This study investigates the fabrication and characterization of Al alloy matrix composites reinforced with graphene oxide (GO) using accumulative roll bonding (ARB). The annealed Al 6061 sheets were processed through 5-pass ARB with GO reinforcement applied during the initial passes. Scanning electron microscopy revealed effective mitigation of GO agglomeration and improved interface bonding due to microscale material mixing. Raman spectroscopy confirmed the strong interaction between GO and the Al alloy matrix, as evidenced by the increased D band intensities and enhanced 2D band symmetry. Mechanical testing indicated an approximately 338.37% increase in yield strength (YS) and 86.42% improvement in hardness for the ARB-processed (ARBed) Al 6061/GO composite (0.2wt%) compared with annealed Al 6061 and an approximately 14.15% increase in YS and 17.23% improvement in hardness for the ARBed Al/GO composite (0.2wt%) compared with unreinforced ARBed Al 6061 specimens after five passes. X-ray diffraction analysis indicated an increased dislocation density, corroborating the observed enhancements in mechanical properties. Fracture surface analysis revealed reduced elongation with deep dimples, highlighting the tradeoff between strength and ductility. These results demonstrate the effectiveness of ARB for integrating GO into the Al 6061 matrix to improve the mechanical performance and interfacial bonding and underscore its potential for advanced composite materials.

The incessant demand for lightweight, multifunctional materials in aerospace, automotive, and defense sectors has spurred the development of advanced cellular metals. While traditional metal foams (MFs) offer benefits, their inherent microstructural irregularities and poor mechanical predictability limit their reliability. This review critically assesses the emergence of Metal Matrix Composite Syntactic Foams (MMCSFs) as a superior alternative, in which a continuous metal matrix is reinforced with engineered hollow spherical fillers to overcome these limitations, resulting in lightweight yet robust composites. Introducing hollow metallic spheres (HMS) into MMCSFs enhances energy absorption by deforming under impact, thereby improving impact resistance and crashworthiness. Recent manufacturing advancements and interface-engineering strategies have markedly improved the mechanical robustness and reliability of MMCSFs, positioning them for structural and functional roles in automotive crash absorbers and lightweight chassis components, aerospace panels and cores, blast- and fragment-mitigating armor for defense, marine buoyancy and hull structures, and bio-adaptable implants and fixation devices. This review critically evaluates the composition, processing routes, microstructure-property relationships, and application landscape of MMCSFs. It identifies key challenges and research opportunities for their deployment in next-generation lightweight engineering systems.

This study examines the corrosion behavior of graphene oxide (GO)-reinforced aluminum alloy 6061 (Al6061) multilayer composites fabricated via accumulative roll bonding (ARB). The corrosion performance was systematically evaluated in acidic, alkaline, neutral, and saline environments using electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, and long-term immersion (weight loss) testing. Results indicate that ARB processing alone enhanced corrosion resistance, reducing the corrosion rate from 0.7634 mm/year (as-received Al6061) to 0.1597 mm/year after five passes. With the incorporation of 0.2 wt.

The modern electronics industry needs lightweight, porous materials with high-performance electromagnetic interference (EMI) shielding effectiveness (SE) and effective thermal management. This study proposes a straightforward electrochemical technique to produce lightweight silver-plated (Ag-plated) graphene-modified carbon foams (Gr@CFs) with good thermal conductivity and outstanding EMI shielding performance. Initially, Gr@CFs were synthesized via a sacrificial template method utilizing phenolic resin as a carbon precursor and graphene nanoplatelets (GNPs) as fillers, followed by carbonization at 1000 degrees C. Subsequently, the synthesized Gr@CFs experienced electroplating with silver (Ag) for varying durations ranging from 1 to 10 minutes. The Ag electroplating contributed to high EMI SE and endowed the Gr@CF with commendable electrical, thermal, and mechanical properties. The resultant Gr@CF with Ag plated for 10 minutes (Gr@CF-Ag10) possesses a remarkable combination of attributes: a high electrical conductivity of 180 S/cm, thermal conductivity of 6.0 W/ m & sdot;K, and excellent EMI SE of 73.5 dB at X-band, along with enhanced compressive strength of 6.5 MPa. Moreover, the fabricated Ag-plated Gr@CFs exhibit outstanding properties that render them well-suited for application in electronic devices requiring EMI shielding and effective thermal management.

This study investigates the effect of Accumulative Roll Bonding (ARB) on the corrosion behavior and mechanical properties of 5052 aluminum alloy. ARB processing was applied up to five passes to fabricate multilayered structures, and the samples were tested under various corrosive conditions to evaluate improvements in durability. Electrochemical techniques, including potentiodynamic polarization and electrochemical impedance spectroscopy (EIS), were performed in 3.5

This study investigates the enhancement of mechanical properties and changes in microstructure in a 6061 aluminum alloy processed through accumulated roll bonding (ARB), a severe plastic deformation process that generates ultra-fine grains. The ARB process was performed without lubrication at an elevated temperature (500 °C) for a maximum of five cycles. After the third cycle, distinct boundaries and ultra-fine grains (UFG) with a crystallite size of 30 nm were observed, which were further reduced to 17 nm after the fifth cycle. After undergoing five ARB cycles, the 6061 alloys exhibited a significant increase in tensile strength, reaching approximately 2.6 times their original value. However, elongation experienced a significant decrease following the first cycle and gradually decreased with subsequent cycles. Regarding hardness, the specimens subjected to one, three, and five cycles exhibited uneven variations along the normal direction, with non-uniform fluctuations. Notably, peak values were observed near the surface and at the center of the specimens. Wire brushing and shear strain were identified as the causes of this uneven hardness distribution. These findings suggest that the ARB method effectively refines and strengthens the grain structure of the Al6061 alloy.

Lightweight hollow metallic spheres are attracting significant interest for nanogenerator applications due to their exceptional combination of low density and high mechanical strength. This balance of structural integrity, reduced mass, and high specific strength is essential for ensuring the durability and long-term performance of nanogenerator devices optimized for efficient mechanical energy harvesting. In this work, we have fabricated lightweight and high-performance Fe-Cr-Ni alloy hollow metallic sphere (HMS) based triboelectric nanogenerators (TENGs) as robust energy-harvesting devices. The HMS was fabricated by using a method involving sacrificial expanded polystyrene (EPS) and a metal slurry to enhance the mechanical properties and energy conversion efficiency of the TENG device as compared to the uncoated EPS based device. Comprehensive characterization of the physical morphology, chemical composition, and microstructural properties of both HMS and EPS was conducted. The electronic properties of HMS, with a work function of 4.23 +/- 0.2 eV, were found to be superior to those of EPS, which exhibited a work function of 4.49 +/- 0.2 eV. This difference, highlighted by significant variances in potential observed in surface Kelvin probe force microscopy (SKPFM) measurements, indicates a higher efficiency in electron transfer and charge storage capabilities for HMS. Furthermore, the dielectric constant (kappa) of HMS was determined to be exceptionally high, measuring 1.6 x 10(7) at a low frequency of 10 kHz and reaching 3.7 x 10(7) at a frequency of 2 MHz. These properties are integral to the high-performance TENGs that incorporate HMS and EPS with a flexible ITO-coated PET substrate, demonstrating remarkable energy-harvesting capabilities. Notably, the HMS-based nanogenerator exhibits an energy output of 25 V even under minimal pressure, significantly outperforming the EPS-based nanogenerator. The findings confirm the potential of HMS-based TENGs as robust, lightweight solutions for effective mechanical energy scavenging, suggesting substantial applicability in current and emerging energy technologies.

Al foam samples were prepared by following the space-holder route using spherical shape carbamide as space-holders and application of various compaction pressures (CPs) (200, 300, 400, and 500 MPa). Al foams prepared with CP 300 MPa (CP300) showed uniform pore distribution with a smooth pore-wall surface and dense matrix microstructure without any internal cracks in the pore walls. However, in case of Al foams made with CP 200 MPa (CP200), 400 MPa (CP400), and 500 MPa (CP500), there were surface irregularities and micro-voids due to cracks in the pore walls. The XRD analysis of sintered Al foam confirmed the absence of any additional phase formation. Al foams with CP300 have also shown higher plateau stress (18 ± 0.8 MPa), energy absorption (11.86 ± 0.5 MJ/m3), improved Young’s modulus (3.03 ± 0.15 GPa) and lower densification strain (0.54 ± 0.0127) than other foams. Al foams made with CP300 demonstrated higher thermal conductivity ( 35 ± 1.48 W/m K) as compared to other foams. From the microstructural, mechanical, and thermal studies, we can conclude that 300 MPa is an optimum compaction pressure for producing high quality Al foams when irregular Al powder of average size 35 µm and carbamide space holder with the size of 1.60-2.0 mm are used as raw materials. The effect of compaction pressure on microstructure and mechanical properties was discussed with clear emphasis on underlying principles.

Red mud (RM) is generated in huge quantities and holds the ability to form radiation shielding structures due to its metal oxide-rich composition. In this work, this metal oxide-rich waste is converted into X-ray shielding sheets via a solution-casting technique incorporating polyvinyl alcohol (PVA) as a binder which holds RM particles together. We show a successful fabrication of sheets employing varying wt.% of RM (60, 70, 80, and 90 wt.%). The linear attenuation coefficient (LAC) values have been compared to analyze what maximum RM wt.% can effectively shield diagnostic X-rays at energies of 60 kVp, 90 kVp, and 120 kVp. Structural characterizations of the fabricated samples have been examined through SEM, XRD, RAMAN, and FTIR. The LAC analysis revealed that 70 wt.% of RM with PVA binder yields highest radiation shielding. However, with increased wt.% of RM there is a catastrophic decrease in strength and shielding capability of the composite due to the formation of voids due to decreased wt.% of polymer binder. So, an innovative polymer-rich coating has been applied to RM composite having 90 wt.% of RM, which boosted the LAC and strength, but not more than RM composite having 70 or 80 wt.% of RM. The UV shielding analysis of best samples having 70 and 80 wt.% of RM was also analyzed to show the capability of RM in shielding UV along with X-ray.

MAX phase materials have attracted considerable attention for a variety of applications, including high temperature structures and coatings, electric contacts, heat exchangers, concentrated solar power, catalysis, owing to their versatile properties that include high corrosion-resistance and mechanical strength, tunable surface kinetics, excellent thermal and radiation stability, etc. However, chemically engineered MAX phase materials are yet to be explored in development of biosensing devices. Here, for the first time, we report the development of MAX-based electrochemical platform, functionalized with polydopamine (PDA), for the reliable detection of Mycobacterium tuberculosis (MTB), a high-risk infectious pathogen that is spreading at an alarming rate regardless of age. The probe DNA immobilizes onto the surface of MAX/PDA via avidin-biotin coupling to construct ssDNA/avidin/MAX/PDA modified biosensing electrode. Cyclic voltammetry and differential pulse voltammetry results confirm the high charge transfer kinetics, good redox behavior, and excellent stability in modified electrode. Moreover, modified biosensing electrode attains extremely low detection limit of 0.1 attomolar, excellent sensitivity of 1.67 x 10(-4) mA mu M-1, and high selectivity with low response time towards MTB. The applicability of developed PDA functionalized MAX bio-electrodes may be extended for the detection of other infectious diseases, thus signifying how crucial is the present discovery from the perspective of controlling conventional and emerging infectious diseases and probing critical biomarkers.

The current study focused on the investigation of the microstructural and compressive properties of Al-SiCMWCNT hybrid composite foams after the implementation of heat treatment. The samples were prepared with varying weight percentages of SiC and MWCNTs, with fixed porosity 86 % (relative density = 0.14). Initially, samples were subjected to solutionizing at 480 degrees C for 10h, followed by rapid water quenching. Subsequently, artificial aging was conducted by applying three different temperatures (150 degrees C, 180 degrees C, and 220 degrees C) for varying durations, ranging from 2 to 10h. The results revealed that significant improvement in mechanical properties and maximum peak compressive stress and microhardness were achieved between 6 and 8h and 8 and 10h, at the aging temperatures of 220 degrees C and 180 degrees C respectively. However, in the case of aging at 150 degrees C, mechanical properties also increased but at a slow rate, but no clear peak values were observed even after 10h of aging. It was observed that in case of HCF (both MWCNTs and SiC added as reinforcement) the plateau stress increased up to 30 to 40 %, whereas in case of AF, CF1, and CF2 foams the properties improved by 20 to 30 %. Also, by utilizing the established Gibson model, the plateau stresses were predicted and validated with experimental results.

In the present work, the thermal conductivity of paraffin wax has been increased using low-cost and lightweight aluminium wire metal foam structures. The designed metal wire foam structures have uniform-sized circular pores forming a convective spring-like network for faster heat transfer. The paraffin wax can easily infiltrate the designed wire woven foam structures even at a lower porosity (similar to 75 vol %). The latent heat thermal energy storage (LHTES) systems which can store up to 500 kJ of thermal energy have been designed using the PCM-wire-woven metal foam composite material. The heating of these composites is carried out both in convection and conduction modes, and their effect has been studied. The effect of using a polymer (acrylic), and a galvanized iron (GI) sheet to encapsulate PCM-metal wire foam composites is also evaluated. Increasing the pore diameters in the wire woven structures, and its effect on the thermal efficiencies of the LHTES system is calculated. The thermal efficiency of the LHTES ranged from 67 to 92 % using an acrylic sheet, and 72 to 77 % using the GI sheet. The heat extraction using cold water could be continued for 8-9 cycles in acrylic, and 5-6 cycles in GI sheet capsulation.

While several coatings exist today to achieve tribological support on practical surfaces, the hunt for easily deployable yet tribological-efficient coatings still continues to fulfill the demand for commercial contact-sliding systems. Solution-based 2D/layered material coatings can be promising in this regard but many uncertainties remain to persist. Here we explored the tribological characteristics of solution-processed monolithic tungsten disulfide (WS2) and multilayer-graphene (mGR) coatings and simultaneously developed a new breed of WS2_mGR composite coating on stainless steel (SS) substrates. We discovered that monolithic WS2 coating (1mg/ml) is tribologically inefficient even at its higher concentration (up to 5mg/ml). The WS2_mGR composite coating demonstrated a remarkable reduction in friction and wear, with a 59% reduction in coefficient of friction (COF) compared to the Bare SS. Additionally, it demonstrated a 57% and 31% reduction in COF with respect to monolithic WS2 and mGR coatings, respectively, both prepared with the same concentration (1mg/ml). Further, we also discovered that at higher concentrations (5mg/ml) the monolithic mGR coating attains the lowest and most stable friction and high wear resistance over a longer period of time, even without the need for intermittent supply of lubricants during contact sliding.

In this study, the Accumulative Roll Bonding (ARB) technique was used to develop an aluminum alloy with an exceptionally refined grain structure. By examining the materials after various ARB cycles, we observed notable improvements in their mechanical properties. X-ray diffraction revealed a significant reduction in crystallite size from 29 nm to 19 nm after five passes through the ARB process. This refinement corresponded with remarkable increases in both yield and ultimate tensile strength, with the yield strength improving by 113

In this study, different configuration of lightweight aluminum hybrid composite foam core sandwich panel using Kevlar and Carbon fibers as a face sheet has been investigated under flexural loading. The flexural rigidity ( 10 times of bare foam) and flexural strength ( 7 times of bare foam) were found significantly high for double layer Carbon fiber sandwich panel. Whereas the energy absorption ( 22 times of bare foam) and specific energy absorption ( 16 times of bare foam) is high for double layer Kevlar fiber sandwich panels. Double layer hybrid fiber sandwich panel shows inclusive properties of both double layer Kevlar fiber sandwich panels and double layer carbon fiber sandwich panels making it suitable for crashworthiness and structural application. Detailed analysis on deformation mechanism was carried out with the help of videography. The contribution of individual failure modes to flexural properties was calculated empirically and compared with experimental data. The results are encouraging for using high-performance foam-core sandwich panels in structural and blast mitigation applications. Graphical abstract of aluminum hybrid composite foam core sandwich panel

Metal foam (MF) is a cellular structure made up of solid metal with a substantial volume of gas-filled pores or hollow reinforcements of the space holder. The porosity of the foam can be isolated, interconnected, or hybrid. These kinds of ultra-light materials typically have 60% to 90% porosity. Based on the porosity content MFs are classified into open, closed, partially open, and syntactic foams. However, foam made from non-flammable metal continues to be non-flammable and can be recycled as base metal. It has a similar coefficient of thermal expansion, while thermal conductivity is drastically reduced. MF has vast applications due to its superior properties, including excellent specific strength, high specific stiffness, extraordinary energy absorption capacity, good vibration damping, and premium sound attenuation capability, especially in foams with isolated or hybrid porosity. At the same time, foams with interconnected porosity have superior heat transfer capability, reasonable electromagnetic shielding, infiltration, and catalytic capability. Despite the current development, several challenges still prevent metallic foams from being commonly utilised in various industrial sectors. These challenges include high manufacturing costs, uncertainty in measured properties, and the lack of proper testing procedures. This article summarises manufacturing routes, associated processing features, and future roadmap with the present state of the art.

In this work, a novel method for coating the polymeric substrate with an aqueous metallic powder (Aluminum) solution was developed. In the modified fluidized bed, assisted bottom spray coater was used to achieve the strong interfacial coating of the aluminum on the fluidized spherical expanded polystyrene (EPS) substrate and polyvinyl alcohol (PVA) as a binder. The coated aluminum metal exhibits a layered thickness of 340 & PLUSMN; 50 & mu;m. The effect of fluidization airflow rate, spray rate, atomization air pressure, and inlet air temperature on the aluminum coating on the EPS spheres was investigated for the first time. The substantial integrity, interfacial bonding and surface morphology of aluminum coating were confirmed through XRD, FTIR, shaking test and SEM analysis. In addition, a remarkably high dielectric constant of 12,000 compared to the dielectric constant of the pristine EPS sphere of 60 at low frequency was observed.

Fully open interconnected Al-foam having different PPI (Pores per inch) was fabricated through the novel template method. The morphology of the open-cell Aluminium foam (OCAF) (strut, pore, and cell size) can be easily tailored with this method. Three different PPI (10, 20, and 30) Al-foams were fabricated through the template method, and show the effect of PPIs' on their microstructure, thermal, electrical, and mechanical properties in detail. With different PPI of the foam, the porosity lies in the range of 85-94%. Through experiments, it was found that with the increase in PPI, the density of the foam gets increases. Complete openness and uniformity in terms of the pore, strut size, and porosity throughout the samples has been easily achieved with this method, which is very difficult with previously reported methods. As the PPI of the foam changes, the properties (electrical, thermal, and mechanical) also change. According to the requirement, one can easily tailor the properties by changing the PPI of the foam. Experimentally evaluated properties were also compared with the theoretically calculated values. The open-cell aluminium foam of 30 PPI (OCAF-30) having RD-0.14 shows electrical conductivity- 0.68 x 106 S/m, thermal conductivity- 6.43 W/m.K, and compressive strength of 0.65 MPa. This study helps the research community to fabricate OCAF according to their requirement with desired thermal, electrical, and mechanical properties for the application of heat transfer, electrocatalysis, and others.

In this study, silver flowers decorated 316L stainless steel foams (SSF) (porosity of SSF= 60 %) were fabricated via the electrodeposition method. The developed SSFs were used for the corrosion behavior for biomedical implant applications. In this respect, constant voltage (0.5 volts) and time variation (300, 600, and 900 s) were applied to decorated silver flowers on the surface of SSF. Results illustrated that the silver flower decorated morphology was modified with the electrochemical deposition time variation. Furthermore, it was found that the corrosion behavior of silver flowers decorated SSF was increased when compared to the undecorated SSF samples.