Advanced Materials Processing Research Articles

Deep Learning Model to Predict Ice Crystal Growth.

The demand for highly specific and complex materials has made the development of controllable manufacturing processes crucial. Among the numerous manufacturing methods, casting is important because it is economical and highly flexible regarding the geometry of manufactured parts. Since solidification is an important stage in the casting process that influences the properties of the final product, the development of a controllable solidification process using modeling methods is necessary to create superior structural properties. However, traditional modeling methods are computationally expensive and require sophisticated mathematical schemes. Therefore, a deep learning model is proposed to predict the morphology of the dendritic crystal growth solidification process, along with a reinforcement learning model to control the solidification process. By training the deep learning model with data generated using the phase field method, the solidification process can be successfully predicted. The crystal growth structures are designed to be altered by adjusting the degree of supercooling in the deep learning model while implementing reinforcement learning to control the dendritic arteries. This research opens new avenues for applying artificial intelligence to the optimization of casting processes, with the potential to utilize it in the processing of advanced materials and to improve the target properties of material design.

Investigations and Applications in Advanced Materials Processing

Advanced structural materials have been widely used in modern industries, such as mining, building, aerospace, chip manufacturing and surface engineering [...]

Marketing analysis of the functioning environment of agrarian enterprises

Before the full-scale invasion of the Russian Federation, the agricultural sector of Ukraine developed dynamically and played a leading role in ensuring domestic and global food security, employment of the population, and the formation of foreign exchange earnings from product exports and state budget revenues. The active phase of the war on the territory of the country radically changed the conditions for the functioning of agricultural enterprises. The purpose of the article is to characterize and assess the influence of certain elements of the external environment on the activities of agricultural enterprises. The research is based on the dialectical method of learning economic processes and the following methods are used: monographic, abstract-logical, PEST analysis, SWOT analysis. The study analyzed the works of Ukrainian scientists on the problems of the functioning of agricultural enterprises and identified the main political, economic, social and technological factors of the influence of the external environment on their activities in the conditions of martial law. It has been established that the political factors of the environment affect the activity of agricultural enterprises mainly positively, economic factors have a mainly negative effect on them, and social and technological factors have different directions. The assessment of the main strengths and weaknesses, opportunities and threats of the environment of agricultural enterprises showed the existence of prerequisites for the quantitative growth of gross volumes of their production and the need to develop a comprehensive strategy of agricultural policy for long-term growth in the conditions of post-war recovery, the key tasks of which should be ecologically oriented nature management, the development of dual education for training highly qualified workers, increasing the volume of production and export of organic and ready-made food products, technical and technological modernization of the production base. Priority stimulation of investments in increasing the volume of production of organic food products, development of primary and advanced processing of agricultural raw materials inside the faucet is proposed. The practical significance of the research lies in the fact that its results can be used by state institutions responsible for the development of the agrarian sphere, when developing a strategy for its development and substantiating measures for its implementation, by agricultural enterprises - when developing marketing strategies, by scientists - when further researching the problems of the influence of the external environment on the development of agricultural production

Femtosecond laser processing of advanced technical materials

Ultra-short pulsed laser ablation may be used for high-precision machining with very low thermal influence on the processed materials. Due to this reason, lasers are increasingly used for processing of advanced materials, such as titanium alloys, nickel-based alloys or steel, every year. In this study, four advanced technical materials were analysed and compared under femtosecond laser irradiation with three different wavelengths. The main laser-material interaction parameters were identified, namely the ablation threshold and removal efficiency parameters. Higher removal rates were found for Ti6Al4V alloy with all three harmonic wavelengths. To increase process productivity, a method of increasing the repetition rate and scanning speed was presented. With the maximum repetition rate, the productivity increased five-fold with a similar removed depth and surface quality. Finally, the suitability of the identified parameters with regard to quality and productivity was demonstrated for fabrication of two complex structures – honeycomb and dot – which has the potential to improve friction properties of advanced materials.

An in-situ study of static recrystallization in Mg using high temperature EBSD

It has been a common method to improve the mechanical properties of metals by manipulating their microstructures via static recrystallization, i.e., through heat treatment. Therefore, the knowledge of recrystallization and grain growth is critical to the success of the technique. In the present work, by using in-situ high temperature EBSD, the mechanisms that control recrystallization and grain growth of an extruded pure Mg were studied. The experimental results revealed that the grains of priority for dynamic recrystallization exhibit fading competitiveness under static recrystallization. It is also found that grain boundary movement or grain growth is likely to show an inverse energy gradient effect, i.e., low energy grains tend to swallow or grow into high energy grains, and grain boundaries of close to 30° exhibit superior growth advantage to others. Another finding is that {10–12} tensile twin boundaries are sites of hardly observed for recrystallization, and are finally swallowed by adjacent recrystallized grains. The above findings may give comprehensive insights of static recrystallization and grain growth of Mg, and may guide the design of advanced materials processing in microstructural engineering.

Analytical modeling and experimental investigation of the particle scale energy absorption mechanism in laser-based directed energy deposition

Despite the tremendous application potential of advanced materials processing using laser-based directed energy deposition (DED), the reproducibility of metallic parts manufactured by this technology is limited due to the complex laser-material interactions during the material deposition process. Energy absorption and radiation by the powder stream attenuate the laser beam energy, thus affecting the actual energy delivered into the molten pool. The geometric and mechanical property irregularities in DED are directly related to the uneven energy input during continuous layers fabrication. This work reports a major advance in the particle scale energy absorption in DED as well as its relationship with the injected powder characteristics and process conditions (laser power, scanning speed, and powder feed rate). A novel simplified analytical model to analyze the effective absorptivity of continuous wave fiber laser is presented based on the stepwise heating method. The analytical model solution suggests that the effective absorptivity of the powder materials shows a slight decrease, from 8 % to 6 %, when the incident laser power increases from 250 W to 350 W. The model solution is verified using data from in-situ absorption measurements with a power meter. Theoretical calculations and experimental results showed that the energy absorption of high-density laser power in DED is not consistent, but negatively correlated with power input. Furthermore, we observed that lower powder temperature enhances energy absorption, which leads to the proposal that inverse bremsstrahlung absorption is the photophysical mechanism responsible for energy absorption by powder stream in DED additive manufacturing.

Study on preparation and wear resistance of NiCrBSi-WC/Co composite coatings by pulsed magnetic field assisted supersonic plasma spraying

Magnetic field-assisted material processing not only offers excellent mechanical properties of the material but also hinders the formation of defects because of its no contiguity to the material. In this work, the effect of the integration of magnetic field with ultrasonic plasma spraying technology to deposit composite coatings was investigated. NiCrBSi coatings with reinforced WC/Co ceramic particles were deposited using a 5T pulsed magnetic field-assisted supersonic plasma spraying process. The film integrity, mechanical properties, and wear resistance outperformed the traditional plasma spraying coating. The stirring effect caused by the pulsed magnetic field reduced the thermal stress and accelerated the solidification. Nickel-based coatings with a pulsed magnetic field exhibited better wear resistance and high bonding strength. It is attributed to the refinement of grain, even distribution of hard ceramic phase, and dense internal structure. This process opens a new gateway for developing advanced material processing and practical application of high-performance coatings.

Modeling Electrostatics and Low-Field Electron Mobility of GaN FinFETs

Gallium nitride (GaN) high electron mobility transistors (HEMTs) are currently being used for RF applications due to the intrinsically high saturation velocity and high mobility of GaN compared to both Silicon and SiC. However, GaN HEMTs suffer from a variety of issues, such as a lack of E-Mode operation and non-linearity, which impacts their widespread adoption in the RF and low-voltage switching devices. Recent advances in material processing, high aspect ratio epitaxial growth, and etching methods has led to an increased interest in 3-D GaN nanostructures such as AlGaN/GaN MIS FinFET wherein a layer of Al <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> surrounds the AlGaN/GaN fin. Theoretical calculations of transport properties of AlGaN/GaN FinFETs are scarce compared to those of their planar HEMT counterparts. This work employs for the first time self-consistent solution of the coupled 1-D Boltzmann – 2-D Schrödinger – 3-D Poisson problem to yield the channel electrostatics and the transport characteristics of AlGaN/GaN MIS FinFETs. The low field electron mobility in the quasi-1-D region is calculated, using 1-D ensemble Monte Carlo method, as a function of temperature and fin width. Acoustic, piezoelectric and polar optical phonon scattering, and interface roughness scattering at the AlGaN/GaN interface, are incorporated in the theoretical model. Our simulations suggest that E-mode FinFETs can be achieved in ultranarrow fin channels. As suggested experimentally, we confirm via simulation experiments that strain relaxation increases the sheet resistance of the channel.

3D-Printed Satellite Brackets: Materials, Manufacturing and Applications

Brackets are the load-bearing components in a satellite. The current age of satellites comprises specific brackets that set out as a link between the bodies of the satellite, reflector parts, and feeder facilities mounted at its upper end. Brackets are used to carry loads of the satellite body frame, supporting elements, batteries, and electronic goods. The article explicates the various brackets used in satellites and aircrafts. The strength of the bracket is of utmost importance since it is an important load supporting member in several assemblies of aircraft and satellites. In addition to the mechanical strength, the weight of the bracket is a major concern as it adds to the total weight of the aircraft and satellite. Thus, weight savings of brackets can be of paramount importance and Additive Manufacturing (AM) is found as an overall solution to achieve the same. Hence, in addition to various brackets used in satellites, the article presents an exhaustive review of the processing of various advanced functional materials using various AM techniques to make high strength-to-weight ratio satellite brackets. The use of DFAM by various satellite manufacturers globally for optimizing the structure of the brackets resulting in a significant weight saving of the brackets is also presented in the article.

Editorial for the Special Issue “Reviews and Advances in Materials Processing”

In the area of Materials Science and Engineering, the tetrahedron comprising of processing, microstructure, properties and performance as four vertex corners is always key to develop new materials and to convert them to a useful shape for end application with the best properties possible [...]

Rapidly Prepared Nanocellulose Hybrids as Gas Barrier, Flame Retardant, and Energy Storage Materials

Cellulose nanofibril (CNF) hybrid materials show great promise as sustainable alternatives to oil-based plastics owing to their abundance and renewability. Nonetheless, despite the enormous success achieved in preparing CNF hybrids at the laboratory scale, feasible implementation of these materials remains a major challenge due to the time-consuming and energy-intensive extraction and processing of CNFs. Here, we describe a scalable materials processing platform for rapid preparation (<10 min) of homogeneously distributed functional CNF–gibbsite and CNF–graphite hybrids through a pH-responsive self-assembly mechanism, followed by their application in gas barrier, flame retardancy, and energy storage materials. Incorporation of 5 wt % gibbsite results in strong, transparent, and oxygen barrier CNF–gibbsite hybrid films in 9 min. Increasing the gibbsite content to 20 wt % affords them self-extinguishing properties, while further lowering their dewatering time to 5 min. The strategy described herein also allows for the preparation of freestanding CNF–graphite hybrids (90 wt % graphite) that match the energy storage performance (330 mA h/g at low cycling rates) and processing speed (3 min dewatering) of commercial graphite anodes. Furthermore, these ecofriendly electrodes can be fully recycled, reformed, and reused while maintaining their initial performance. Overall, this versatile concept combines a green outlook with high processing speed and material performance, paving the way toward scalable processing of advanced ecofriendly hybrid materials.

Polyethylene and Semiconducting Polymer Blends for the Fabrication of Organic Field-Effect Transistors: Balancing Charge Transport and Stretchability

Polyethylene is amongst the most used polymers, finding a plethora of applications in our lives owing to its high impact resistance, non-corrosive nature, light weight, cost effectiveness, and easy processing into various shapes from different sizes. Despite these outstanding features, the commodity polymer has been underexplored in the field of organic electronics. This work focuses on the development of new polymer blends based on a low molecular weight linear polyethylene (LPE) derivative with a high-performance diketopyrrolopyrrole-based semiconducting polymer. Physical blending of the polyethylene with semiconducting polymers was performed at ratios varying from 0 to 75 wt.%, and the resulting blends were carefully characterized to reveal their electronic and solid-state properties. The new polymer blends were also characterized to reveal the influence of polyethylene on the mechanical robustness and stretchability of the semiconducting polymer. Overall, the introduction of LPE was shown to have little to no effect on the solid-state properties of the materials, despite some influence on solid-state morphology through phase separation. Organic field-effect transistors prepared from the new blends showed good device characteristics, even at higher ratios of polyethylene, with an average mobility of 0.151 cm2 V−1 s−1 at a 25 wt.% blend ratio. The addition of polyethylene was shown to have a plasticizing effect on the semiconducting polymers, helping to reduce crack width upon strain and contributing to devices accommodating more strain without suffering from decreased performance. The new blends presented in this work provide a novel platform from which to access more mechanically robust organic electronics and show promising features for the utilization of polyethylene for the solution processing of advanced semiconducting materials toward novel soft electronics and sensors.

The microstructure evolution and precipitation behavior of TiB2/Inconel 718 composites manufactured by selective laser melting

Additive Manufacturing is an advanced material processing technology emerging in recent years. However, coarse columnar grain structure of additive manufactured metals reduces the performance of the material. Facilitating the columnar to equiaxed transition (CET) has become a research hotspot. In this paper, the equiaxed grain of additive manufactured Inconel 718 was achieved by adding TiB2 particles. Simultaneously, the microstructure evolution and precipitation behavior with nano-TiB2 particles addition were studied. The results show that the grain morphology of Inconel 718 exhibited coarse columnar grains with epitaxial growth and strong <100> texture. When 3 wt% TiB2 was added, the columnar grains became finer, further increased the content of TiB2 to 5 wt%, the equiaxed grains were obtained and the texture intensity decreased significantly. In addition, TiB2 partially melted under the high laser energy changed the phase precipitation behavior of Inconel 718 from chain-like Laves phase to reticulated (γ + M3B2) eutectics, which lead to the hardness increased from 276 HV to 578 HV when 5 wt% TiB2 was added. After heat treatment, the precipitation of high density γ′ and γ″ strengthening phase were promoted the hardness increased by 87% to 516 HV in Inconel 718. However, the hardness of TiB2 reinforced samples showed a little change, which could be attributed to the partial dissolution of M3B2 boride during the heat treatment.

MENUS—Materials engineering by neutron scattering

Materials engineering by neutron scattering (MENUS) at the second target station will be a transformational high-flux, versatile, multiscale materials engineering diffraction beamline with unprecedented new capabilities for the study of complex materials and structures. It will support both fundamental and applied materials research in a broad range of fields. MENUS will combine unprecedented long-wavelength neutron flux and unique detector coverage to enable real-time studies of complex structural and functional materials under external stimuli. The incorporated small angle neutron scattering and transmission/imaging capabilities will extend its sensitivity to larger length scales and higher spatial resolution. Multimodal MENUS will provide crystallographic and microstructure data to the materials science and engineering community to understand lattice strain/phase transition/microstructure/texture evolution in three orthogonal directions in complex material systems under combined extreme applied conditions. The capabilities of MENUS will open new scientific opportunities and meet the research needs for science challenges to enable studies of a range of phenomena and answer the key questions in material design/exploration, advanced material processing, transformative manufacturing, and material operations of national impacts in our daily life.

Metal-Organic Framework Nanosheets (MONs): A Review On Interfacial Syntheses And Applications Of Coordination Nanosheets

Two-dimensional (2D) nanomaterials such as metal-organic nanosheets (MONs) are exceptionally fascinating for electronics, photonics, optoelectronics, spintronics, and magnetism due to their enticing properties such as tuneable structures of ligands and metal complexes, intensify porosity and conductivity as well as successful facile fabrication of larger domains of the 2D materials. Owing to their unique qualities, such as intrinsic electronics and optical attributes, 2D materials have achieved tremendous breakthroughs in the direct applications of MONs. Based on recent research findings, MONs have been regarded as promising materials for surface functioning. At the same time, the intrinsic band structure and electronic properties may be rationally regulated via structural change, which can be the focal point of advanced materials design, processing, and progress. In this context, the potential to utilize different ligands and a vast number of coordinative atoms become important in designing 2D materials to address the tremendous needs of industry players. This review focuses on coordination nanosheets, a type of molecule-based nanosheets. The examples of coordination nanosheets are discussed in Section 1. In Section 2, surveys research on bottom-up coordination nanosheets synthesized through the liquid/liquid and gas/liquid interfacial reactions are discussed. Section 3 discusses the potential applications of coordination nanosheets in nanomaterial science. Overall, this review provides a useful source of information for researchers working on advancing 2D nanomaterials, particularly coordination nanosheets.

Metal-Organic Framework Nanosheets (MONs): A Review On Interfacial Syntheses And Applications Of Coordination Nanosheets

Two-dimensional (2D) nanomaterials such as metal-organic nanosheets (MONs) are exceptionally fascinating for electronics, photonics, optoelectronics, spintronics, and magnetism due to their enticing properties such as tuneable structures of ligands and metal complexes, intensify porosity and conductivity as well as successful facile fabrication of larger domains of the 2D materials. Owing to their unique qualities, such as intrinsic electronics and optical attributes, 2D materials have achieved tremendous breakthroughs in the direct applications of MONs. Based on recent research findings, MONs have been regarded as promising materials for surface functioning. At the same time, the intrinsic band structure and electronic properties may be rationally regulated via structural change, which can be the focal point of advanced materials design, processing, and progress. In this context, the potential to utilize different ligands and a vast number of coordinative atoms become important in designing 2D materials to address the tremendous needs of industry players. This review focuses on coordination nanosheets, which is a type of molecule-based nanosheets. The examples of coordination nanosheets are discussed in Section 1. In Section 2, surveys research on bottom-up coordination nanosheets synthesized through the liquid/liquid and gas/liquid interfacial reactions are discussed. Section 3 discusses the potential applications of coordination nanosheets in nanomaterial science. Overall, this review provides a useful source of information for researchers working on advancing 2D nanomaterials, particularly coordination nanosheets.

High peak/average power picosecond pulsed MOPA system with tapered large mode area double-clad Yb-doped fiber

In this paper, a high peak/average power picosecond pulsed master‑oscillator power‑amplifier (MOPA) system utilizing tapered large mode area double-clad fiber (T-DCF) is presented. In a high average power regime, we report a pulsed MOPA laser system with average power up to 613 W at 20 MHz repetition rate with 50 ps pulse duration (613 kW of peak power and 30.6 μJ pulse energy). In high peak power regime, over 3MW of peak power pulses (at seed source bandwidth) at 1 MHz repetition rate (310 μJ pulse energy and 310 W average) was demonstrated. The outstanding properties of T-DCF for amplification of laser signals to high power/energy levels with maintaining the excellent beam quality open a new horizon for advanced laser material processing.

Crucible considerations in induction furnace degassing

In a number of advanced materials processing applications, including float zone refining of electronic materials, forming of metallic glasses and induction melting of light alloys, oscillatory and non-oscillatory electromagnetic forces associated with the processing application are found to enhance surface shape, nucleation of precipitates, evolution of crystal nucleation sites, segregation of alloy components, grain refinement and degassing [1]--[3]. For cases where the material being processed is containerized and where the time dependence is oscillatory, these forces give rise to acoustic waves which carry energy to the boundaries of the containerized volume leading to a reduction in process efficacy should the container not present the proper acoustic impedance. This paper considers acoustic energy exchange between the molten alloy and the crucible of an induction furnace and the attendant impact on degassing. Tables 1, Figs 4, Refs 11.

Combined sterilization and fabrication of drug-loaded scaffolds using supercritical CO2 technology

The access of biodegradable scaffolds to the clinical arena is constrained by the absence of a suitable sterilization technique for the processing of advanced polymeric materials. Sterilization with supercritical CO2 (scCO2) may circumvent some technological limitations (e.g., low temperature, no chemical residues on the material), although scCO2 can plasticize the polymer depending on the processing conditions used. In this latter case, the integration of the manufacturing and sterilization processes is of particular interest to obtain sterile and customized scaffolds in a single step. In this work, scCO2 was exploited as a concomitantly foaming and sterilizing agent for the first time, developing a one-step process for the production of vancomycin-loaded poly(ε-caprolactone) (PCL) bone scaffolds. The effect of the CO2 contact time on the sterility levels of the procedure was investigated, and the sterilization efficiency was evaluated against dry spores (Bacillus stearothermophilus, Bacillus pumilus and Bacillus atrophaeus). Vancomycin-loaded PCL scaffolds had relevant sustained release profiles for the prophylaxis of infections at the grafted area, even those caused by methicillin-resistant Staphylococcus aureus (MRSA). The biological performance of the scaffolds was evaluated in vitro regarding human mesenchymal stem cells (hMSCs) attachment and growth. Finally, the biocompatibility and angiogenic response of the manufactured sterile scaffolds was assessed in ovo through chick chorioallantoic membrane (CAM) assays.

Degradation of Methylene Blue with Layered Ni-Fe/WO3 Nanostructured, Composite Films Electrodeposited Onto Graphite

Dyes from textile companies, such as methylene blue (MB), stain water bodies and result in harmful environmental effects. They can also change the color of water bodies, which inhibits aquatic photosynthesis and lowers oxygen levels, compromising aquatic health. In order to treat dye contamination in water, several methodologies exist, including electrochemical oxidation with boron-doped diamond, TiRuO2 1 and Ti/Pt2 anodes. In the search for a lower cost anode material and thus a more cost-effective electrochemical oxidation process, a composite photoelectrocatalyst composed of tungsten trioxide, nickel-iron, and graphite was fabricated. Both decolorization and degradation of MB were examined in a chloride mediated electrolyte.Ni-Fe clusters were electrochemically deposited onto a graphite surface using recurrent galvanic pulses. WO3 was then electrochemically deposited through the generation of base method, potentiostatically. Cyclic voltammetry (CV) using an electrolyte containing 10 mM MB in 10 mM phosphate buffer saline and 100 mM potassium chloride at room temperature on screen-printed electrodes identified the region where the Ni-Fe/WO3 graphite composite catalyst resulted in a large anodic current, which included the oxidation of water, chlorine and organic. Electrolysis by chronoamperometry was implemented with and without light, in a single compartment electrochemical cell. The color change was measured using absorbance spectrophotometry. In order to confirm oxidation of total organic, COD measurements provided insight on whether the observed color change was caused by decomposition of MB at the working electrode or conversion to leucomethylene blue, at the counter electrode. Since Ni-Fe can oxidize under electrolysis conditions for MB degradation, the survivability of Ni-Fe underneath WO3 was inspected. Both scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) verified the presence of discrete Ni-Fe islands surrounded by WO3; after 16 hrs of electrolysis at 1.9 V vs Ag changes in the composition as well as the WO3 morphology was observed.Overall, with an increase in the electrolysis time there was a clear change in the electrolyte color. After 2 hours, the coloration of the MB solution dropped by 78% and after 16 hours, 89%. COD analysis confirmed the degradation of methylene blue by the Ni-Fe/WO3 graphite catalyst, and it was enhanced by 100 W/m2 UV light, with less conversion of methylene blue to leucomethylene blue, and an overall more efficient degradation. Acknowledgments: The authors thank The Center for Advanced Materials Processing at Clarkson University for use of their equipment and guidance provided by Hubert Bilan. This work was funded in part by NSF #20-508484 REU Site: Aquatic Sciences, Engineering, and Technology (ASET). Panizza, A. Barbucci, R. Ricotti, G. Cerisola, Separation and Purification Technology, 54 (2007) 382–387.Rodrigues de Oliveira, N. S. Fernandes, J. Vieira de Melo, D. Ribeiro da Silva, C. Urgeghe, C. A. Martínez-Huitle, Chemical Engineering Journal, 168 (2011) 208–214.