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Molybdenum (Mo), characterized by its high melting point, low thermal expansion coefficient, and excellent electrical and thermal conductivities, is widely considered an ideal metal material for applications in aerospace, nuclear fusion, electronics, and medical fields. Nevertheless, the major drawback of pure Mo is its significant brittleness, which restricts its practical utilization. This work presents a comprehensive review of the research progress on Mo alloys in recent years, covering preparation routes from composite powder preparation to advanced sintering technologies as well as performance evaluations (including mechanical properties and oxidation resistance). Additionally, it offers an outlook on the research prospects and development directions of Mo alloy composition design and preparation routes. [ABSTRACT FROM AUTHOR]

Laser-layered scanning techniques have achieved considerable success in cutting and drilling applications. However, their effectiveness in processing SiC f /SiC ceramic matrix composites—critical materials for next-generation aerospace thermal components—remains less than optimal. This study addresses the challenge of enhancing the quality and efficiency of cutting thick samples by being the first to highlight the crucial influence of focus increment adjustments in the laser-layered scanning process. Specifically, it examines the relationship between the predetermined laser focus drop per layer and the actual ablation depth achieved. Systematic analysis explores the impact of focus increment adjustments on both the macroscopic structural alterations during cutting and the microstructural characteristics of the cut surfaces. The findings demonstrate that the UV nanosecond laser multi-line layered scanning technique is particularly effective for processing thick SiC f /SiC samples, achieving a surface area of 5 × 5 mm² (Sa 366.92 nm) in just 117.58 s. By optimising the focus increment, a high and stable material removal rate is maintained throughout the process, reducing surface oxidation, minimising the formation of a recast layer, and reducing fibre interface debonding. Additionally, the study reveals the mechanism behind the formation of surface taper and presents a method to achieve a taper-free surface by adjusting the laser incidence angle. These findings provide valuable insights for the rapid and high-quality machining of matrix composites, offering significant improvements over existing methods. [Display omitted] • UV laser MLLS offers advantages in processing SiC f /SiC composites. • Optimized focus increment improves cutting performance of thick SiC f /SiC composites. • Elucidating the influence mechanism of focal increment on layered scanning technology. • Taper-free cuts achieved by adjusting laser incidence angle and focus increment. • Insights to enhance quality and precision in advanced material machining [ABSTRACT FROM AUTHOR]

The multilayer materials in aerospace applications generally subject to thermal shock, which may significantly affect the interfacial thermal resistance (ITR) and cause serious overheating issues. Therefore, understanding the interfacial thermal transport under temperature shock is essential for effective thermal management in aerospace devices. In the present study, the variation in ITR within the diamond/Cu/carbon nanotube tri-layer after thermal cycles was investigated through non-equilibrium molecular dynamics (NEMD) simulations. We conducted four groups of investigations, exploring the impact of maximum cycle temperature, heating/cooling rates, number of cycles, and interfacial structure on ITR. The results demonstrate that while the matching degree of phonon density of states remains almost constant, the ITR varies significantly among all groups. The structural deformations and changes in lattice type can be observed in the Cu layer. Based on these findings, we proposed an "atomic distribution method" to elucidate the mechanism behind ITR variation, which was verified as applicable and precise. Additionally, the thermal rectification results demonstrate the significant effect of interfacial structure on the rectification coefficient, indicating that interfacial transport and lattice thermal conduction deserve more in-depth study in the future. This work provides a novel perspective on understanding thermal transport across the irregular and complex interfaces, which is significant for the thermal management in aerospace field. [ABSTRACT FROM AUTHOR]

• High fiber volume fraction 2D carbon fiber fabric-reinforced composites with both shape memory and self-healing properties are investigated. • Shape memory effect of polymer matrix found to promote impact plastic deformation recovery of composites. • Fiber cracks and matrix cracks reduce the shape memory properties of the specimen. • Addition of thermoplastic PCL to epoxy matrix increases impact resistance and self-healing ability of materials. Fiber-reinforced thermoset polymers are widely used in aerospace as a material with excellent performance. However, for the low-velocity impact damage to which they are most susceptible, existing repair methods are difficult to maintain the aerodynamic performance of the components (back to its pre-damage shape) after repair. In this study, the multiple impact deformation recovery, internal damage healing, and post-repair impact properties of epoxy-PCL (ε-caprolactone) 2D carbon fiber fabric-reinforced polymers with shape memory and self-healing properties were investigated. The material is manufactured using a hot press tank-prepreg process, curing at 160 °C for 3.5 h at 6 atmospheres. The results show that the incorporation of thermoplastic PCL into the composite matrix can enhance the self-healing ability and impact resistance of the material. Composites after lower energy impacts retain their structural integrity and mechanical properties after healing. Materials can recover effectively from a single impact, but repeated impacts can lead to more extensive damage, which makes healing more difficult and causes a decrease in Healing efficiency. The shape memory effect of composites can restore plastic deformation caused by impact, which highlights the potential of shape memory smart composites for aerospace applications. [ABSTRACT FROM AUTHOR]

Aircraft designers have been looking for light-weight and robustness from natural fibers since the earlier times. To address this concern, scientists are currently working together on the bamboo long fiber reinforced bio-based matrix composite (BAMCO) project. This study focused on Bambusa vulgaris , a dominant bamboo species in Cameroon, to evaluate its potential for use in airline industries. The aim of the study is to determine the age at which Bambusa vulgaris fibers have the best mechanical and thermal properties for the manufacture of hybrid composites applied to aeronautics and aerospace. B. vulgaris plants aged 1–3 years, 4–5 years and 7 years were characterized, by submitting specimens to several tests: 1) density measurement, 2) tensile tests, 3) scanning electron microscopy (SEM), 4) Fourier-transform infrared spectroscopy (FTIR), 5) thermal conductivity, 6) thermogravimetric analysis (TGA), 7) specific heat capacity measurement, 8) dynamic mechanical analysis (DMA), and 9) ILSS test. A comparative study of the properties of other natural fiber tested in the aeronautic and aerospace industries revealed that, 7-year-old B. vulgaris has good properties for the airline industry. This study provides evidence that a 7-year-old B. vulgaris plant has a potentially important role in aeronautical and aerospace composite materials. • B. vulgaris aged 1–3 years, 4–5 years and 7 years were characterized. • From results 7-year-old B. vulgaris has the potential for aeronautic applications. • A hybrid composite made of B. vulgaris fiber is propose. [ABSTRACT FROM AUTHOR]

• Advanced stator blade design enhances aero engine efficiency. • Optimization of fiber lay-up, preform preparation, and forming temperature. • Successful preparation of CF/Al composite stator blades at 680°C. • Vibration mode simulations confirm suitability under 1st-order modes. The advancement of high-performance stator blades stands as a critical avenue for enhancing the efficacy of aero engines. This study aims to prepare carbon fiber reinforced aluminum matrix (CF/Al) composite stator blades with high-quality shapes and properties, optimize the lay-up design using Fibersim software, and investigate the effect of extrusion temperature on the forming quality. The mechanical properties and damage behavior were systematically analyzed by tensile, compression, and interlaminar shear tests. In addition, the vibration mode simulation reveals the force state under the 1st to 8th-order vibration modes. Results indicate that the [0°/+45°/0°/-45°/90°/-45°/0°/+45°/0°] lay-up parameters were optimal, achieving excellent shape and performance of curved preforms after curing. Composite blades fabricated at an extrusion temperature of 680°C exhibited clear contours, consistent dimensions, and no macro defects. SEM and EDS analyses showed uniform impregnation in all regions of the blade, high density, and good densification. Compared with the matrix alloy, the tensile strength of the composite blade was improved by 64.94%, the compressive strength by 35.7%, and the interlayer shear strength was as low as 72.6 MPa. The vibration mode simulation verified the applicability of the blade in the first-order vibration mode, which provides strong support for the application of composite materials in the aerospace field. [ABSTRACT FROM AUTHOR]

• Analyzed the effects of uniform and non-uniform factors on the anisotropic thermal conductivity of SFRC. • Established a joint rapid analysis method of uniform unit cell and correction unit cell. • The joint rapid analysis method can accurately predict the anisotropic thermal conductivity range of SFRC. Carbon fiber is commonly used as a heat dissipation filler for composite materials in aerospace and electrical systems. Based on representative volume element (RVE) finite element simulation and mathematical analysis, the anisotropic thermal conductivity of short carbon fiber/polymer (SCF/polymer) composites under non-uniform factors was predicted and analyzed. A joint analysis method was proposed for uniform unit cell (UUC) model considering uniform factors and correction unit cell (CUC) model considering non-uniform factors. This article establishes a UUC model for SCF/polymer composites and investigates the effects of factors such as the thermal conductivity of the polymer matrix, the anisotropic thermal conductivity, aspect ratio, and deflection angle of SCF, and interfacial thermal resistance on the anisotropic thermal conductivity of the composite material. In order to study the influence of non-uniform factors, a CUC model of SCF/polymer composite materials was established, and the effects of position offset, angle deviation, and distribution ratio of SCF in different directions on the anisotropic thermal conductivity of composite materials were discussed. The results of the above non-uniform factors were analyzed, and the range of correction factors for three non-uniform factors was obtained. The accuracy of the joint analysis method of UUC and CUC in predicting the anisotropic thermal conductivity of SCF/polymer composites was verified by comparing experimental results. [Display omitted] [ABSTRACT FROM AUTHOR]

The article reviews the development, current use, and future potential of magnesium alloys in the aerospace industry. Magnesium alloys are valued for their high specific strength, stiffness, excellent damping properties, electromagnetic shielding, and thermal conductivity. These properties make them particularly useful for manufacturing critical components in aircraft, missiles, and spacecraft, as they reduce weight and enhance performance. China is a leading producer of magnesium alloys, with substantial use in aerospace, contributing to lighter aircraft and spacecraft, improved maneuverability, and lower launch costs. Despite their advantages, magnesium alloys face challenges, including poor corrosion resistance, low strength at high temperatures, and casting difficulties. The paper discusses the evolution of magnesium alloys, noting their early use in the 20th century and a resurgence in the 1990s. It highlights ongoing research to develop magnesium-rare earth (Mg-RE) alloys, which offer better strength and high-temperature resistance. The paper also outlines the limitations of magnesium alloys compared to aluminum alloys, which remain dominant due to superior overall performance. In the future, advancements in surface treatments, manufacturing processes, and alloy compositions are crucial for overcoming current limitations, enabling broader use of magnesium alloys in aerospace applications. [ABSTRACT FROM AUTHOR]

In aerospace engineering, the demand for lightweight materials with superior strength and endurance drives the search for advanced composites. Carbon fiber composites offer exceptional strength-to-weight ratios but are vulnerable to high-temperature oxidation. To address this, protective coatings are crucial. Zirconium diboride (ZrB 2) shows promise due to its high melting point and stability but faces challenges in application. Here, we propose a sustainable solution-based method using gum arabic, a natural polysaccharide, as a precursor to coat carbon fibers followed by pyrolysis to form ZrB 2. Our technique simplifies production while enhancing coating effectiveness and adhesion. X-ray diffraction and microscopy analyses confirm successful ZrB 2 formation and uniform coating. Thermal analysis demonstrates improved oxidative stability compared to pristine carbon fibers. This eco-friendly approach presents a novel avenue for aerospace materials synthesis, offering enhanced performance and sustainability. The study underscores the potential of solution-based techniques and natural precursors in advancing composite materials for extreme environments. [Display omitted] • Sustainable ZrB 2 coating method uses gum arabic for carbon fiber composites. • Solution-based synthesis achieves ZrB 2 formation at lower temperatures (1100–1400°C). • Enhanced oxidative stability shown in ZrB 2 -coated fibers vs pristine carbon fibers. • SEM and TEM confirm uniform ZrB 2 coating with nanosized crystallites. • Eco-friendly process promotes applications with improved thermal stability. [ABSTRACT FROM AUTHOR]

Due to the vast applications in biomedical materials and aerospace industry, smart slippery liquid-infused porous surfaces (SLIPSs) have attracted remarkable attention. However, there are still challenges in the fabrication of durable SLIPS. In this work, based on linear polyurea and silicone oil, a series of durable anti-icing surface were fabricated. Based on the long-lasting secretion of lubricant, the ice adhesion strength of 60-PUa was 2.7 ± 0.5 kPa and could remain below 10 kPa even after 30 icing-deicing cycles. And the icing delay time of 60-PUa could be extended up to 870 s at a temperature of −15 °C. The introduction of large numbers of reversible hydrogen bonds in the system and silicone oil made it possible to achieve high self-healing efficiency under natural conditions. The coating system not only improved the ice removal ability, but also had excellent water-sliding properties, the droplet could slide under its own weight on 60-PUa at a tilt angle of 4.7°. This work provides an easy way to fabricate multi-functional SLIPS with durability. • Silicone oil content has a significant impact on the anti-icing properties and durability. • The system achieves seamless integration through hydrogen bonding and silicone oil. • The ice adhesion strength of the coating is low as 2.7 ± 0.5 kPa. [ABSTRACT FROM AUTHOR]

Titanium (Ti) alloys are widely used in high-tech fields like aerospace and biomedical engineering. Laser additive manufacturing (LAM), as an innovative technology, is the key driver for the development of Ti alloys. Despite the significant advancements in LAM of Ti alloys, there remain challenges that need further research and development efforts. To recap the potential of LAM high-performance Ti alloy, this article systematically reviews LAM Ti alloys with up-to-date information on process, materials, and properties. Several feasible solutions to advance LAM Ti alloys are reviewed, including intelligent process parameters optimization, LAM process innovation with auxiliary fields and novel Ti alloys customization for LAM. The auxiliary energy fields (e.g. thermal, acoustic, mechanical deformation and magnetic fields) can affect the melt pool dynamics and solidification behaviour during LAM of Ti alloys, altering microstructures and mechanical performances. Different kinds of novel Ti alloys customized for LAM, like peritectic α-Ti, eutectoid (α + β)-Ti, hybrid (α + β)-Ti, isomorphous β-Ti and eutectic β-Ti alloys are reviewed in detail. Furthermore, machine learning in accelerating the LAM process optimization and new materials development is also outlooked. This review summarizes the material properties and performance envelops and benchmarks the research achievements in LAM of Ti alloys. In addition, the perspectives and further trends in LAM of Ti alloys are also highlighted.

Shape memory polymers (SMPs), a class of polymers exhibiting the unique ability to restore deformation induced during the programming process in response to external stimuli, have garnered significant attention. In this study, our objectives were two-fold: to develop an efficient device for programming SMP hinges crafted from polyetheretherketon (PEEK) and to optimize their performance for potential utilization in space applications. Two versions of the programming device were constructed and compared. Through three systematic experiments, we identified optimal programming and recovery conditions for the hinges, revealing the best shape memory effects (SMEs) at a programming temperature of 250 °C. Remarkably, the hinges were able to recover the previously induced deformation up to 100%, maintaining functionality down to a lower temperature limit of 150 °C. Notably, these hinges demonstrated a wide operational range of over 180°, rendering them promising for space applications, as extensively discussed within the manuscript. However, challenges arise due to the high recovery temperature of 150 °C, presenting obstacles in achieving optimal functionality in the demanding conditions of a space environment.

Ganoderma is a genus of fungi that has been the subject of much research, largely due to its medicinal or therapeutic qualities. However, the structure of their sporocarps (similar to mushrooms) and their mechanical and material properties have been largely ignored. Three characteristic structures created by Ganoderma fungi are described with a focus on their structural and mechanical properties: the layered sporocarp structure, the vegetative mycelia that create filamentous networks, and the double-walled spore. The Ganoderma sporocarp has a layered, porous mesostructure that provides for a macrostructure that is both lightweight and mechanically tough and could provide inspiration for materials in aerospace applications. Ganoderma mycelia networks, which make use of three different types of constitutive filaments (hyphae), can naturally bind substrates and provide increased mechanical properties than fungi with simpler microstructures. These networks can be implemented into engineering applications as natural binders or textiles. The reinforced walls of and porous internal structure of Ganoderma spores provide a mechanically resistant structure irrespective of the orientation of the load. This protective, hollow structure may provide inspiration for the creation of energy storage materials. [ABSTRACT FROM AUTHOR]

Birds are notable for their ability to seamlessly transition between different locomotory functions by dynamically leveraging their shape-shifting morphology. In contrast, the performance of aerial vehicles is constrained to a narrow flight envelope. To understand which functional morphological principles enable birds to successfully adapt to complex environments on the wing, engineers have started to develop biomimetic models of bird morphing flight, perching, aerial grasping and dynamic pursuit. These studies show how avian morphological capabilities are enabled by the biomaterial properties that make up their multifunctional biomechanical structures. The hierarchical structural design includes concepts like lightweight skeletons actuated by distributed muscles that shapeshift the body, informed by embedded sensing, combined with a soft streamlined external surface composed of thousands of overlapping feathers. In aerospace engineering, these functions are best replicated by smart materials, including composites, that incorporate sensing, actuation, communication, and computation. Here we provide a review of recently developed biohybrid, biomimetic, and bioinspired robot structural design principles. To inspire integrative smart material design, we first synthesize the new principles into an aerial robot concept to translate it into its aircraft equivalent. Promising aerospace applications include multifunctional morphing wing structures composed out of smart composites with embedded sensing, artificial muscles for robotic actuation, and fast actuating compliant structures with integrated sensors. The potential benefits of developing and mass-manufacturing these materials for future aerial robots and aircraft include improving flight performance, mission scope, and environmental resilience. [ABSTRACT FROM AUTHOR]

The chopped carbon fiber reinforced SiC (C f /SiC) composite has been regarded as one of the excellent high-temperature structural materials for applications in aerospace and military fields. This paper presented a novel printing strategy using direct ink writing (DIW) of chopped fibers reinforced polymer-derived ceramics (PDCs) with polymer infiltration and pyrolysis (PIP) process for the fabrication of C f /SiC composites with high strength and low shrinkage. Five types of PDCs printing inks with different C f contents were prepared, their rheological properties and alignment of carbon fiber in the printing filament were studied. The 3D scaffold structures and bending test samples of C f /SiC composites were fabricated with different C f contents. The results found that the C f /SiC composite with 30 wt% C f content has high bending strength (∼ 7.09 MPa) and negligible linear shrinkage (∼ 0.48%). After the PIP process, the defects on the C f /SiC composite structures were sufficiently filled, and the bending strength of C f /SiC composite can reach up to about 100 MPa, which was about 30 times greater than that of the pure SiC matrix without C f. This work demonstrated that the printed C f /SiC composites by using this method is beneficial to the development of the precision and complex high-temperature structural members. • The chopped fibers reinforced direct ink writing with PIP processing was proposed. • The carbon fibers reinforced polymer-derived SiC composites were prepared. • The C f /SiC composite with 30 wt% fiber has excellent linear shrinkage (< 0.5%). • The reinforced C f /SiC composite has satisfactory bending strength (∼ 103.14 MPa). [ABSTRACT FROM AUTHOR]

Fiber‐metal laminates (FMLs) are attracting much attention from researchers as emerging aerospace materials. In this paper, 1060‐H112 aluminum alloy‐carbon/glass fiber laminates were prepared by vacuum bagging method. Subsequently, based on tensile, three‐point bending and low‐velocity impact experiments, the quasi‐static mechanical properties as well as the dynamic response to impact of the two fiber laminates were investigated. The results show that the carbon fiber metal laminate (CARALL) has stronger tensile strength and inter‐ply tensile consistency, while the glass fiber metal laminate (GLARE) has better bending resistance. The impact response of CARALL and GLARE is closely related to the impactor shape and impact energy. The peak loads of the FMLs increased with increasing impact energy over the range of impact energies tested. However, the peak load of CARALL is more sensitive to the impact energy, while the deformation of GLARE is more sensitive to the impact energy. With complete penetration of the impactor into the target, the fibers of GLARE were ductile fracture and fibers of CARALL were brittle fracture for the blunt impactor impact, while the fibers of both GLARE and CARALL were ductile fracture for the hemispherical impactor impact. Under the impact of both impactors, two types of FMLs showed matrix broken, delamination, and local debonding. [ABSTRACT FROM AUTHOR]

The rapid development of the aviation industry has put forward higher and higher requirements for material properties, and the research on smart material structure has also received widespread attention. Smart materials (e.g., piezoelectric materials, shape memory materials, and giant magnetostrictive materials) have unique physical properties and excellent integration properties, and they perform well as sensors or actuators in the aviation industry, providing a solid material foundation for various intelligent applications in the aviation industry. As a popular smart material, piezoelectric materials have a large number of application research in structural health monitoring, energy harvest, vibration and noise control, damage control, and other fields. As a unique material with deformation ability, shape memory materials have their own outstanding performance in the field of shape control, low-shock release, vibration control, and impact absorption. At the same time, as a material to assist other structures, it also has important applications in the fields of sealing connection and structural self-healing. Giant magnetostrictive material is a representative advanced material, which has unique application advantages in guided wave monitoring, vibration control, energy harvest, and other directions. In addition, giant magnetostrictive materials themselves have high-resolution output, and there are many studies in the direction of high-precision actuators. Some smart materials are summarized and discussed in the above application directions, aiming at providing a reference for the initial development of follow-up related research. [ABSTRACT FROM AUTHOR]

The development of intelligent techniques based on real-time monitoring for machining applications is one of the challenges of Industry 4.0, as in the Aerospace Industry. Drilling is the most used process before the assembly of airplane sheets, that nowadays are composed of different layers of materials with different optimized cutting conditions. The fault diagnosis during drilling stack materials is important to reduce cost and improve the process quality. Using a machine-tool, it is important that the fault diagnoser does not use a large amount of memory and be capable of detecting faults in a fast manner. In this paper, we propose a timed automaton model representing the drilling process of a Titanium plate on a CNC machine, which is suitable for fault diagnosis without any additional sensors. The diagnoser uses only the spindle power and Z axis displacement read directly from the system controller. The target faults in this case are: (i) excessive tool-wear or tool breakage; (ii) the tool finds an off-centered hole while producing a blind-hole; (iii) the tool finds an under layer of a different material, as it occurs in a bi-layer material; and (iv) the plate thickness is below the desired one and a though hole is produced. The results show that the model is capable of identifying all faults and it could be used to alert a problem on the sequence of machining holes in the industry [ABSTRACT FROM AUTHOR]

Sidewall tapering is one of the main limitations in ultrashort pulse (USP) laser machining and is associated with the beam shape and self-limiting effect. Laser processing with a precession beam is a potential solution to overcome this limitation. A study into the effects of precession parameters on the taper angle in microhole drilling of a nickel alloy is reported in this paper. The effects of three key precession parameters, i.e., incident angle, relative distance between the focuses of the precession and individual beams, and scanning speed, have been investigated in detail. Experiments were performed to drill through holes with aspect ratios up to 20:1 and diameters ranging from 100 to 500 μm over 0.6–2 mm thick nickel alloy substrates. Experiment results showed that all the considered parameters/factors were significant and affected the hole tapering in different ways. In addition, there were important interaction effects between two of the factors, i.e., incident angle and focus position, in some cases. The optimal parameters to minimize the tapering effect are suggested, and the mechanism is discussed in detail. The precession laser machining showed clear advantages in overcoming the limitations to associated with conventional USP laser machining. Fabricating microholes with high geometrical accuracy, i.e., with straight side walls and zero taper angles, is feasible with the use of a precession beam. The results clearly show the potential of precession laser processing and the capabilities that the technology can offer for a range of laser micromachining applications in different industries, such as microelectronics, automotive, and aerospace. [ABSTRACT FROM AUTHOR]

Magnesium (Mg) and its alloys are considered an ideal material for aerospace, medical, energy, and automotive purposes, because of their low density and high specific strength. Researchers are interested in AZ alloys because of their superior flow characteristics. This review makes an effort to summarise the numerous processing methods that have been adapted for use with AZXX alloy. One of the main obstacles to Mg alloys being used in their intended context is the difficulty of processing Mg and its alloys. Curiously, the homogenization process is often used in tandem with extrusion and rolling. It also gives an insight into the microstructure, mechanical (hardness, tensile, impact, fatigue, and creep), and electrochemical corrosion properties of AZXX alloys. The improvement of AZXX alloy can be attributed to the grain boundary strengthening and the second phase strengthening mechanisms. The effects of Al content and phases on properties are extensively discussed. This article summarises what has recently happened with AZXX wrought Mg alloy and offers some predictions for its future. [ABSTRACT FROM AUTHOR]

AlSiCp Metal Matrix Composites (AlSiCp MMC) possess a variety of desired mechanical properties such as high strength-to-weight ratio, rigidity modulus, resistance to wear, corrosion and thermal shock. Due to this, it finds application in aerospace and automotive sector. Preparation of such composites is difficult, yet there are several methods to do it. One of them is stir casting, which is not only easy but also inexpensive. Being a high-demand material in aerospace industry, fabrication of AlSiCp MMC with Al2024 as base material and silicon carbide powder as reinforcement is chosen for the study. An attempt has been made to develop the aforementioned composite in three variants with weight fraction of 3, 5 and 7 percent of silicon carbide. Experimentations reveal that the hardness increased nearly by 30% with respect to base material. Microstructural study by Scanning Electron Microscope (SEM) shows the uniform distribution of the reinforcement, especially in composite with 5% reinforcement. [ABSTRACT FROM AUTHOR]

To solve the problems of high cutting forces, severe tool wear, and poor surface integrity faced by advanced materials in aerospace manufacturing, multi-dimensional vibration machining (MDVM) is receiving unprecedented attention. MDVM utilizes workpiece and/or tool vibration excited in different directions to achieve high quality and efficient machining of aeronautical hard-to-cut materials. This paper covered typical MDVM hardware systems based on different vibration mechanisms, vibration application methods, and control methods, discussed the machining mechanisms such as friction reversal and contact-separation, and displayed the application effects in extending tool life, improving surface integrity, and manufacturing functional surfaces. The diversity of vibration mechanisms and the complexity of vibration modes of the MDVM system made it difficult to develop a unified design method for vibration systems and to demonstrate the machining mechanism under the coupling of different ultrasonic-induced effects. Therefore, it is an important development direction for future research to investigate the vibration and machining characteristics of MDVM systems and reveal the unified law. [ABSTRACT FROM AUTHOR]

By their unique compositions and microstructures, recently developed high-entropy materials (HEMs) exhibit outstanding properties and performance above the threshold of traditional materials. Wear- and erosion-resistant materials are of significant interest for different applications, such as industrial devices, aerospace materials, and military equipment, related to their capability to tolerate heavy loads during sliding, rolling, or impact events. The high-entropy effect and crystal lattice distortion are attributed to higher hardness and yield stress, promoting increased wear and erosion resistance in HEMs. In addition, HEMs have higher defect formation/migration energies that inhibit the formation of defect clusters, making them resistant to structural damage after radiation. Hence, they are sought after in the nuclear and aerospace industries. The concept of high-entropy, applied to protective materials, has enhanced the properties and performance of HEMs. Therefore, they are viable candidates for today's demanding protective materials for wear, erosion, and irradiation applications. [ABSTRACT FROM AUTHOR]

Lightweight SiC-ZrB 2 porous ceramics is of great potential as thermal insulation material used in aerospace, chemical and energy industries. In this work, a series of SiC bonded ZrB 2 (SiC b -ZrB 2) porous ceramics with porosity high up to 86.9% were prepared by a simple foam gel-casting method. The SiC b -ZrB 2 porous ceramic prepared at 1573 K exhibited a low thermal conductivity of 0.280 W/(m∙K) and a reasonable compressive strength of 0.52 MPa. It could maintain the original geometric shape and microstructure after a secondary heat treatment at 1473 K in inert atmosphere. When heating the samples with thickness of 30 mm for 12 min with an alcohol spray lamp (∼1273 K), the temperatures of the cold sides of SiC b -ZrB 2 ceramics were all lower than 432 K, demonstrating their exceptional insulation capabilities. The present work provides a simple route to produce robust and thermally-insulating non-oxide porous ceramics for use under high temperature. [ABSTRACT FROM AUTHOR]

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The friction characteristics of two-dimensional materials in the ultraviolet (UV) radiation environment are important to the reliability of two-dimensional material nano-structures of space equipment. A novel mechanism of UV light-sensitive nano-friction on graphene was proposed by ultraviolet vacuum irradiation modification using an atomic force microscope (AFM). The surface roughness, adhesion force, and friction of graphene were gradually reduced over a time of irradiation below 3 min. UV185 passes through graphene and causes photochemical reactions between its bottom layer and Si/SiO2 substrate, resulting in hydroxyl, carboxyl, and silanol suspension bonds and sp3-like bonds, which enhances the binding energy of graphene on the substrate and inhibits the out-of-plane deformation resulting in roughness and friction reduction. However, as the irradiation time increased to 5 min, the friction force increased rapidly with the aging effect and the breakdown of sp3-like bonds between the graphene–substrate interface. This study presents a new method of controlling nanofriction on graphene based on UV irradiation-sensitive posterities in vacuum conditions, which is essential to the application of two-dimensional materials in aerospace equipment, to improve anti-aging properties and wear reduction. [ABSTRACT FROM AUTHOR]

Based on the principle of the curved trajectory of scissor mechanisms, authors conducted a finite element simulation analysis of the impact load on the truss beam structure, a theoretical analysis of the impact response and a relevant prototype bench-top experiment, completing a full study on the impact resistance mechanism of the designed variant truss beam structure under the impact load. This paper proposes an optimization strategy for the variant truss beam structure with the energy absorption rate as the optimization index through extensive analysis of the parameter response surfaces. The Special Issue (SI) "Dynamics and Application of Modern, Smart, and Active Elements or Structures" is focused on covering all of the newest outcomes and trends in the nonlinear mechanics of systems and structures with smart, active, and modern materials. The strategy integrates analyses on the response characteristic analysis of various configuration materials to obtain an optimal combination of component parameters that ensures that the strength of the truss beam structure meets set requirements. [Extracted from the article]

Kapton film is a polymeric material widely used on low-Earth-orbit (LEO) spacecraft surfaces. In the LEO environment, atomic oxygen (AO) is spaceflight materials' most destructive environmental factor. The erosion mechanism of AO on Kapton films has long been an important issue, where the parameter dependence of the AO effect has received increasing attention. Studies of AO energy and cumulative flux have been extensively carried out, while the influence mechanism of the incidence angle and flux density is not fully understood. The AO incidence angle and flux density in space are diverse, which may cause different damage effects on aerospace materials. In this paper, the dependence of the incidence angle and flux density in the damaging effect of AO on Kapton films was investigated using ground-based AO test technology and the reactive molecular dynamics (ReaxFF MD) simulation technique. Firstly, the ground-based experiment obtained the mass loss data of Kapton films under the action of AO with a variable incidence angle and flux density. Then, the mass loss, temperature rise, product, and erosion yield of Kapton during AO impact with different incidence angles and dose rates were calculated using the ReaxFF MD method. The influences of the incidence angle and flux density on the damage mechanism of the AO effect were discussed by comparing the simulation and test results. The results show that the AO effect in the lower incidence angle range (0–60°) is independent of the incidence angle and depends only on the amount of impacted atomic oxygen. AO in the higher incidence angle range (60–90°) has a surface stripping effect, which causes more significant mass loss and a temperature rise while stripping raised macromolecules from rough surfaces, and the erosion effect increases with the increasing incidence angle and amount of impacted atomic oxygen. There is a critical value for the influence of flux density on the AO effect. Above this critical value, AO has a reduced erosive capacity due to a lower chance of participating in the reaction. The amount of each main product from the AO effect varies with the incidence angle and flux density. Nonetheless, the total content of the main products is essentially constant, around 70%. This work will contribute to our understanding of the incidence angle and flux density dependence of the AO effect and provide valuable information for the development of standards for ground simulation tests. [ABSTRACT FROM AUTHOR]

Adhesive joints have been an effective alternative to conventional mechanical fasteners for joining materials in the aerospace and automotive industries. Although adhesive joints have various advantages, including uniform stress distribution, lower weight, improved corrosion tolerance, and design flexibility, there can be various defects in adhesive joints, which have limited wider application. This paper investigates the effect of a contaminant on the chemical and mechanical properties of the epoxy-adhesive and seeks to determine if a second harmonic generation method can reliably detect and characterize the degree of contamination in the epoxy-adhesive. A contact based ultrasonic through-transmission method was used to measure nonlinearity and then the nonlinearity parameter was calculated using the measured fundamental and second harmonic frequency components in the signals. It was found that there is higher sensitivity to contaminant concentration, up to 1.5%, of the nonlinearity parameter than that for the sound velocity. These data were also found to correlate with changes in the mechanical hardness, which was measured by the Rockwell hardness testing, with different four levels of contamination. Differential scanning calorimetry (DSC) and the thermogravimetric analysis (TGA) were also conducted to assess the effect of the contaminant on thermal properties of the epoxy-adhesive. The DSC and TGA techniques were used to evaluate the curing reaction and the thermal stability of the epoxy-adhesive respectively. [ABSTRACT FROM AUTHOR]

Inconel 625 alloy has advantageous properties, such as heat resistance and corrosion resistance, which make it a suitable material in aerospace, energy, and marine industries. However, it is also difficult-to-machine because of factors such as work hardening, low thermal conductivity, and high tool affinity. Therefore, the problems of tool wear, chipping, and adhesion often occur in milling of Inconel 625 alloy using end mills. We conducted experiments on the cutting of Inconel 625 alloy by high-speed milling using carbide ball end mills to investigate the tool wear, chipping, and adhesion under three spindle revolution speeds and two feed rates, and determine the optimal cutting conditions. The effects of spindle revolution speed on the tool and workpiece were clarified, and the optimal speed was established to achieve long tool life. [ABSTRACT FROM AUTHOR]

This paper is a study on the results of strength tests on single-lap joints used primarily in the aerospace industry, based on a Hi-Lok fastener. Two popular structural materials used in the aerospace industry were considered in this work. The test specimens were fabricated from the EN-AW 2024 T3 aluminium alloy and a carbon composite. It was decided to use the Naftoseal MC780 type C adhesive as a sealant to form the required hermetic, air-tight lap joints. In the definition of the joint type used, the results are presented for the tests of selected 2D and 3D surface roughness parameters, with isometric imaging of the surfaces related to this analysis. Microscopic images acquired at a magnification of x500 illustrate the surface quality. This work concludes with a discussion of the test results and conclusions. [ABSTRACT FROM AUTHOR]

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A near-equiatomic multi-principal element alloy of Cu40Nb30(TiB2)20C10 with both nano-particle size (14 nm) and micron-particle sizes (−44 µm) of Nb was designed and made via the spark plasma sintering technique at two different sintered temperatures of 650 °C and 700 °C with other SPS parameters being constant. The sintering mode, microstructures, microhardness, density, relative density, wear behavior, and corrosion properties of the alloys were investigated and compared to ascertain the best for aerospace applications. The SPS technique was applied to produce the tested samples in this study. The results showed that the alloys with nano-particles of Nb sintered faster, with the lowest wear rate, and their microstructure shows a dendritic configuration with the existence of graphite-rich and niobium-rich nano-segregations in the inter-dendritic areas with the lowest coefficient of friction, Cu-NbTiB2C with nano-particles of Nb sintered at 650 °C recorded the highest microhardness value (786.03 HV0.2), and CuNbTiB2C with micro-particles of Nb sintered at 700 °C exhibited the best anti-corrosion characteristics in a sulphuric acid environment. The results obtained in this study correspond to the requirements for high-performance engineering materials, which will make the novel materials relevant in the aerospace industry. [ABSTRACT FROM AUTHOR]

This article, titled "Editorial: Lightweight mechanical and aerospace structures and materials," discusses the importance of lightweight structures in mechanical and aerospace applications. The article highlights the use of innovative manufacturing technologies, such as additive manufacturing and auto fiber placement, to fabricate high-performance lightweight structures. It emphasizes the need to understand the structural performance of these structures under various operational environments. The article also mentions four research articles related to the topic, which focus on the mechanical performance of lightweight structures and explore various analysis approaches. These studies cover topics such as protecting penetration fuzes, buckling response of composite plates, optimization of integrally stiffened shells, and design and analysis of lightweight gear transmission systems. The article concludes by emphasizing the transformative potential of advanced materials and engineering designs in driving progress across multiple fields. [Extracted from the article]

Intermetallic alloys such as titanium aluminides (TiAl) are potential materials for aerospace applications at elevated temperatures. TiAl intermetallics have low weight and improved efficiency under aggressive environments. However, there is limited information about wear behavior of these alloys and their microstructure. The present work aims to study the influence of the microstructure in the tribological behavior of TiAl intermetallic alloy (45Al-2Mn-2Nb(at%)-0.8 vol%TiB2). Wear tests were performed on samples manufactured by centrifugal casting (CC) and hot isostatic pressure (HIP). Reciprocating sliding wear test was carried out for TiAl, it was combined with different loads and frequencies. Wear tracks were analyzed through opto-digital microscopy and electron microscopy (SEM). The results obtained reveal that CC intermetallics present the lowest volume wear lost, approximately 20% less than HIP intermetallics. This good behavior could be related to the high hardness material, associated with the main microstructure where CC intermetallic has nearly lamellar microstructure and HIP intermetallics present duplex microstructure. [ABSTRACT FROM AUTHOR]

Recent advances in aircraft materials and their manufacturing technologies have enabled progressive growth in innovative materials such as composites. Al-based, Mg-based, Ti-based alloys, ceramic-based, and polymer-based composites have been developed for the aerospace industry with outstanding properties. However, these materials still have some limitations such as insufficient mechanical properties, stress corrosion cracking, fretting wear, and corrosion. Subsequently, extensive studies have been conducted to develop aerospace materials that possess superior mechanical performance and are corrosion-resistant. Such materials can improve the performance as well as the life cycle cost. This review introduces the recent advancements in the development of composites for aircraft applications. Then it focuses on the studies conducted on composite materials developed for aircraft structures, followed by various fabrication techniques and then their applications in the aircraft industry. Finally, it summarizes the efforts made by the researchers so far and the challenges faced by them, followed by the future trends in aircraft materials. [ABSTRACT FROM AUTHOR]

Designing aramid nanofiber (ANF) aerogel with excellent microstructure and high thermal insulation property is benefit for applications in integrated thermal management system. To obtain a structurally controllable ANF‐based aerogel, the cellulose nanofiber (CNF) and poly (vinyl alcohol) (PVA) were 'stiff–soft' synergistic to improve the microstructure. The cobweb like structures distributed in the honeycomb layered pores of the CNF/PVA/ANF composite aerogel which was conducive to the performance and application of composite aerogel. The resulting CNF1/PVA1/ANF composite aerogels are highly porous (99.12%) and tiny volume shrinkage (4.65%), leading to excellent thermal insulation performance (26.83 mW/m·K). The 'stiff–soft' feature endows the composite aerogels high flexibility as well as large compression strength. These favorable multi‐features make the CNF/PVA/ANF composite aerogels ideal advanced material for aerospace, industrial, and commercial applications. [ABSTRACT FROM AUTHOR]

Carbon fiber-reinforced polymers are important constituents of aerospace materials. However, due to the inert surface of CFs, their interfacial property is relatively weak, which severely hinders their practical applications. Here, we deposited multi-walled carbon nanotubes (MWCNTs) along with a coupling agent on the surface of carbon fiber to improve the interfacial properties of the carbon fiber/resin. Via a simple dip-coating method, the MWCNTs were uniformly distributed on the CF surface with the assistance of the pre-coated coupling agent. The interfacial shear strength between the fiber and the matrix was significant enhanceed when the CF was loaded with the coupling agent and the MWCNTs. In addition, the MWCNTs were used as sensors to in-situ monitor the interfacial state in order to elucidate the interfacial strengthening mechanism. It revealed that the collaborative contribution of the coupling agent and the MWCNTs in the interphase region is the key to the high interfacial strength. [ABSTRACT FROM AUTHOR]

In this work in order to determine the relevant directions of research of different scientific components of the process of selective laser melting (SLM), as well as technological measures affecting the final structure, mechanical and service characteristics of a manufactured part, a literary review of the materials was made devoted to different directions of research of SLM technology. The directions of scientific works considered in this review were: research and deepening knowledge on the influence of the energy component of SLM process; possibilities of SLM process modification by the control of laser focus value; study of modes and methods of SLM processing as well as final microstructure of samples; study of corrosion resistance of products, manufactured using SLM. Based on the results of the literary analysis, the problems and prospects of studying SLM processes for materials of aerospace industry are shown, the need in creating a systematic comprehensive approach to the study of the components of SLM process, as well as deepening knowledge about the technological capabilities of its use. [ABSTRACT FROM AUTHOR]

Ti2AlNb intermetallic is a potential substitute for Ni-based superalloys in next-generation aerospace materials. In the current work, the structural, mechanical, and thermodynamic properties of the Ti2AlNb in B2 phase are studied at various temperatures by implementing first principle calculations under quasi-harmonic approximations. The lattice parameter, elastic moduli, and linear coefficient of thermal expansion (CTE) are well reproduced according to the experimental reports. The intermetallic remains mechanically and dynamically stable at all temperatures. The elastic moduli and microhardness decrease slightly from 0 to 1300 K. Furthermore, the calculations reveal that Ti2AlNb remains ductile at all temperatures. Phonon calculations show that Nb atoms are dominant contributor to the vibrational modes. The temperature-dependent heat capacities, entropy, CTE, and isothermal bulk modulus are further investigated. Present calculations predict that the B2 phase Ti2AlNb is a suitable candidate for the manufacturing of high-temperature application parts such as turbine blades of aerospace engines. [ABSTRACT FROM AUTHOR]

It has been previously noted that the development of aerospace material technology and breakthroughs are inseparable when obtaining great achievements in the aerospace industry. Materials are the basis and precursor of modern high technology and industry. As one of the most powerful aluminium alloys, 7050 is widely used in the aerospace field. In this manuscript, the vibration fatigue behaviour of aircraft aluminium alloy 7050 is studied based on experiments. A vibration fatigue experiment and the traditional fatigue testing of aluminium alloy 7050 were performed. We found that there was an extreme difference between the vibration fatigue and the traditional fatigue curves. In addition, the experimental end criteria for the vibration fatigue experiment of aluminium alloy 7050 was obtained from the acceleration reduction and the frequency reduction value. For the acceleration experimental end criterion, 2% was the acceleration reduction value for the vibration fatigue experimental end criteria of aluminium alloy 7050. For the frequency experimental end criterion, 2% was the frequency reduction value for the vibration fatigue experimental end criteria of aluminium alloy 7050. [ABSTRACT FROM AUTHOR]