Search

Porous ceramics find extensive applications in aerospace and other fields, and the measurement of their electromagnetic parameters is helpful in optimization of material properties and device designs. In this paper, a free-space 8f quasi-optical measurement system consisting of a vector network analyzer, a 325–500 GHz frequency expansion module, and four off-axis parabolic mirrors have been established to measure the transmission parameter S21 of porous ceramics. The complex permittivity was extracted according to the Newton-Raphson iterative method utilizing its measured S21 parameters based on flat mode. The porous ceramics with different porosity and density were measured and the relationships between their permittivity and porosity and density was established, respectively. These results are beneficial to the quality evaluation and application design of porous ceramic materials in the aerospace field. [ABSTRACT FROM AUTHOR]

TB18 is a newly developed high-strength metastable β-titanium alloy, commonly used in aerospace structural materials, which demands high mechanical performance. By altering the alloy's microstructure, heat treatment can affect its mechanical characteristics. The alloy was solution treated for one to four hours at 870 °C in order to examine the impact of solution treatment duration. Using X-ray diffraction (XRD) and scanning electron microscopy (SEM), the effects of solution treatment time on the β-phase grain size and its effect on stress distribution during tensile testing were examined. The findings showed that stress concentration during the tensile process was successfully decreased by refining the β-phase grain size. Sample solutions treated for two hours at 870 °C were then aged at various temperatures (510 °C, 520 °C, 530 °C, and 540 °C) to examine the impact of aging temperature. While the mass proportion of the α-phase first climbed and subsequently declined, reaching its maximum at 530 °C, the size of the α-phase increased monotonically as the aging temperature increased. The varies of mass fraction is associated with how the aging temperature affects α-phase nucleation. Tensile studies on TB18 alloy aged at various temperatures showed that while the alloy's ductility reduced, its strength increased as the aging temperature rose. The Hall-Petch relationship explains this tendency. [ABSTRACT FROM AUTHOR]

High-volume fraction silicon carbide particle-reinforced aluminum matrix (SiCp/Al) composites are crucial materials in the aerospace industry, requiring precision milling to ensure accurate mating surfaces. However, achieving low-damage machining of SiCp/Al remains challenging. Traditional dry machining methods often affect surface integrity, while minimum quantity lubrication (MQL) has emerged as a more sustainable alternative to flood cooling. Despite this, the tool's air barrier layer in MQL limits the lubricant flow to the tool-workpiece interface, reducing cooling and lubrication efficiency. To overcome this, an ultrasonic-enabled MQL (UV-MQL) technique for milling SiCp/Al is proposed. However, research on the effects and mechanisms of ultrasound-enabled nanolubricants in the milling of SiCp/Al composites remain limited. To fill this gap, milling experiments were conducted under various cooling and lubrication conditions. The performance of UV-MQL was assessed using key parameters such as milling force, specific cutting energy, and surface topography. Results showed that UV-MQL and UV-NMQL reduced specific cutting energy by 25.44% and 32.55%, respectively, compared to conventional MQL milling, while surface roughness (Sa values) decreased by 14.44% and 38.22%. To further explain these outcomes, the anti-friction mechanism of the ultrasonically enabled nanolubricant was analyzed, focusing on droplet wetting, penetration, and film formation. These findings provide valuable insights for improving surface integrity in the SiCp/Al milling process. [ABSTRACT FROM AUTHOR]

Ceramic Matrix Composites (CMCs), specifically SiC/SiC composites, represent a significant innovation in aerospace material technology, offering superior performance over traditional nickel-based superalloys in high-temperature turbine blade applications. This study presents a novel techno-economic assessment, filling a critical gap in the literature by directly comparing the economic and technical viability of CMCs versus superalloys. Unlike previous studies, which primarily focus on technical performance or cost analysis independently, this work integrates both aspects, providing a holistic comparison across key economic metrics, including acquisition, machining, maintenance, and recycling costs. The results demonstrate that SiC/SiC blades offer a 15–20% higher Net Present Value (NPV) and a 17% greater Internal Rate of Return (IRR) over a 20-year lifecycle than superalloys. Despite higher initial costs, CMCs achieve an estimated 2 to 3 years reduction in payback period, mainly due to their superior thermal and creep resistance, leading to fewer maintenance interventions and longer operational lifetimes. Although machining costs for CMCs are higher, these are more than offset by the long-term savings achieved through improved fuel efficiency and lower maintenance costs. A comprehensive sensitivity analysis, incorporating fluctuations in discount rates and material costs, further validates the economic robustness of CMCs in various operational scenarios. This study is the first to compare CMCs and superalloys, offering new insights into the financial implications of material selection in aerospace manufacturing. The findings present critical engineering recommendations that empower aerospace manufacturers and decision-makers to optimise material selection for improved efficiency and cost-effectiveness in high-performance turbine applications. [ABSTRACT FROM AUTHOR]

Near‐β titanium alloys are used as promising structural materials for aerospace, biomedical, and other advanced applications due to their excellent combination of high specific strength and superior corrosion resistance. Precise control of the microstructure and mechanical properties through thermomechanical processing and heat treatment is paramount for exploiting the full potential of these alloys. This review article provides a comprehensive and critical assessment of the state‐of‐the‐art research on the microstructure evolution, deformation mechanisms, and oxidation behavior of near‐β titanium alloys. Furthermore, the challenges and emerging opportunities in the development of near‐β titanium alloys have also been identified, ranging from alloy design and processing optimization to multiscale characterization and integrated computational materials engineering. This review article provides a timely and comprehensive roadmap for the research and development of near‐β titanium alloys, paving the way for unlocking their full potential in critical industries. [ABSTRACT FROM AUTHOR]

In this work, a novel universal multifunctional coating for insulation materials was prepared by using polyethyleneimine as the coating substrate, low-temperature molten glass powders and MXene as additives. Meanwhile, the universal coating was tightly adhered to the surface of the insulation materials through a surface activation strategy based on the synergistic effects of hydrogen bonding, electrostatic adsorption, and chemical bonding. The shear strength data showed that the adhesion between the universal coating and the three types of insulation material were higher than that of most commercial adhesives. In the case of EPDM, for example, the adhesion of the coating is 4.17 (epoxy glue), 1.04 (chemlok) and 1.67 (Neoprene) times that of commercial adhesives, respectively. In addition, the universal coating showed good heat resistance and thermal insulation, and formed a complete and dense char on the surface after exposure to flame. The maximum mass loss temperatures of the three coated insulation materials were 2.8, 6.5, and 9.3 °C higher than the original samples, respectively. Thermal insulation tests showed that the coated insulation materials reduced the average top surface temperature by 29.68 %, 40.84 % and 29.06 %, respectively, compared to the original samples. The results of anti-migration tests showed that the prepared universal coatings displayed generally superior anti-migration properties to the insulation materials, with equilibrium migration concentrations reduced by up to more than 80 % compared to the original samples, which is better than the previous products of the same type. In addition, the application potential of the advanced multifunctional insulation materials obtained from the preparation was evaluated, resulting in an increase of more than 35 % in peel strength and more than 20 % in shear strength for all insulation materials with propellants. This work provides a simple and environmentally friendly generalized strategy to develop high performance insulation materials for aerospace fields. A surface activation strategy with synergistic hydrogen bonding, electrostatic adsorption and chemical bonding is proposed to construct strongly adherent and universal multifunctional composite coatings on the surface of rocket motor insulation. The results show that the adhesion of the coatings on the three insulation substrates is stronger than that of most commercial adhesives, opening new possibilities for the development of high-performance heat-resistant materials in aerospace. In addition, the multifunctionality of the coating was demonstrated by its excellent heat resistance and insulation properties as well as outstanding anti-migration performance. The excellent adhesion to the propellant demonstrates the potential of the universal coating for use in solid rocket motors. [Display omitted] [ABSTRACT FROM AUTHOR]

Highlights The increasing demand for high‐performance materials in aerospace, automotive, and industrial applications has driven research into carbon fiber reinforced polyetherketoneketone (CF/PEKK) composites. This study introduces a novel slurry method for preparing CF/PEKK prepregs and investigates the impact of fiber surface treatments—desized and non‐desized carbon fibers—on the mechanical properties of the resulting composites. CF/PEKK prepregs were successfully prepared by dispersing PEKK powder in deionized water to create a slurry, which was used to impregnate carbon fibers. After hot‐pressing, mechanical testing revealed that composites with desized fibers outperformed those with non‐desized fibers in tensile strength (3.29%), flexural strength (22.12%), and interlaminar shear strength (18.29%). Furthermore, desized composites exhibited improved impact toughness (24.29%) and reduced fiber pull‐out during tensile testing. Scanning electron microscopy (SEM) analysis confirmed enhanced fiber‐matrix bonding in desized composites, with fewer voids and better fiber dispersion. These findings underscore the effectiveness of the slurry method and fiber desizing in improving the mechanical performance of CF/PEKK composites, offering potential for advanced applications in high‐performance sectors. Thermoplastic CF/PEKK prepregs successfully developed using slurry method. Novel slurry method enhances prepreg quality in CF/PEKK composites. Desized carbon fibers improve interfacial bonding and strength. Desized composites exhibit reduced fiber pull‐out during tensile testing. [ABSTRACT FROM AUTHOR]

The work is devoted to the study of laser shock treatment of structural materials used in aviation and space technology with powerful nanosecond pulses in order to reduce surface damage, as well as resistance to crack growth. The hardening effect is achieved due to the mechanical deformation produced by the shock wave from the laser pulse due to the rapidly expanding plasma in the area of the irradiation spot. In this work, laser parameters for processing structural materials are calculated to ensure the required laser radiation power density. The results of laser processing with high-power nanosecond pulses of materials such as oxygen-free copper, aluminum alloy and germanium at various energy densities, with and without a protective coating and a water layer are shown. • Laser shock treatment of structural materials by nanosecond pulses was presented. • A plastic deformation on oxygen-free copper was shown (depth up to 5 μm). • A plastic deformation on aluminum alloy was in a form of hollow with 3 μm depth. • Power density of laser pulses was up to 3.2 GW/cm2. [ABSTRACT FROM AUTHOR]

The growing demand for lightweight and high-strength materials in the aerospace and automotive industries, as well as the need for highly conductive materials such as heat sinks, electrodes and integrated circuits, has fueled the exploration of innovative composites. Metal matrix composites (MMCs) reinforced with graphene offer a promising solution, combining the inherent properties of metals with the unique characteristics of graphene. However, the fabrication of MMCs reinforced with graphene poses several challenges such as poor wettability of graphene within the metal matrix, a non-uniform distribution of graphene and graphene clustering. Various fabrication methods have been used to address these challenges; among them, high-pressure torsion (HPT) is a promising solution due to the introduction of a fine- or even nanograined structure with well-distributed graphene within the matrix through severe shear deformation. Grain boundary strengthening, Orowan bypassing due to the presence of non-shearable graphene particles, stress transfer to the reinforcements and the inherent properties of graphene can also enhance the mechanical properties of the graphene-containing MMCs produced by HPT. On the other hand, HPT negatively affects the electrical conductivity of the metal matrices by increasing the dislocation density and the number of grain boundaries. Nevertheless, graphene can also enhance the electrical conductivity of the composite by endowing the metal matrix with its π electrons. A current comprehensive examination of the literature provides valuable insights into the development of graphene-reinforced metal matrix composites fabricated by HPT and gives additional information on their potential applications. [ABSTRACT FROM AUTHOR]

High-energy photons in space environments, such as X-rays, thermal neutrons, and gamma rays, can cause ionization in polymer materials, leading to covalent bond breakage and degradation reactions. These reactions result in effects such as embrittlement, loss of elasticity, flaking, softening and stickiness, loss of mechanical strength, and gas emission, which can cause temporary damage or permanent failure of aerospace materials or devices. Rare earth elements have excellent radiation resistance to neutrons, high-energy photons and gamma rays due to their high absorption cross sections and atomic numbers. The photoelectric effect, Compton effect and electron pair effect of rare earth elements are firstly introduced in this paper. Next, the domestic and international research progress on the radiation resistance of rare earth elements in polymer materials, including fibers, plastics, rubber, epoxy resins, polyvinyl alcohol (PVA), and chitosan are reviewed. The discussion covers the incorporation of rare earth elements through doping, nanomaterial formation, and organic salts, utilizing preparation techniques such as co-precipitation synthesis, copolymerization, blending and extrusion, and molding. Testing methods include cobalt irradiation, neutron radiation, Monte Carlo simulations, and MCNP program calculations for neutron shielding. Comparative results with heavy metal lead demonstrate that rare earth elements significantly enhance the radiation resistance of polymer materials. Given their non-toxic and lightweight advantages, rare earth elements are expected to replace heavy metals like lead in applications within the medical, nuclear, and aerospace industries. The paper also provides a forward-looking perspective on the development of rare earth-based radiation-resistant polymer composite shielding materials in space environments. [ABSTRACT FROM AUTHOR]

The emphasis has shifted away from synthetic fibres and towards natural fibres as a result of the increased industrial demand for environmentally friendly products. Natural fibres are suitable candidates for use in modern industrial applications since they are biodegradable, lightweight, affordable, and environmentally beneficial. One fibre that has very good mechanical properties is abaca fibre. This paper reviews the literature on abaca fibres as a reinforcing material. The composition and properties of abaca fibres are discussed, along with various studies on abaca-reinforced composites. Abaca reinforced composite's difficulties and future work are therefore investigated. Research shows that pre-treating abaca fibres improves the composite's mechanical characteristics. Also, there have been attempts to improve the mechanical characteristics and environmental performance of current synthetic composites by adding abaca fibres. Abaca is anticipated to become one of the most effective sources of reinforcing fibre for use in the building of a variety of components, including aerospace and automotive materials. [ABSTRACT FROM AUTHOR]

Copyright of Cotton Textile Technology is the property of Cotton Textile Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The increasing demands on global resources due to technological development driven by consumer expectations and demands have resulted in significant problems with ecological sustainability and material availability. The creation of biocomposites has resulted in notable advancements in the green industry within the materials science area this century, owing to concerns regarding sustainability and the environment. Globally, there is a surge in the creation of highly efficient materials derived from natural resources. In aviation applications, plant fiber-supported polymer composite materials are becoming increasingly popular. Aerospace materials are typically used in aircraft construction as structural materials to support loads throughout different flight phases. There are many diverse mechanical qualities of natural fibers; therefore, selecting one for the interior parts of an aircraft cabin based only on its attributes leads to a multiple-attribute decision-support issue. In this paper, the effective natural fiber and polymer choice for use as reinforcing materials in composite materials is represented as the composite materials' improvement to aircraft cabin luggage for aerospace implementations. This study can guide material designers in investigating different hybrid materials with the most effective natural fiber and polymer obtained by hierarchical strategy by elucidating the effective material choice to meet the criteria determined for the aircraft cabin luggage. For this purpose, the definitive rankings of the twelve polymers and sixteen natural fibers in terms of performance score were assessed using a hierarchical strategy methodology. [ABSTRACT FROM AUTHOR]

Hollow glass microsphere (HGM) reinforced composites are a suitable alternative to energy absorption materials in the automotive and aerospace industries, because of their high crush efficiency and energy absorption characteristics. In this study, a polyurethane elastomeric matrix was reinforced with HGMs for HGM loadings ranging from 0 to 70 vol% (volume fraction). Quasi-static uniaxial compression tests were performed, subjecting the composite to compressive strains of up to 65%, to assess stress vs. strain and energy absorption characteristics. The results reveal that samples with a higher concentration of spheres generally exhibit better crush efficiency. Specifically, the highest crush efficiency was observed in samples with a 70 vol% HGM loading. A similar relationship was reflected in the energy absorption efficiency results, with the highest energy absorption observed in the 65 vol% sample. A correlation exists between the concentration of HGMs and important metrics such as mean crush stress and energy absorption efficiency. However, it is crucial to note that the optimal choice of sphere concentration varies depending on the desired performance characteristics of the material. [ABSTRACT FROM AUTHOR]

Multifunctional recyclable glassy polymeric materials (GPMs) are sustainable substitutes for high‐performance protective materials in aerospace, transportation, construction, and electronics; however, only a few such materials have been reported. This study presents a novel material design including the modular construction, utilization of self‐reinforcing polysilsesquioxane (POSS), and self‐enrichment strategy to integrate multifunctions in recyclable GPMs. Specifically, rigid self‐reinforcing thiol‐capped POSS (module 1) are connected with isocyanate‐terminated polyurethane precursors (module 2) by forming dynamic thiourethane covalent bonds to fabricate recyclable GPMs. Particularly, based on the modular construction and self‐enrichment strategy, functional module 3 can be introduced to endow recyclable GPMs with programmable multifunctionality. Demonstrating remarkable properties, including high transparency (>85% transmittance), hardness (up to 5H), good flexibility, and exceptional wear resistance, these materials also exhibit impressive shape reconfigurability and robustness after numerous thermal recycling or remolding cycles. Moreover, the introduction of functional module 3 (e.g., polydimethylsiloxane prepolymer) can self‐enrich onto the surface to endow the materials with anti‐liquid adhesion, self‐cleaning, and deicing properties while having a slight impact on their mechanical properties. This study presents a universal and tunable approach for the future design of multifunctional recyclable GPMs applicable in flexible electronics, aircraft vehicles, and architectural windows. [ABSTRACT FROM AUTHOR]

Poly(para‐xylylene) (PPX) is a robust and biocompatible coating material that is widely used in various applications, including electronics, aerospace and defense materials, automotive materials, and biomaterials. In this progress report, recent developments in PPX technology ranging from the advancement of physical chemistry properties and structural properties for device integration to the transformation of 3D monolith materials of PPX with controls in outer and inner structures at the micro‐ and nanometer scales are highlighted. Based on emerging chemistry studies on [2.2]paracyclophanes, which are primarily used precursors to synthesize PPX via vapor deposition polymerization, functionalization, and the creation of a wide variety of functional PPX derivatives are demonstrated without resistance. Widely used as an interface coating material, PPX is processed to form integrated structural materials and has already been found to be useful in the market as part of electronic and medical implant products. Using a newly innovated transformation to fabricate PPX through templates (metal‐organic frameworks, liquid crystal, ice crystal), 3D monoliths, nanoscale particles, hierarchical and gradient interior structures, and dynamically transformable shapes at the nanoscale are demonstrated. A vast landscape of novel applications and device products is expected based on the already established R&D and market maturity of PPX. [ABSTRACT FROM AUTHOR]

The increasing need for lightweight, high strength and cost-effective materials for automotive and aerospace industries worked as the impetus for this investigation. E-glass fibers are layered with 3K-carbon fibers in proportions of 7:6 & 6:7 for fabricating hybrid fiber reinforced polymer (FRP) composites. First stage of the study involves the identification of the optimized fiber stacking pattern. Later, nanocomposites were made for further enhancement of tensile properties by infusing titanium dioxide (TiO2) nanoparticles to hybrid FRP composite ‘C2G3C3G3C2’ with optimized stacking pattern. The TiO2 nanoparticles are equally disseminated in the epoxy resin using ultrasonication with five different wt. % of 0, 1.25, 2.5, 3.75, and 5. The peak load, ultimate tensile strength (UTS), tensile modulus, and % elongation at break were examined as per ASTM D3039 tensile testing. The UTS of optimized hybrid FRP composite, carbon non-hybrid FRP composite, and nanocomposite (at 2.5 wt. % TiO2 nanoparticles) were 424.98 MPa, 429.0 MPa, and 478.51 MPa, respectively. Further, the cost of optimized hybrid FRP composite and nanocomposite (at 2.5 wt. % of TiO2 nanoparticles) is approximately 36.93% and 21.51% less than most expensive carbon non-hybrid FRP composite. The morphological analysis revealed that TiO2 added composites up to 2.5 wt. % exhibit fewer defects, indicating a better interaction between the matrix and the fibers. [ABSTRACT FROM AUTHOR]

The use of microwave absorption (MA) materials in practical aerospace applications would be challenging without a dependable mechanical support structure. However, achieving a wide effective absorption bandwidth (EAB) in aramid honeycomb structures at low weight gain is crucial for the practical aerospace applications of MA materials. To address this challenge, this study proposes a combination of porous carbon foam and high structural strength honeycomb to achieve broadband microwave absorption in structural devices through the synergistic effect of carbon foam absorption and honeycomb structure. The uniform filling process of ultra-lightweight reduced GO aerogel is achieved through freeze-drying, solving the issues of uneven dispersion and incomplete filling of traditional absorbers in honeycombs. Further optimization and comprehensive evaluation of filling concentration and reduction process were carried out. The freeze-drying process combined with chemically reduced honeycomb samples filled with different concentrations of GO all exhibit broadband absorption performance. At a specific standard honeycomb thickness of 15 mm, uniformly filled honeycomb samples with 0.1 to 0.3% GO exhibit triple resonance peaks near 2–3 GHz, 8–9 GHz, and 15 GHz, with effective absorption peaks all below − 10 dB. Moreover, the incorporation of transparent wave honeycomb walls in conjunction with honeycomb materials enhances the overall impedance matching, leading to a further improvement in the EAB to 10.53 GHz for the honeycomb sample filled with 0.2% freeze-dried and reduced GO. CST simulation data confirms that the loss in the honeycomb samples originates from uniform conduction loss, and the electric field stably enters the interior of the honeycomb. This approach, based on the rapid and efficient filling of uniform RGO by freeze-drying, provides a new way to achieve broadband microwave absorption in aramid honeycombs and has significant potential for development in the field of aerospace stealth. [ABSTRACT FROM AUTHOR]

[Display omitted] • Eh-pH diagram of K-S-Fe-H 2 O system is established to analyze the iron removal. • Controlling high potential and a certain pH value are good for jarosite process. • Efficient and selective iron removal from acid solution has been achieved. • Regular ellipsoidal particles of jarosite with even particle size are obtained. • The crystallization mechanism and kinetics of jarosite formation are analyzed. Aerospace magnetic material scraps are abundant in cobalt and nickel. Sulfuric acid leaching process is an efficient method for extracting them. But it is a non-selective process, a significant amount of iron dissolves in the solution. This study focuses on the selective removal of iron from this solution using the jarosite process. E h -pH diagram of K-S-Fe-H 2 O system was established. Based on thermodynamic analysis, H 2 O 2 is used to oxidize Fe2+ into Fe3+, achieving efficient and selective removal of iron from the solution containing cobalt and nickel. The optimal conditions are as follows: temperature 95°C, K 2 SO 4 dosage coefficient 1.5, seed dosage 10 g/L, time 90 min, pH 1.76, and endpoint pH controlled at approximately 3. Under these conditions, the iron removal efficiency is above 99%, while the loss ratios of cobalt and nickel are below 2%. The product is characterized by XRD and SEM-EDS. Results indicate that the product is jarosite ((K,H 3 O)Fe 3 (SO 4) 2 (OH) 6), exhibiting an ellipsoid structure with the mean particle size in the range of 0.2–5.0 μm. Temperature, pH value and seed dosage significantly affect reaction rate, particle size and crystallinity, and K 2 SO 4 dosage mainly affects reaction rate and the morphology of jarosite. The jarosite crystallization kinetics can be described by the Avrami equation, with an Avrami index (n) of approximately 2.5 and the apparent activation energy of 42.68 kJ/mol. [ABSTRACT FROM AUTHOR]

A silicon‐containing arylacetylene resin (PSA)/SiO2 syntactic foam was prepared through a chemical foaming approach, with PSA serving as the matrix, quartz sand (QS) and nanosilica (nSiO2) acting as fillers, and their structures and properties were characterized. The results show that the incorporation of appropriate amounts of QS and nSiO2 can reduce the cell size and apparent density of the syntactic foam, and improve its heat resistance, dielectric properties and wave transmission properties. The addition of QS can increase the compressive strength of the syntactic foam, while the addition of nSiO2 decreases the compressive strength. The apparent densities of the PSA/9QS and PSA/9nSiO2 syntactic foams with 9% filler addition are 0.242 g cm−3 and 0.157 g cm−3, respectively, and the temperatures at 5% weight loss (Td5) under a nitrogen atmosphere were 692 °C and 658 °C, respectively. The dielectric constants were 1.59 and 1.25, respectively. The wave transmittance within the frequency range of 8.2–12.4 GHz was 98.5% and 96.8%, respectively. PSA/SiO2 syntactic foam can be used as a lightweight and high‐temperature‐resistant wave‐transmission material in aerospace and other fields. [ABSTRACT FROM AUTHOR]

This study aims to enhance understanding of material wear behavior by investigating the microstructure and wear characteristics of AA7178 matrix alloy reinforced with varying wt.% (0, 1, 2, and 3%) of nano-SiC particles, fabricated through stir-casting. The research addresses deficiencies in current materials used in aerospace components, where wear resistance is crucial. These materials often suffer from inadequate wear resistance, surface damage susceptibility, and rapid degradation under abrasive conditions, resulting in increased maintenance costs, reduced component lifespans, and diminished system efficiency. To address these issues, the hypothesis posits that integrating nano-SiC particles into the AA7178 matrix alloy will enhance wear resistance and advance high-performance metal matrix composites. The dry sliding wear behavior of the nanocomposites was examined using a pin-on-disc wear test apparatus with EN31 steel as the counterbody material. Systematic variations in sliding velocity (1, 2, 3, and 4 m/s), distance (500, 1000, 1500, and 2000 m), and load (10, 20, 30, and 40 N) were conducted. Employing the L16 Taguchi method, experimental research and wear analysis revealed that the most influential factor affecting wear rate was the applied load (67.39%), followed by the SiC wt.% (30.85%), with an R2 value of 99.80%. Optimization of wear process parameters was achieved through metaheuristic techniques, encompassing the Rao-1, Particle Swarm Optimization (PSO), and Artificial Bee Colony (ABC) algorithms. The Rao-1 technique demonstrated robustness at approximately 98%, displaying higher efficiency in parameter optimization. Optical microscope analysis identified micro-cutting and micro-ploughing as the primary wear mechanisms. Under specific conditions—9.81 N applied load, 4 m/s sliding speed, 500 m wear distance, and a 3% SiC wt.%—the AA7178/SiC composites exhibited optimal wear resistance, measuring 1.7088*10−3 mm3/m. These findings offer critical guidance for engineering high-performance metal matrix composites, effectively addressing the inherent deficiencies in aerospace component materials. [ABSTRACT FROM AUTHOR]

NiAl-based alloys possess desirable characteristics such as lightweight, high modulus, and excellent oxidation resistance, making them promising materials for aerospace and other applications. However, the limited room-temperature plasticity of NiAl alloy hinders its manufacturing and practical use. The incorporation of Mo and Co through alloying treatment can significantly enhance the room-temperature plasticity of NiAl-based alloys. A series of eutectic high-entropy alloys, (NiAl)65V20Cr10Mo5−xCox (x = 0, 1, 2, 3, 4, and 5), were fabricated through non-consumable vacuum melting. The influence of Co and Mo contents on the microstructure and mechanical properties of these alloys was investigated. The findings indicate that the phase composition of the alloy remains unaffected by the presence of Mo and Co in its content. With an increase in Co content and a decrease in Mo content, the primary B2 phase gradually increases in the alloy, leading to a microstructural transition from complete eutectic structure (x = 0) to hypoeutectic structure (x > 1). The strength of the alloy exhibits an initial increase followed by a decrease. At low Co contents, the fracture strength and strain of the alloy experience significant enhancement. (NiAl)65V20Cr10Mo3Co2 demonstrates superior compressive properties, with its yield strength, fracture strength, and plasticity reaching 1761 MPa, 3009 MPa, and 33.5%, respectively. The changes in the mechanical properties of alloys are primarily attributed to solid solution strengthening, lattice misfit, fine crystal strengthening, and relative variations in phase content. [ABSTRACT FROM AUTHOR]

GH4169 superalloy is an outstanding material used in aerospace, and precision grinding is widely applied to machine GH4169 superalloy, where the grinding force plays essential role on the ground surface quality and the achieved surface topography. In this paper, the material removal mechanism under different machining parameters is analyzed in cylindrical grinding of GH4169 superalloy. The interaction process between abrasive grain and workpiece material is investigated to establish the simulation model of material removed based on the kinematics. The random wheel topography is constructed statistically using the probability density function that characterizes the distribution of the grains. The simulated grinding force and surface topography are in good agreement with the experimental results. Specifically, the errors of the tangential and normal grinding force are 5.33% and 6.33% and the errors of the roughness Sa and Sz are 5.51% and 7.40%, respectively. Based on the simulation model and calculation results, the machining parameters are optimized for cylindrical grinding of GH4169 (vs = 45 m/s, f = 150 mm/min, ap = 3 μm, vw = 0.262 m/s) to improve the achieved surface quality. [ABSTRACT FROM AUTHOR]

This article is about Green Metal Matrix Composites (GMMCs) produced with aluminum alloys and reinforcements include silicon carbide and eggshell powder. The GMMCs offer a new approach to sustainable materials through the use of ecofriendly reinforcements. A novel class of composites results from a combination of silicon carbide, which has superior mechanical properties, and agricultural waste based eggshell powder. Furthermore, eggshell powder mainly comprised of calcium carbonate lowers its density as well as serves as long-term reinforcement. Silicon carbide enhances their mechanical properties in terms of strength and hardness respectively. This report involves a systematic study using mechanical testing and scanning electron microscopy to explain microstructural evolution and evaluate performance during mechanical loading. Further, wear resistance gives indications on suitability for different industrial applications. Variations in reinforcement contents were done so as to include 3–12% silicon carbide, and 2–8% eggshell powders in the aluminum alloys. Production strictly adhered to guidelines that controlled some variables such as stirring speed and duration which was aimed at achieving exact control. These cast composites were subjected to wear tests, tensile tests, and hardness tests as well as microstructural analysis. EDS-SEM results demonstrate successful incorporation of the reinforcements into the hybrid composites. Unveiling a surprising evenness of distribution of reinforcements throughout the Aluminum matrix through Microstructural examination is amazing. Unique wear behavior trends are presented here. The matrix alloys show mainly adhesive wear while the composites display abrasive wear mediated by reinforcements. This research proposes an eco-friendly method for metal matrix composites, thus advancing sustainable materials and offering hope for strong yet lightweight green materials suitable for aerospace, automotive and other engineering sectors. [ABSTRACT FROM AUTHOR]

Hybrid nanocomposites have emerged as a groundbreaking class of materials in the aerospace industry, offering exceptional mechanical, thermal, and functional properties. These materials, composed of a combination of metallic matrices (based on aluminum, magnesium, or titanium) reinforced with a mixture of nanoscale particles, such as carbon nanotubes (CNTs), graphene, and ceramic nanoparticles (SiC, Al2O3), provide a unique balance of high strength, low weight, and enhanced durability. Recent advances in developing these nanocomposites have focused on optimizing the dispersion and integration of nanoparticles within the matrix to achieve superior material performance. Innovative fabrication techniques have ensured uniform distribution and strong bonding between the matrix and the reinforcements, including advanced powder metallurgy, stir casting, in situ chemical vapor deposition (CVD), and additive manufacturing. These methods have enabled the production of hybrid nanocomposites with improved mechanical properties, such as increased tensile strength, fracture toughness, wear resistance, and enhanced thermal stability and electrical conductivity. Despite these advancements, challenges remain in preventing nanoparticle agglomeration due to the high surface energy and van der Walls forces and ensuring consistent quality and repeatability in large-scale production. Addressing these issues is critical for fully leveraging the potential of hybrid nanocomposites in aerospace applications, where materials are subjected to extreme conditions and rigorous performance standards. Ongoing research is focused on developing novel processing techniques and understanding the underlying mechanisms that govern the behavior of these materials under various operational conditions. This review highlights the recent progress in the design, fabrication, and application of hybrid nanocomposites for aerospace applications. It underscores their potential to revolutionize the industry by providing materials that meet the demanding requirements for lightweight, high-strength, and multifunctional components. [ABSTRACT FROM AUTHOR]

Carbon/carbon composites (C/Cs) are extensively utilized as structural materials and functional materials in the aerospace industry. Laser processing technology is an effective means of precision manufacturing C/Cs parts, with the advantages of no mechanical impact and high efficiency. Accurately predicting the material removal of C/Cs during laser processing is of great significance for the precision manufacturing of C/Cs parts. However, the numerical simulation models that can directly display the microstructure of C/Cs are still inadequate, and measuring the sublimation temperatures of two different phases of carbon is challenging. This paper establishes a three-dimensional microscopic heterogeneous finite element (FE) model of C/Cs, and the FE simulation of quasi-continuous wave (QCW) laser ablation of C/Cs is optimized using the restart method taking into account the residual temperature. Combining the optimized FE model, the material parameters of C/Cs are inverted using response surface methodology and genetic algorithm, resulting in the sublimation temperatures of the fiber phase being 4029.01 K and the matrix phase being 3481.86 K. After these parameters are substituted into the FE model, the resulting simulations are then compared with the experiments of QCW laser processing C/Cs, which reveals high correspondence between simulated morphology and experimental data, with the relative error of predicted ablation depth not exceeding 6.169%. The revised FE model can guide the laser processing of C/Cs, and the inverted material parameters can provide references for the theoretical study of the laser processing of C/Cs. [ABSTRACT FROM AUTHOR]

316 L stainless steel powder with varying particle sizes was chosen as the raw material for the fabrication of metal hollow spheres using powder metallurgy techniques. The powder's particle size, composition, and micro-morphology were examined, followed by porosity and capillary force calculations, compressive testing, and fracture analysis. The findings reveal significant disparities in the micro-morphology and mechanical properties among the metal powders with different particle sizes. Smaller particle sizes result in denser bonding of the hollow spheres, leading to higher compressive yield strength. Conversely, larger powder particle sizes substantially increase the porosity of the hollow sphere wall, resulting in a sharp decline in mechanical properties and a transition from ductile fracture to brittle fracture in its failure mode. This study's innovation lies in its meticulous examination of the relationship between particle size distribution and the resulting microstructural and mechanical properties of 316 L stainless steel hollow spheres, providing valuable data that enhances the understanding of powder metallurgy processes and drives the development of advanced materials for aerospace applications. [ABSTRACT FROM AUTHOR]

Highlights Carbon fiber reinforced polyetherketoneketone (CF/PEKK) possess excellent mechanical properties and also meet low‐carbon environmental standards, leading to their increasingly widespread application in recent years. To ensure the strength of mechanical connections, it is crucial to minimize drilling damage. This paper utilizes Ultrasonic Vibration‐Assisted Drilling (UVAD) to enhance hole‐making quality, comparing multiple drilling performance indicators with Conventional Drilling (CD), including thrust force, drilling temperature, delamination factor, and burr factor. The results demonstrate that UVAD significantly reduces thrust force and drilling temperature, decreases delamination and burring damage, and effectively improves hole quality. To further optimize processing parameters, the Non‐dominated Sorting Genetic Algorithm II (NSGA‐II) was used, targeting thrust force, Material removal rate (MRR), and delamination factor as optimization goals. The reliability of the model was verified through experimentations. This paper provides an effective technical approach for high‐quality drilling in CF/PEKK materials, offering significant practical application value for material processing in aerospace and other fields. The quality of CF/PEKK processed by CD and UVAD was compared. UVAD can effectively improve the quality of drilling. The drilling parameters were optimized by NSGA‐II. The reliability of the prediction model was verified by experiments. [ABSTRACT FROM AUTHOR]

In carbon allotropes, interfacial engineering of various sp2 nanocarbon building blocks has shown great promise in designing and fabricating creative nanocarbon assemblies with novel structural and functional properties. Here, a robust, flexible, metal‐like heterostructured carbon nanotube (CNT) film formed of amorphous graphene nanosheets (AGNs) on CNT networked film is demonstrated, presenting a sp3‐sp2 dominated interfacial heterostructure. Extensive characterization reveals that AGN exhibits a complete absence of long‐range periodicity with twisty six‐member rings. Such 2D graphene mailed 1D CNT structure endows the heterostructured carbon nanocomposite film with a combination of unique properties, including surface nano‐flattening (flatness fourfold of the raw CNT film), excellent anti‐wear performance, greatly enhanced modulus (enhanced by 400%), hardness (enhanced by 300 times), and conductivity (enhanced by 270%). Unlike conventional carbon‐based materials, such flexible films show distinct substantial deformability and rapid resilience over wide temperatures (−196–≈1300 °C), which facilitate the design of new‐concept lightweight high‐temperature resistant and shape‐transformable materials for advanced aerospace applications under extreme conditions. [ABSTRACT FROM AUTHOR]

Al–Li alloys, characterized by their lightweight and high strength, are essential structural materials in aerospace industry. Unraveling the atomic mechanisms that enhance the modulus of Al–Li alloys is key to developing the next-generation alloys. Utilizing first-principles methods, we systematically explored the influence of alloying elements on mechanical properties, ranging from binary solid solutions to Al3X precipitates and extending to ternary Al–Cu–Li alloys. Li significantly improves the modulus due to its size effects, low density, high solubility and easy precipitation. In binary A–Li solutions, the formation energy decreases (− 0.007 to 0.030 eV/atom) and the Young's modulus rises (80.2–88.4 GPa) as Li concentration increases (0–12.5 at.%). This increase in modulus is due to the compression of Al–Al bonds by Li atoms. The binary Al3Li phase, with reinforced bonds and lower density, exhibits a higher specific E modulus (49.2 GPa/g cm−3). In the ternary phase T1 (Al6Cu4Li3), the synergistic strengthening of both Al–Al and Cu-X (X = Al, Cu) bonds results in an elevated Young's modulus of 120.3 GPa, establishing it as a pivotal strengthening phase for the third-generation alloys. Subsequent theoretical calculations show superior elastic modulus in Al-X (X = Be, Si, Cr, Mn, Ni) solutions and Al3X (X = Sc, Ti, V, Zr) phases. Additionally, Zn can participate in the precipitation of the T1 phase, thereby enhancing the mechanical properties of the alloy. Gaining insights into atomic interactions and their influence on the modulus could inform the future design and optimization of multi-element Al–Li alloys. [ABSTRACT FROM AUTHOR]

This paper introduces a damage diagnosis method based on the reassignment method and matching networks (MNs) to study the structural health monitoring of aerospace composite material components. This aims to facilitate the mapping of signal features to complex failure modes. We introduce a signal processing technique based on the reassignment method, employing a sliding analysis window to re‐estimate local instantaneous frequency and group delay. By utilizing the short‐time phase spectrum of the signal, we correct the nominal time and frequency coordinates of the spectrum data, aligning them more accurately with the true support region of the analyzed signal. Subsequently, this paper developed a deep matching network (DMN) damage diagnosis model based on MNs. This model utilizes a convolutional neural network (CNN) to extract damage‐related features from the signal and introduces the full context embedding (FCE) method to enhance the compatibility of sample embeddings. In this process, the embeddings of each sample in the training set should be mutually independent, while the embeddings of test samples should be regulated by the distribution of training set sample data. Ultimately, the damage category of test samples is determined based on cosine similarity. We validate our model using damage sample data collected from experiments and simulations conducted under varying components and operating conditions. Comparative assessments with five mainstream methods reveal an average accuracy exceeding 96%. This underscores the exceptional recognition accuracy and generalization performance of our proposed method in cross‐operating condition fault diagnosis experiments concerning aircraft composite material components. [ABSTRACT FROM AUTHOR]

Petroleum-based cured epoxy polymers, used widely in aerospace, marine, and automotive industries, pose environmental threats due to their toxicity. Therefore, developing alternative curing systems for epoxy resin is crucial. This study explores the use of bio-based phenalkamines as curing agents for epoxy resin to enhance the mechanical properties of polymer composites and fiber-reinforced laminates. The functional groups, morphology, and thermal properties of the composites were analyzed using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). Mechanical properties of two epoxy systems—EP-TETA (triethylenetetramine-cured) and EP-PA (phenalkamine-cured)—were evaluated according to ASTM standards. EP-PA exhibited approximately 318% greater elongation, indicating improved ductility, and 16% higher ultimate force and stress compared to EP-TETA, suggesting its suitability for load-bearing applications. Additionally, phenalkamine-cured epoxy resin composites with adequate thickness demonstrated excellent performance. Glass fiber-reinforced GEP-PA showed 5.3 times greater toughness and adhesion in end notch tests compared to GEP-TETA. These results offer valuable insights for material selection in aerospace and automotive applications. [ABSTRACT FROM AUTHOR]

Vitrimers are reprocessing and recycling thermosetting plastics. They possess reconfigurable polymer networks that allow for unlimited transformation in shape in principle. However, current strategies to reshape the vitrimers typically involve heat or light, which often induces undesirable oxidation and decomposition. To address this issue, here a water‐assisted approach is proposed for programming epoxy vitrimers' shapes. In this design, water molecules are utilized to reversibly dissociate the hydrogen bonds in epoxy vitrimers to enable the polymer segments to move flexibly. The hydrated epoxy vitrimers can then be reprogrammed and retained into different temporary shapes by removing the water. Such samples would be recovered to their original shapes by rehydration, exhibiting water‐induced shape memory property. More than temporary deformation, the permanent figures of the hydrated vitrimers can also be permanently changed at room temperature (rt) or elevated temperatures in the presence of transesterification catalysts. Combing the shape memory and high temperature plasticity or utilizing rt plasticity, sophisticated shapes such as spiral shapes are demonstrated. It is envisioned that this water‐assisted methodology can be useful in programming cross‐linked polymers into diverse 3D structures, which has wide practical applications in soft robots, deployable devices, aerospace materials, etc. [ABSTRACT FROM AUTHOR]

Thermal protection was always a prominent issue in the aerospace industry. For vehicle safety, reliability and payload requirements, thermal protection materials were usually expected to possess low density, superior mechanical and thermal insulation properties. Here, lightweight and high-strength porous mullite-silica ceramics were manufactured using particle-stabilized foaming technique. The strength and thermal insulation properties of porous ceramics modified with hollow silica spheres were significantly enhanced. A 10 wt% hollow spheres addition achieved a 28.9 % increase in strength and a 33.4 % decrease in thermal conductivity with almost constant porosity (from 86.39 % to 87.04 %). Considering the characteristics of light weight, high compression strength and superior thermal insulation performance, porous ceramics could be applied as thermal protection materials in the aerospace sector. [ABSTRACT FROM AUTHOR]

Copyright of Foundry Technology (1000-8365) is the property of Foundry Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Nanoclays, a specific type of nanomaterial, have emerged as versatile and dynamic materials, with tremendous potential for advanced functional applications. Despite publishing a large number of research articles, there are relatively few review articles on this topic. This comprehensive review delves into the most widely used nanoclays and explores the diverse range of applications in different fields, such as aerospace, automobile, construction, biomedical, food packaging, and polymer composites. With their ability to enhance the performance of materials and products, nanoclays have become a highly desired material in various industries. The challenges associated with nanoclays like complex properties, difficulty in developing new synthesis methods, and challenges in investigating long‐term durability and stability have been summarized. The future research directions with the exciting possibilities to develop future innovative materials have been highlighted at the end of the article. Highlights: This review provides an extensive examination of the most widely used nanoclays, detailing their properties, types, and limitations.A summary of publication trends over the last 15 years, based on Scopus data up to 2024, indicates growing interest and research output in nanoclays.Applications of nanoclays span across aerospace, automobile, construction, biomedical, food packaging, and polymer composites, showcasing their versatility.Key challenges discussed include complex properties, difficulties in new synthesis methods, and issues in long‐term durability and stability.Future research directions highlight the potential for developing innovative materials using nanoclays. [ABSTRACT FROM AUTHOR]

The object of the study is the global aerospace market status, segment analysis, dynamics, competition, and prospects. The methods of searching and analyzing literature data, summarizing, systematizing, and visualizing data with diagrams are used. The aerospace industry is at the forefront of technological innovation and is constantly searching for new advanced materials to improve productivity, efficiency, and safety. The aerospace market encompassing the design, manufacture, and maintenance of aircrafts, space vehicles, and related systems. It includes the commercial and military sectors, as well as the space exploration field. The world market of the aerospace industry was studied. Factors affecting the market positively and negatively were identified. According to the global aerospace market segmentation by vehicle types, the leading position in 2023 was occupied by the commercial aircrafts segment with a share of 63.4 %; by the vehicle size – by the narrow-body aircraft segment (72.4 %); by the end consumer – by the private sector segment (65.4 %); by operation – by manually operated aircrafts segment (79.4 %); and by geographic regions – by the North American segment (47.3 %). The main strategic trends and directions of the further aerospace market development are presented. The world market of aerospace materials was studied. Factors affecting market dynamics are identified, and market challenges are highlighted. According to the world aerospace market segmentation by the materials types, the leading place in 2022 belonged to the composite materials segment with a share of 69 %; by the aircraft type – to the commercial aircrafts segment (51 %); and by geographical regions – to the European segment (35.0 %). The trends of the sustainable aerospace industry development are summarized: modern aircraft design, use of sustainable aviation fuel, urban air mobility, modern traffic technology, and air transportation management optimization. For each trend, possible actions leading to changes in the aerospace industry are considered. The question of the nanomaterials use in the space industry is considered. Some characteristics and possibilities of application of nanocomposite materials, nanocoatings, nanofluids, nanosensors, and carbon nanotubes, as well as examples of the nanomaterials application in aircraft components are given. The industry problems are identified, and their possible solutions are given. [ABSTRACT FROM AUTHOR]

Due to the prominent advantages of low density, high elastic modulus, high specific strength and specific stiffness, cast Al-Li alloys are suitable metallic materials for manufacturing complex large-sized components and are ideal structural materials for aerospace, defense and military industries. On the basis of the microstructural characteristics of cast Al-Li alloys, exploring the role of alloying and micro-alloying can stabilize their dominant position and further expand their application scope. In this review, the development progress of cast Al-Li alloys was summarized comprehensively. According to the latest research highlights, the influence of alloying and heat treatment on the microstructure and mechanical properties was systematically analyzed. The potential methods to improve the alloy performance were concluded. In response to the practical engineering requirements of cast Al-Li alloys, the scientific challenges and future research directions were discussed and prospected. [ABSTRACT FROM AUTHOR]

To meet the demands for high-temperature performance and lightweight materials in aerospace engineering, the Au-Ni solder is often utilized for joining dissimilar materials, such as Ti3Al-based alloys and Ni-based high-temperature alloys. However, the interaction between Ti and Ni can lead to the formation of brittle phases, like Ti2Ni, TiNi, and TiNi3, which diminish the mechanical properties of the joint and increase the risk of crack formation during the welding process. Cu doping has been shown to enhance the mechanical properties and high-temperature stability of the Au-Ni brazed joint's central area. Due to the difficulty in accurately controlling the solid solution content of Cu in the Au-Ni alloy, along with the high cost of Au, traditional experimental trial-and-error methods are insufficient for the development of Au-based solders. In this study, first principles calculations based on density functional theory were employed to analyze the effect of Cu content on the stability of the Au-2.0Ni-xCu (x = 0, 0.25, 0.5, 0.75, 1.0, 1.25 wt%) alloy phase structure. The thermal properties of the alloy were determined using Gibbs software fitting. The results indicate that the Au-2.0Ni-0.25Cu alloy exhibits the highest plastic toughness (B/G = 5.601, ν = 0.416, Cauchy pressure = 73.676 GPa) and a hardness of 1.17 GPa, which is 80% higher than that of Au-2.0Ni. This alloy balances excellent strength and plastic toughness, meeting the mechanical performance requirements of brazed joints. The constant pressure specific heat capacity (Cp) of the Au-2.0Ni-xCu alloy is higher than that of Au-2.0Ni and increases with Cu content. At 1000 K, the Cp of the Au-2.0Ni-0.25Cu alloy is 35.606 J·mol−1·K−1, which is 5.88% higher than that of Au-2.0Ni. The higher Cp contributes to enhanced high-temperature stability. Moreover, the linear expansion coefficient (CTE) of the Au-2.0Ni-0.25Cu alloy at 1000 K is 8.76 × 10−5·K−1, only 0.68% higher than Au-2.0Ni. The lower CTE helps to reduce the risk of solder damage caused by thermal stress. Therefore, the Au-2.0Ni-0.25Cu alloy is more suitable for brazing applications in high-temperature environments due to its excellent mechanical properties and thermal stability. This study provides a theoretical basis for the performance optimization and engineering application of the Au-2.0Ni-xCu alloy as a gold-based solder. [ABSTRACT FROM AUTHOR]

A precise Johnson-Cook (J–C) constitutive model is the foundation for precise calculation of finite-element simulation. In order to obtain the J–C constitutive model accurately for a new cast and forged alloy GH4198, an inverse identification of J–C constitutive model was proposed based on a genetic–particle swarm algorithm. Firstly, a quasi-static tensile test at different strain rates was conducted to determine the initial yield strength A, strain hardening coefficient B, and work hardening exponent n for the material's J–C model. Secondly, a new method for orthogonal cutting model was constructed based on the unequal division shear theory and considering the influence of tool edge radius. In order to obtain the strain-rate strengthening coefficient C and thermal softening coefficient m, an orthogonal cutting experiment was conducted. Finally, in order to validate the precision of the constitutive model, an orthogonal cutting thermo-mechanical coupling simulation model was established. Meanwhile, the sensitivity of J–C constitutive model parameters on simulation results was analyzed. The results indicate that the parameter m significantly affects chip morphology, and that the parameter C has a notable impact on the cutting force. This study addressed the issue of missing constitutive parameters for GH4198 and provided a theoretical reference for the optimization and identification of constitutive models for other aerospace materials. [ABSTRACT FROM AUTHOR]

Al-Mg alloys are widely used as important engineering structural materials in aerospace engineering, transportation systems, and structural constructions due to their low density, high specific strength, corrosion resistance, welding capability, fatigue strength, and cost-effectiveness. However, the conventional Al-Mg alloys can no longer fully satisfy the demands of practical production due to difficulties caused by many defects. The high strength of Al-Mg alloys as non-heat treatment precipitation-strengthened alloys is achieved primarily by solid solution strengthening along with work hardening rather than precipitation strengthening. Therefore, severe plastic deformation (SPD) techniques can be often used to produce ultrafine-grained structures to fabricate ultra-high strength aluminum alloys. However, this approach often achieves the strengthening of material at the cost of reduced ductility. This paper comprehensively summarizes the various approaches of ultrafine/nanocrystalline materials for enhancing their plasticity, elaborates on the creation of a bimodal microstructure within the alloy, and discusses the formation of a nanotwin microstructure within the alloy and the incorporation of dispersed nanoparticles. The mechanisms underlying both the strengthening and toughening during large plastic deformation in aluminum alloys are summarized, and the future research direction of high-performance ultrafine crystalline and nanocrystalline Al-Mg aluminum alloys is prospected. [ABSTRACT FROM AUTHOR]

The yield strength and Young's modulus of lattice structures are essential mechanical parameters that influence the utilization of materials in the aerospace and medical fields. Currently, accurately determining the Young's modulus and yield strength of lattice structures often requires conduction of a large number of experiments for prediction and validation purposes. To save time and effort to accurately predict the material yield strength and Young's modulus, based on the existing experimental data, finite element analysis is employed to expand the dataset. An artificial neural network algorithm is then used to establish a relationship model between the topology of the lattice structure and Young's modulus (the yield strength), which is analyzed and verified. The Gibson–Ashby model analysis indicates that different lattice structures can be classified into two main deformation forms. To obtain an artificial neural network model that can accurately predict different lattice structures and be deployed in the prediction of BCC-FCC lattice structures, the artificial network model is further optimized and validated. Concurrently, the topology of disparate lattice structures gives rise to a certain discrete form of their dominant deformation, which consequently affects the neural network prediction. In conclusion, the prediction of Young's modulus and yield strength of lattice structures using artificial neural networks is a feasible approach that can contribute to the development of lattice structures in the aerospace and medical fields. [ABSTRACT FROM AUTHOR]

Performance of rotary ultrasonic machining (RUM) system greatly influences by appropriate design of ultrasonic horn. Ultrasonic stepped horn gives high amplitude of vibration and better cutting efficiency but design and integration of horn with RUM system is highly intricate. Therefore, systematic study on design and implementation of ultrasonic stepped horn was needed in order to achieve better efficiency of RUM process. This paper focuses on design aspects of ultrasonic stepped horn by theoretical, FE simulations and modeling techniques. The designed horn was integrated with RUM system, performance was measured in terms of ultrasonic resonant frequency through FE simulations and modeling on ANSYS workbench. Finally, fabricated ultrasonic stepped horn was validated by performing experiments on rotary ultrasonic machine tool for Nomex honeycomb composites (NHCs). FE simulations and experimental results prove that the designed ultrasonic stepped horn achieves reasonable vibration amplitude at desired resonant frequency to perform RUM process on NHCs materials. [ABSTRACT FROM AUTHOR]

Shape memory or stimuli responsive polymers have established a unique grouping of smart materials. The technical merit of these polymers has been evaluated in aerospace sector, since last few decades. Particularly, the stimuli responsive polymers render inherent competences to recuperate the structural damages in exterior/interior space architectures. In this context, both the thermoplastics as well as thermosetting polymers depicted essential stimuli responsive behaviour. As interpreted in this state-of the-art review, the carbonaceous reinforcement like carbon fibers and nano-reinforcements including nanocarbons (graphene, carbon nanotube) have been employed in the shape recovering matrices. The performance of ensuing shape retrieving aerospace materials was seemed to be reliant on the polymer chain crosslinking effects, filler/nanofiller dispersal/alignment, microstructural specs, interfacial contour and interactions, and processing techniques used. Consequently, the shape actuations of polymer/carbon fiber composites were found to be instigated and upgraded through the inclusion of nanocarbon nano-additives. The ensuing high-tech shape memory composites/nanocomposites have anomalous significance for various aero-structural units (fuselage, wings, antennas, engines, etc.) due to prevention of possible thermal/shock/impact damages. Future implications of carbonaceous shape memory composites/nanocomposites in aerospace demands minimizing the structure-property-performance challenges and large scale fabrication for industrial scale utilizations. In this way, deployment of carbonaceous nanofiller/filler based composites revealed enormous worth due to low density, anti-fatigue/wear, anti-corrosion, non-flammability, self-healing, and extended durability and long life operations. However, there are certain challenges associated with the use of nanocarbons and ensuing nanocomposites in this field markedly the adoption of appropriate carbon fiber coating technique, aggregation aptitude of nanocarbons, additional processing steps/cost, nanoparticle initiated invisible defects/voids, difficulty in machinability operations due to presence of nanoparticles, and corrosion risk of composite structures in contact with metal surfaces. By overcoming these hinderances, nanoparticles modified carbon fiber based composites can be promising towards a new look of upcoming modernized aerospace industry. [ABSTRACT FROM AUTHOR]

Innovative high-performance composite materials are the need of the hour required by modern manufacturing techniques such as 3D printing due to less weight with high mechanical and thermal properties-based materials required. The application domain of 3D-printed high-performance composite materials includes aerospace, automobile, tissue engineering, soft robotics, sensors, and actuator applications. In this regard, the combination of metal-reinforced polymer composites has emerged as one of the most innovative sources for 3D printing applications in such sectors. The present study detailed the state-of-the-art review of the metal reinforcement in the polymer's matrix fit for 3D printing applications. The reinforcement of the metal in the polymers tunes the mechanical, thermal, chemical, morphological, electrical, and sensing properties that are very crucial for high-performance applications. The main outcomes of this study are to determine the best suitability of composite materials in accordance with requirements. In this study, the high-performance metals reinforcement materials such as Ag, Al, Cu, and Au have been discussed with their potential applications (medical, electronics, household, sports, communications, military, business, industry, marine, energy, civil, aerospace, and the automobile) as per required properties. This study is supported by the direction of future studies for extending the innovations and applications. [ABSTRACT FROM AUTHOR]

Copyright of Acta Materiae Compositae Sinica is the property of Acta Materiea Compositae Sinica Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The inferior creep ductility of Inconel 718 (IN718) fabricated by selective laser melting (SLM), which is unable to meet aerospace material specification (≥4%), limits its engineering application. Despite persistent optimization efforts in the SLM process and post-heat treatment, this issue remains unresolved. This study involved SLM fabrication of the modified IN718 with trace amounts of LaB6 and/or P, followed by homogenization and double aging heat treatment. The addition of trace LaB6 notably influenced the recrystallized grain structure and carbide precipitation at grain boundaries, while trace P addition had minimal impact. All samples exhibited similar γ′ and γ″ strengthening precipitates. Creep tests conducted at 650°C/690 MPa revealed that the individual modification of LaB6 showed limited improvement in creep performance and P showed no improvement, but the combined addition of LaB6 and P led to a substantial enhancement in creep performance, especially reaching as high as 8.6% creep strain. This remarkable improvement in creep ductility is unlikely to arise from the altered grain structure and grain boundary precipitates induced by LaB6 but predominantly arises from the synergistic effect of P and B in enhancing resistance to crack propagation during the third stage of creep. [ABSTRACT FROM AUTHOR]

Carbon fiber-reinforced plastic (CFRP) is a widely used material in the aeronautical and aerospace industry. Hole-making operations on CFRP frequently generate hole-exit damages which are related to the axial cutting force. As an alternative hole-making process, helical milling presents several advantages when compared to conventional drilling process. In order to study the mechanism of hole-exit damages in helical milling of CFRP, the axial cutting force during cutting process should be investigated in advance. Although CFRP is known as a difficult-to-cut material just because of being composite and non-homogeneous, the impact of composite structure and non-homogeneity on the axial cutting force has rarely been considered in the published researches of helical milling. This paper aims to investigate the axial cutting force in helical milling of CFRP, considering the composite structure and non-homogeneity of workpiece. The detailed laminated structure of the CFRP workpiece was investigated and the experiments of axial cutting forces were carried out. The results show that a periodic and fluctuant axial cutting force is generated in helical milling of CFRP. The periodic fluctuation of the axial cutting force was verified to be related to both the composite structure and the deformation of uncut material. Then, a cutting model was built to explain the changing process of axial cutting force during cutting process. [ABSTRACT FROM AUTHOR]