This review discusses acoustoplastic treatment as a modern surface engineering technique using ultrasonic vibrations to enhance the material properties including elongation-to-failure, strength, corrosion resistance, and fatigue life. The reduction of an object's resistance to plastic deformation upon subjecting it to intense mechanical vibrations at ultrasonic frequency (most often 20–40 kHz) is known as acoustoplasticity. This review covers the mechanisms of ultrasonic softening (including grain boundary growth and dislocation behavior) as well as applications of the ultrasonic-aided methods including hybrid processes, additive manufacturing, and surface processing. Process-specific outcomes are quantified for a range of materials (aluminum, steel, titanium, etc.), and they highlight future avenues for energy-efficient and scalable surface treatments. Existing constraints are also elucidated, and directions for future research and implementation of this technology are discussed.
High-strength Al alloys, often referred to as Al alloys with mechanical strengths reaching 300–400 MPa, have widespread industrial applications. Recent applications call for Al alloys with much enhanced mechanical strength (> 600 MPa), good ductility, and high temperature thermal stability. However classical strengthening mechanisms for Al alloys, including precipitation-hardening (e.g., age-hardening), grain refinement, and solid-solution strengthening often lead to only moderate strength improvement. New mechanisms that can significantly improve the strength and thermal stability of Al alloys are urgently needed. In this review, we summarize strategies and mechanisms that may lead to ultrahigh-strength Al alloys defined as Al alloys with yield strength > 600 MPa . The mechanisms that improve ductility of ultrahigh-strength Al alloys are also discussed. This review article also points out challenges and future research directions for the discovery of ultrahigh-strength Al alloys with good ductility and high temperature thermal stability.
Lithium metal is a critical material in advancing energy storage technologies, particularly for next-generation lithium metal batteries (LMBs). However, industrial lithium metal production relies predominantly on LiCl–KCl electrolysis. This process faces several challenges and limitations, such as the need for high-purity LiCl, low current efficiency, and the generation of chlorine (Cl 2 ) gas as a by-product. To ensure a sustainable and affordable lithium supply, recent studies have focused on improving process efficiency and developing alternative production routes. Despite this accelerating research activity, the lack of a unified and critical assessment of lithium metal production technologies hinders informed technology selection and scale-up. This review addresses this gap by examining recent advances in lithium metal production technologies, with a focus on improvements to conventional molten salt electrolysis, including feedstock optimisations, electrolyte modifications, and cell design innovations aimed at enhancing yield, purity, and energy efficiency. In addition, alternative low-temperature electrolysis enabled by aqueous-based lithium compounds, innovative electrochemical extraction methods, and thermochemical approaches using carbon and metallic reductants are summarised. The review also considers process–structure–performance relationships, highlighting how production conditions influence lithium metal microstructure and electrochemical properties. Finally, the review discusses the challenges associated with each method and highlights potential improvements to achieve more sustainable large-scale lithium metal production.
Metallothermic reduction using aluminum (aluminothermic) is a versatile and potentially energy-efficient metallurgical process to produce metals and alloys from the oxides and compounds, leveraging the exothermic nature of the reaction. Importantly, when powered by low-carbon aluminum production using renewable electricity, aluminothermic reduction offers a near-zero-carbon reduction route, eliminating direct fossil fuel use and associated CO 2 emissions from the reduction step. This paper examines the thermodynamic principles, kinetic mechanisms, and practical applications of aluminothermic reduction across diverse systems, including for production of iron, magnesium, titanium, rare earth metals, and processing of waste materials. Key factors such as stoichiometry composition, flux additives, and reaction conditions (temperature, pressure) are analyzed to optimize metal recovery and slag separation. Reaction mechanisms, process parameters, reactor innovations, and challenges of exothermic control, slag viscosity, impurity management, and aluminum reductant cost relative to metal product value are discussed. Secondary aluminum materials as the reductant are also reviewed as a significant alternative to reduce the cost and minimize the lifecycle emissions. The paper concludes with suggestions for future directions towards scaling aluminothermic reduction, emphasizing hybrid processes and circularity integration.
Excipients could modulate drug delivery profiles of pulmonary medicine. This review explores potential bioactive excipients for asthma medicine development which could serve as therapeutic as well as drug carrier. Polysaccharides and oligo derivatives, and synthetic and coordination polymers could curb asthma through mitigating allergic and inflammatory responses of respiratory cells via inhibiting T-helper cell maturation, cytokines and IgE release, mast cell degranulation and MAPK/NF-kβ signaling pathways by binding to Toll like/CR3/dectin-1/mannose receptors of immune/epithelial cells. They can remove allergens via complexation, reduce mucus production by goblet cells, fluidize respiratory mucus and enlarge mucus pores to ease allergen removal or cellular drug uptake. Polymers < 1600 kDa and specifically < 10 kDa possess anti-asthmatic effects. Sugar moieties of excipients exert immuno-modulatory actions via specific lung epithelial and immune cell receptor binding as a function of branching/esterification degree, chemical bond saturation, glycosidic linkage and graft characteristics. To materialize anti-asthmatic excipients in pulmonary medicine development, efficient purification and clinical safety evaluation are imperative. To exploit such excipients as pulmonary therapeutic and/or drug carrier, particle design of excipients into required aerodynamic diameter and targeting behaviour is essential. Polysaccharides and oligo derivatives, and synthetic and coordination polymers are potential anti-asthmatic therapeutics and alternative drug carriers to the existing inhalable lactose.
This review focuses on the critical issue of water and related impurities in halide salts, particularly relevant in the context of high-temperature energy storage and conversion systems like molten salt nuclear reactors, concentrating solar power, pyroprocessing of nuclear fuel, and thermal energy storage. The corrosive nature of molten halide salts is exacerbated by hydroxides, oxides, oxyhalides, and hydrogen halide acids that form when halide salts are heated and fused with water present. Precise quantification of water and related species is vital for advancing fundamental research necessary for the development of these systems and for safe and economical operation of commercial systems in the future. The literature regarding (i) the structure and speciation of water and water-related impurities, (ii) drying and purification methods to reduce water in halide salts, and (iii) methods for detecting and quantifying water and related reaction products have been reviewed and compiled here. This review highlights the complex behavior of water in halide salts and the challenges involved in rigorous quantification. Pathways towards better understanding fundamental molten salt chemistry and developing quantification methods with improved accuracy are also discussed. Development of complementary analytical techniques will not only be crucial for high-fidelity molten salt experimental research but also essential for developing and optimizing the safety, performance, and longevity of molten halide salt-based energy systems.
Mixed matrix membranes (MMMs) have emerged as an attractive category of nanofiltration (NF) membranes, offering a promising solution to address the intrinsic trade-off that exist between permeability and selectivity in conventional polymeric membranes. This review article aims to comprehensively discuss advances reported over the past 5–10 years achieved in the field of MMMs and critically analyzes the mechanisms through which a diversity of additives affects nanofiltration behavior. The discussed researches primarily address the separation of target solutes including salts, dyes, pharmaceuticals, and heavy metals, with primary applications in water treatment and wastewater reuse. Particular emphasis is placed not only on material design but also on interfacial compatibility, performance limitations, and the permeability-selectivity trade-off. Advanced inorganic fillers, such as metal-organic frameworks (MOFs), covalent organic frameworks (COFs), and MXenes, have attracted many attentions because of providing special architecture, great specific surface area, and ability to give selective transport pathways. Traditional inorganic fillers (TiO 2 , ZnO, SiO 2 , halloysite nanotubes, Fe 3 O 4 , and ZrO 2 ), carbon-based materials (including graphene derivatives, carbon nanotubes, and graphitic carbon nitride), and organic fillers (such as porous organic cages (POCs), and β-cyclodextrin) are comparatively discussed in terms of their merits and practical restrictions. This review indicates the relationships existing between structure, properties, and performance in various MMM designs, and provides some suggestions for future research directions. Beyond performance enhancement, this review discusses trade-offs between permeability and selectivity, filler dispersion challenges, interfacial defects, long-term stability concerns, and scalability constraints that may hinder practical implementation. The eventual aim is to develop the next generation of nanofiltration mixed matrix membranes possessing high efficiency, improved selectivity, and long-term stability.
Metallic conductors such as Al and Cu wires are essential materials in power transmission systems, where both high strength and excellent electrical conductivity (EC) are required. However, traditional strengthening strategies often degrade EC, resulting in an intrinsic strength-EC constraint. This review addresses this long-standing dilemma by summarizing the microstructure design principles, quantitative models, and processing strategies for achieving high-strength and high- EC metallic wires. We begin by outlining four key design principles including fine-long grains, <111 > texture, nano-scale precipitate, and low solid solubility alloying. These principles are theoretically analyzed and quantitatively described through newly developed models that capture the effects of grain morphology parameters and precipitate radius on both strength and EC. Furthermore, various preparation techniques are reviewed, including multi-stage drawing with intermediate annealing, directional solidification, pre-aging treatments, and compositional design. These techniques are demonstrated to effectively construct microstructures with ultra-fine-long grains structure, pronounced <111 > fiber texture, and uniformly distributed nano-precipitates. Finally, the performance advantages of the resulting microstructure optimized wires including pure Al, pure Cu, Al-Mg-Si, and Al-Fe alloys are demonstrated in terms of their outstanding strength-EC synergy. This review provides a comprehensive and practical foundation for the future design of high-strength and high-EC metallic materials.
Borosilicate glasses, known for their thermal resistance, chemical inertness, and mechanical strength, play a crucial role in technical applications as well as in the pharmaceutical industry. Despite their widespread use and versatility, most borosilicate glass wastes (BSGW) end up in landfills or are incinerated, rendering this valuable resource useless. This review provides an overview of recycling strategies for borosilicate glasses, with emphasis on technological approaches and potential applications spanning building and construction, insulation and filtering, functional materials, and materials for radiation shielding or nuclear waste immobilization, as well as opportunities for material recovery within the ceramics and glass industry or a source of boron or other critical raw materials. The economic viability and life cycle assessment (LCA) of GW recycling are addressed, considering energy consumption, scalability, and output quality across various technologies versus virgin material production. Furthermore, the review considers policies, such as the European Union's goal of fully recyclable packaging by 2030, and discusses limitations and challenges, such as the need to sterilize pharmaceutical GW and contamination risks of borosilicate GW streams with soda lime glass, as well as commercialization barriers and incentive schemes to promote BSGW recycling. New perspectives based on laser processing of borosilicate GW are also shown and aimed to open pathways toward full recyclability of these materials. This approach contributes not only to improved environmental sustainability but also promotes the use of BSGW in advanced technological applications. Finally, research priorities and underexplored areas are discussed to inspire and guide future investigations.
Oxide dispersion-strengthened (ODS) alloys are a critical class of structural materials for extreme environments, owing to their unique combination of high-temperature strength, thermal stability, and radiation tolerance, enabled by a very high density of nanoscale oxide dispersoids. These features make ODS alloys attractive for advanced nuclear systems, aerospace applications, and other harsh-service conditions where conventional alloys rapidly degrade. Despite decades of development, key challenges remain in understanding how nanoscale oxides interact with matrix microstructures, alloy chemistry, and irradiation-induced defects to control macroscopic performance. This review provides a focused, mechanism-based synthesis of the microstructural features that govern the properties of ODS alloys. Emphasis is placed on grain structure evolution, dispersoid size and distribution, matrix–particle interfaces, and the role of alloying elements in stabilizing oxide nanoparticles and controlling phase composition. Distinctions between ferritic, ferritic–martensitic, and austenitic ODS systems are discussed where relevant, highlighting how microstructural differences influence strengthening mechanisms, creep resistance, and thermal stability. The relationships between microstructure and properties are critically examined, including room- and elevated-temperature mechanical behavior, and long-term thermal stability. Particular attention is given to how dispersoid characteristics and grain-boundary structures influence deformation mechanisms, grain-boundary migration, and dispersoid stability during prolonged service. A dedicated section addresses radiation effects in ODS alloys, synthesizing insights from ion- and neutron-irradiation studies. Key phenomena such as defect sink behavior, He and hydrogen trapping, irradiation-induced dispersoid evolution, and changes in mechanical performance are discussed, supported by evidence from advanced characterization techniques, including TEM and atom probe tomography. Challenges associated with simulating neutron damage and predicting long-term irradiation performance are also highlighted. By integrating microstructure, mechanical properties, and irradiation response, this review provides a coherent framework to guide the design and assessment of next-generation ODS alloys for extreme environments.
High-entropy alloys (HEAs), or multi-principal element alloys (MPEAs), constitute a paradigmatic class of metallic materials whose entropy-stabilized solid solutions exhibit unique physical and chemical attributes unattainable in conventional alloys. Their exceptional capacity to reconcile strength and ductility under impulsive loading has positioned them at the forefront of impact engineering. Hitherto, investigations of dynamic mechanical response have focused almost exclusively on strain rate, at the expense of the enthalpy-entropy interplay that governs the coupled evolution of temperature, strain rate, and microstructure. Consequently, a rigorous correspondence between macroscopic stress-strain trajectories and the multiscale evolution of underlying microstructures remains elusive. Likewise, physics-based constitutive laws that incorporate temperature- and rate-sensitive kinetics remain in their infancy. Emerging evidence indicates that deliberate departure from equiatomic stoichiometry, together with microstructural architecting, can confer synergistic gains in mechanical properties within specific temperature-strain rate windows, surpassing the performance of conventional alloys. Yet the non-monotonic decline in flow stress with elevated temperature, particularly in the adiabatic regime prevailing at strain rates exceeding 10 3 s −1 , continues to elude quantitative interpretation, hindering a unified mechanistic understanding. This review thoroughly examines the extensive yet fragmented literature on the origins and effects of strain rate and temperature on the dynamic mechanical behavior of HEAs. We decipher dynamic plastic flow and fracture through the lens of microstructure, revealing how thermomechanical fluctuations govern the competitive activation of deformation mechanisms such as dislocation glide, twinning, phase transformation, and shear banding. Furthermore, we rigorously evaluate contemporary efforts to predict these behaviors using multiscale modeling, in situ diagnostics, and thermodynamics-informed machine learning. Finally, we advocate for a mechanism-guided, closed-loop design paradigm to extend the performance limits of these materials in extreme environments. By providing a critical assessment, this review aims to deliver a definitive roadmap to overcome theoretical barriers and experimental bottlenecks in the field.
Two-dimensional metal-organic frameworks (2D MOFs) have emerged as a highly promising class of materials for gas sensing applications due to their unique physicochemical properties, including high surface area, tunable porosity, and structural versatility. This review focuses specifically on MOF-derived 2D materials (as distinct from broadly-defined MOF-based sensors) and systematically examines (i) synthetic strategies that yield 2D morphologies and MOF-derived oxides, (ii) structure–property relationships governing sensitivity and selectivity, (iii) device integration approaches and transduction mechanisms, and (iv) pathways to scale-up and commercialization. To enable a clear and consistent comparison across the literature, key performance metrics (limit of detection, response/recovery time, operating temperature, power consumption, stability, and reproducibility) will be compiled and presented in a normalized framework. These characteristics make them particularly suitable for detecting hazardous and volatile gases at low concentrations. With the alarming rise in air pollutants and environmental contaminants, there is a growing urgency to develop next-generation gas sensors that are more sensitive, selective, energy-efficient, and capable of operating under ambient conditions. Recent advances in the design, synthesis, and functionalization of 2D MOFs have opened new avenues for achieving enhanced sensitivity, selectivity, and stability in gas detection systems. By combining critical analysis, quantitative benchmarking, and a focus on commercialization, this review provides a distinctive and timely perspective that complements existing surveys and aims to guide both fundamental research and industrial application in gas sensing.
Osteochondral tissue exhibits a complex multilayered structure with distinct structural and physiological properties. Recent advancements in extrusion bioprinting have enabled the layer-by-layer assembly of multilayered osteochondral constructs. Alginate, a natural polysaccharide widely used in bioinks, offers tunable properties for supporting cellular functions and engineering tissues. Alginate derived from different sources differ in β-D-mannuronate and α-L-guluronate contents, as well as the length of each block, possesses carboxylate groups that facilitate cross-linking with divalent cations and further functionalization. Several chemical and processing routes can be envisioned to achieve desired processability, mechanical, and biological versatility. Despite its potential, challenges remain in meeting the mechanical and biological requirements for osteochondral grafts. Herein, we examine the technical challenges associated with osteochondral tissue repair and discuss extrusion bioprinters’ requirements and advances in bioprinting methods to address these challenges. We highlight the last decade's key findings dealing with the chemistry and functionalization of alginate-based (bio)inks for osteochondral tissue engineering. Engineering strategies for modulating alginate-based (bio)inks with optimized rheological features, printability, and shape fidelity are overviewed. Finally, obstacles, opportunities, and emerging solutions for better developing alginate (bio)inks for osteochondral tissue engineering are explored, considering advances in artificial intelligence and machine learning.
Power modules in electric vehicles (EVs) are essential electronic components that manage and convert electrical power between the battery and other vehicle systems, such as the motor. The electronics are required to operate at higher temperatures (>200 o C) and fields (>0.5 MV/cm) than in conventional consumer goods such as phones and tablets. This requires the use of, e.g., SiC based semiconductor technology, along with associated filters/capacitors that can withstand high temperature/fields. Such capacitors have a large energy density arising from the ability of the dielectric to withstand repeated application of high fields (>0.5 MV/cm) without breakdown. This article reviews examples and presents new data and concepts on high energy density dielectrics intended for use in power electronic. In particular, the article focuses on a new class of dielectrics which have high permittivity (>1000) but do not saturate at high field and exhibit a quasi-linear polarisation-field response. The roles of chemical, polar and octahedral tilt disorder are assessed and a new mechanism proposed by which tilt disorder restricts strain coupling and therefore polar coupling, leading to a quasi-linear response in polarisation-field (P-E) loops. The influences of local variations in stoichiometry and multi-valent and multi-sized substituents in these polar lattices to attain enhanced resistivity are also discussed. The article therefore illustrates how a combination of high resistivity and tilt disorder are pivotal in the design of a new generation of high energy density capacitors for power electronics.
Electrical steels, also known as silicon steels, play an essential role in the generation, transmission, and use of electricity. The magnetic quality of electrical steels and thus the energy efficiency of electromagnetic devices are highly dependent on the thermomechanical processing procedures employed to manufacture the electrical steel sheets. Every processing step, from casting, hot rolling, cold rolling to annealing, introduces a specific microstructure and texture, which influences the microstructure and texture of next processing steps as well as the final magnetic properties. In this paper, both types of electrical steel, i.e., grain-oriented electrical steel (GOES) and non-oriented electrical steel (NOES), are reviewed bearing in mind that NOES has perhaps received less attention till now. The magnetism of ferromagnetic materials and the metallurgical factors that affect the magnetic properties of electrical steels are first briefly discussed. The effect of each thermomechanical processing step on the formation of the microstructure and texture of the final electrical steel sheets is then scrutinised. The status and challenges in optimising the crystallographic texture of electrical steels are discussed. Future directions to the development of energy-efficient and cost-effective electrical steels are pointed out.
The unique properties of ZrB 2 -based ceramics are suitable for ultra-high temperature structural applications such as re-entry space vehicles, hypersonic vehicles, and propulsion systems. Monolithic ZrB 2 is associated with challenges during processing and sintering, limiting its widespread application, in addition, its physical and mechanical properties degrade at above 1200 °C due to its critical oxidation resistance. These problems are partially addressed by adding carbides, like SiC and ZrC, into ZrB 2 ceramic. The synthesis and sintering of ZrB 2 -based ceramics are much more accessible than monolithic ZrB 2 , resulting in overall better performance. The present review focuses on the processing route and sintering techniques of ZrB 2 -based binary, ternary ceramics and composite and their effect on physical and mechanical properties. Also, novel advanced processing and fabrication techniques of ZrB 2 -based materials are mentioned. This research article tackles the drawbacks and challenges present in the existing literature and how a sustainable approach can rectify these issues.
Functionally graded materials (FGMs) are special advanced composite materials. The significant capabilities of additive manufacturing (AM) technology in material and structural control offer promising opportunities for designing and fabricating next-generation FGMs. However, the current fabrication of FGMs using AM technology (AM-FGMs) is often relies on empirical methodologies, limiting the exploitation of the distinctive features of high-performance FGMs. Therefore, we propose a "bottom-to-top" design concept for AM-FGMs aimed at achieving high performance, versatility, and suitability for industrial applications in extreme environments, integrating optimal design with AM technology. Initially, this paper discusses the optimal design of AM-FGMs, emphasizing multi-scale and multi-functional design driven by AM technology. Subsequently, the advantages and disadvantages of different AM-FGMs fabrication methods, process optimization, and post-processing optimization are discussed. Finally, the versatile applications, research challenges, and prospects of AM-FGMs are summarized. This work contributes to advancing the realization of high-performance AM-FGMs and offers valuable guidance for the fabrication in the future.
By control of their constituents, interfaces and architectures, composite materials can display a much broader suite of beneficial material properties than is possible for single-phase materials. Furthermore, advanced manufacturing techniques are increasing the freedom to operate of composite designers. While much can be achieved with idealised models of composites, models are needed that more accurately reflect the non-ideal placement of reinforcement, matrix-free regions and manufacturing defects that occur in practice. At the same time, imaging techniques, and X-ray computed tomography in particular, have radically increased the level of information that can be obtained in three dimensions and over time about real composite microstructures, both about the as-manufactured condition and their behaviour in-service. This review considers all aspects of image-based modelling of composite materials across the length scales. It also discusses establishing the appropriate constitutive equations for deterministic and stochastic (e.g., fibre fractures) elements of behaviour, as well as methods for validation. A range of actual and potential applications from the literature are showcased throughout. It explores approaches to bridging the scales and techniques, such as surrogate and homogenised models, to ensure models are computationally feasible. It covers a wide range of composites, spanning polymer, metal and ceramic matrices, continuous and short fibres, as well as particulate reinforcements. It also briefly extends to how such approaches can be applied to other ‘composite’ systems, such as concrete and hard metals. Overall, this is a one-stop review for those considering multiscale modelling of composites based on realistic, often multiscale, composite architectures.
A comprehensive review focuses on powder-based metal additive manufacturing (AM), providing a systematic examination of the formation mechanisms, characterization techniques, control strategies, and performance implications of porosity defects. First, it systematically categorizes the three primary types of porosity defects—lack-of-fusion defects, gas-induced pores, and keyhole defects—elucidating the complex interactions among process parameters, material properties, and environmental factors in their formation. Next, various advanced detection techniques are compared, including metallographic analysis, X-ray computed tomography, in situ monitoring, optical layer-by-layer inspection, and laser ultrasound imaging, evaluating their advantages and limitations in terms of resolution, real-time capability, and quantitative analysis. This analysis provides a theoretical foundation for multi-scale defect characterization. Subsequently, preventive and corrective strategies are summarized across three key stages: pre-processing, in-process optimization, and post-processing. These strategies include thermo-fluid-solid coupled numerical simulations, data-driven machine learning approaches, external field interventions (magnetic, acoustic, thermal, and mechanical), as well as post-processing techniques such as hot isostatic pressing and surface enhancement. Current state of these techniques is discussed, including their effectiveness in enhancing part density and service performance, and their inherent limitations. Finally, key challenges are identified in the field and future research directions are outlined, emphasizing real-time monitoring, multi-scale coupled modeling, and intelligent adaptive process control. This review aims to provide theoretical insights and technical guidance for minimizing defects and improving the overall performance of metal AM components.
Ultrasonic processing in the liquid state has been identified as an effective method to improve the mechanical properties of Al and Mg alloys. Ultrasonic melt processing is capable of enhancing material properties through the application of high-frequency, high-power vibrations that form cavitation bubbles which pulsate and collapse throughout the melt volume. Thus, this technology has excellent potential in engineering high performance lightweight materials. With global trends converging toward greener energy, reduced greenhouse gas (GHG) emissions and increasingly stringent efficiency standards, lightweight and high-strength alloys such as aluminum (Al) and magnesium (Mg) are becoming an area of high interest. The aim of this review is to analyze the literature on ultrasonic processing of Al and Mg alloys in the last 15 years. This review discusses ultrasonic processing equipment, experimental set-ups, mechanisms of ultrasonic cavitation and acoustic streaming. As well, the effects of processing time, vibrational amplitude, and temperature on microstructure and properties are elucidated. Furthermore, it aims to investigate how a combination of sonication and particle reinforcement can affect the properties of Al and Mg alloys. The challenges of ultrasonic processing have been identified and expanded on in this review. This includes energy consumption, equipment complexity, temperature control, process optimization and limited industrial adoption.
