Aluminum-based Alloys Research Articles

Investigate the mechanical properties of Aluminium Metal Matrix Composite

Abstract The objective of this study is to produce metal matrix composites with aluminium as the matrix material and beryl as the reinforcing particles. Given the comparable density of beryl particles to Aluminum-based alloys, it is anticipated that enhancements in strength and ductility properties will lead to increased mechanical and tribological characteristics, including hardness and wear resistance. Extensive research has been conducted on aluminum-based metal matrix composites (MMCs) in the recent past, specifically focusing on the utilisation of ceramic reinforcements such as silicon carbide (SiC), titanium nitride (TiN), Titanium Diboride (TiB2), zirconia (ZrO2), and alumina (Al2O3). Typically, the ceramic particles employed for reinforcement exhibit notable hardness and high density, resulting in enhanced hardness and improved Tribological wear characteristics. Aluminium-based metal matrix composites (AMMC) were produced by including varying concentrations of beryl (3%, 8%, and 13%) through two distinct fabrication methods: the liquid metallurgy vortex route and the powder metallurgy approach. The beryl mineral phase was initially subjected to crushing and mechanical sieving processes to get particle sizes with an average of 50 ± 10 and 100 ± 10 μm. The mechanical qualities, including hardness and tensile strength, were examined using the Brinell hardness machine and the Universal testing equipment.

OBTAINING THE NECESSARY MECHANICAL PROPERTIES OF BLANKS OF PARTS MADE OF ALUMINUM ALLOY 7075 BY PHYSICAL MODELING

The article considers physical modeling for aluminum alloy 7075, widely used in mechanical engineering, in particular for elements of aircraft structures. This alloy differs from other rolled aluminum-based alloys not only by high values of strength properties, but also by the presence of a large number of intermetallic compounds of alloying elements. The workpiece for the parts is a round rolled product with regulated mechanical properties. Thus, the purpose of this work was to determine the effect of the deformation pattern that occurs in metal during bar rolling on the mechanical properties of blanks of parts made of aluminum alloy 7075. The present study draws attention to the importance of physical modeling in determining the characteristics of materials necessary for effective management of plastic processing processes. Analyzing the results of physical modeling, we identify the optimal parameters of material processing, such as microstructure, mechanical properties and chemical composition. The results obtained allow a deeper understanding of the physical mechanisms underlying the production of blanks (rods) from aluminum rods of alloy 7075 by rolling, as well as optimizing it to achieve the required technical characteristics of products. Thus, as a result of physical modeling of the rolling process of bars made of aluminum alloy 7075, it was found that when the samples are deformed at a temperature of 250 ° C, the value of the plasticizing stress decreases by about 18%, and a more uniform distribution of microhardness over the transverse and longitudinal sections was obtained compared with deformation at a temperature of 200 °C. The research is of practical importance for the metalworking industry, and can also be used for educational purposes to train specialists in the field of materials science and metalworking. Keywords: workpiece parts, physical modeling, aluminum alloy 7075, metalworking, aluminum alloy microstructure, deformation of samples.

Механічні властивості аморфних металевих сплавів системи Al87(Ni,Fe)8(REM)5 після короткочасного відпалу

The phase transition temperatures for amorphous metals based on aluminum Al87(Ni,Fe)8(REM)5 system were determined by differential scanning calorimetry (DSC). The mechanisms of formation and growth of nanocrystals in an amorphous matrix were predicted using kinetic models (Matusita model). It was found that after annealing at the temperature of stable nanocrystalline growth, an X-ray amorphous structure with a volume fraction of disordered nanocrystalline phases of solid state of Al(X), GdFe2, AlFe2Ni, GdFe2 for the amorphous metal alloy (AMA) Al87Y4Gd1Ni4Fe4 alloy and microcrystalline phases of solid state of Al(X), GdFe2 AlFe2Ni for the Al87Gd5Ni4Fe4 alloy are formed, which significantly affects the mechanical properties of the Al87(Ni,Fe)8(REM)5 system. The effect of annealing on the mechanical properties of amorphous aluminum-based alloys was investigated using Oliver-Pharr and Young's modulus methods it was found that thermal modification of AMAs: Al87Gd5Ni4Fe4 as a result of heat treatment of AMAs from 5 to 15 min., the microhardness increases from 0.20 GPa to 2.75 GPa, and when heat treated for 60 min at a temperatures of T3 = 645±5 K, 647±5 K, it decreases to 0.35 GPa and 0.45 GPa, respectively.

The Effect of CuO on the Thermal Behavior and Combustion Features of Pyrotechnic Compositions with AN/MgAl

Ammonium nitrate (AN) is of considerable interest to researchers in developing new types of energetic mixtures due to the release of environmentally benign gaseous products during burning and thermal decomposition. However, poor ignition and a low burning rate require special additives to speed up this process. The advantage of this research is the use of high-energy aluminum-based alloys as fuel to compensate for the disadvantages of AN. In addition, the effect of copper oxide (CuO) on the burning kinetics and thermodynamics of the energetic mixture based on ammonium nitrate–magnesium–aluminum alloys (AN/MgAl) is investigated. Alloys based on aluminum were created through a process of high-temperature diffusion welding, conducted in an environment of argon gas. The structure and thermal characteristics of alloys are determined by X-ray diffraction, scanning electron microscopy, and DTA-TG analyses. It has been found that CuO has significant effects on the thermal decomposition of an AN/MgAl-based energetic mixture by shifting the decomposition temperature from 269.33 °C to 261.34 °C and decreasing the activation energy from 91.41 kJ mol−1 to 89.26 kJ mol−1. Adding CuO reduced the pressure deflagration limit from 2 MPa to 1 MPa, and the linear burning rate of the AN/MgAl energetic mixture increased approximately twice (rb = 6.17 mm/s vs. rb = 15.44 mm/s, at a chamber pressure of P0 = 5 MPa).

Thermodynamic study of molten pool during selective laser melting of alsi10mg alloy

A study of the thermodynamic behavior during the Selective Laser Melting process of AlSi10Mg alloy was conducted using a combined numerical simulation and experimental approach. A multiphase flow model incorporating gas-liquid-solid phases was established. The numerical simulation results aligned well with experimental findings, affirming the reliability of the numerical model. Insufficient and excessive laser power densities respectively led to incomplete fusion defects and spherical pore defects. The evolution of the melt pool was primarily influenced by recoil pressure, Marangoni force, and surface tension, resulting in keyhole formation, convective flow, and liquid surface oscillation as characteristic features of melt pool evolution. Solidification process and mechanical analyses revealed that the central region of the melt pool exhibited smaller temperature gradients and higher solidification rates. Properly increasing the scanning speed under suitable laser power conditions is more conducive to optimizing the solidification structure and enhancing the mechanical properties of SLM components. This study elucidates the thermodynamic evolution mechanism during the SLM process of aluminum-based alloys, providing theoretical support and guidance for optimizing the SLM process.

Corrosion properties of aluminum-based alloys used in building constructions for different purposes

The corrosion resistance of an aluminium alloy АD 31, that is used in building constructions, is investigated. The connection between change of samples weight and time of corrosion tests is established. It is shown, that the corrosion is accompanied by simultaneous course of two processes: by oxide film formation and dissolution of more active metal. The temperature dependences have shown, that with the temperature increase higher 80°С the corrosion resistance is reduced. The accounts of weight and deep parameters of corrosion are made.

Enhancement effect of Li addition on nitriding reaction and combustion of Al-Li alloy in N2

For aluminum-based alloy particles, the addition of alloying element lithium (Li) with the properties of a high chemical activity and a low melting/boiling point can significantly improve the thermo-reactive properties of aluminum (Al) particles. To further reveal the combustion mechanism, this paper presents the nitriding reaction and combustion characteristics of Al-Li alloy in nitrogen (N2) through thermogravimetric analysis and differential scanning calorimetry (TG-DSC) analysis at a low heating rate and laser-induced ignition experiments at a high heating rate, considering the influences of two kinds of Li contents (1.0 wt% @ Al-1.0Li and 2.5 wt% @ Al-2.5Li) on these characteristics and making a comparison to the counterpart Al. Al-Li alloy powders as-prepared by gas atomization method showed the texture of the Li-rich eutectic phase compounds on the surface by scanning electron microscope (SEM) characterization. The TG-DSC results demonstrated that the thermal nitriding reaction of Al-Li alloy in N2 was significantly faster than that of pure Al. The nitriding reaction temperature decreased from 853 °C for pure Al to 245 °C for Al-2.5Li alloy with a reduction of 71 %. The final weight gain of Al-2.5Li alloy was almost three times higher than that of pure Al in N2. The SEM photograph of intermediate nitriding products revealed that the cracks and loose “island” structures in the Li-rich zone on the Al-Li surface were the key to preventing the formation of a “passivation effect” into Al and promoting N2 uptake during melting. In addition, Li also acts as a catalytic carrier and “oxygen absorber” to enhance the Al-N reaction. The combustion of single Al-Li alloy microparticles induced by laser showed two stages: preheating and rapid nitriding. Al-Li alloy particles were ignited more rapidly and showed typical gas-phase / surface combustion modes different from pure Al. According to these findings, the combustion mechanism was proposed to help guide the development of Al-based solid propellants containing Li and the synthesis of AlN/Al composites in nitrogen-rich environments.

Impact of age hardening on the corrosion characteristics of dissimilar aluminum alloys welded using an innovative MIG welding approach

An innovative metal transfer technique in MIG welding was utilized to join aluminum-based alloys such as 6061 and 5083. Following welding, the specimens underwent heat treatment to explore their corrosion resistance by modifying their microstructure. Tafel polarization curve analysis was employed to evaluate the corrosion performance of the weld zone. The findings indicated that finer microstructures in the weldment led to a notable shift towards less negative corrosion potentials compared to coarser microstructures observed in the as-welded condition. Scanning electron microscopy and X-ray diffraction were used to investigate the microstructural morphology and phase identification of the weld zone. The findings of these tests revealed a link between microstructure and corrosion behaviours.

Identification and optimization of material constitutive equations using genetic algorithms

The modeling and simulation of engineering materials using constitutive equations requires a large set of optimized coefficients that characterize the hardening or softening behavior. Optimizing this large set of coefficients with multiple constraints is very challenging using conventional optimization methods. This research proposes a novel model-agnostic framework based on genetic algorithms to identify and optimize the set of coefficients of the constitutive equations of engineering materials. The proposed framework demonstrates solution convergence, scalability to available data, and high explainability over a wide range of engineering materials, including titanium-based, iron-based, and aluminum-based alloys. The experimental test data for necessary validation of the computational framework was generated using the MTS fatigue testing machine equipped with a highly sensitive extensometer. The Chaboche unified visco-plasticity material model has been implemented as an example in this study which can deal with both cyclic effects, such as combined isotropic and kinematic hardening, and rate-dependent effects associated with visco-plasticity. The experimentally obtained cyclic response of three different classes of materials was compared with their optimized simulated constitutive equations, and the results were in good agreement. Furthermore, the proposed multi-objective optimization using genetic algorithm methodology avoids local optimality and converges to the optimal solution much faster than commercially available software.

Experimental study on the effects of three alloying elements on the mechanical, corrosion and microstructural properties of aluminum alloys

Aluminum is widely used in industries such as automobile and aerospace due to its lightweight, but its pure form lacks sufficient strength and the properties of aluminum can be modified by adding alloying elements. This paper presents the effect of adding Magnesium (Mg), Copper (Cu), and Zinc (Zn) on the mechanical, microstructural, heat treatment properties, and corrosion behavior of aluminum-based alloys. The aluminum-based alloys were manufactured with varying percentages (1 %, 3 %, 5 %, 8 %, and 10 %) of the three alloying elements using sand casting. Tension, compression, Brinell hardness, and corrosion tests were conducted to examine the effect of these alloying elements on the alloys' properties. The tensile strength is improved significantly with the increase in alloying elements for all alloys but the compressive strength and hardness are improved for Al–Cu alloy only. After heat treatment, the hardness of Al–Mg alloy increased at 8 % and 10 % Mg content while the hardness of Al–Cu alloy decreased after heat treatment for all concentrations of Cu. The hardness of Al–Zn alloys remained unaffected by the heat treatment process. The corrosion rate is minimum for Al–Mg and it is maximum for Al–Cu alloys but at 10 % concentrations, the corrosion rate of Al–Mg alloy is higher than Al–Cu alloy. The microstructural observation before and after heat treatment revealed that the grain refinement occurred for Al–Mg and Al–Cu alloys but the microstructure remained unaffected for Al–Zn alloys. The outcomes of this study offer valuable insights into customizing the mechanical characteristics of aluminum-based alloys to suit particular applications.

Hydrogen trapping and permeability in carbon fiber reinforced aluminum alloys

Carbon fibers and aluminum-based alloys are the most common choice for today's advanced hydrogen storage solutions due to their lightweight. They also combine exceptional mechanical performance and resistance to most chemicals. However, carbon fibers alone are the primary cost driver for hydrogen storage systems and high-strength aluminum alloys suffer from hydrogen embrittlement. Therefore, alternative carbon fiber-reinforced aluminum alloys can be considered to optimize storage tank costs. But, the effect of adding of carbon fibers on hydrogen trapping in an aluminum-based matrix has not yet been understood. To elucidate this, in this study, the interaction between hydrogen and a carbon fiber-reinforced aluminum alloy was investigated by correlating nano/microstructure characterization, hydrogen mapping techniques, and high-pressure hydrogen permeation tests. It is suggested that carbon fiber-reinforced aluminum alloy has three additional hydrogen trap sites compared to the reported traps for the aluminum alloy. The results showed that hydrogen trapping at these traps reduces the hydrogen permeability of composite material compared to a monolithic aluminum alloy.

Development of low-carbon energy storage material: Electrochemical behavior and discharge properties of iron-bearing Al–Li-based alloys as Al–air battery anodes

With inevitable introduction of Fe in aluminum processing, a method for achieving high-value utilization of iron-bearing aluminum-based alloys is essential. Aluminum–air batteries are among the most promising power sources and have attracted the attention of researchers. In this study, the electrochemical behavior and discharge properties of Al–0.5Fe and Al–0.5Mn–0.5Fe–0.1Sn–xLi (x = 0, 1, 2, and 3 wt %) alloys as Al–air battery anodes are investigated in 4 M NaOH. Using x-ray diffraction (XRD) and scanning electron microscopy (SEM), the constituents and distributions of the main phases are discussed. Alloying improves electrochemical behavior and discharge properties of Al–0.5Fe. The static and dynamic electrochemical experiments indicate that Al–0.5Mn–0.5Fe–0.1Sn–2Li exhibits the best corrosion resistance. The discharge performances of the five alloys show that the average voltages decrease with increasing current density and Li content. Based on the electrochemical and discharge results, Al–0.5Mn–0.5Fe–0.1Sn–2Li is an excellent candidate for use in Al–air battery anodes, reaching a peak anodic efficiency of 77.86% at a relatively high current density of 80 mA cm−2, with a power density and specific energy of 83.60 mW cm−2 and 1618.06 mW h g−1, respectively. The optimal discharge performance is attributed to dispersed AlLi particles and the fragmentation effect of AlLi on the long strip-like Al6Mn(Fe) phase.

Evaluating the Cavitation Erosion of 7075-T651 Aluminum Alloy Heat Treated by Artificial Aging at 140 °C for 12 Hours

Aluminum-based alloys, due to their high properties compared to pure aluminum, have expanded their use in building the aircraft strength structures, in the automotive construction and in the naval field. Some of these, such as the radome (aircraft nose) and the wings of the airplane, are exposed also to intense stress from the erosion created by the impact with the raindrops. The literature considers this type of damage to be assimilated by the erosion trough cavitation. Therefore, the paper presents the results of the behavior and resistance to erosion trough vibratory cavitation of the 7075 - T651 aluminum alloy structure, heat treated by artificial aging at 140 °C for 12 hours. The research has been carried out on a standard device that complies with the requirements described in ASTM G32-2016. The structure strength obtained through the researched heat treatment, is evaluated through comparison with the state obtained by artificial aging at 180 °C with a similar duration of 12 hours. The evaluation is done by comparing the parameters recommended by the ASTM G32-2016 norms of the two heat treatments. The results show that the achieved gain is slightly increased.

The Influence of Heat Aging Treatments on the Cavitation Erosion Behavior of a Type 6082 Aluminum Alloy.

It is known that a number of parts that operate in liquid media, such as the propellers of motorboats and pleasure river vessels, as well as the rotors of household pumps and the radiators and pumps in the cooling system of motor vehicles are made, as a rule, of aluminum-based alloy. Research during maintenance leads to the conclusion that, in certain operating conditions, due to the turbulent character of the flow, with pressure drops to below the vaporization level, it inevitably reaches the threshold of cavitation, which manifests itself through its effects, especially through erosion. To increase the lifetime, these alloys are currently subjected to techniques to improve the structure's resistance to the cyclic stresses of cavitational microjets. Among these techniques are volumetric heat treatments, which lead to changes in the microstructure and mechanical property values, with an effect on the behavior and resistance to cavitation erosion. This paper studies the influence of heat aging treatments on the cavitation erosion behavior of an aluminum alloy type 6082, in the cast state. The heat treatments applied were 140 °C/1 h, 12 h, 24 h and 180 °C/1 h, 12 h, 24 h. The MDEmax and MDERs parameters were determined and a correlation could be made between the values of the mechanical-resilient characteristics and the resistance to cavitation erosion in the case of aluminum alloy 6082.

Experimental investigation of phase equilibria in the Al–Ag–Si system

The phase equilibria of the Al-Ag-Si ternary system at 500 °C and 600 °C were investigated by X-ray powder diffraction (XRD) and electron probe microanalysis (EPMA). Three two-phase regions ((Al) + (Si), (Si) + Ag2Al, and (Si) + (Ag)) and two three-phase regions ((Si) + (Ag) + Ag2Al and (Si) + (Ag) + Ag2Al) were observed at 500 °C. The (Si) + Ag2Al and (Si) + (Ag) two-phase regions and (Si) + Ag2Al + liquid and (Si) + (Ag) + Ag2Al three-phase regions were identified in the isothermal section at 600 °C. A vertical section of the Al–Ag–Si system along Al0.6Si0.4–Al0.8Ag0.2 was investigated using differential scanning calorimetry (DSC) from which the temperatures of the phase-transition reactions were determined. The isothermal and vertical sections obtained in this study provide fundamental data for the thermodynamics of the Al–Ag–Si system and knowledge of the thermodynamics associated with aluminium-based alloys.

Comparative Study on Combustion Behavior of Aluminum-Based Alloy Fuels and Aluminum Powder in Solid Propellants

In order to reduce the ignition temperature and improve the combustion efficiency of aluminum powder, three aluminum-based alloy fuels, Al–Mg, Al–Zn, and Al–Si–Mg, were prepared by the atomization method. The oxidation, ignition, and combustion performance of alloy fuels were investigated, and the results showed that, using pure aluminum powder as a reference, the weight gain of alloy fuels increased from 10% to 84%, the reaction activation energy decreased from 582 kJ·mol−1 to 208 kJ·mol−1, the alloy fuels containing Mg had good ignition response, and aluminum-based alloy fuels showed high calorific value and efficient combustion as a whole. In order to investigate the combustion behavior of alloy fuels in the solid propellant, tests were conducted on the mechanics, safety, process, and combustion properties of propellant according to the national standard, and the test results showed that, compared with the propellant made of aluminum powder with same quality, the propellant made of alloy has better mechanical properties, higher frictional sensitivity, lower electrostatic sensitivity, comparable process performance, and increased combustion calorific value and combustion speed. Engine test results confirmed that Al–Zn and Al–Si–Mg alloy fuels could effectively improve the specific impulse efficiency of the solid propellant and reduced the residual rate of the engine.

A critical review of recent advances in the aerospace materials

The pursuit for improved performance in the aerospace and aviation industries has inspired the development, investigation, and research of advanced materials. Since the last few years, a lot of research on different alloys, composites and some other advanced materials has been performed to perfectly meet the needs of the aerospace field such as basic frames of aircraft, fuselages, engine parts, wings etc. Various aluminium, magnesium, titanium, and nickel-based alloys have been developed with certain advantages like strength-to-weight ratio, corrosion resistance, wear resistance etc. However, there are major challenges to aerospace materials such as insufficient mechanical and chemical properties, overall weight of aircraft, fretting wear, stress corrosion cracking, incapability at high temperatures, and low oxidation resistance. Therefore, vast studies have been conducted for the development of next-generation aerospace materials. In the present article, attention has been made to study the contemporary materials, current research going on and future trends on advanced materials in the field of aerospace engineering. Aluminium-based alloys are found as the most widely used metal alloys in the aerospace sector for their strong mechanical properties. However, polymer matrix composites and metal matrix composites have gained popularity due to their exceptional strength and stiffness. Titanium-based alloys are favoured for their strength and corrosion resistance, leading to increased adoption.

Experimental and Numerical Study of Al2219 Powders Deposition on Al2219-T6 Substrate by Cold Spray: Effects of Spray Angle, Traverse Speed, and Standoff Distance.

Cold spray (CS) is an emerging technology for repairing and 3D additive manufacturing of a variety of metallic components using deformable metal powders. In CS deposition, gas type, gas pressure, gas temperature, and powder feed rate are the four key process parameters that have been intensively studied. Spray angle, spray gun traverse speed, and standoff distance (SoD) are the other three process parameters that have been less investigated but are also important, especially when depositing on uneven substrates or building up 3D freeform structures. Herein, the effects of spray angle, traverse speed, and SoD during CS deposition have been investigated holistically on a single material system (i.e., Al2219 powders on Al2219-T6 substrate). The coatings' mass gain, thickness, porosity, and residual stress have been characterized, and the results show that spray angle and traverse speed exercise much more effects than SoD in determining coatings' buildup. Finite element method (FEM) modeling and computational fluid dynamic (CFD) simulation have been carried out to understand the effects of these three parameters for implementing CS as repairing and additive manufacturing using aluminum-based alloy powders.

Influence of aging heat treatment at 180 °C on cavitation erosion for aluminum alloy type 5083 in cold rolled state

Aluminum-based alloys have wide applicability in the construction of aircraft, vehicles, and ships. Some of their components, during operation, such as the radiators and the rotors of the cooling pumps in the vehicles, and the propellers of fishing and pleasure boats are affected by the abrasive, chemical and cavitational corrosive action of the water. At certain hydrodynamic flow regimes, the most dangerous becomes the corrosion through cavitation. Operation in such regimes inevitably leads to damaging the structure, due to cyclic stresses of the micro-jets and shock waves generated by the implosion of cavitation bubbles. Although the chemical constitution and alloying with other chemical elements increase the mechanical properties, the service life is still limited when operating in high-intensity cavitation flows. Therefore, researchers are looking for solutions to improve this resistance through various treatments, such as bulk heat. Research heading the same direction, but, made on 5083 alloy, is presented in this paper. The results highlight the behavior of a modified structure compared to the semi-fabricated state (obtained by rolling), through three durations regimes (one hours, 12 hours and 24 hours) of aging heat treatment to 180 °C temperature, after hardening treatment at 450 °C. The cavitation tests were performed in the Laboratory of the Polytechnic University of Timisoara, on the standard vibrating device with piezoceramic crystals. The results were expressed by curves and parameters specific to the evaluation of cavitation resistance, and by macro and microscopic images, showing the unique aspects of the connection between the structure and the mechanical properties obtained through heat treatment regimes. Thus, comparison of the results, including with the delivery state (laminated product), shows that the highest resistance is provided by the treatment at 24 hours. At the same time, the erosion, of pitting and caverns type, and differs from one structure to another.

Cavitation behavior study of the aging heat treated aluminum alloy 7075

Aluminium-based alloy type 7075 is known for its good ductility, high mechanical strength, toughness and high fatigue strength, which is why it is mainly used in the construction of dynamically stressed parts in the structure of airplanes, vehicles and ships. Although it has these qualities, at present its behavior has not been studied at the hydrodynamic stresses that allow it to be used in parts that work in cavitation conditions, such as pump rotors and boat propeller blades. Therefore, the research in this paper highlights the behavior of laminated semi-finished structures and obtained by heat treatment of artificial aging at 180°C, with a maintenance time of one hour. Of the 7075 alloy at the demands generated by the vibrating cavity, created by the standard vibrating device with piezoceramic crystals (frequency of 20 kHz, amplitude of 50 µm and electrical power of 500 W). Analysis based on the curves MDE (t) and MDER (t), of the specific parameters of cavitation erosion MDEmax and MDERs as well as of the macro and microscopic images of the eroded structures of cavitation show that, compared to the delivered state (semi-finished), by the heat treatment applied the microstructure does not change cavitation