Search

3D printing enables the creation of complex and sophisticated designs, offering enhanced efficiency, customizability, and cost-effectiveness compared to traditional manufacturing methods. Ceramics, known for their heat resistance, hardness, wear resistance, and electrical insulation properties, are particularly suited for aerospace, automotive, electronics, healthcare, and energy applications. The rise of 3D printing in ceramics has opened new possibilities, allowing the fabrication of complex structures and the use of diverse raw materials, overcoming the limitations of conventional fabrication methods. This review explores the transformative impact of 3D printing, or additive manufacturing, across various sectors, explicitly focusing on ceramics and the different 3D ceramics printing technologies. Furthermore, it presents several active companies in ceramics 3D printing, proving the close relation between academic research and industrial innovation. Moreover, the 3D printed ceramics market forecast shows an annual growth rate (CAGR) of more than 4% in the ceramics 3D printing market, reaching USD 3.6 billion by 2030. [ABSTRACT FROM AUTHOR]

Carbon fibers have been technically applied in high performance materials and industrial scale applications. Importantly, carbon fiber reinforced composite materials have found applications in aerospace industries. These properties of carbon fiber reinforced composites depend upon the carbon fiber features such as length, orientation, surface properties, adhesion with matrices, etc. To improve the surface properties of carbon fibers and adhesion and interactions with polymers, fiber modification has been suggested as an efficient approach. Carbon nanoparticle or nanocarbon functionalized carbon fibers have been manufactured using various facile physical and chemical approaches such as electrospraying, electrophoretic deposition, chemical vapor deposition, etc. Consequently, the modified carbon fibers have nanocarbon nanoparticles such as graphene, carbon nanotube, nanodiamond, fullerene, and other nanocarbons deposited on the fiber surface. These nanocarbon nanoparticles have fine capability to improve interfacial linking of carbon fibers with the polymer matrices. The chemical vapor deposition has been adopted for uniform deposition of nanocarbon on carbon fibers and chemical methods involving physical or chemical modification have also been frequently used. The resulting advanced epoxy/carbon fiber/nanocarbon composites revealed improved tensile and physical profiles. This review basically aims manufacturing and technical aspects of polymer/fiber/nanofiller nanocomposites toward the development of high performance structures. The resulting morphology, strength, modulus, toughness, thermal stability, and other physical features of the nanocarbon functionalized carbon fibers have been enhanced. In addition, the fabricated polymer/fiber/nanofiller nanocomposites have fine interfacial adhesion, matrix-nanofiller-filler compatibility, and other characteristics. The application areas of these nanomaterials have been found wide ranging including the strengthened engineering structures, supercapacitors, shape memory materials, and several others. [ABSTRACT FROM AUTHOR]

The aerospace industry is pivotal for global transportation and is a cornerstone of high-tech industry growth in both developed and developing nations. Ensuring the integrity of aircraft products and components, maintenance, repair, and overhaul (MRO) operations is critical to the sector's success. This paper presents a linear programming model for scheduling aircraft C-check and D-check maintenance operations with multiple component treatment options: replacement, repair, and remanufacturing. Risk of component failure before the next maintenance is integrated into the model. The objective is to minimize maintenance cost while adhering to safety standards. The model also incorporates allocation of maintenance resources including labor and machinery capacities. Scenario analyses are conducted to assess varying parameters such as resource availability, unplanned maintenance costs, and penalty on the model solutions. The potential for remanufacturing to reduce maintenance expenses in MRO operations is evaluated. The main contribution of this work lies in its novel approach to integrating risk assessment with resource optimization in MRO scheduling with remanufacturing and in providing a comprehensive framework to enhance decision-making for MRO maintenance operations. [ABSTRACT FROM AUTHOR]

Zinc electrodeposition serves as a crucial electrochemical process widely employed in various industries, particularly in automotive manufacturing, owing to its cost effectiveness compared to traditional methods. However, traditional zinc electrodeposition using aqueous solutions faces challenges related to toxicity and hydrogen gas generation. Non-aqueous electrolytes such as ionic liquids (ILs) and deep eutectic solvents (DESs) have gained attention, with choline-chloride-based DESs showing promise despite raising environmental concerns. In this study, zinc electrodeposition on mild steel was investigated using three distinct electrolytes: (i) halide-free aqueous solutions, (ii) chloride-based DES, and (iii) halide-free acetate-based organic solutions. The study examined the influence of deposition time on the growth of Zn on mild steel substrates from these electrolytes using physical characterization techniques, including scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results indicate that glycol + acetate-based non-aqueous organic solutions provide an eco-friendly alternative, exhibiting comparable efficiency, enhanced crystalline growth, and promising corrosion resistance. This research contributes valuable insights into the impact of electrolyte choice on zinc electrodeposition, offering a pathway towards more sustainable and efficient processes. Through a comprehensive comparison and analysis of these methods, it advances our understanding of the practical applications of zinc electrodeposition technology. [ABSTRACT FROM AUTHOR]

The effect of glycol derivatives including ethylene glycol (EG), diethylene glycol (DEG), and triethylene glycol (TEG) has been investigated on the characterization Al2O3 coating of anodized 7075-T6 aluminum in 20% w/w sulfuric acid, current density 4 A/dm2, and time 50 min. The thickness and hardness of Al2O3 layer measured and characterized by X-ray diffraction patterns, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The Tafle plots of linear polarization method and electrochemical impedance spectroscopy technique used to investigate the resistance to corrosion Al2O3 layer. The results showed that the thickness, hardness, and resistance to corrosion of Al2O3 film are increased, respectively, 30, 42, and 40% in the presence of glycols (10% w/w). The ratio of dielectric constant (ε) to dynamic viscosity (η) of TEG, DEG, and EG, respectively, is 0.48, 0.89, and 2.28 that is due to improvement of anodized aluminum in the presence glycol derivatives as EG > DEG > TEG. [ABSTRACT FROM AUTHOR]

Background: Chronic Neck Pain (CNP) among rotary-wing aircrew is thought to stem from night vision goggles (NVG) and counterweight (CW) systems which displace the centre of mass of the head. This investigation aimed to quantify the loads acting on the neck as a function of movement magnitude (MM), helmet conditions, and movement axes in rapid movements. Methods: Cervical spine kinematics during rapid head repositioning tasks for flexion-extension (FE) and axial rotation (AR) movements were measured from 15 males and 15 females. Participants moved in either a 35° (Near MM) or 70° arc (Far MM), while donning a helmet, helmet with NVG, helmet with NVG and a typical CW, and a CW Liner (CWL). Measured EMG from three muscles bilaterally and used to drive a biomechanical model to quantify the compression and shear acting at the C5-C6 joint. Results: In AR, the NVGs were associated with the largest compression magnitudes, 252 (24) N. CW conditions decreased the maximum compression to 249 (53) N. For FE, the compression was 340 N for the Far MM trials and 246 N for Near MMs. Changing the helmet configuration only modestly influenced these magnitudes in FE. Conclusion: Every 30° of MM increased compression by 57 to 105 N. The reduction of the moment of inertia by 16% in the CWL did not reduce reaction forces. Joint loads scaled proportionately with head-supported weight by a factor of 2.05. The magnitudes of loads suggest a cumulative loading pathway for CNP development. [ABSTRACT FROM AUTHOR]

Copyright of Computer Measurement & Control is the property of Magazine Agency of Computer Measurement & Control 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 present research aims at studying both dry machining and alternative solutions to wet machining in the drilling of carbon fiber-reinforced polymers (CFRPs). CFRPs are key materials in aerospace and their drilling is critical and challenging. Specifically, cryogenic fluids such as CO2 and N2 were investigated. Drilling tests were performed using three different CFRP laminates. These CFRP laminates are composed of various unidirectional plies of different orientations. Thus, the configurations to analyze were: 0/90/45, 30/60 and 0/90. As output variables, surface roughness, diameter deviation, delamination and thrust forces were analyzed. In general, the internal application of CO2 and dry machining were the best- and worst-performing techniques for surface roughness, respectively. Regarding the dimensional quality, both CO2 and dry machining offered the best results. In the case of LN2 or LN2 + CO2, the results showed that the CFRP configuration is critical for the obtained results. However, it was identified that cryogenics can improve the results of the dry machining process under certain conditions in terms of delamination. Finally, in general, CO2 provided the worst results when attending to the thrust forces. [ABSTRACT FROM AUTHOR]

In the world of space systems and launchers in particular, there is always a strong demand for the reduction of the weight of all components/subsystems that are not related to the payload and simplification of the integration phase. A possible solution to both these problems is the replacement of cables and connectors with wireless systems for communication and power supply. With this aim, a survey was carried out through an analysis of the technical/scientific literature available on wireless communication standards and electric power transfer methods. To evaluate wireless systems' effective applicability, the existence of applicable standards and commercial components that could facilitate their implementation was also verified. To provide information on specific applications, a synthesis of experiences in the aeronautical and space fields of wireless system demonstrators was reported. Consequently, it is clear that there is interest in the subject, but some applications are still limited to the demonstration of systems or, at most, to non-critical functions. Since wireless power transfer methods need less energy from the sensor nodes, a brief investigation into the architectures and components necessary to implement low-power sensor nodes is also included in this study. [ABSTRACT FROM AUTHOR]

Copyright of Refractories / Naihuo Cailiao is the property of Naihuo Cailia (Refractories) 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.)

This contribution addresses the complete process chain of an annular aerospike breadboard engine fabricated by laser powder bed fusion using the nickel-based superalloy Inconel® 718. In order to qualify the material and process for this high-temperature application, an extensive material characterization campaign including density and roughness measurements, as well as tensile tests at room temperature, 700, and 900 °C, was conducted. In addition, various geometric features such as triangles, ellipses, and circular shapes were generated to determine the maximum unsupported overhang angle and geometrical accuracy. The results were taken into account in the design maturation of the manifold and the cooling channels of the aerospike breadboard engine. Postprocessing included heat treatment to increase mechanical properties, milling, turning, and eroding of interfaces to fulfill the geometrical tolerances, thermal barrier coating of thermally stressed surfaces for better protection of thermal loads, and laser welding of spike and shroud for the final assembly as well as quality assurance. This contribution goes beyond small density cubes and tensile samples and offers details on the iterations necessary for the successful printing of large complex shaped functional parts. The scientific question is how to verify the additive manufacturing process through tensile testing, simulation, and design iterations for complex geometries and reduce the number of failed prints. [ABSTRACT FROM AUTHOR]

This work focuses on MAR-M247 Ni-based superalloy manufactured via directional solidification at various withdrawal rates (3.4 or 5.0 mm/min) and shell mold temperatures (1510 °C or 1566 °C) after solution heat-treatment (SHT). Observations and analyses of four casting variants were carried out using thermodynamic simulations, differential scanning calorimetry (DSC), X-ray diffraction (XRD), light microscopy (LM), scanning electron microscopy (SEM), X-ray spectroscopy (EDX), and tensile tests at ambient temperature. The solidus and liquidus temperatures were very similar for all variants and were in the range of 1263–1264 °C and 1356–1359 °C, respectively. The presence of the γ, γ′, MC carbides, and M5B3 phases was confirmed. Microstructure differences were observed depending on the manufacturing parameters. The castings' dendritic regions consisted of γ′ precipitates surrounded by the matrix, with a mean size ranging from 0.203 to 0.250 μm, depending on the casting parameters. The amount of the MC carbides in the interdendritic spaces was in the range of 1.87–1.92%. The tensile tests determined that castings produced with preheat temperature of 1566 °C were characterized by higher elongation and slightly lower yield strength in comparison to 1510 °C. [ABSTRACT FROM AUTHOR]

Remote work is becoming increasingly common, a trend accelerated by the global COVID‐19 pandemic. Existing remote work research fails to address the challenges and needs of engineers working remotely in Complex Aerospace System Development (CASD), the field responsible for creating and operating aerospace systems. This article presents an exploratory study to understand the challenges, benefits, and strategies when working remotely in CASD. We interviewed 12 CASD engineers working remotely at a major aerospace corporation. We ground our findings in six characteristics of CASD work (complex systems; design paths and feedback loops; relationships with suppliers, customers and regulators; distinct knowledge and skills; one‐off innovation; and high cost of experimentation) and discuss how each of these characteristics challenges remote work. The findings show that CASD requires many teams to work together, and this is encouraged through informal communication, which almost disappears in a remote setting. CASD requires frequent feedback, and we found that feedback was slow when working remotely. Participants found it challenging to demonstrate systems to customers and verify drawings with suppliers, and the interpersonal relationships, which help to bridge disciplinary divides, were harder to maintain remotely. The one‐off nature of the systems designed meant that conceptual work was important, but participants lacked the virtual tools to do this effectively. Lastly, testing hardware components required close virtual communication between technicians and engineers, which was tricky in a detail‐oriented context. This study motivates areas for future work to better understand and address the nuances of remote work by engineers in CASD. [ABSTRACT FROM AUTHOR]

BACKGROUND: In this study, we investigated the impact of a loss of horizon due to atmospheric conditions on flight performance and workload of helicopter pilots during a low-altitude, dynamic flight task in windy conditions at sea. We also examined the potential benefits of a helmet-mounted display (HMD) for this specific task. METHODS: In a fixed-based helicopter simulator, 16 military helicopter pilots were asked to follow a maneuvering go-fast vessel in a good visual environment (GVE) and in a degraded visual environment (DVE). DVE was simulated by fog, obscuring the horizon and reducing contrast. Both visual conditions were performed once with and once without an HMD, which was simulated by projecting head-slaved symbology in the outside visuals. Objective measures included flight performance, control inputs, gaze direction, and relative positioning. Subjective measures included self-ratings on performance, situation awareness, and workload. RESULTS: The results showed that in DVE the pilots perceived higher workload and were flying closer to the go-fast vessel than in GVE. Consequently, they responded with larger control inputs to maneuvers of the vessel. The availability of an HMD hardly improved flight performance but did allow the pilots to focus their attention more outside, significantly improving their situation awareness and reducing workload. These benefits were found in DVE as well as GVE conditions. DISCUSSION: DVE negatively affects workload and flight performance of helicopter pilots in a dynamic, low-altitude following task. An HMD can help improve situation awareness and lower the workload during such a task, irrespective of the visual conditions. [ABSTRACT FROM AUTHOR]

This paper examines the design aspects of small unmanned aerial vehicles (UAVs) in tandem wing configuration. This type of wing configuration is gaining increasing attention due to its enhanced capabilities of stability, maneuverability, and efficiency. Through a detailed analysis of the main design aspects, this paper explores the integration of tandem wing configurations in small UAVs. The results and conclusions presented here aim to provide useful guidance into optimizing performance and improving operational characteristics of these aerial systems. [ABSTRACT FROM AUTHOR]

This research employs generative design methodologies to optimize the internal structure of a small unmanned aerial vehicle (UAV) configured with tandem wings, with the explicit goal of achieving a lightweight architecture. The need for UAV internal structures to prioritize weight reduction while upholding structural integrity facilitates the application of generative design techniques. Through a meticulous analysis of generative design principles and their application in UAV structural engineering, this study highlights the potential advantages and challenges inherent in integrating generative design strategies into the development of tandem wing UAVs. The insights presented aim to underscore the opportunities involved in harnessing generative design methodologies to achieve lightweight yet robust internal structures for tandem wing small UAVs. [ABSTRACT FROM AUTHOR]

Deep microhole machining is currently a prominent research area within the aerospace field, encompassing blade film cooling and fuel injection control technologies. However, taper defects in metal materials may lead to performance degradation or even structural damage over a component's lifetime. Trepanning and helical drilling, facilitated by ultrashort pulse lasers, have proven more suitable for achieving high-precision, deep holes in metal materials. Nonetheless, excessive repetition rates can also result in severe thermal damage. Various methods are commonly employed for controlling taper, including parameter optimization, assistance, and secondary modification. Tilted laser beam drilling is widely utilized and has been integrated into relevant machining systems for commercial applications. Typical deep microholes include film cooling holes and injection microholes. Laser drilling is a potential machining method for new materials in the aerospace field. Although laser drilling processing has been studied, numerous related scientific challenges and technical difficulties must be addressed before practical implementation. [ABSTRACT FROM AUTHOR]

Green innovation refers to developing and implementing new technologies, practices, products, and processes that promote sustainability and reduce environmental impacts. This article postulates the conceptualisation and implementation of an intelligent decision support system (IDSS) tailored to the aerospace technology sector. The data were collected from open sources such as social media and analyzed using the natural language processing tool. The envisaged IDSS is a comprehensive and seamlessly integrated platform designed to undergird decision-making, problem-solving, and research initiatives within the aerospace industry. Catering to the sector's engineers, technicians, and managerial cadres, it aims to unravel complex datasets, proffer incisive analyses, and furnish prudent advice and recommendations. Its multifaceted capabilities range from data search and optimisation to modelling and forecasting. With an emphasis on harmonious integration with extant aerospace systems, it strives to provide engineers and technicians with enriched data insights. Moreover, its design ethos is centred on user-friendliness, underscored by an intuitive graphical interface that expedites seamless access and utilisation. Ultimately, the envisioned IDSS will augment the aerospace industry's analytical prowess and will serve as a potent instrument for effective decision-making. [ABSTRACT FROM AUTHOR]

Introduction: Robotics uptake in the aerospace industry is low, mainly due to the low-volume/high-accuracy production that aerospace manufacturers require. Furthermore, aerospace manufacturing and assembly sites are often unstructured environments not specifically suitable for robots to operate in.Methods: This paper introduces a robotic visual inspection system using off-the-shelf components able to inspect the mounting holes for wing slat actuators without the need for fixed-coordinate programming; the part just needs to be left within reach of the robot. Our system sets one of the opposed pairs of mounting holes as a reference (the “datum”) and then compares the tilt of all other pairs of mounting holes with respect to it. Under the assumption that any deviation in the mounting hole tilt is not systematic but due to normal manufacturing tolerances, our system will either guarantee the correct alignment of all mounting holes or highlight the existence of misaligned holes.Results and Discussion: Computer-vision tilt measurements are performed with an error of below 0.03° using custom optimization for the sub-pixel determination of the center and radius of the mounting holes. The error introduced by the robot’s motion from the datum to each of the remaining hole pairs is compensated by moving back to the datum and fixing the orientation again before moving to inspect the next hole pair. This error is estimated to be approximately 0.05°, taking the total tilt error estimation for any mounting hole pair to be 0.08° with respect to the datum. This is confirmed by manually measuring the tilt of the hole pairs using a clock gauge on a calibrated table (not used during normal operation).

The utilization of high-strength materials that can retain their strength after successive use under high mineral moisture (maximum weight of 1098 kg) for aerospace, automotive, and electromagnetic devices is challenging. Generally, coatings of nickel (Ni) and its alloys are utilized in the aforementioned applications, but the continuous use of the system degrades its mechanical stability and structural integrity. For the automotive and aerospace uses, the material should have high mechanical strength, wear tolerance, corrosion resistance, and magnetism. The bare Ni coatings can be altered with enhanced mechanical, tribological and electrochemical performances by using various reinforcements in the coatings. The abundantly used reinforcing agents are mainly carbonaceous nanoallotropes (such as graphene, carbon nanotubes, and diamond) for the fabrication of composite coatings. The current review unfolds the introduction of nickel and the major cause of damage to bare nickel coatings. Moreover, the review sheds light on how to mitigate the damage of nickel coatings with an emphasis on giving a flavor of distinct carbonaceous nanoallotropes. The conjugated studies on mechanical, wear, corrosion, and magnetic behavior of electrodeposited Ni-carbonaceous composite coatings are embraced in the review. Therefore, the present review can be endorsed by the readers for the protection of aircraft, automotive, and electromagnetic appliances.