Carbon fiber–reinforced polymers (CFRPs) have gained widespread use across the aerospace, automotive, and energy sectors due to their high strength‐to‐weight ratio. Many structural applications require joining CFRPs to aluminium alloys, with adhesive bonding offering several advantages over mechanical joining methods, including uniform stress distribution and compatibility with CFRPs. Among various strategies to improve bond strength, surface preparation plays a critical role. This study investigates the effect of chemical etching on CFRP using sulfuric acid solution to enhance bond strength in single‐lap joints with aluminium alloys when tested in lap shear test. Experimental results show that optimised chemical etching can triple the lap shear strength compared with untreated samples. Acid concentration significantly influences joint performance; furthermore, the soaking method of etching can yield stronger bonds than the pipette method. Additionally, chemically etched CFRP–Al joints can outperform those treated with conventional sandpaper abrasion. These findings demonstrate the effectiveness of controlled chemical etching in improving the structural integrity of CFRP–metal adhesive joints and provide insights for designing more robust hybrid structures for lightweight applications.

Reusable air filtration systems are increasingly explored as sustainable solutions for indoor air quality control, provided that effective sterilization and long-term antimicrobial performance can be guaranteed. This study investigates thin ceramic-based nanocomposite coatings applied to conventional air filter media to enable dry-heat sterilization and repeated reuse. Silver nanoclusters embedded in silica (SiO2) or zirconia (ZrO2) matrices were deposited by radio-frequency co-sputtering onto metallic, glass-fiber, and polymeric substrates. Thermally stable ceramic oxides were selected to preserve coating integrity, regulate silver ion release, and maintain the original filter porosity. Morphological and structural characterization (FESEM, TEM, UV-Vis, XRD) revealed porous amorphous SiO2-based coatings and denser ZrO2-based coatings, both featuring a uniform distribution of silver nanoclusters. Antibacterial and antifungal activity against Staphylococcus epidermidis, Escherichia coli, and Candida albicans was confirmed through inhibition halo tests, CFU quantification, and aerosol contamination experiments. A key outcome is the demonstrated thermal regenerability of the coated filters, which retained antimicrobial efficacy after multiple dry-heat sterilization cycles at 200 degrees C. While silica-based coatings exhibited higher silver ion release, zirconia-based coatings provided improved release control and structural stability. These results highlight ceramic-based nanocomposite coatings as a promising approach for durable, regenerable, and scalable antimicrobial air filtration systems.

The SiC-based materials, particularly SiC-fiber-reinforced SiC matrix (SiC/SiC) composites, show strong potential for structural and functional applications in future fusion power plants because they can operate at high temperatures with a range of coolants and breeders, thereby enabling higher energy conversion efficiency. This paper presents recent advancements in the development of SiC-based materials, focusing on processing techniques and material performance and resistance under fusion-relevant environments. The processing activities have emphasized near-net-shape fabrication and the joining of SiC subcomponents, with processing methods and material compositions informed by previous irradiation experiments on various grades of SiC. Research on irradiation effects has remained focused on degradation mechanisms and the microstructural optimization of SiC/SiC composites irradiated to high neutron damage levels. Analysis of irradiation defects in SiC has advanced via the application of cutting-edge characterization methods, among which Raman spectroscopy is becoming a common tool to assess atomic-scale chemical disorder. Fusion–fission crosscutting irradiation research has explored combined effects in SiC/SiC composites with application-relevant geometries, including bowing of SiC/SiC composite channels under neutron flux gradients, stress evolution in SiC/SiC composite tubes under through-thickness temperature gradients, and irradiation-enhanced corrosion in SiC. Finally, research opportunities for component testing and assessment under fusion-relevant conditions, in support of emerging concepts from the private fusion sector, are discussed.

Ceramic matrix composites (CMC), particularly oxide fiber-reinforced oxide matrix (ox/ox) composites, offer a viable alternative to traditional materials, due to their high temperature thermo-mechanical stability, intrinsic oxidation resistance and low density compared to metals.However, a joining material having the same thermo-mechanical behavior and oxidation stability as the ox/ox composites is still an open issue.In this respect, joining by a preceramic polymer offers a unique option, in principle enabling the fabrication of robust ceramic joints; since the process can be done at lower temperatures in respect to traditional methods such as brazing, it can also be attractive from an energy saving point of view.This study investigated the use of a polysilazane-based preceramic polymer (Durazane 1800) filled with an increasing amount of alumina particles and 1 wt % chopped alumina fibers to join and coat ox/ox composites. The process was the same for joining and coatings: i.e. curing at 180°C and pyrolysis up to 1200°C in air, followed by microstructural and mechanical characterization on each sample.Lap-shear tests were done on joined samples at room temperature, at 300°C and at 600°C, in air. Fracture surfaces exhibited cohesive failure, indicating sound adhesion between the joining material and the ox/ox composites. However, residual porosity and incomplete covering of the joined area were identified as a limiting factor affecting the joint strength.X-ray computer tomography (CT) was used to measure the volume of residual porosity, cracks and lack of coating material after curing and pyrolysis on coated samples.

Silicon carbide fiber-reinforced composites (SiC/SiC) are leading candidates to replace zirconium-based alloys as cladding in light water reactors (LWR), owing to their exceptional oxidation resistance and mechanical performance under accident conditions.However, pressure-less joining methods compatible with the extreme chemical and thermal environment of LWRs remain a major technological hurdle.This work evaluates two promising joining materials—Mo-wrap (a MoSi₂/Si composite) and SAY (a silica–alumina–yttria glass-ceramic)—under simulated LWR conditions.Joining was performed using both conventional furnaces and laser-assisted techniques.Joint integrity and microstructure were assessed by SEM/EDS and X-ray computed tomography. Hydrothermal stability was evaluated in static and flowing-water (loop) autoclaves up to 30 days at 330 °C and 150–155 bar.Mo-wrap joints showed partial degradation due to silicon dissolution, while SAY joints retained good structural integrity in static tests but suffered phase-selective corrosion under flowing conditions, with keivite emerging as the most stable crystalline phase.Laser-processed amorphous SAY joints exhibited improved corrosion resistance, though still limited under prolonged exposure.These findings advance the understanding of joining performance in nuclear-relevant environments and support the development of accident-tolerant fuel cladding.

The urgent need to mitigate climate change has driven the exploration of innovative materials and processes to achieve net-zero carbon emissions. This work investigates the potential of ceramic matrix composites (CMCs) as alternatives to traditional metals in high-temperature industrial applications, within the European Union project CEM-WAVE. Various joining materials, including glass-ceramics, metallic brazes, and pre-ceramic polymers, are evaluated for their effectiveness in creating robust CMC joints. The study demonstrates the viability of CMCs in steelmaking and other energy-intensive sectors, highlighting their resistance to extreme conditions and potential to replace metallic alloys. The findings underscore the need for continued research to optimize manufacturing processes and reduce costs, paving the way for broader adoption of CMCs in achieving sustainable industrial practices.

The IDEA project, developed in the frame of MOST—National Centre for Sustainable Mobility—addressed the growing need for reliable bonded joints in fibre-reinforced polymer composite structures used in transportation. Purely bonded joints are preferred for their lightweight and cost-efficient properties, but contamination and defect detection issues often make them unreliable. To solve this, the project developed innovative surface treatments, a methodology for the safe, optimized design of bonded joints, and structural health monitoring solutions, viable for real-time assessment. These advancements aim to increase the reliability and safety of bonded connections, helping industries adopt lighter, purely bonded joints over heavier, hybrid bonded/bolted options.

Perhydropolysilazane (PHPS) pre-ceramic polymer was used to join soda lime silicate glass at temperatures below 200 degrees C under pressureless conditions. The results show that: (i) the junction material is largely converted to silica at 100 degrees C and fully converted to glass at 150 degrees C; (ii) the samples treated at room temperature and 100 degrees C show a perfectly dense and clean bond, whereas porosity develops starting from 150 degrees C as a result of the hydrolysis reactions and solvent evaporation; (iii) a maximum tensile bond strength of about 5-6 MPa is obtained after treatments at 100 degrees C. Remarkably, after treatment at 500 degrees C, the junction remains intact. These preliminary findings provide the first successful attempt regarding the use of PHPS as a joining material to produce inorganic and transparent bonds for glass at relatively low temperatures.

The influence of aging and thermal shock processes on polymer coating reinforced with various rubber fillers on an aluminum substrate was investigated. The coatings were made from a polyurethane matrix and two different reinforcement materials: EPDM and SBR rubber waste fillers. The samples were subjected to 100 thermal shock cycles. Each cycle lasted 1 h, comprising 30 min at 100 °C followed by 30 min at 40 °C. The aging tests were conducted in a SUNTEST XLS+ aging chamber from Atlas Material Testing Technology GmbH, in accordance with the applicable ISO 4892-1:2016 standard. Thermal shocks increased the impact resistance of coatings with EPDM and SBR fillers. Neither UV aging nor thermal shocks affected the impact or abrasion resistance of unfilled polyurethane coatings. FTIR analysis revealed that UV exposure significantly accelerates chemical degradation of PUR, though fillers—especially EPDM—enhanced stability by mitigating this effect. Thermal shocks induced surface-level changes, including the formation of oxygenated groups and the rearrangement of hydrogen bonds. Rubber waste fillers influenced surface and thermal properties, with EPDM maintaining better hydrophobicity and oxidation resistance, while SBR-filled coatings demonstrated higher thermal stability but greater flexibility and susceptibility to degradation after aging.

This study investigates the soldering process for joining silicon nitride (Si 3 N 4 ), a commonly used ceramic, to Invar42, a low thermal expansion alloy. The focus lies on analyzing interfacial reactions and evaluating the bonding performance of the Si 3 N 4 —Invar42 joint. Field emission scanning electron microscopy (FESEM) and energy‐dispersive X‐ray spectroscopy (EDS) were employed to examine the microstructure, elemental distribution, and chemical composition of the interfacial region. The results underscore the critical role of interfacial reaction layers in the soldering process. Mechanical testing (single lap offset, SLO, lap shear tests) was conducted to assess the bonding strength and mechanical integrity of the soldered joints. Furthermore, the thermal stability and reliability of these joints were evaluated through SLO tests at 300°C. This study contributes to the advancement of a user‐friendly, pressureless, localized heating and field‐deployable technique for soldering Si 3 N 4 to Invar42, thereby facilitating the fabrication of advanced engineering systems in industrial environments.

Silicon carbide (SiC) is a high-performance ceramic renowned for its excellent strength, thermal stability, and corrosion resistance, making it highly critical for advanced applications. Yet, achieving reliable joints remains challenging, especially given the need for localized heating rather than bulk heating of an entire SiC component. Laser-assisted joining has emerged as a promising alternative, offering the advantages of localized heating, rapid processing without the need for pressure, and precise energy control that significantly minimizes impact on adjacent materials. This study examines the feasibility of using two different infrared diode lasers for pressure-less, localized joining of SiC/SiC tubes to SiC/SiC end-plugs. The results are compared with those obtained using conventional furnaces. A silica-alumina-yttria-based glass is utilized as the joining material. The morphology, microstructure, and mechanical strength of the joints are analyzed, with strength evaluated through push tests designed to detach the end-plug from the tube.

Applying an alumina-based coating at the sealant interface on interconnects can significantly reduce degradation and extend the lifetime of Solid Oxide Cell (SOC) stacks. This study introduces an innovative aluminization process achieved through Electrophoretic Deposition (EPD) of metallic aluminum powder on Crofer22APU stainless steel, reported here for the first time. The EPD suspensions and coating consolidation treatments were optimized for intermediate temperature applications in SOC stack interconnects. The alumina-based coating enhances steel resistance to high-temperature oxidation and improves the interface at the joined areas with the sealant by increasing surface roughness. Alumina-coated interconnect-glass sealant samples were subjected to static air ageing at 850 degrees C for up to 1000 h to evaluate interface evolution and potential corrosion product formation. The mechanical resistance of the alumina-coated steel joints, both in their initial state and after 1000hour aging, was assessed via torsion tests, with a shear strength of 31.2 +/- 2.0 MPa and 33.0 +/- 1.0 MPa for asprepared and aged samples, respectively, revealing a cohesive fracture mode and no interface degradation even after prolonged aging.

This study evaluates the effectiveness of a silica preceramic polymer for joining and coating Plasma Electrolytic Oxidated (PEO) aluminum components at temperatures below 200 °C. PEO aluminum slabs were coated and joined with a silica precursor polymer (Durazane1800, Merck, Darmstadt, Germany), both with and without the addition of 48 wt% silica nanoparticles, and cured at 180 °C for 4 h in air. Thermogravimetric analysis assessed the curing process and thermal stability, while X-ray diffraction confirmed the polymer’s conversion to amorphous silica after heating at 1200 °C. Resistance to humid environments was tested by soaking coated samples in tap water for a week, with no mass variation observed. Mechanical testing through tensile mode and tensile lap tests showed that adding 48 wt% silica nanoparticles significantly improved joint cohesion and nearly quadrupled mechanical strength. Fracture surfaces were examined using Field Emission Scanning Electron Microscopy, and composition analysis was performed with Energy Dispersion X-ray Spectroscopy. Crack detection was conducted using Computer Tomography with an in situ bending test setup to obtain the mechanical resistance of the PEO coating. The results indicate that the silica preceramic polymer is suitable for joining and coating PEO aluminum components, with silica nanoparticles enhancing mechanical strength and providing excellent thermal stability and resistance to humidity.

This study investigates the impact of exposure to aggressive environments, specifically saline conditions per ASTM B117 standard, on the shear strength of adhesive‐bonded joints, crucial for ensuring structural integrity in various industrial applications like automotive, aerospace, and construction. Using an epoxy‐based adhesive to bond AISI304 steel, specimens undergo 14‐ and 28‐day salt spray treatments to simulate harsh working conditions. Torsional shear strength assessment of steel‐to‐steel adhesive joints is conducted using a torsion test methodology, with an analytical approach used to extrapolate adhesive joint shear strength. This research contributes to understanding adhesively bonded joint performance in challenging environmental conditions, and how the shear strength of the bonded joints changes in relatively small amount of time, offering valuable insights for robust structural designs across industrial sectors.

Today, aramid fibers are well known as a high-performance and ideal material for reinforcement purposes in rubber product manufacturing including hoses, tires, cables, and conveyors composites. However, surface modification of aramid fiber is necessary to solve poor interfacial adhesion between aramid fibers and the rubber matrix. Accordingly, in the present study, the effect of the surface modification of aramid fibers using atmospheric pressure plasma treatment with different precursors on adhesion to the rubber matrix was investigated. For that, the plasma coating was conducted using argon as the main working gas, and toluene, acetonitrile, tetraethyl orthosilicate (TEOS), and hexamethyldisiloxane (HMDSO) as liquid precursors. The physical-chemical characterization of the layer confirmed the successful deposition of amorphous carbon, amorphous nitride-carbon, SiO2, and Polydimethylsiloxane (PDMS)-like coating layers on the surface of aramid fibers by using toluene, acetonitrile, TEOS, and HMDSO as precursors, respectively. Overall, the result showed that the plasma surface modifications with acetonitrile precursor leads to the increase in interfacial adhesion of aramid/rubber composite, while retaining the tensile strength, and flame resistance properties of aramid as original fibers. Notably, the results of this study confirm the potential use of atmospheric pressure plasma for surface modification of aramid yarn to produce functional aramid for use in rubber composites.Highlights The plasma-coated aramid using HMDSO, TEOS, toluene, and acetonitrile precursors was prepared; and its effect on the tensile properties of aramid fiber as well as interfacial adhesion between aramid/rubber composite was investigated. The positive effect of atmospheric pressure plasma coating using HMDSO precursor on the tensile properties of aramid fiber was revealed. The positive effect of atmospheric pressure plasma coating using toluene and acetonitrile on the interfacial adhesion between aramid/rubber composite was revealed. The positive effect of atmospheric pressure plasma coating using TEOS precursor on the flam resistance property of aramid fiber was revealed. This study provides valuable insights into the effect of the different plasma-coated organosilicon and hydrocarbon precursors on the interfacial adhesion between aramid/rubber composite. Improvement in interfacial adhesion of aramid/rubber composite using atmospheric pressure plasma image

Airborne pollutants containing harmful microorganisms like bacteria and fungi pose serious health risks through inhalation, leading to conditions like asthma and infections. The recent pandemic has highlighted the urgency of improving air quality. The aim of this work is to develop reusable antimicrobial filters, depositing two composite coatings, composed of silver nanoclusters within two matrices, namely silica or zirconia, with a focus on the resistance of antibacterial activity of the coatings after thermal regeneration. The coatings were deposited via co-sputtering technique on different filters made from metallic, fiberglass, and polymeric materials. These coatings revealed uniform distribution and homogeneity, stability, and strong antibacterial activity, effectively inhibiting bacteria also after subjecting to the thermal regeneration treatment, without affecting porosity and filtering performance.

The indoor air quality should be better controlled and improved to avoid numerous health issues. Even if different devices are developed for air filtration, the proliferation of microorganisms under certain conditions must be controlled. For this purpose, a silver nanocluster/silica composite coating was deposited via a cosputtering technique onto fiber glass and polymeric based substrates. The aim of this work is focused on the evaluation of the antibacterial and antiviral effects of the developed coating. The preliminary results of the compositional and morphological tests showed an evenly distributed coating on filters surfaces. Several antibacterial tests were performed, confirming strong effect both in qualitative and quantitative methods, against S. epidermidis and E. coli. To understand if the coating can stop the proliferation of bacteria colonies spread on it, simulation of everyday usage of filters was performed, nebulizing bacteria solution with high colonies concentration and evaluating the inhibition of bacteria growth. Additionally, a deep understanding of the virucidal action and mechanism of Ag nanoclusters of the coating was performed. The effect of the coating both in aqueous medium and in dry methods was evaluated, in comparison with analysis on ions release. The virucidal performances are assessed against the human coronavirus OC43 strain (HCoV-OC43).

Municipal solid waste (MSW) production in the world has increased by 60 % in recent years. Incineration of MSW reduces their volume in conjunction with energy recovery. Incineration produces two residues, namely bottom ash (BA) and fly ash (FA), with high concentration of heavy metals and organic pollutants, especially for FA, making them an environmental concern. Vitrification is a costly, highly safe high temperature treatment, ensuring encapsulation of heavy metals. FA vitrification requires a source of silica to be able to get vitrified. In this study, we have proposed valorizing treated (vitrified) FA through the production of porous glass-ceramics, subsequently to MSWI. The entire process, from incineration to glass-ceramics production, was evaluated for several scenarios by Life Cycle Assessment (LCA) using Sima Pro 9.0. Three main scenarios were analysed; each one considering a different silica source: bottom ash (BA), glass cullet (G) and silica sand (S), and for each scenario, three thermal recovery subscenarios were assumed: no thermal recovery used to heat FA prior to vitrification (N), heating FA prior to vitrification using incineration gases thermal recovery (T) and methane combustion-aided thermal recovery, which exploits methane combustion to further increase the gases temperature (M). Results proved that vitrification was a technically feasible and environmentally-energetically sustainable technology. The result indicates that the most eco-sustainable scenario was using bottom ashes as a silica source together with methane-combustion-aided recovery: 0.467 kgCO2,eq, 5.83 x 10-8 carcinogenic-CTUh and 9.26 MJ required per kg of glass-ceramics produced.

High photocatalytic activity layers were obtained by combining a TiO2 nanostructured coating support with 10 nm and 20 nm NiO layers synthesized by direct current (DC) magnetron sputtering. In order to improve the TiO2 crystallinity several sputtering process parameters were studied. The TiO2 and NiO/TiO2 coatings were characterized through XPS, XRD, FESEM, AFM and UV transmittance measurements, in the latter case, for band gap determination. The photocatalytic activity of the coatings was tested through methylene blue degradation under UV light. The formation of a p-n heterojunction between the TiO2 and NiO layers improved the degradation rates, compared to the bare TiO2 layers; however, almost no difference can be seen when increasing the NiO sputtering power and subsequently the coating thickness to higher values than 20 nm.