Aircraft Structures Research Articles

Comparison of Repair Methods for Cracked Titanium Alloy Aircraft Structures with Single-Sided Adhesively Bonded Composite Patches.

Composite patches are widely accepted as a useful practice for the repair of cracked aircraft components and the repair method is of vital importance to the final performance of the repaired structures. The present research experimentally studied the repair efficiency and processing stability of pre-cured, prepreg (including unidirectional and plain weave prepregs) and wet-layup methods for use on cracked Ti-alloy panels through the configuration of a butt joint bonded with a one-sided composite patch. The efficiency and stability of these repair methods were elaborately evaluated and compared via the load bearing behavior, the microstructure of the bonding interface, and the structural failure morphology through two batches of testing specimens. Typical patterns were found in load-displacement curves where the initial damage and ultimate bearing load points divided them into elastic-linear, damage propagation and complete fracture phases. Although the co-cure process of both unidirectional prepreg and wet-layup methods can form a jigsaw-like demarcation interface between the adhesive layer and the composite patch to achieve a good bonding force and a high recovery of loading performance, the latter presents porous patches with a high coefficient of variation in load-carrying capacity. Conversely, the pre-cured laminate and the plain weave prepreg patches failed to restore the mechanical properties owing to the weak bonding interface and the low axial patch strength, respectively. The unidirectional prepreg patch was proven to be the optimal repair method for the cracked metallic structures when balancing repair efficiency and processing stability.

Dynamic instability analysis of timoshenko FG sandwich nanobeams subjected to parametric excitation

According to the nonlocal theory, the dynamic instability and vibration of functionally graded (FG) porous sandwich nanobeams resting on a visco-elastic foundation under axial harmonic load are studied. In this paper the Timoshenko and nonlocal continuum theory are employed to take shear deformation, rotational bending and small-scale effects into account. The governing equations of motion are extracted using the nonlinear Von-Karman, and Hamilton approaches. Then, to turn the partial differential equations (PDEs) into ordinary differential equations (ODEs) in the case of equations of motion, the method of Galerkin is employed, followed by the use of the multiple time scale method to solve the resulting equations. According to the results of this study, it can be claimed that the porosity ratio is more effective than porosity distribution and nonlocal parameters on the amplitude response and dynamic instability regions. Moreover, to examine thermal increments, foundation characteristics, slenderness, and thickness ratios, the bifurcation diagrams are drawn and discussed. It is found that foundation and geometric characteristics are of the highest significance in the nonlinear response of the Timoshenko nanobeams. The main intention of this study is to present a holistic idea about the porous materials used in sandwich structures which can be used in many composite structures in aircraft and automobiles.

Evaluation of Intergranular Corrosion in 7050-T7451 Aluminum Structures Influenced by Temperature and Contact with Cutting Fluid

This research presents a practical approach to the development of the intergranular corrosion in 7050 - T7451 aluminum alloy used in the construction of manifold components of an aircraft structure. At first, it is presented what type of corrosion this is and how it develops in the crystalline structure, noting which variables contribute to the aggravation of this problem and their impacts on aviation, since this is the beginning of a number of structural defects included fatigue, which stands out even more because of the circumstances that are presented. The performance of the tests in laboratory seeks to evaluate the reactions of the material when exposed to cutting fluid and thermal variations for a long period; the development of corrosion in the microstructure has been simulated, and with this the loss of mechanical resistance of the samples could be evaluated. The results obtained indicate that the cutting fluid even slowly, showed effects in the propagation of corrosion in the alloy of aluminum studied and reduced your mechanical strength.

Investigation of the mechanical properties of nanocomposites with multi-wall carbon nanotube reinforcement and carbon fiber/epoxy

In this study, the focus is on exploring the remarkable world of aircraft structures with the aim of creating a material that pushes boundaries and garners global attention. The successful formulation of a composite material is investigated by skillfully manipulating weight and quantity ratios. To achieve the desired outcome, different weight ratios of multi-walled carbon nanotubes (MWNTs), specifically 8g and 16g, are combined. Furthermore, these MWNTs are proportionately mixed with epoxy in volumes of 200ml, 400ml, 600ml, and 800ml, following a valence equation that correlates the gram ratio of MWNTs with epoxy. For the purpose of ensuring homogeneity and facilitating optimal component blending, an electric convector with a magnetic core is employed to generate vortices, aiding in the thorough mixing of the constituents. Subsequently, the mixture is hardened after proper placement. Prior to casting, the introduction of the hardener, whether in its liquid state or by incorporating reinforcement layers of carbon nanofibers (ranging from 0 to 16 layers), enhances and fortifies the desired properties of the material. The ingenuity of this approach is showcased by the exceptional results obtained from the evaluation of tensile stress and impact. Through rigorous testing and meticulous analysis, the findings validate the theoretical foundation upon which this endeavor is built, underscoring the success of this innovative concept.

Aeroelasticity Model for Highly Flexible Aircraft Based on the Vortex Lattice Method

With the increasing use of composite materials in aviation, structural aircraft design often becomes limited by stiffness, rather than strength. As a consequence, aeroelastic analysis becomes more important to optimize both aircraft structures and control algorithms. A low computational cost aeroelasticity model based on VLM and rigid-body dynamics is proposed in this work. UAV flight testing is performed to evaluate the accuracy of the proposed model. Two flight sections are chosen to be modeled based on recorded aerodynamic surface control data. The calculated accelerations are compared with recorded flight data. It is found that the proposed model adequately captures the general flight profile, with acceleration peak errors between −6.2% and +8.4%. The average relative error during the entire flight section is 39% to 44%, mainly caused by rebounds during the beginning and end of pull-up maneuvers. The model could provide useful results for the initial phases of aircraft control law design when comparing different control algorithms.

Friction forge riveting of AA7075-T6 sheets with large diameter 2117-T3 rivets

PurposeThe purpose of this paper is to examine the effect of changing some riveting parameters on the riveting quality of a riveted aircraft structure. In this study, riveting was performed by applying friction under pressure.Design/methodology/approachDuring this friction riveting process, a feed of 3 mm/min was applied in the axial direction. Rotation speed values of 2,000, 2,200 and 2,400 rpm were selected. A 3-axis die milling machine was used to achieve the required positioning, pressing force and friction effect. 1.27 mm-thick Al 7075-T6 sheets and 2117-T3 forged rivets were used. The feed rate was applied at 1 mm/min in both tensile shear and cross-tensile tests.FindingsThe feasibility of friction riveting in 2117-T3 rivets was examined, it was shown that it could be done, and the most suitable rotation value for this process was determined.Originality/valueClamping force is one of the most important parameters for riveting quality. This study will contribute to a better understanding of the friction-forging riveting process along with the effects of riveting parameters. At the same time, it will lead to more research and expand the application of friction forging riveting to more structural connections.

METHOD OF CALCULATING THE UNSTATIONARY TEMPERATURE FIELD PARTS OF THE SPHERICAL FORM OF THE STRUCTURE FLIGHT APPARATUS OF UNMANNED AVIATION COMPLEXES

The design of unmanned aircraft vehicles during operation is exposed to significant temperature effects, which causes changes in the dielectric characteristics of radio technical elements and can lead to failures of on-board radio electronic equipment, as a result of which the task of determining the amount of temperature change in the compartments where the radio electronic equipment is located is performed. At the same time, some external elements of the aircraft vehicle can have complex structures with shapes close to spherical and different thicknesses in each cross-sectional structure.
 There is a need to develop a method for calculating the non-stationary temperature field with the purpose of finding out the real conditions in which all the elements of the aircraft structure work, which would help to determine how the temperature of the structure changes during any flight. At the same time, it is necessary to take into account the three dimensions of temperature gradients on spherical parts of structures of various shapes, namely nose part, rounded wing and others. In them, as a rule, each cross-section of the wall has its own thickness and, according to each cross-section, the temperature distribution along the thickness of the wall will correspond, that is, it is necessary to ensure the redistribution of temperature along the structural element, the calculation of which month. In addition, it is necessary to note that the wall of the aircraft can be multi-layered and the properties of its material can change along with the change in temperature. Considering the fact that it is impossible to take into account all the listed features by analytical methods, when choosing a calculation method, it will be advisable to stop at numerical methods.
 One of the most well-known numerical methods is the finite difference method with an implicit calculation scheme, which has an indisputable advantage for modeling - absolute stability with sufficient changes in time and coordinate steps. We will use the level of thermal conductivity in spherical coordinates in order to increase the accuracy of the calculation, for which solution, after finding out the boundary conditions, we will perform a one-dimensional calculation of the temperature by thickness in each mesh section of the structure, and also perform a calculation of the two-dimensional "heat flow" along the solid between the points, that are located on the same thickness, but have a temperature difference. Thus, when calculating the temperature field, the sphericity and multi-lay redness of the structural elements is taken into account, and the property of the material of the aircraft structure changes depending on the temperature.

Nonlinear size-dependent aerodynamics of axially reinforced doubly curved micropanel with GPLs: Application of innovative artificial neural network model

Recent years have seen significant research on oscillations in aircraft structures. A self-excited oscillation known as flutter is known to wear down aircraft equipment. So, in this work, the graphene nanoplatelets reinforced composite (GPLRC) micropanel’s nonlinear aerodynamics are modeled in this paper, and the nonlinear aerodynamics properties are validated using an artificial neural network technique. The axial direction and the material characteristics of the current system are graded. The relationship between the input layers of composite weight fraction, mode number, and slenderness ratio and the output layer of nonlinear vibrations derived from mathematical simulation has been estimated using an artificial neural network model. As a training algorithm, Levenberg–Marquardt back-propagation is employed. This study is new in that it attempts for the first time to estimate the nonlinear vibration properties of micropanels built of axially graded GPLRC material using the aforementioned input layer. Without the need to solve any differential equations or go through time-consuming experimental procedures, the suggested artificial neural network model can forecast linear or nonlinear natural frequencies. The findings demonstrate that axially graded GPLRC micropanel linear/nonlinear vibration problems can be effectively addressed using artificial intelligence techniques. Future vibration analyses of the microstructures for engineering reasons can use the provided mode.

Review of high temperature materials

High-temperature materials play a significant role in sustainable engineering across various industries and applications. Sustainable engineering aims to design, develop, and implement solutions that minimize environmental impact, enhance resource efficiency, and promote long-term sustainability. The availability of substances that can be used efficiently at high temperatures allows pushing the limits of possible measurable demands. These substances include ceramics, polymers and metals. It is used in elevated temperature materials, aircraft and space structures, and space exploration. In this study, high temperature metals are classified including superalloys, platinum and refractory metals, refractory metals such as W, Nb, Mo, Ta. Also, ceramic materials are high temperature materials. Ceramics are criticized to use in elevated temperature due to their high hardness, extraordinary strength in compression, excellent thermal stability, short-term thermal extension and tremendously great melting temperature. Ceramics that encounter these standards are carbides and borides of Zr, Nb, Ta, Ti and Hf. In addition, steel, nickel and copper alloys used in aircraft engines, space shuttles and turbine blades from aerospace materials were investigated. In addition, powder metallurgy and sintering techniques, which are the most widely used production methods of high temperature materials, are emphasized. In this study, important characterization techniques for analyzing some sample surface and subsurface properties are reviewed. Again, in this study, the use of AES, XPS, SSIMS and LEED methods for the chemical examination of surfaces is discussed. Optical, electron, and scanning probe microscopy is used for pictorial inspection of inspection specimens and structures, obtaining data on surface, shape, colors, and numerous additional physical properties. Here, AFM, SEM, TEM, EDX, FIB and EMP methods are discussed. Among the material analysis devices, XRD, x-ray fluorescence spectrometry, low energy electron diffraction, neutron diffraction and electron microprobe devices were examined.

Dynamic impact behavior and notched fatigue life of GLARE laminates

As a member of the fiber metal laminates (FMLs) family, GLARE laminates have been widely used in aircraft skin structure due to the excellent resistance to dynamic impact and fatigue loadings. The low-velocity impact of GLARE laminates are conducted to explore the mechanical response on the impact energy and punch shape. The impact indentations are characterized by the damage morphology and quantitative dimension analysis. The mechanism of impact damage resistance is illuminated by the contact force-time curve, intra-laminar and inter-laminar damage modes. The lagrangian SPH modelling is employed to numerically analyze the bird-strike behavior of GLARE laminates, revealing the variation of bird particle flow and impact energy with different impact attitudes. The tension-tension fatigue of GLARE laminates is experimentally performed subjected to different stress levels. The influence of the circular open-hole on the fatigue residual life of GLARE laminates is studied. Considering the uncertainty of S-N curves, the probabilistic fatigue life P-S-N curves are developed under different survival probabilities. These would be more positive for the fatigue life estimation and reliability design for GLARE laminates in aircraft engineering application.

Fatigue Behavior and Mechanism Study on Lugs of TC18 Titanium Alloy

Aerospace structural components are in a complex stress state when they undertake load due to their specific geometric construction. Their fatigue behavior is quite different from the materials that undertake the standard stress state. The research on fatigue behavior of aircraft structures was the foundation of their design and life prediction. Lugs are one of the important connected components of aircrafts. In this paper, the mathematical mechanics’ method was used to calculate the structural feature parameters of TC18 Titanium alloy lugs under several specific loads. The design reference values of structural feature parameters were put forward for lugs. The fatigue behavior and fatigue failure characteristics under specific loads were studied experimentally. The fatigue experiment was conducted to verify the criterion, and the validity of the criterion mentioned above was confirmed by the test results. The fatigue life S-N curves under different loading forms and different mean stresses were researched. The fatigue failure characteristics, such as fatigue crack initiation, propagation, and final fracture, were also studied. These studies provided theoretical support for the anti-fatigue damage design of lugs.

Effect of internal defects on tensile strength in SLM additively-manufactured aluminum alloys by simulation

This research investigates the effect of internal defects on the tensile strength of Selective Laser Melting (SLM) additively-manufactured aluminum alloy (AlSi10Mg) test parts used for civil aircraft light weight design. A Finite Element Analysis (FEA) model containing internal defects was established by combining test data and the stress concentration factor comparison method. The effect of variation in the number, location and shape of defects on the finite element results was analyzed. Its results show that it is reasonable to use spherical defect modeling. The finite element modeling and analysis methods are also applied to the study of the effect of internal defects on tensile strength in additive manufacturing of other metallic materials. According to the FEA results of single defects at different scales, the formula for calculating the weakening degree of tensile strength applicable to the defective area of less than 15% was established. The result of the procedure is reliable and conservative. This research results can guide the selection of process parameters for the additive manufacturing of aluminum alloys. Further, the research results can promote the application of metal additive manufacturing in designing light-weight civil aircraft structures.

Equivalent initial damage sizes (EIDS) for type 1C anodised aluminium alloy 7085-T7452 under variable amplitude loading

Aluminium alloy (AA) 7085-T7452 is a high strength, low weight alloy used in large forgings in primary airframe applications. For corrosion protection, airframe components are anodised and this study looks at the influence of type 1C anodising on the fatigue crack growth behaviour in AA 7085-T7452 specimens that were fatigue tested with fighter wing spectrum loading. Surface etch pits formed during essential anodising preparatory processes were the primary cause of fatigue crack nucleation. The severity of the early crack growth caused by those etch pits that nucleated the worst crack in each specimen was evaluated using quantitative fractography-based fatigue crack growth measurements and the equivalent initial damage size (EIDS) of those etch pits was determined. Characterising the EIDS distribution of aircraft alloys with representative surface treatments is a fundamental input into Linear Elastic Fracture Mechanics (LEFM) based fleet failure analysis of aircraft structures. In this study, a notable increase in the average EIDS value for the worst crack present was observed whenever material or loading condition changes led to a significantly increased number of crack nucleation sites. In particular, an increase in the cyclic stress spectrum’s severity increased the number of nucleation sites in a specimen and significantly increased the average EIDS. It appears that due to variable nucleating discontinuity properties (e.g. size, shape and orientation) and material property variations, an increased number of nucleation sites increases the probability that the worst crack present will nucleate at a location that is conducive for relatively fast early crack growth. This will potentially cause shorter overall airframe component fatigue lives and so both the mechanisms and conditions of etch pit fatigue nucleation in this material and material finish shall be discussed for the benefit of failure analysts evaluating unexpected fleet fatigue cracking.

Impact monitoring on complex structure using VMD-MPE feature extraction and transfer learning

Impacts are common damage events in aviation scenarios that can cause damage to the structural integrity ofan aircraft and pose a threat to its safe operation. Therefore, it is crucial to monitor impact events. A region-to-point monitoring method is proposed to address the challenges posed by the large area of monitored aircraft structures and the long distance between sensors. Firstly, to fully use the information in the original impact signal and reduce the aliasing effect caused by the reinforced structure, the original signal is decomposed into several modes with different frequency bands by Variational Mode Decomposition (VMD). The Multi-scale Permutation Entropy (MPE) value is then calculated to reflect the various characteristics of each mode, which is used as a basis for classification. Secondly, Transfer Component Analysis (TCA) is selected as a transfer learning method to reduce the difference between the features of the source domain and the target domains' features. Thirdly, the TCA-transformed source domain data are used to train the Probabilistic Neural Network model (PNN), and the unfamiliar target domain data are used to verify the impact area identification. Finally, based on regional location, the system identification technology and weighted centroid algorithm can be used to obtain the history of impact force and the precise coordinates of the impact location.

Investigation of the autorotation stability of a turbofan engine with a detached fan blade

One of the requirements for the aircraft being designed is the ability to continue flying and landing if one engine fails. One of the calculated cases of engine failure is the separation of the fan blade. This phenomenon causes large vibrations in both the engine itself and the aircraft structure. A calculation model and method for studying engine oscillations with damage in the form of blade separation have been developed. Numerical studies of the oscillations of the engine suspended on a pylon were conducted. The operation of an engine with an unbalance of the fan after switching off during the transition to autorotation is considered. Numerical simulation was performed using the ANSYS Workbench package. The front supports of the rotors are ball bearings installed in the elastic elements of the "squirrel cage". Ball bearings are modeled as a rigid hinge. There are two thin-walled shells, which are intermediate power elements outside the elastic element. With an increase in the imbalance of the fan rotor, the gap in the oil damper closes, the damper housing sits on the shells, switching on their rigidity to work. Thus the support stiffness characteristic is bilinear. The stiffness coefficients of the elastic element "squirrel cage" and the shells of the front support are determined by numerical simulation. The fan rotor is modeled as a rigid body on bearings. The motor stator is modeled by a rigid body on an elastic suspension. The pylon and elements of the elastic suspension of the engine are modeled by beams of variable section, working simultaneously in tension, torsion, and bending. Numerical analysis of the transient oscillations of the D-436-148FM engine mounted on the pylon of the AN-178 aircraft was performed. The amplitude-frequency response of oscillations is obtained in the frequency range below the fan speed in the cruising mode. The stability of engine oscillations at a resonant frequency close to the autorotation frequency has been studied. The results of the numerical simulation are presented in the form of diagrams. Orbits of the centers of gravity of the fan rotor and the motor casing in the resonant mode are constructed. Poincaré mappings of oscillations of the same points of the structure are also constructed.

Exploring the formability of GLARE laminates enhanced with hybrid nanofillers through formability index, anisotropy, and surface crack length analysis

AbstractThe present study highlights the formability of hybrid nanofiller modified Glass Reinforced Laminate (GLARE) laminate, by considering the formability index, anisotropic characteristics, and surface crack length, which represent the considerations of forming capability, inherent material property, and damage tolerance, respectively. The GLARE laminates were manufactured by using hybrid fillers, multi‐walled carbon nanotube/nanoclay (MWCNT/NC), and multi‐walled carbon nanotube/Mg‐Al layered double hydroxide (MWCNT/Mg‐Al LDH). The formability analysis was carried out through the results of tensile test and Erichsen cupping test. The anisotropy of the laminate was accounted by considering the parameters, normal anisotropy, and planar anisotropy. The microscopic analysis was performed after the formability test to measure the surface crack length to interpret the forming response of the laminate with hybrid fillers. Desirability function approach (DFA) was applied to prioritize the laminates against the formability index, the anisotropy characteristics, and surface crack length. The results showed that the GLARE laminates with single filler are more suitable for forming operations than the laminates with hybrid fillers. The nanofillers with mixed morphology induced brittleness in the binder. Among the laminates with hybrid fillers, the combination of MWCNT/Mg‐Al LDH exhibited improved compliance with the forming operation. Nanofillers modified adhesives used in the fabrication of GLARE laminates proved to enhance the mechanical properties of laminates. The results of the present study showed an insight into the formability of the laminate. The understanding about the formability of GLARE laminate enables the designer to design automotive and aircraft lightweight structures.

Математична модель розрахунку аеродинамічних сил, утворюваних роторним рушієм для пропульсивних крил

The subject of the study is the modeling and obtaining of aerodynamic characteristics and determining the aerodynamic forces acting on an aircraft with a propulsive wing using a mathematical model. The research is based on mathematical methods and proposes a comprehensive model that accurately describes the interaction of airflow with wing and rotor propulsion. The aim of this study is to find solutions for faster calculations and approximate analysis of wings and aircraft that use them, compared to CFD methods. The task is to find methods that can perform calculations based only on geometric shapes and a minimal set of data that can be obtained by the researcher. The article begins with a review of previous research in the field of aerodynamics, demonstrating the need for the development of new models to better understand the aerodynamic forces generated by wing and rotor propulsion. A new mathematical model is considered, using methods based on Bernoulli's equation and taking into account parameters such as wing shape, angle of attack, airflow velocity, and rotor propulsion characteristics. This article describes the mathematical equations and approaches used to model aerodynamic forces. They include physical laws such as Newton's laws, the conservation of mass and momentum, and basic aerodynamic equations. Validation of the model was conducted by comparing the obtained results with experimental data. To verify the correctness of the presented claims, a series of computational experiments using numerical methods are performed to calculate the dynamic characteristics for different wing and rotor propulsion configurations, and the obtained data are compared. Through careful experiments and data analysis, the research results are expected to provide valuable insights into the practical implementation of an integrated tangential fan system in a wing by evaluating its efficiency, limitations, and potential advantages. This work can help engineers determine optimal wing and rotor propulsion configurations to achieve better aerodynamic efficiency and ensure the desired flight characteristics. This research can make an important contribution to the development of aviation technology and to the improvement of aircraft with rotor propulsion. Conclusions: the article proposes a new mathematical model for calculating the aerodynamic forces generated by wing and rotor propulsion and demonstrates its speed and efficiency by comparing it with experimental data. This research is just the first step in creating a mathematical framework. To improve calculation results and enable automation for greater variability in shape, the panel-vortex method with the consideration of flow acceleration over panel surfaces is more suitable. However, even at this stage, the research results can contribute to the development and optimization of aircraft structures with propulsive devices embedded in the wing design.

Design of Self-Integrating Transient Surface Current Density Sensor Integrated Fiber Transmission Link.

The transient surface current density reflects the external coupling of the electromagnetic pulse (EMP) to the tested device. In this paper, the generation mechanism and measurement principle of conductor surface current density are introduced, and the surface current density distribution irradiated by EMP on a typical aircraft structure is simulated and analyzed. The traditional surface current density is usually measured by B-dot antenna, but its output signal is the differential of the measured signal, so additional integrators or numerical integration of the measured data are required. In this paper, a self-integrating surface current sensor based on optical fiber transmission is designed based on the shielded loop antenna with gap structure. The output signal is the real signal waveform to be measured. Compared with coaxial cables, integrated optical fiber transmission improves the anti-interference ability of long-distance transmission signals. At the same time, the design process of the sensor is introduced in detail. The bandwidth of the sensor is 300 kHz~500 MHz, the sensitivity is calibrated at 1.23 (A·m-1)/mV, and the dynamic range is ±25~1400 A·m-1 (35 dB). The surface current of a metal plate is measured in a bounded wave electromagnetic pulse simulator using a detector developed in this paper. The test results show that the developed sensor has good engineering applicability.

Synthesis and characterization of DOE-based stir-cast hybrid aluminum composite reinforced with graphene nanoplatelets and cerium oxide

Purpose This research outlines the development and characterization of advanced composite materials and their potential applications in the aerospace industry for interior applications. Advanced composites, such as carbon-fiber-reinforced polymers and ceramic matrix composites, offer significant advantages over traditional metallic materials in terms of weight reduction, stiffness and strength. These materials have been used in various aerospace applications, including aircraft, engines and thermal protection systems. Design/methodology/approach The development of design of experiment–based hybrid aluminum composites using the stir-casting technique has further enhanced the performance and cost-effectiveness of these materials. The design of the experiment was followed to fabricate hybrid composites with nano cerium oxide (nCeO2) and graphene nanoplatelets (GNPs) as reinforcements in the Al-6061 matrix. Findings The Al6061 + 3% nCeO2 + 3% GNPs exhibited a high hardness of 119.6 VHN. The ultimate tensile strength and yield strength are 113.666 MPa and 73.08 MPa, respectively. A uniform distribution of reinforcement particulates was achieved with 3 Wt.% of each reinforcement in the matrix material, which is analyzed using scanning electron microscopy. Fractography revealed that brittle and ductile fractures caused the failure of the fractured specimens in the tensile test. Practical implications The manufactured aluminum composite can be applied in a range of exterior and interior structural parts like wings, wing boxes, motors, gears, engines, antennas, floor beams, etc. The fan case material of the GEnx engine (currently using carbon-fiber reinforcement plastic) for the Boeing 7E7 can be another replacement with manufactured hybrid aluminum composite, which predicts weight savings per engine of close to 120 kg. Originality/value The development of hybrid reinforcements, where two or more types of reinforcements are used in combination, is also a novel approach to improving the properties of these composites. Advanced composite materials are known for their high strength-to-weight ratio. If the newly developed composite material demonstrates superior properties, it can potentially be used to replace traditional materials in aircraft manufacturing. By reducing the weight of aircraft structures, fuel efficiency can be improved, leading to reduced operating costs and environmental impact. This allows for a more customized solution for specific application requirements and can lead to further advancements in materials science and technology.

Additive manufacturing of titanium alloy based composites using directed energy deposition: Study of microstructure, mechanical properties and thermal conductivity

Titanium (Ti) alloys are widely used in aircraft structures, aero-engines, space infrastructure and biomedical applications. However, their low thermal conductivity limits their broader application. In this study, directed energy deposition (DED) was employed for the first to successfully 3D print Ti6Al4V/diamond metal matrix composites (MMCs) with enhanced thermal conductivity and mechanical strength. By careful control of the printing parameters, a high proportion of the diamond (up to 29 wt%) survived the laser melting process. The microstructures, phases, density, hardness, compressive strength, elastic modulus, and thermal properties of the composites were studied. Compared to the directed energy deposited Ti6Al4V alloy, a 200% increase of thermal conductivity at 400 °C was achieved by an incorporation of nominal 40 wt% diamond. Increases in compression strength and modulus were also found in the composites with a nominal diamond loading up to 20 and 30 wt% respectively and the reasons for these variations are explained. These 3D printed metal matrix composites with improved thermal and mechanical properties show a high potential in space applications and as biomedical devices.