techniques, a sample must be loaded into the chamber of the instrument which is then pumped down to low vacuum conditions. In the process of removing a sample from its packaging and mounting it on the SEM/FIB stage, the sample is briefly exposed to atmosphere. This is problematic for researchers who are interested in investigating air sensitive samples or samples for which atmospheric contamination would detract from the investigation. This set of samples includes metals commonly used as battery materials such as lithium and sodium, which are highly reactive with elements in the air such as moisture or oxygen.We present a prototype for a glove box load lock that addresses this problem directly. This device attaches directly onto the side of a SEM/FIB and allows researchers to remove a sample from packaging and transfer it directly on the stage via an accessory port of the SEM/FIB in an oxygen-free environment and then pump the tool down to vacuum without any atmospheric exposure in the process, eliminating the use of an intermediary shuttle from a separate glove box. We call this device Noble Dome.In order to test Noble Dome’s ability to protect samples from atmosphere, we imaged and collected EDS spectra on the same location of a lithium metal sample in a pristine state, after sitting in Noble Dome for 30 minutes, and after sitting in atmosphere for 30 minutes.We note that there was very little change in the surface topography and oxygen counts between the sample in its pristine state and the sample after sitting in Noble Dome for 30 minutes. However, there is a marked increase in surface oxidation and topography after the sample sat in atmosphere for 30 minutes.Lithium-ion batteries are increasingly prolific in the landscape of modern technology. In order to improve the energy density, life cycle and safety of lithium-ion batteries, researchers require significant amounts of materials characterization pre-assembly, post-assembly and after several charge/discharge cycles. Electron microscopy is crucial for effective materials characterization, which necessitates a solution for loading samples into the vacuum chamber of the microscope without exposing these reactive samples to air.Other solutions currently on the market for loading air sensitive samples into a SEM/FIB involve manipulating the sample in a glove box which is separate from the instrument, loading the sample into an inert gas transfer shuttle which is closed by remote control, removing the shuttle from the glovebox, loading the shuttle into the SEM/FIB, and then opening the sample again via remote control. These solutions are not ideal because they're very expensive, have a variety of limitations on sample size, stage travel, and signal strength, and are high tech solutions prone to costly malfunction. These drawbacks highlight the demand for a more practical and efficient approach.The presented prototype, Noble Dome, addresses the challenge of loading air-sensitive samples into SEM/FIB instruments with a practical and innovative approach. The device eliminates the need for an intermediary glove box and inert gas transfer shuttle, allowing direct sample transfer onto the stage in an oxygen-free environment. The results demonstrate Noble Dome's efficacy in preserving sample integrity by minimizing atmospheric exposure, as evidenced by the minimal changes observed in surface topography and composition compared to samples exposed to atmosphere. Noble Dome enables research on reactive samples, used to pursue a carbon-free future. Figure 1

Screening and Stress Responsive Characteristics of Potential Hyperaccumulator of Pb, Zn, and Cd Compound Heavy Metals

To screen for Pb, Zn, and Cd composite heavy metal hyperaccumulator plants, a survey, sampling, and analysis of dominant plants in typical lead-zinc mines and smelter areas in Baoji City were conducted. Potential Pb, Zn, and Cd composite heavy metal hyperaccumulator plants were initially screened, and a pot experiment of soil cultivation was carried out to observe the response characteristics of chlorophyll （chlorophyll a, chlorophyll b, carotenoids, and total chlorophyll）, antioxidant enzymes （SOD, CAT, and POD）, and other physiological indicators （MDA and proline） under the stress of Pb, Zn, and Cd composite heavy metals. A field experiment was also conducted to further verify and determine their enrichment ability for Pb, Zn, and Cd composite heavy metals, aiming to provide scientific basis and technical support for the remediation of Pb, Zn, and Cd composite heavy metal-polluted soil. The field survey revealed that Symphytum officinale L. met the international hyperaccumulator plant index requirements for the enrichment of Pb, Zn, and Cd, with enrichment quantity, bioconcentration factor （BCF）, and transfer factor （TF） all meeting the requirements. It was a potential hyperaccumulator plant for Pb, Zn, and Cd composite heavy metals. The soil cultivation pot experiment showed that as the gradient of Pb, Zn, and Cd composite heavy metal stress increased, the content of chlorophyll a, chlorophyll b, and total chlorophyll in S. officinale L. leaves gradually decreased, causing disruption to the plant's photosynthetic system when the gradient was greater than or equal to IV. The chlorophyll content in Ricinus communis L. leaves exhibited a "low-stimulation-high-inhibition" phenomenon, while excessive stress stimulated the activation of its own protective systems, leading to reduced toxicity. In addition, there were significant differences （P < 0.05） in the content of chlorophyll a, chlorophyll b, carotenoids, and total chlorophyll between S. officinale L. and R. communis L. both compared to the control treatment and between stress gradients. The SOD activity in the leaves of S. officinale L. and R. communis L. showed a trend of increasing first, then decreasing, and then increasing. The CAT activity in the leaves of S. officinale L. exhibited a "low-stimulation-high-inhibition" effect, whereas the CAT activity in the leaves of R. communis L. showed a trend of continuous decrease. The POD activity in the leaves of S. officinale L. generally increased, whereas in the leaves of R. communis L., it increased first, then decreased, and then increased. The MDA content in the leaves of S. officinale L. generally decreased, whereas in the leaves of R. communis L., it exhibited an upward trend. In addition, whether compared to the control between stress gradients, there were significant differences （P < 0.05） in the SOD, CAT, POD, MDA, and proline content of S. officinale L. and R. communis L. The field experiment results indicated that S. officinale L. could meet the hyperaccumulator plant index requirements for the enrichment of Pb, Zn, and Cd, making it a potential germplasm resource for Pb, Zn, and Cd composite heavy metal hyperaccumulator plants. It can be an ideal choice for the remediation of Pb, Zn, and Cd composite heavy metal-polluted soil.

High-density sampling of soil heavy metals in the upper Bailang River basin: contamination characteristics, sources, and source-oriented health risk assessment.

Heavy metals (HMs) seriously harm soil environment and threaten crop quality and human health. The aim of the study was to investigate the characteristics, quantify the sources and assess the risks of HMs in soil of upper Bailang River Basin (UBRB). The results indicated that the soils in UBRB were at a non-polluted level and posed a low ecological risk to the environment as a whole. The main pollutants were Ni and Cr obtained by indices Pi and Igeo. Based on the consideration of toxicity, the fuzzy comprehensive evaluation model and Ei index revealed that Hg and Cd were dominating pollutants and ecological risk factors of soil in UBRB. The positive matrix factorization model ascertained five potential sources of soil HMs, namely, plastic processing, energy activities, parent material, transportation and agriculture mixed source and industrial manufacturing, with contribution rates of 17%, 7%, 15%, 29% and 32%, respectively. Natural source primarily determined the non-carcinogenic risk for all populations, accounting for about 43% of the total risk. Industrial manufacturing mainly determined the carcinogenic risk, accounting for about 45%. For adults, the risk was acceptable for most of the sample points. For children, potential non-carcinogenic risks were present in 13.19% of the sample sites, which were mainly located in the west, and unacceptable carcinogenic risks were present in 57.21% of the sample sites, which were mainly concentrated in the western and central parts.

Stress related magnetic imaging of iron-based metallic glass produced with laser beam powder bed fusion

Additive manufacturing makes the production of bulk metallic glasses possible in thicknesses exceeding the critical casting thickness. However, a crucial challenge is the build-up of thermally induced stress, often resulting in printed parts suffering from cracking. In this study, the process parameters are optimised for printing soft-magnetic metallic glass samples of an Fe-based alloy (Fe73.8P10.6Mo4.2B2.3Si2.3C6.7), using laser beam powder bed fusion. In addition, the structural and magnetic properties of as-received and heat-treated powder are investigated and compared to those of the printed samples. Kerr microscopy is used for imaging the magnetic domains on single track cross-sections produced on top of a polished printed sample. This reveals the shape of the melt pool of a single laser track, as well as the magnetic domains around it and in other regions of the printed sample. The shape and size of the magnetic domains reflect the residual stress in the sample through the effect of magneto-elastic coupling. This magnetic contrast could be used to get further insights into how to control the development of stress during the printing process.

High energy absorption design of porous metals using deep learning

Due to its remarkable energy absorption properties, porous metals have widespread applications in engineering. However, the high randomness of pore morphology greatly hinders the effective design and analysis of high energy absorption structures. To address this challenge, this paper first introduces a deep learning-based framework for high energy absorption-oriented design of random porous metals structures. The framework comprises two steps: (i) a generator powered by Wasserstein deep convolutional generative adversarial network is developed to swiftly generate a vast design space (∼one million samples) of porous metals with real random pore morphology. (ii) an inverse search strategy based on convolutional neural network is applied to quickly pick out the optimal structure with the best energy absorption from the design space. Results show that the optimal energy absorption is about 17.71 % higher than the maximum value of initial structures from CT scan. Additionally, a 575-fold increase in computational efficiency is achieved compared to the traversal search using finite element method. Subsequently, the deformation process of the optimal structure is analyzed focusing on the pore morphology and compression performance, showing that random porous metals with uniformly sized pores are capable of withstanding higher stress under the same strain and exhibit no yield band during compression. Inspired by this, a structural homogenization method is introduced and validated to create porous metal structure with stable microstructure evolution, extended plateau stress and high energy absorption.

In-situ composition analysis during laser powder bed fusion of Nd-Fe-based feedstock using machine-integrated optical emission spectroscopy

Powder bed fusion of metals using a laser beam (PBF-LB/M) is a widely used additive manufacturing (AM) technique that enables the material-efficient fabrication of complex geometries in metallic parts. However, achieving high-quality parts with desired properties heavily depends on variances in the manufacturing process and powder composition, making quality control an indispensable aspect of almost all applications. Today, mainly grayscale imaging, photodiodes, or pyrometry are employed, whereas in-situ recording of chemical (compositional) information has rarely been done during PBF-LB/M. This pilot study uses Nd-Fe-B as a compositional sensitive model material to explore the feasibility of in-situ optical emission spectroscopy (OES) for elemental analysis of metallic samples during PBF-LB/M, validated by ex-situ analysis. Our results show that the Boltzmann-corrected local emissivity of the Fe and Nd lines in the plume is a reliable indicator for determining the temperature and elemental material concentration voxel-wise, which could enable a digital 3-D reconstruction of the material composition of a printed part in the future.

Determination and study of correlations of relative sensitivity factors in metal and metal oxide samples by glow discharge mass spectrometry

The determination of relative sensitivity factor (RSF) plays a crucial role in achieving accurate quantitative analysis in glow discharge mass spectrometry (GD-MS). In this study, the RSF of typical elements in 14 metal and metal oxide matrices were determined, and their correlation with discharge parameters, matrix effects, the first ionization energies and sample shapes were investigated. It was found that discharge gas flow exerted a minor influence on RSF values in a nickel (Ni) metal sample, whereas discharge current significantly affected RSF, with variations up to 57.00 % for cobalt (59Co). The results revealed that matrix effects were more pronounced in metal oxides, with the relative standard deviation (RSD) of RSF for typical elements ranging from 25.17 % to 101.04 %. RSF values for the same element across different metal oxides showed a correlation with lattice binding energy (U0). Particularly, RSF values for 12 elements including 23Na, 27Al, 28Si, 45Sc, 52Cr, 56Fe, 59Co, 88Sr, 130Te, 138Ba, 139La and 140Ce within 7 metal oxides showed a significant correlation with U0 of the metal oxides. In terms of sample shape, pin samples generally yielded higher RSF values than flat samples in both metals and oxides. RSF accuracy was confirmed with standard samples of zirconium (Zr 73 MR10002 and Zr IARM 705–18) and iron oxides (Fe2O3-1 and Fe2O3-2) with relative errors within 17.50 % except for 12C. Subsequently, these RSF values were effectively utilized for the quantitative analysis of samples collected from the China Space Station (CSS). This comprehensive analysis elucidates the multifaceted influences on RSF values, enhancing the precision of trace element quantification in GD-MS.

Laser spot overlap in scanning laser ablation ICP-MS analysis: Impact on analytical signal and properties of the generated aerosol

The aim of this study was to determine whether the degree of pulse overlap affects the analytical response of LA-ICP-MS when utilized in scanning mode. The investigation focused not only on the analytical signal but also on the properties of the generated aerosol and the morphology of ablation craters. Ablation was carried out using a nanosecond ablation system on single-element samples of metals and metalloids, specifically Cr, Hf, Sb, Si, Ta, and W. Pure single-element standards were selected to eliminate elemental fractionation and ensure the chemical composition of the generated aerosol was consistent across all particle sizes. The effect was studied on the surfaces of the samples prepared in various ways, including polished and two types of roughened finishes. It was found that the degree of laser pulse overlap significantly influences the quantity of generated particles, their size, and consequently the measured analytical signal, altering it by tens of percent. Slightly different properties were observed in the groups of metal and metalloid samples. For metals, an increasing overlap of pulses resulted in a decrease in the analytical signal across all types of surfaces. For metalloids, the results were different on polished surfaces. The study shows that adjusting the pulse overlap by combining the scan speed and laser repetition rate can have a significant effect on the LA-ICP-MS analysis results.

TINGKAT PENCEMARAN LOGAM Cd, Fe, Cr DAN Cu AIR SUMUR GALI DI Eks-TPA TALANG GULO KOTA JAMBI

Former solid waste disposal at Talang Gulo TPA Jambi City implements a waste management system using a controlled landfill. Leachate and rainwater absorb into the soil and accumulate to become polluted groundwater. Furthermore, the polluted water flows into the dug well water and can reduce the quality of the dug well water. The aim of this study is to determine the heavy metal pollution index of residents' dug well water and the influence of the distance between the ex-TPA and dug well water. This research method is purposive sampling based on the distance of heavy metal sample points, namely 70 m, 230 m and 300 m. Sample analysis used an Atomic Absorption Spectrophometer (AAS) in the laboratory. The results were classed and indexed (C/P), the groundwater was very lightly contaminated with Cd (<0.1), heavily contaminated with Fe (0.51-0.75), very lightly contaminated with Cr (<0.1), and moderately contaminated with Cu (0.26-0.50). Based on the R value of the four metals, it shows that there was a very high influence between the distance between the well water sample and the former solid waste disposal leachate product.

Analysis of Results of Impact Bending Tests of Base Metal Samples and Welded Joints of Pipes From Low-Carbon Pipe Steels

Analysis of Results of Impact Bending Tests of Base Metal Samples and Welded Joints of Pipes From Low-Carbon Pipe Steels

Studying the Reasons behind the Occurrence of Cracks in the Bucket Elevator in the Lebda Cement Factory

Bucket elevators always face problems during the accumulation of loads. When buckets are damaged, the bucket elevator breaks down. Replacing or repairing damaged buckets increases overall maintenance costs; it takes technicians at least several days, depending on how severe the damage is, which will result in decreased productivity and increased downtime. The main goal of this paper is to find out the reason for the cracks that occur at the edges of the bucket conveying cement in the Al- Lebda Cement Factory. According to the manufacturer's catalogue, the material of the bucket is made of EU EN S235JR steel. To study this problem, we conducted a series of tests on samples of the bucket's metal, including chemical composition analysis, tensile strength testing, hardness testing, and microscopic examination. We then compared the results of these tests to the standard specifications for the S235JR steel grade. The results of bucket samples showed the carbon content was C 0.1107 Wt. %, yield strength was 350 N/mm2, ultimate tensile strength was 445 N/mm2 and hardness test was 77HRB, and the metallurgical analysis indicated an irregular distribution of the grain boundaries with, the accumulation of cementite in several areas. It should be noted that the temperature of the cement was not taken into consideration in this study.

Local and quantitative measurement of mechanical properties by electrical-nanoindentation in situ SEM: Application to a multi-phase AgCuPd alloy

Nanoindentation has now become the key technique for measuring the mechanical properties of materials at small scales. However, the quantitative and accurate processing of nanoindentation data relies on a physical quantity that is not directly available: the contact area (Ac) between the indenter tip and the sample under test. In complex systems, determining Ac is challenging due to the limitations of standard methods: analytical models have restricted validity domains (sample homogeneity and rheology), and post-mortem observations of residual imprints are time-consuming, do not appraise property gradients and cannot be applied to materials with significant elastic recovery.In this paper, a comprehensive methodology is proposed to continuously measure contact area during indentation. The proposed methodology, referred to as electrical-nanoindentation (ENI), is based on real-time monitoring of the electrical contact resistance (ECR). The protocol only requires mechanical and electrical calibrations of the indenter tip on reference materials, leading to one-to-one relationship between ECR and contact area. An original approach is also proposed to deal with the presence of surface passivating layers that generally disturb ECR measurements. As an illustration, the methodology is applied to the characterization of a multi-phase alloy (MPA) composed of silver, copper and palladium. This alloy raises the same challenges as those usually faced by nanoindentation in advanced metallurgy: heterogenous distribution of individual phases at the micro-scale, composite response of a complex mixture of hard/stiff and ductile/soft phases, … In addition, the ohmicity of contact is disturbed by surface passivating layers. Despite these numerous hindrances, the proposed methodology is successfully applied to this material. The evolution of contact area is compared with standard methods: an impressive accuracy of <2% standard-deviation is achieved when compared to post-mortem observations. The elastic moduli and hardnesses of individual phases are then accurately extracted. In addition, in order to gain in spatial definition, the ENI set-up is integrated into a scanning electron microscope (SEM), enabling indent positioning with a precision close to 100 nm.Two challenges are successfully met with the ENI methodology. On a mechanical point of view, the response of individual phases can be identified despite the complex rheology of heterogeneous materials, proving the approach applies to all mechanical behaviors (sink-in or pile-up rheologies, homogeneous or heterogeneous materials, with or without elastic recovery, …). On an electrical point of view, even if contact ohmicity is the only requirement of the methodology, it is possible to identify and overcome deviations from contact ohmicity induced by surface passivation. In particular, the non-linear resistive contribution of insulating layers fades during indentation thanks to its dependence as the reciprocal of the square of contact radius. The present work provides the keys to monitoring the contact area on any metallic sample, whether oxide-free or oxidized, making this methodology a promising alternative to standard methods.

Cryogenic temperature 3D mapping via a distributed temperature sensor with centimeter resolution

We conduct 3D mapping of cryogenic temperatures via a Raman-based distributed temperature sensor, employing standard telecom single-mode fibers and polarization-independent superconducting nanowire single photon detectors (SNSPDs). By coiling a test fiber around various stages of a liquid helium cooled cryostat, our device demonstrates a lower temperature sensing limit of (48 ± 2) K, below the nitrogen boiling point. This achievement is made possible by the low dark count rates of SNSPDs, as validated by theoretical simulations. Furthermore, we utilize our device to map cryogenic temperatures on the 350 cm2 surface of a specially designed hollow cylindrical aluminum sample, accommodating approximately 2 m of standard single-mode optical fiber. During nitrogen cooling, we monitor the temporal evolution of the spatially dependent temperature gradient on the metallic sample with a temporal sampling down to one minute. Fiber-based distributed temperature sensing with centimetric spatial resolution can be effectively applied for 3D mapping at cryogenic temperatures of superconducting, quantum computing and aerospace instrumentation.

How to perform corrosion experiments for proton exchange membrane water electrolysis bipolar plates

Ex-situ corrosion experiments are very common to identify the suitability of metallic materials for various applications. While for proton exchange membrane (PEM) fuel cells the US Department of Energy (DoE) gives a clear guidance on how to perform corrosion experiments, no such guidance exists for PEM water electrolyzer (PEMWE) applications. For the latter, much higher anodic potentials (when compared to fuel cells) of up to +2 V vs. RHE must be considered for bipolar plates. Consequently, in aqueous electrolytes oxygen evolution via water splitting takes place in parallel and the two processes corrosion vs. oxygen evolution cannot easily be separated. We herein demonstrate how corrosion experiments for PEMWE applications can be performed and ascribe the contribution of oxygen evolution during such experiments. Together with the shown comprehensive surface analysis of the metallic sample and analysis of the electrolyte via ICP-MS a clear picture of the stability of 316L stainless steel under electrolysis conditions is given. The described method allows both, the evaluation of metals and alloys as well as coatings on different metals for electrolyzer applications.

Waste heat recovery from exhaust gases using porous metal fins: a three-dimensional numerical study

Abstract The objective of this study is to investigate the impact of different porous metal samples on the hydro-thermal characteristics of a single cylinder with porous fins using computational fluid dynamics. Commercially used porous samples with pore densities of 10, 20, and 40 PPI were used in this study for heat recovery from exhaust flue gas. The three-dimensional computational domain with porous aluminium fins attached to a tube over which high-temperature exhaust gas flows in a crossflow arrangement mimics a waste heat recovery system. Computations were performed at Reynolds number of 6000-9000, using the realisable κ-ϵ turbulence model. Three fin diameter to tube diameter ratios (Df/D = 2, 2.5, and 3) were considered. The local thermal non-equilibrium model is implemented for energy transfer, as it is more accurate for a high-temperature gradient scenario in a waste heat recovery system. The foam sample with the highest pore density was observed to have the highest pressure drop due to low permeability. A maximum heat transfer and Nusselt number were achieved for a 40 PPI foam sample due to a reduced flow rate inside the porous zone. The overall performance of metal foam samples at varying fin diameters was evaluated based on the area goodness factor (j/f) and a heat transfer coefficient ratio to pumping power per unit heat transfer surface (Z/E). Analysis of these two parameters suggests using 20 PPI foam at Df/D = 2.

Low-cost visible spectrophotometer for detecting absorption and emission in metallic blends of colorful samples solution

The innovative, affordable assembled visible spectrophotometer employed in this study aims to analyze the absorption and emission of colorful metallic blends of colorful samples solution. It features a tungsten white light bulb source, an ammeter as a detection element, a digital voltmeter, a diffraction grating for light dispersion, a converging lens for light collimation, and filters of various wavelengths (blue, red, yellow, and yellow-green). The light bulb source was powered by a standard supply set at 6 V. Using metallic solutions of chromium chloride (CrCl3) and copper sulphate (CuSO4) with different filter wavelengths, the performance was assessed. The transmittance and absorbance of these metallic solution samples exhibit a linear relationship with approximately 3 % deviation compared to results from a commercial UV–VIS spectrophotometer (DR-6000). Similar investigations were conducted with equivalent quantities of CuSO4, CrCl3, and nickel chloride (NiCl2) solutions, showing a discrepancy ranging from 2 % to 8 % when compared with the commercial UV–VIS spectrophotometer. Therefore, in low-income countries like Ethiopia, colorful metallic solution samples can be effectively analyzed using the newly designed low-cost spectrophotometer.

RESEARCH ON THE RELATIONSHIP BETWEEN THE THICKNESS AND THE STRUCTURAL CONDITION OF ROLLED METAL FROM LOW-CARBON LOW-ALLOY STEEL 10G2FB

When choosing steels for the design of high-rise and long-span buildings with increased load-bearing capacity, it is advisable to give preference to thick rolled steel from low-carbon, low-alloy steels, since it, with the same level of strength as construction steels, has a higher level of plasticity. At the same time, the problem of using thick rolled steel from low-carbon, low-alloy steels in the construction industry are the anisotropy of the rolled metal properties, which can increase with an increase in the thickness of the rolled metal. Currently, in Ukraine, controlled rolling is one of the most promising technologies of high-temperature thermomechanical processing for the production of thick rolled metal from low-carbon, low-alloy steels. At the same time, with an increase in the thickness of the rolled metal, which is produced with this technological scheme, the effect of the regulated formation of the structural state decreases due to the influence on the temperature of the surface layers of the rolled metal, the thermodynamic state of the inner layers and the inability of the rolling equipment available at domestic enterprises to deform the metal over the entire cross-sectional area. Therefore, the task of obtaining such a structural state in the thick sheet metal roll, which will ensure the reduction of the anisotropy of the properties, which will allow the use of such rolled metal in the construction industry, is urgent. Purpose of the article is to study of the structural state of low-carbon low-alloy steel 10G2FB, which was produced using the technology of controlled rolling, depending on the thickness of the rolled metal. Conclusion. The relationship between the structural state and the thickness of rolled metal from low-carbon low-alloy steel 10G2FB, which was produced by controlled rolling technology, was studied. It was established that with the increase in thickness, the percentage content of the ferrite component increases with a simultaneous decrease in the percentage content of the pearlite phase. It is shown that changes in the formation languages of structural components begin with an increase in the thickness of the rolled metal over 30 mm, which is explained by the influence of the temperature of the inner layers on the processes of forming the structural state, namely, with an increase in the thickness of the rolled metal, the thermodynamic rate of phase transformations in the middle layers of the rolled metal samples decreases. This conclusion is confirmed by two factors: firstly, an increase in the size of pearlite colonies, and secondly, a change in the morphology of the cementite framework of pearlite colonies from zigzag (thickness 16...30 mm) to ribbon (thickness 40...100 mm).

Novel Cardiovascular Stent Based on Hibiscus-Aestivation-Inspired Auxetic Unit Cell

Conventional stents have some limitations, such as dogboning and foreshortening, that can lead to issues like in-stent restenosis and thrombosis. Negative Poisson's ratio stents, called auxetic stents, are known as a solution to overcome these challenges due to their unique deformation mechanism. Auxetic stents are scale-independent, and their behavior depends solely on their geometry. In this study, a novel auxetic unit cell inspired by aestivation mechanism of the Hibiscus flower is designed, developed, and implemented in plane, and a tube to achieve a novel NPR cardiovascular stent. The stent structure is fabricated using two methods, including a novel 7-axis laser cut method capable of producing stents the same size as human blood vessels from an SS 316 L tube, and fused deposition modelling 3D printing at a scale 20 times larger than the metallic sample using PLA filaments. Novel laser cut effectively overcame some challenges in laser cutting stents, including HAZ and thermal shocks. SEM images are taken from the laser cut sample, and the manufacturing method's accuracy and surface quality are investigated. Fabricated metallic and polymeric stent samples proposed negative Poisson's ratio equal to 0.89 with an average of 4.38 and 14.8% errors, respectively, compared with finite element analysis. Finally, the structure's stress, strain energy distribution pattern, and unit cell distribution have been examined. Furthermore, the stent thickness parameter, drug release patch application, and stent implementation process are also investigated using FEM method. Proposed geometry in stent application showed solutions to conventional positive Poisson's ratio stent challenges.

ИДЕНТИФИКАЦИЯ И ВЫЯВЛЕНИЕ ПРИРОДЫ НЕМЕТАЛЛИЧЕСКИХ ВКЛЮЧЕНИЙ В НЕПРЕРЫВНОЛИТОЙ ЗАГОТОВКЕ ИЗ СТАЛИ 26ХГМФ

The article presents data on the identification of inclusions in metal samples of continuously cast blanks. The counting and identification of inclusions was carried out using the automatic particle analyzer EDAX Particle/Phase Analysis Software. The study established the predominant type of non-metallic inclusions. It is shown that a large proportion of inclusions are endogenous and have a steelmaking nature of origin. It is shown that inclusions are unevenly distributed over the section of the cast workpiece, and the axial volumes of the workpiece have the maximum contamination. At the same time, the distribution of oxide and oxysulfide inclusions is opposite, which is associated with the course of liquation processes during solidification.

First X-ray spectral ptychography and resonant ptychographic computed tomography experiments at the SWING beamline from Synchrotron SOLEIL.

X-ray ptychography and ptychographic computed tomography have seen a rapid rise since the advent of fourth-generation synchrotrons with a high degree of coherent radiation. In addition to quantitative multiscale structural analysis, ptychography with spectral capabilities has been developed, allowing for spatial-localized multiscale structural and spectral information of samples. The SWING beamline of Synchrotron SOLEIL has recently developed a nanoprobe setup where the endstation's first spectral and resonant ptychographic measurements have been successfully conducted. A metallic nickel wire sample was measured using 2D spectral ptychography in XANES mode and resonant ptychographic tomography. From the 2D spectral ptychography measurements, the spectra of the components of the sample's complex-valued refractive index, δ and β, were extracted, integrated along the sample thickness. By performing resonance ptychographic tomography at two photon energies, 3D maps of the refractive index decrement, δ, were obtained at the Ni K-edge energy and another energy above the edge. These maps allowed the detection of impurities in the Ni wire. The significance of accounting for the atomic scattering factor is demonstrated in the calculation of electron density near a resonance through the use of the δvalues. These results indicate that at the SWING beamline it is possible to conduct state-of-the-art spectral and resonant ptychography experiments using the nanoprobe setup.