Titanium Aluminum Alloy Research Articles

The use of ANSYS for modelling the energy distribution in steady mode with electron beam welding

The article is devoted to solving the problem of modelling the distribution of energy in the steady mode with electron beam welding with the means of ANSYS Academic Student. The authors propose the implementation of the simulation model to allow evaluating the density of the heat field in the assembly unit of the product when it is connected to its elements by means of electron beam welding. Two imitation models are implemented for one of the types of aerospace products, made of titanium alloy and aluminum alloy. Such models allow research to assess the effect of technological parameters of the process of electron beam welding on the heating intensity of the zone near the weld. A series of experiments with visualization of their results for various power values was carried out.

HVAF deposition mechanism of γ-TiAl-based coating containing β phase

The Ti-45Al-7Nb-4V, Ti-45Al-7Nb-4Cr, Ti-45Al-7Nb-2V-2Cr alloy coatings were prepared on the surface of the aluminum alloy by high-velocity-air-fuel (HVAF). The surface and cross-section of three kinds of titanium aluminum alloy coatings and the micromorphology of the bonding interface between the coating and substrate were observed by scanning electron microscope (SEM) and transmission electron microscope (TEM). The deformation behavior of titanium aluminum alloy particles and the phase composition of the titanium aluminum alloy coating were analyzed by X-Ray Diffraction (XRD) and energy dispersive x-ray analysis (EDAX). The results show that the coordinated deformation between TiAl particles and Al alloy matrix is a necessary condition for the deposition of the first layer of titanium‑aluminum alloy particles. The bonding mechanism of the TiAl coating and the matrix is mechanical bonding, and there are both mechanical bonding and metallurgical bonding between spraying particles. In the process of coating deposition and formation, the β phase grains undergo coordinated deformation to form typical structures such as striped grains and circular columnar crystals. The deformation mechanism of the titanium aluminum alloy particles is the slip and kink mechanism in the grains, and the sliding and rotation mechanism of the grain boundary and the phase boundary. Adiabatic shear instability and dynamic recrystallization occurred during the formation of titanium aluminum alloy coating.

Electrodeposition of aluminium-titanium alloys from molten fluoride-oxide electrolytes

This study reports the direct production of an aluminium-titanium alloy during aluminium electrolysis in fluoride-based melts. Experiments were conducted in a laboratory cell dedicated to current efficiency measurements. The temperature was varied from 960 to 980 °C at a cathodic current density (CCD) of 0.9 A/cm2 and a cryolite ratio (CR) of 2.2. The titanium content was up to 1.0 wt%. Titanium was added in the form of a TiO2 precursor. Bath samples were collected regularly and analyzed with ICP-MS to observe the decay of titanium during electrolysis. The current efficiency for electrodeposition of Al–Ti alloys was estimated to be at least around 90%. The surface of the solidified metal deposits was mostly flat, but some deposits were partially deformed.

Ti3Al matrix alloy refined and reinforced by in-situ synthesized SiCw/Nb4C3 core-shell structure

Hot deformation as a general fabrication method for Titanium-Aluminum alloy could enhance the mechanical properties due to the refining of grain size and lamellar width. Compared with the hot deformation method, here we report a casting strategy in which a Ti3Al matrix alloy was effectively reinforced by in-situ ceramic particles meanwhile modified by inoculants. The average lamellar width is refined from about 3300 nm to about 37 nm. Samples exhibit an ultimate compressive strength of 2.76 GPa with a strain of 17.3%. SiC/Nb4C3 core-shell structure was observed in the interface between reinforcement and matrix, and its interface microstructure was studied in detail.

Robust material of propeller blade for its Eigen frequency

Light weight structural components used in industries have a direct impact on the fuel economy and the overall performance of vehicle. The main function of propeller blades is to rotate the shaft and apply force for the movement of an vehicle. Proper mounting of a propeller is very important for the efficient performance of the machine. In a vehicle, a propeller is subjected to very high vibration that’s why the material used for manufacturing should be very reliable. In this study, we are determining the Eigen frequency of an vibration of a propeller for three different materials, which are aluminium alloy, stainless steel and Titanium alloy. Subsequently, three materials are analysed to determine the well-suited material for manufacturing of the propeller. An 3D CAD model of a propeller is modelled using CREO and the finite element analysis (FEA) based structural mechanics Eigen frequency analysis is carried out using COMSOL Multiphysics software.

Finite element machining simulations of aerospace materials

In this study, a comparison between the conventional machining and ultrasonic vibration-assisted (UVA) machining of aerospace materials has been addressed. The aerospace materials that have been taken into consideration for this study are aluminium alloys, titanium alloys, and Inconel-718. Aluminium alloys are one of the commonly used materials due to its lightweight and corrosion-resistant properties. Titanium alloys are making more and more presence in the aerospace industries for its high-temperature performance. Inconel-718 is a Nickel-based alloy and an aerospace material that makes it as one of the materials in demand. Titanium alloys and Nickel-based alloys are hard and hence difficult to machine. The numerical analysis for both the machining method will consist of the analysis of forces on the cutting tool, thermal effects, and the morphology of the chip formation. The numerical results are compared with experiments. Usage of dynamic, temperature - displacement, explicit solver along with Johnson Cook parameters to simulate machining is suggested for its close resemblance with real simulation. Based on the results, it is found that the UVA is much more effective method of machining as compared to conventional machining. UVA machining reduces the temperature in the contact zone, machining forces, and the machining-induced effects like the development of work-hardened layer.

Summary of Composite Material-Metal Connection Technology

As high-performance and lightweight materials, such as aluminum alloy and titanium alloy, metals are still used in aerospace and aircraft industry. Therefore, the bonding process of composite materials and metals is one of the key issues to be urgently solved and developed in the aerospace industry. Therefore, the connection technology of CFRP to metal is reviewed in this paper. The implementation process of laser welding, friction welding and resistance welding and the types of connection materials are summarized.

An advanced modelling to improve the prediction of thermal distribution in friction stir welding (FSW) for difficult to weld materials

This study explores the thermal distribution of high-strength engineering alloys during the friction stir welding process (FSW). Materials which are difficult to weld or are unweldable by conventional welding processes can be successfully welded by FSW. The specific analysis and modification of the process require an understanding of the actual mechanism of the process. Therefore, a transient, three-dimensional, thermo-mechanical finite element model (FEM) for FSW was developed. The model calculates the temperature distribution during the welding process considering various boundary conditions such as rotational speed, linear speed, normal pressure, tool diameter and material properties. The thermo-mechanical FEM calculations consider the effects of conduction and convection heat transfer. The numerical results are successfully compared and validated by experimental results published in the literature for aluminium alloy, titanium alloy and steel (mild and bainitic) as workpiece materials. The model was found to be useful for understanding the effects of changes in different system parameters, and for selecting the optimum welding conditions before undertaking high-cost physical testing.

Creep deformation and rupture time evaluation for Ti43Al5V4Nb at 1033 K using the θ-projection method

ABSTRACT In this study, the creep rupture time and creep properties of Ti43Al5V4Nb were evaluated at 1033 K (760°C), which was the designed maximum usage temperature for the material. A titanium–aluminium alloy with added V and Nb elements displayed higher elongation at a higher temperature than at lower temperatures. Almost all creep strain curves for Ti43Al5V4Nb consisted of tertiary stage creep. In this study, a numerical analysis method was adopted to investigate the creep properties. The creep strain curve was precisely determined using the θ-projection method when experimental data, until a life ratio of 0.9, were used to calculate the θ-parameters. The predicted creep rupture and creep strain occurrence times obtained using the θ-projection method showed good agreement with the experimental results.

Prediction of fatigue–crack growth with neural network-based increment learning scheme

An increment learning scheme based on fully-connected neural network is proposed to predict the fatigue–crack growth in middle tension, M(T), specimens of 7B04 T6 aluminum and TA15 titanium alloy under constant amplitude stress. Usually, the measurement of fatigue–crack growth rates is labor-intensive and time-consuming, and the dataset of fatigue–crack growth is small. Neural networks with back-propagation algorithm are not good at training on small dataset. Here we design network inputs which employ multiple increment information to overcome this shortage. Given the first part data points of crack growth in a specimen, the trained network can predict the rest for both aluminum alloy and titanium alloy without any prior knowledge. The trained network learns the underlying rules in experimental data of crack growth. Our method shows superiority to conventional fitting formulas and common neural networks such as recurrent neural network and long short-term memory method. Our work demonstrates the capacity of neural network and provides an alternative method to predict fatigue–crack growth.

Exploration of Aluminum and Titanium Alloys in the Stream-Wise and Secondary Flow Directions Comprising the Significant Impacts of Magnetohydrodynamic and Hybrid Nanofluid

This exploration examines the nonlinear effect of radiation on magnet flow consisting of hybrid alloy nanoparticles in the way of stream-wise and cross flow. Many experimental, as well as theoretical explorations, demonstrated that the thermal conductivity of the regular liquid increases by up to 15 to 40% when nanomaterials are mixed with the regular liquid. This change of the thermal conductivity of the nanoliquid depends on the various characteristics of the mixed nanomaterials like the size of the nanoparticles, the agglomeration of the particles, the volume fraction, etc. Researchers have used numerous nanoparticles. However, we selected water-based aluminum alloy (AA7075) and titanium alloy (Ti6Al4V) hybrid nanomaterials. This condition was mathematically modeled by capturing the Soret and Dufour impacts. The similarity method was exercised to change the partial differential equations (PDEs) into nonlinear ordinary differential equations (ODEs). Such nonlinear ODEs were worked out numerically via the bvp4c solver. The influences of varying the parameters on the concentration, temperature, and velocity area and the accompanying engineering quantities such as friction factor, mass, and heat transport rate were obtained and discussed using graphs. The velocity declines owing to nanoparticle volume fraction in the stream-wise and cross flow directions in the first result and augment in the second result, while the temperature and concentration upsurge in the first and second results. In addition, the Nusselt number augments due to the Soret number and declines due to the Dufour number in both results, whereas the Sherwood number uplifts due to the Dufour number and shrinks due to the Soret number in both results.

Structure and Properties of Titanium Aluminum Alloy Produced by Friction Stir Welding

The paper deals with the fabrication of lap joints of titanium ОТ4-1 alloy and aluminum AlMg5 alloy sheets by means of friction stir welding (FSW). The X-ray diffraction and energy dispersive X-ray analyses show that in the FSW zone, the formation of four intermetallic compounds occurs, viz. TiAl3, TiAl, TiAl2 and Ti3Al. It is found that the lower plunge depth into the substrate and the increased FSW rate do not prevent the intermetallics formation. The microhardness distribution in the FSW joint is non-uniform and its maximum value reaches 4 GPa.

Machine Learning Reinforced Crystal Plasticity Modeling Under Experimental Uncertainty

This Paper addresses a two-step computational approach to building a robust modeling environment for the titanium–aluminum alloy, Ti-7Al, a candidate aerospace material owing to superior mechanical performance under high stresses. To be used in aerospace applications, the large deformation behavior of the alloy should be investigated with a high-fidelity crystal plasticity model. However, there is no universal agreement on the crystal plasticity parameters, and previous efforts are only based on deterministic techniques. Therefore, our goal is to build a crystal plasticity model for Ti-7Al, which is validated for the global (component-scale) and local (grain-level) features by considering the experimental uncertainty. In the first step, the lower and upper bounds of the crystal plasticity parameters are determined with an inverse problem that is solved to match the computations with the experimental stress-strain data. The second step validates the local features by solving an optimization problem that minimizes the difference between the simulated and experimental microstructural textures. The optimization is performed using an Artificial Neural Network (ANN-)based surrogate model that is trained within the lower and upper limits of the parameters obtained in the first step. The outcomes of the two-step approach demonstrate significant improvement over the previous deterministic solutions.

The formation and accumulation of radiation-induced defects and the role of lamellar interfaces in radiation damage of titanium aluminum alloy irradiated with Kr-ions at room temperature

A transmission electron microscopy (TEM) specimen of a titanium aluminide (TiAl) alloy was irradiated in-situ, at the IVEM-TANDEM facility, with 1 MeV Kr ions to a maximum fluence of 1.25 × 1019 ions m−2 at room temperature. The irradiated microstructure was then investigated ex-situ using advanced analytical TEM in combination with TEM image simulations and molecular dynamics (MD) simulations. The TEM examination showed that dot-like defects first formed in both the α2-Ti3Al and γ-TiAl phases of the irradiated microstructure. With increasing irradiation dose planar defects formed and propagated within the γ phase, and most of the planar defects were accompanied by the dot-like defects. The TEM image simulations and MD irradiation simulations revealed that the origins of the dot-like and planar defects were interstitial clusters and stacking faults, respectively, and large interstitial clusters were surrounded by dislocation loops. The interstitial clusters formed and grew in the irradiated microstructure due to much faster diffusion of interstitials than that of vacancies at room temperature. Local stress concentrations increased near large interstitial clusters and lamellar interfaces, which resulted in the nucleation and propagation of stacking faults. Moreover, the configurations of the lamellar interfaces in the start microstructure were found to play an important role in the formation and accumulation of the radiation-induced interstitial clusters and stacking faults at room temperature.

Mechanical properties of dissimilar Ti-Al resistance spot welds

Abstract In this study, the mechanical behavior of titanium (ASTM Grade 2) alloy sheet, resistance spot welded with 5754 aluminum alloy, was investigated with respect to nugget formation and mechanical properties. The welding operations were performed using resistance spot welding at various welding currents (10, 12.5 and 15 kA), welding times (10, 15 and 20 cycles) and electrode forces (5, 10 and 15 kN). The weld nugget diameter and nugget center height, hardness, and tensile-shear test results of the welded samples were examined, and the mechanical properties were compared. As a result of the tests, it was seen that the welding parameters have a significant effect on the mechanical properties of the titaniumaluminum alloy welding joints. The tensile-shear load of the resistance spot welded joints increased as the welding current increased, and welding time increased for 15 cycles. On the other hand, when the electrode force increased, the tensile-shear load decreased markedly.

Mechanical properties of dissimilar Ti-Al resistance spot welds

AbstractIn this study, the mechanical behavior of titanium (ASTM Grade 2) alloy sheet, resistance spot welded with 5754 aluminum alloy, was investigated with respect to nugget formation and mechanical properties. The welding operations were performed using resistance spot welding at various welding currents (10, 12.5 and 15 kA), welding times (10, 15 and 20 cycles) and electrode forces (5, 10 and 15 kN). The weld nugget diameter and nugget center height, hardness, and tensile-shear test results of the welded samples were examined, and the mechanical properties were compared. As a result of the tests, it was seen that the welding parameters have a significant effect on the mechanical properties of the titaniumaluminum alloy welding joints. The tensile-shear load of the resistance spot welded joints increased as the welding current increased, and welding time increased for 15 cycles. On the other hand, when the electrode force increased, the tensile-shear load decreased markedly.

A state-of-the-art review on energy consumption and quality characteristics in metal additive manufacturing processes

This paper aims to study the energy consumption and quality characteristics of the parts fabricated by additive manufacturing (AM) technologies with a special focus on metal AM processes. AM is a family of manufacturing techniques, which is broadly used to fabricate complex and lightweight structures. The energy savings during AM processes have a significant influence on the AM industry, only if the quality of the fabricated part meets the requirements. The quality is generally represented by the surface and dimensional quality, mechanical properties, relative density, hardness, etc. The energy saving is important for environmentally benign and cleaner production, and improved product quality is useful for its application as a functional part in the aerospace, automobile, and biomedical industries. A comprehensive review of the energy consumption and quality characteristics of AM-fabricated (with special focus on metal AM) parts was carried out. Firstly, the specific energy consumption of various AM techniques has been reviewed to address the importance of energy and cleaner production. Then, the qualifications of products fabricated by different metal AM techniques have been discussed for different materials, such as titanium alloys, steel alloys, nickel alloys, and aluminum alloys. Also, by considering the practical importance of thin-walled structures fabricated by AM, a detailed analysis of their qualification has been presented. Moreover, different optimization techniques have also been reviewed for various AM process parameters and objectives. Overall, this paper provides an overview of AM, including a survey on the energy consumption and quality characteristics with the development of AM technologies for manufacturing of quality products. Finally, several future research directions are suggested, specifically the need for a framework for metal AM processes for the fabrication of quality products with minimum energy consumption.

Microstructure evolution and mechanical properties of Ti–46Al–4Nb alloy modified by in-situ Si3N4-graphene core-shell nanoparticles

This paper reports a new casting strategy of titanium aluminum alloy: Si3N4-graphene core-shell nanoparticle (SGP) inoculant prepared by high-energy ball milling was added to Ti–46Al–4Nb alloy. The graphene and Si3N4 in the inoculant has an in-situ reaction with TiAl melt to form SiC and Ti2AlN particles. TiC@SiC core-shell structure can be observed in TiAl matrix, which indicates Si3N4 particles could be wrapped by graphene after milling treatment. Compared with matrix alloy, the microstructure of composite consists of full lamellar (FL) equiaxed grains. The grain size and lamellar spacing were significantly refined with the increase of inoculant content. Compression experiments were carried out at room temperature and high temperature respectively, and the results show that the specimens exhibit a compressive strength of 2.53 GPa with a strain about 16.0% in 273 K and 711 MPa in 1273 K. The increase of compressive strength may be related to the fine Si5C3 particles at the grain boundary. After that, the refining effect and the micromechanics model were discussed in detail.

Structural Analysis of Alloy Wheels

The wheel of a car plays a pivotal role to endure the weight applied on it. Usually spokes behave as the supports between the hub and the rim. These spokes must have adequate stiffness and strength to dodge the failure of the wheel. In current days these wheels are comprised of, magnesium alloy, steel and aluminum alloy. To decrease the weight of the wheel, numerous wheel designs are executed and applied for automobiles. As regard to the study of the vehicle stability, it is adequate to perform the structural analysis of the wheels so as to know the equivalent modal considerations.In this work, a Cad model of a typical alloy wheel was designed in SOLIDWORKS software and dynamic analysis is performed on this model. The Stress analysis and Fatigue analysis was done on the chosen design. By observing the results we can see whether the design of wheel and the material is feasible or not under applied load conditions. A comparative study is performed by using results of the analysis of the wheel using different materials. The materials used are: Magnesium Alloy, Stainless Steel and Aluminum Alloy and Titanium Alloy in the end best suitable material for the wheel is determined

Laser Welding of Dissimilar Materials Based on VT20 Titanium and V-1461 Aluminum Alloys

This paper describes the experimental study of strength characteristics and the microstructure of a permanent joint of dissimilar materials (VT20 titanium alloy and V-1461 aluminum alloy), obtained by laser butt welding. Optical and electron microscopy, X-ray spectral and phase analysis, and the transmission diffraction method with the help of synchrotron radiation are all used to investigate the properties of a weld. It is shown that the laser radiation offset relative to the contact surface of dissimilar materials significantly changes the microstructure and phase composition of the intermetallic interlayer formed between the materials welded, thereby affecting the strength of dissimilar welded joints.