Advanced Engineering Materials Research Articles

Synthesis of hierarchical porous carbon scaffold derived from red kidney bean peels for advanced Li–Se and Na–Se batteries

Incorporating selenium into high-surface-area carbon with hierarchical pores, derived from red kidney bean peels via simple carbonization/activation, yields a superior Li–Se battery cathode material. This method produces a carbon framework with 568 m2 g−1 surface area, significant pore volume, and improves the composite’s electronic conductivity and stability by mitigating volume changes and reducing lithium polyselenide dissolution. The Se@ACRKB composite, containing 45 wt% selenium, shows high discharge capacities (609.13 mAh g−1 on the 2nd cycle, maintaining 470.76 mAh g−1 after 400 cycles at 0.2 C, and 387.58 mAh g−1 over 1000 cycles at 1 C). This demonstrates exceptional long-term stability and performance, also applicable to Na–Se batteries, with 421.36 mAh g−1 capacity after 200 cycles at 0.1 C. Our study showcases the potential of using sustainable materials for advanced battery technologies, emphasizing cost-effective and scalable solutions for energy storage.

Achieving excellent mechanical and robust lubrication behavior in the CoCrNi medium-entropy alloy via in-situ graphite

The unsatisfactory wear resistance and lubrication performance of CoCrNi multi-principal elements alloys (MPEAs) have emerged as critical challenges, impeding their extensive utilization as advanced engineering materials, despite their desirable mechanical and physical properties. Incorporating graphite to obtain MPEAs-based self-lubricating composites is believed to improve the wear resistance. However, it is challenging to prepare composites with high strength, large plasticity, and excellent anti-friction performance simultaneously. The present study reports the fabrication of novel CoCrNi MPEA-based self-lubricating composites, consisting of in-situ graphite and high-hardness silicides/carbides as reinforcement, prepared by powder metallurgy and reactive sintering. The 20.6 vol% Gr@CoCrNi–SiC composite exhibits an optimal trade-off between strength and ductility, along with anti-friction and wear resistance which is superior to the reported composites with different solid lubricants. The wear mechanism is attributed to the coordinated deformation mechanism between the CoCrNi FCC matrix and silicides/carbides, and the stabile lubrication effect supported by the structural transformation from the original polycrystalline lattice structure to core-shell nanocomposite structure (similar to diamond-like carbon) of the in-situ graphite. This simple, economical and practical strategy contributes to the development of MPEA self-lubricating composites with excellent comprehensive properties.

Influence of aluminium in wetting characteristics of Zn-Al alloy

In this article, the effect of aluminium in Zn-5 wt%Al alloy is studied after heat treatment at 375 ⁰C focusing particularly on its effect at grain boundaries or grain boundary junctions. The understanding of such behaviour is crucial for microstructural controlling during alloy processing, ensuring better alloy performance for various applications. Using Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD), the microstructural and crystallographic study of the alloy was carried out. The SEM results of the annealed sample show a lenticular-shaped wetting layer corresponding to the lower energy of the grain boundary. It was observed that Zn is distributed throughout the sample, while the concentration of Al is increased at the grain boundaries as evidenced by the elemental spectra. XRD result confirms that no new phases are formed thereby confirming the formation of an Al-rich solid solution at the grain boundary. The absence of new phases indicates that aluminium in the alloy tends to lower grain boundary energy by occupying grain boundary positions, rather than forming a new compound, thereby reaching thermodynamic equilibrium. This study is important for developing advanced engineering materials with solid-state lubrication capabilities, for diverse industrial applications.

Healable, Recyclable, and Upcyclable Gel Membranes for Efficient Carbon Dioxide Separation.

Ionic liquids (ILs) are prized for their selective dissolution of carbon dioxide (CO2), leading to their widespread use in ionogel membranes for gas separation. Despite their advantages, creating sustainable ionogel membranes with high IL contents poses challenges due to limited mechanical strength, leakage risks, and poor recyclability. Herein, we leverage copolymerized and supramolecularly bound ILs to develop ionogel membranes with high mechanical strength, zero leakage, and excellent self-healing and recycling capabilities. These membranes exhibit superior ideal selectivity for gas separation compared to other reported ionogel membranes, achieving a CO2/nitrogen selectivity of 61.7 and a CO2/methane selectivity of 24.6, coupled with an acceptable CO2 permeability of 186.4 Barrer. Additionally, these gas separation ionogel membranes can be upcycled into ionic skins for sensing applications, further enhancing their utility. This research outlines a strategic approach to molecularly engineer ionogel membranes, offering a promising pathway for developing sustainable, high-performance materials for advanced gas separation technologies.

Nanostructured Titanium with Ultrafine‐Grained Structure as Advanced Engineering Material for Biomedical Application

Titanium and its alloys are popular materials for medical application, particularly in implant devices, where high mechanical properties and osseointegration are critical factors for successful implantation. In this work, the progress in the studies of nanostructured commercially pure Grade 4 titanium (nanoTi) is demonstrated, in which an ultrafine‐grained structure with nanoscale grain size is formed using severe plastic deformation processing. Nanostructured Grade 4 Ti has a very high strength, and its physical nature and strengthening mechanisms are analyzed herein. NanoTi proved also to have very high osseointegration during in vivo experiments. At the same time, the highest biofunctionality is demonstrated by the etched nanoTi samples with pronounced surface roughness, the latter being revealed from precise roughness measurements. The present study provided convincing evidence of accelerated bone formation on nanoTi, which is very promising for manufacture of dental and maxillofacial implants.

Periodic spinodal decomposition in double–strengthened medium–entropy alloy

Achieving an optimal balance between strength and ductility in advanced engineering materials has long been a challenge for researchers. In the field of material strengthening, most approaches that prevent or impede the motion of dislocations involve ductility reduction. In the present study, we propose a strengthening approach based on spinodal decomposition in which Cu and Al are introduced into a ferrous medium–entropy alloy. The matrix undergoes nanoscale periodic spinodal decomposition via a simple one-step aging procedure. Chemical fluctuations within periodic spinodal decomposed structures induce spinodal hardening, leading to a doubled strengthening effect that surpasses the conventional precipitation strengthening mechanism. Notably, the periodic spinodal decomposed structures effectively overcome strain localization issues, preserving elongation and doubling their mechanical strength. Spinodal decomposition offers high versatility because it can be implemented with minimal elemental addition, making it a promising candidate for enhancing the mechanical properties of various alloy systems.

Periodic spinodal decomposition in double–strengthened medium–entropy alloy

Achieving an optimal balance between strength and ductility in advanced engineering materials has long been a challenge for researchers. In the field of material strengthening, most approaches that prevent or impede the motion of dislocations involve ductility reduction. In the present study, we propose a strengthening approach based on spinodal decomposition in which Cu and Al are introduced into a ferrous medium–entropy alloy. The matrix undergoes nanoscale periodic spinodal decomposition via a simple one-step aging procedure. Chemical fluctuations within periodic spinodal decomposed structures induce spinodal hardening, leading to a doubled strengthening effect that surpasses the conventional precipitation strengthening mechanism. Notably, the periodic spinodal decomposed structures effectively overcome strain localization issues, preserving elongation and doubling their mechanical strength. Spinodal decomposition offers high versatility because it can be implemented with minimal elemental addition, making it a promising candidate for enhancing the mechanical properties of various alloy systems.

Development and parametric study of reversible motion-wire electrochemical spark machining (RM-WECSM) setup for micro-width curve profile cutting on Al2O3 epoxy nanocomposites

The development of wire electrochemical spark machining setup is always challenging in the form of industrial viable for machining advanced engineering materials such as polymer nanocomposites, quartz, glass, ceramics, etc. Because of some drawbacks associated with it, like irregularity in kerf width, poor surface finish, no spark formed at high wire velocity, wire breaking at high voltage, etc. In the present work, a newly developed hybrid machining process that is reversible motion-wire electrochemical spark machining (RM-WECSM) has been developed for curve profile cutting, especially on non-conducting workpieces such as aluminum oxide epoxy nanocomposite of 3.5 mm thickness. The effect of NaOH concentration, applied voltage, reversible wire velocity, pulse on-and-off time, on material removal rate and average surface roughness have been studied using a one-parameter-at-a-time approach. Sparking occurred from the electrolyte surface to 10 mm above the electrolyte surface to cut the workpiece. The spark length is equal to the workpiece thickness. A continuous, stable spark has been formed at a high reversible wire velocity (19.8 m/min). Simultaneously, self-electrolyte flow has been generated, due to which melted materials have been washed out of the cut-surface and provided the smooth (1.987 µm) cut-surface of the workpiece. The maximum MRR is found as 1.63 mg/min. Thermal cracks, heat-affected zones and recast layers were not found on the curve cut-surface, and it was analyzed by a field emission scanning electron microscope.

Simulation and experimental study for enhancing surface integrity of micro-slots processed on Nimonic-263 super alloy via electrochemical machining

ABSTRACT The potential of micro electrochemical slotting is significant due to its adaptability and usefulness across diverse manufacturing applications. This technique holds potential, particularly for handling advanced engineering materials like superalloys, with a focus on applications requiring high strength, i.e., micro-cutting for gas-turbine parts, biomedical applications, etc. With this view, this article has been attempted to explore the influence of various considered machining factors, namely as; applied potential difference, tool feed rate (TFR), pulse supply, and modes of tool insulation on the performance measures, i.e. material removal rate (MRR) and surface roughness (Ra) while attempting micro-slotting in Nimonic-263 superalloy work samples. The entire experimentation was conducted on the in-house fabricated 3-axis micro-electrochemical setup designed for performing various complex machining operations at a miniature scale. Furthermore, this study has also been focused toward investigating the impact of varying the electrical conductivity by employing different tool materials (i.e. copper and SS304) on the process characteristics measured. The observed effects of the tool electrode’s conductivity have also been expressed and supported by performing the simulation for electric field distribution using COMSOL Multiphysics software. The experimental results have revealed that the process input variables remarkably influence MRR and Ra, mainly applied voltage and TFR. The best values of MRR and Ra attained with SS304 and copper tool electrodes were 1.521 mg/min and 0.721 mg/min, and 0.038 µm and 0.029 µm, correspondingly. The microstructure analysis has further been conducted on machined micro-slotted work samples that provided detailed insights into various surface integrity aspects, which are essential for microdevice applications.

Advanced material technologies for space and terrestrial medicine

Advanced material technologies for space and terrestrial medicine

A Comprehensive Review of Radiation-Induced Hydrogels: Synthesis, Properties, and Multidimensional Applications.

At the forefront of advanced material technology, radiation-induced hydrogels present a promising avenue for innovation across various sectors, utilizing gamma radiation, electron beam radiation, and UV radiation. Through the unique synthesis process involving radiation exposure, these hydrogels exhibit exceptional properties that make them highly versatile and valuable for a multitude of applications. This paper focuses on the intricacies of the synthesis methods employed in creating these radiation-induced hydrogels, shedding light on their structural characteristics and functional benefits. In particular, the paper analyzes the diverse utility of these hydrogels in biomedicine and agriculture, showcasing their potential for applications such as targeted drug delivery, injury recovery, and even environmental engineering solutions. By analyzing current research trends and highlighting potential future directions, this review aims to underscore the transformative impact that radiation-induced hydrogels could have on various industries and the advancement of biomedical and agricultural practices.

High-support Mould Construction and Risk Assessment in Civil Engineering Works

With the rapid development of the construction industry, advanced construction technology and new building materials continue to emerge. High-supporting mould technology, with the advantages of large bearing capacity, convenient erection and strong applicability, has been widely used in the field of construction engineering. However, due to the high height, large span, many rods, complex and variable force and other characteristics of the highly supported mould frame, there is a risk of tilting or collapsing in the process of building construction, which has a very high risk. This paper from the high supporting mould technology, frame erection technology key points, safety monitoring and evaluation of the detailed description, and targeted to put forward the corresponding reasonable suggestions, in order to be able to protect the smooth progress of construction.

Biomedical Efficacy of Garlic‐Extract‐Loaded Core‐Sheath Plasters for Natural Antimicrobial Wound Care

AbstractThis work explores the application of Allium sativum (Garlic) extract, in the creation of novel polymeric core‐sheath fibers for wound therapy applications. The core‐sheath pressurized gyration (CS PG) technology is utilized to mass‐produce fibers with a polycaprolactone (PCL) core and a polyethylene oxide (PEO) sheath, loaded with garlic extract. The produced fibers maintain structural integrity, long‐term stability and provide a cell‐friendly surface with rapid antibacterial activity. The physical properties, morphology, therapeutic delivery, cytotoxicity, thermal and chemical stability of PCL, PEO, PEO/Garlic, Core‐Sheath (CS) PEO/PCL and PEO/Garlic/PCL fibers are analyzed. Findings show that the addition of garlic extract greatly increases the fibers’ thermal durability, while decreasing their diameter, thus improving cell adhesion and proliferation. In‐vitro release tests reveal a rapid release of garlic extract, which has significant antibacterial action against both Gram‐negative Escherichia coli (E. coli) and Gram‐positive Staphylococcus aureus (S. aureus) bacteria species. Cell viability experiments validate the fiber samples' biocompatibility and nontoxicity, making them appropriate for integrative medicine applications. These core‐sheath structures emphasize the potential of combining natural therapeutic agents with advanced material technologies to develop cost‐effective, sustainable and highly effective wound dressings, offering a promising solution to the growing concerns associated with conventional synthetic antibacterial agents.

Commercialising the Advanced Materials R&D in the Indian Ecosystem

Research and Technology Organisations (RTOs) are expected to manage the value chain involving the development, demonstration and transfer of technologies. Different technology commercialisation (TC) models, which provide a guiding framework for the management of this value chain, have been proposed in the recent past. The capability of these TC models to address challenges specifically associated with the commercialisation of advanced materials technologies is assessed and a conceptual model is proposed. A case study associated with the commercialisation of advanced materials technology is used to refine the conceptual model. It was found that the conceptual model requires appropriate adjustments especially when an RTO and an industrial organisation have collaboratively worked to realise successful commercialisation.

Preparation and characterization of high-performance water-based graphene dispersions for conductive coating on textiles

Studies on e-textile applications have gained momentum with advanced material technologies. Graphene derivatives have become the focus of e-textile advanced studies due to their high conductivity potential. The chemical selection while preparing graphene dispersions to functionalize textiles affects the dispersion quality and integration into the fabric. In this study, water-based green graphene dispersions were prepared using sodium dodecyl benzene sulfonate (SDBS) as a surfactant and polyvinyl alcohol (PVA) as a binder due to its high solubility in water. The stability of graphene nanoplatelets (GNP), GNP/SDBS and GNP/SDBS/PVA dispersions were examined with the naked eye at certain time intervals. UV–vis spectroscopy results indicated that SDBS provided better dispersion and stability of graphene. The XPS results showed a strong interaction between GNP and SDBS, while the binding of PVA and SDBS in the dispersion was supported by FTIR results. Overall, the dispersion quality of water-based graphene dispersion was enhanced using PVA and SDBS for e-textile application. The electrical conductivity and tensile strength of the graphene-coated fabrics increased up to ∼1.6 (MΩ/☐) and 388%, respectively, in compared to the intact fabric.

High-strength 91W-6Ni-2Co-1Fe tungsten heavy alloys prepared by laser melting deposition using granulated powder

This study introduces a new approach for fabricating high-strength 91W-6Ni-2Co-1Fe tungsten heavy alloys (WHAs) using laser melting deposition (LMD) with a specially formulated granulated powder, characterized by near-spherical particles and a dense structure with fine W grains (2.6 μm). Thin plate samples were prepared using laser powers from 500 W to 900 W, revealing increased density at higher laser power, while the W grain size remains relatively stable. A near-fully dense sample (99% density) with the finest W grain size of 2.8 μm is obtained at a laser power of 900 W, while the highest hardness of 482 HV is achieved at 700 W. The contributions of the high cooling rate of LMD, the Co addition, as well as the use of fine-grained granulated powder to enhance the high strength are discussed. These findings offer significant insights into optimizing WHA fabrication using LMD, highlighting its potential in advanced materials engineering.

Nonvolatile and reconfigurable two-terminal electro-optic duplex memristor based on III-nitride semiconductors

With the fast development of artificial intelligence (AI), Internet of things (IOT), etc, there is an urgent need for the technology that can efficiently recognize, store and process a staggering amount of information. The AlScN material has unique advantages including immense remnant polarization, superior temperature stability and good lattice-match to other III-nitrides, making it easy to integrate with the existing advanced III-nitrides material and device technologies. However, due to the large band-gap, strong coercive field, and low photo-generated carrier generation and separation efficiency, it is difficult for AlScN itself to accumulate enough photo-generated carriers at the surface/interface to induce polarization inversion, limiting its application in in-memory sensing and computing. In this work, an electro-optic duplex memristor on a GaN/AlScN hetero-structure based Schottky diode has been realized. This two-terminal memristor shows good electrical and opto-electrical nonvolatility and reconfigurability. For both electrical and opto-electrical modes, the current on/off ratio can reach the magnitude of 104, and the resistance states can be effectively reset, written and long-termly stored. Based on this device, the “IMP” truth table and the logic “False” can be successfully reproduced, indicating the huge potential of the device in the field of in-memory sensing and computing.

A study on the effects of objective weighting methods on TOPSIS-based parametric optimization of non-traditional machining processes

Developing advanced engineering materials with enhanced mechanical and metallurgical properties has caused non-traditional machining (NTM) processes to emerge as cost-effective and energy-efficient options. Improper settings of the input parameters of those processes may often lead to inferior quality and accuracy of the finished products. Multi-criteria decision-making (MCDM) methods appear as potent tools for multi-objective optimization of those processes. Determining criteria weights is a crucial step in any MCDM problem; subjective approaches for evaluating criteria weights may result in inconsistent judgments. In this paper, the effects of ten different objective weighting methods, i.e., equal weight, entropy weight, Criteria Importance Through Inter-criteria Correlation (CRITIC), Method based on Removal Effects of Criteria (MEREC), Logarithmic Percentage Change-driven Objective Weighting (LOPCOW), Symmetry Point of Criterion (SPC), Criteria Impact Loss (CILOS), Integrated Determination of Objective Criteria Weights (IDOCRIW), Principal Component Analysis (PCA) and Weighted Principal Component Analysis (WPCA) are studied on Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS)-based optimization of two NTM processes. In the first example, the optimal parametric combination computed using equal weight, entropy, MEREC, LOPCOW, PCA, and WPCA is noticed to be the same. In contrast, a different set of optimal parameters is derived by applying CRITIC, SPC, CILOS, and IDOCRIW. In the second example, seven out of ten approaches obtain a unique set of parametric combinations, while CILOS, IDOCRIW, and PCA lead to a different set of intermixes. It can be concluded that the ranks of the experiment trials for both the examples are almost similar irrespective of the objective criteria weighting technique employed.

Selective growth of recrystallizing grains into well-characterized deformed aluminum at hardness indentation

The selective 3D growth of multiple recrystallization nuclei/grains around a hardness indentation into a deformed Al grain has been quantified through a new approach that combines two synchrotron techniques: 3D X-ray Laue micro-diffraction and diffraction contrast tomography. The former is used to characterize the deformed microstructure and nucleation, while the latter to track the nuclei's growth during interrupted in situ annealing. The combined 4D (x,y,z,t) datasets enable a detailed quantification of the local deformed microstructure consumed by the nuclei/grains and the boundary characteristics between them, including the stored energy and anisotropy of the orientation distribution of the deformation matrix, as well as the misorientation of the moving and non-moving boundary segments. It is found that only certain nuclei can grow into large sizes, and the growth is heterogeneous both among recrystallizing grains and along different directions. Neither the local stored energy nor the boundary misorientation, whether considered individually or in combination, can fully account for the observed growing and shrinking behavior. The growth difference along different directions is related to the deformation microstructure, specifically the geometrical alignment of dislocation boundaries. Furthermore, the effects of impingement of other recrystallizing grains, recovery of the matrix, and elastic strain/stress, on the growth heterogeneities are discussed in detail with a view towards developing advanced modeling with improved predictability of local recrystallization phenomena. The present study demonstrates the effectiveness of the new approach in enabling 3D analysis of recrystallization in complex materials, with potential applications in the development of advanced engineering materials.

Modulating the d-Band Center of Palladium via Ethylene Glycol Modification: Accelerating Had Desorption for Enhanced Formate Electrooxidation.

This study addresses the critical challenge in alkaline direct formate fuel cells (DFFCs) of slow formate oxidation reaction (FOR) kinetics as a result of strong hydrogen intermediate (Had) adsorption on Pd catalysts. We developed WO3-supported Pd nanoparticles (EG-Pd/WO3) via an organic reduction method using ethylene glycol (EG), aiming to modulate the d-band center of Pd and alter Had adsorption dynamics. Cyclic voltammetry demonstrated significantly improved Had desorption kinetics in EG-Pd/WO3 catalysts. Density functional theory (DFT) calculations revealed that the presence of EG reduces the d-band center of Pd, leading to weaker Pd-H bonds and enhanced Had desorption during the FOR. This research provides a new approach to optimize catalyst efficiency in DFFCs, highlighting the potential for more effective and sustainable energy solutions through advanced material engineering.