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This document discusses the determination of residual stress in aluminum alloy aerospace components using the blind hole drilling method and optical interferometric measurements. The study presents experimental procedures and uncertainty analysis for measuring residual stresses in materials. The results show that the method provides accurate and reliable results with a low level of uncertainty. The document also provides a list of references related to the measurement of residual stresses, discussing various methods and their applications in different fields. [Extracted from the article]

Al alloys and aluminum matrix composites (AMCs) are characterized by high specific strength, high specific modulus, and low density. As one of the most promising advanced lightweight materials, Al alloys and AMCs are widely used in high-speed railway, aerospace, defense, and other cutting-edge fields. However, with the urgent demand for lighter and more complex structures in these high-tech fields, traditional processing methods have shown huge limitations, such as long manufacturing process, low material utilization, restricted design and structure of parts. Fortunately, the rapid development of additive manufacturing technology in recent years has greatly expanded the flexibility of design and manufacturing. As a representative technology of metal additive manufacturing, laser powder bed fusion (LPBF) has outstanding advantages such as high accuracy, high material utilization and short production cycle. LPBF of Al alloys and AMCs is an effective method for producing complex and lightweight structural parts, however, at the meantime, it also faces huge challenges. In this article, the current research status of the LPBF processed Al alloys and AMCs are reviewed with main focus on powder preparation, LPBF technology and subsequent treatments. [ABSTRACT FROM AUTHOR]

The development of high-strength cold spray deposits using amorphous/nanocrystalline aluminum high-entropy alloy (Al HEA) powder is hindered by the lack of understanding of correlations between powder microstructure and its deformation behavior. In this study, gas-atomized Al HEA powder (Al90.05-Y4.4-Ni4.3-Co0.9-Sc0.35 at.%) is devitrified at 298, 345, 362, and 450 °C to optimize strength and deformation for cold spraying. Devitrification-induced atomic rearrangement developed equiaxed Al grains and Al3Ni and Al3Sc precipitates. The amorphous content, growth of grains, hard precipitates, and reduced dislocation density increased the hardness by 16% to 515 HV at 298 °C and decreased the hardness by 55% to 190 HV at 450 °C. The compressive strength of Al HEA powder increased by 5% to 1559 MPa at 298 °C and decreased by 49% to 760 MPa at 450 °C. To enhance the limited sprayability of Al HEA powder, compressive strength is used to model optimized cold spray process maps. Helium gas with temperatures from 300 to 800 °C and a pressure of 40 bar can produce cold spray deposits with deposition efficiency greater than 70%. The scientific insights acquired from the present study provide a gateway toward developing novel lightweight and high-strength aluminum alloy deposits, thus marking an advancement in cold spray technology. [ABSTRACT FROM AUTHOR]

The efficient hydrogen-production through the Aluminum-water reaction has become a prominent subject of interest. The impediment encountered in the reaction can be effectively alleviated by Aluminum-based alloy. In this study, density functional theory (DFT) was utilized to explore the mechanism of water decomposition stage on the surface of aluminum and gallium alloy (AGA). Through surface reaction calculations of 12 stable AGA configurations, it was gradually revealed that the optimal alloy ratio was gallium-to-aluminum at 3.5:1. Analysis of the density of states (DOS) indicated that the presence of gallium amplified the activity of surface aluminum. Moreover, frontier orbital theory and charge density maps confirmed that, due to the weak interaction between Ga and ions, the presence of H 2 inhibited Ga passivation, thereby enhancing the reactivity of AGA. This paper provided valuable insights into the surface reaction mechanisms of AGA using DFT, offering theoretical support for hydrogen production processes. • Density functional theory investigated the early stages of AGA-water reaction. • Modeling AGA (Ga proportions 73.8%–81.2%) yields 12 stable configurations. • Ga:Al = 3.5:1 exhibits highest energies for O 2 , H 2 O, and co-adsorption. • Ga enhances AGA's catalytic activity, shown in DOS graphs comparisons. • AGA plays dual roles in surface hydrogen dynamics. [ABSTRACT FROM AUTHOR]

Cylindrical foam castings of Al and A356 alloy were produced using a melt foaming method with the introduction of Ca and TiH2. Foam crystallization takes place in a cooled thin-walled metal mold. Samples cut off from the foam castings are investigated by X-ray tomography, quantitative data for porosity, average pores diameter and average cells wall thickness are obtained. It is found that the porosity is mainly open. Same samples are tested in quasi-static mode and the compressive strength is determined. The influence of porosity on compressive strength is analyzed. [ABSTRACT FROM AUTHOR]

Friction stir welding (FSW) emerges a broad application and development prospects in the joining of dissimilar materials. Friction stir lap welding (FSLW) of 6061-T6 aluminium (Al) alloy sheet with different depths groove pretreatment and polycarbonate (PC) sheets is investigated. Weld surface defects are studied by visual inspection. The analyses of microstructures and mechanical tensile properties of the dissimilar joints are carried out by optical microscopy (OM) and tensile tests. Results indicate that the groove depth is a significant factor affecting the welding surface morphology. Tensile strength reaches the maximum with the average value of 29.05 MPa at the groove depth of 0.2 mm, which is equivalent to 58% of the PC base material strength. Microstructure analysis indicates that the molten PC and Al alloy fragments flow along the groove at the action of the pin tool. Simultaneously, Al alloy fragments are inserted into the molten PC material. The two materials form a compact mixed structure, which improves the tensile strength. [ABSTRACT FROM AUTHOR]

Background: Residual stress development in precipitation strengthened aluminium foundry alloys has seen little attention, despite the prevalence of their use over a wide array of applications. Objective: This study aims at the evaluation of the residual stress in a cast aluminium benchmark that develops during precipitation heat treatment and determines the preferable stress relaxing techniques for such applications. Methods: The stress states in the as-cast, T4 and T6 tempers of the same AlSi7Cu0.5Mg (A356 with 0.5 wt% Cu) sample were determined through a novel application of the contour method, standard hole drilling, deep hole drilling and incremental deep hole drilling. Results: The results of all measurement techniques lie within approximately 40 MPa for all regions available for comparison, with the greatest differences occurring between the contour method and deep hole drilling for the T6 component. It is shown that the peak tensile residual stresses are almost identical between the heat-treated components (75 MPa), but the distribution and magnitude of compressive residual stress are found to be significantly different. Conclusions: Among the measurement techniques evaluated, the contour method and incremental hole drilling are found to be more suitable for T6 temper, while all techniques perform equally well for T4 temper due to its relatively low strength. It is hypothesised that the difference between the as-cast and heat-treated samples is due to solution heat treatment and quenching, while the difference in T4 and T6 tempers is attributed to the response to ageing. [ABSTRACT FROM AUTHOR]

The effects of vacuum induction melting and various concentrations (range of 0–8% by weight) of the titanium aluminium carbide (Ti2AlC) phase on the mechanical and tribological properties of Aluminium hypereutectic alloy (A390) were investigated. The addition of Ti2AlC particles enhances the strength and wear resistance of A390 alloy and also exerts a positive effect on its ductility, Moreover aerospace and automotive brake rotors deserved high strength and high wear resistance. The quick induction heating process could decrease the thermal energy degradation of the Ti2AlC particles into an Al alloy matrix alloy. The structural, microscopic and elemental analysis carried out to observe the hard precipitate components and reveal the various phases of the composites. The addition of Ti2AlC inclusions altered the morphology of eutectic silica to be globular and improved the grain size and evenly distributed within the A390 (Al-16Si) matrix. As the content of Ti2AlC reaches 8 wt% the strength and microhardness of the composites increased 74% and elongation decreased 2.1% (UTS = 285 MPa, H = 127VMH and EI = 1.1%). The tensile and fracture behaviour of the composites has been studied at 30 °C, 150 °C, and 250 °C. The Johnson-Cook model theoretically calculated the accurate flow stress of the Al-16Si/Ti2AlC composites. The negligible decrease in strength and ductility at 250 °C was observed. The root mean squared error (RMSE) and mean absolute percentage error (MAPE) values for the stress-strain curves prove the higher relationship between the theoretical and experimental values. The composites containing 8 wt% Ti2AlC reinforcement significantly enhanced the mechanical behaviour with a porosity < 2.23%.Therefore this composite exhibited appreciable tribological properties. It appeared that the wear mechanism of the composites abrasive wear at applied pressure 0.2 MPa with sliding distance 2000 m was prevailing. The ANN model addressing the parameters which influence the wear rate and friction coefficient as well as the experimental wear analysis of these composites was correlated precisely with the results of this model. [ABSTRACT FROM AUTHOR]

This document is a compilation of various research papers and articles that discuss the use of machine learning and other techniques to predict fatigue lifetimes in different materials and structures. The papers cover topics such as the use of neural networks, XGBoost, and physics-informed machine learning models for fatigue prediction. The research focuses on different materials, including aluminum alloys and lead-free solders, and explores the effects of factors such as wear, lubrication, corrosion, and stress on fatigue life. The papers provide insights into the application of machine learning techniques in predicting fatigue lifetime and offer potential solutions for improving the accuracy of these predictions. [Extracted from the article]

Additive manufacturing (AM) is a highly advanced manufacturing technology that involves metal layers deposition in order to increase the efficiency of component production and costs reduction. Current study includes examining the effects of adding aluminium as an additional alloying element to austenitic stainless-steel SS 309L. Metal Inert Gas (MIG) welding apparatus was used as a heat source for the deposition of the steel in the Wire Arc Additive manufacturing method. Simultaneously during the building process, three different percentages (0, 2.5%, and 5%) of an external aluminium alloy 4043 (E4043) cold wire was introduced into the fusion zone. The focus of the study is to highlight the influence of adding E4043 on the microstructure and mechanical properties of additively manufactured SS309L. For the microstructural investigations, optical microscopy and scanning electron microscopy (SEM) were used, whereas a Vickers microhardness test was used to investigate the effect of these additions on the local mechanical properties. On the other hand, the mechanical behavior of the deposited parts was examined using tensile test. The results of the study demonstrated that the addition of the aluminum alloy is significantly affect the mechanical properties of the deposited portions. The quantity of the added aluminum is discovered to have an influence on the microstructure, hardness, and tensile strength. Moreover, the homogenizing thermal treatment improved the samples' microstructure and overall properties. The found results highlights the importance of considering double wire feeding in additive manufacturing processes to reach the desired microstructural and mechanical properties in the final products. [ABSTRACT FROM AUTHOR]

This paper proposes a Whipple structure to enhance the impact resistance of graphene/aluminum alloy composites by varying the interlayer spacing between graphene and aluminum alloy. The increased interlayer spacing provides more deformation space for the graphene to absorb more deformation energy, and enables the formation of a debris cloud from the bullet fragments and graphene fragments, significantly reducing the impact energy per unit area of the next material. The impact limit serves as a critical metric for assessing the impact resistance of the Whipple structure. Based on molecular dynamics simulations, we developed a machine learning model to predict the protection of aluminum alloy, and quickly determined the impact limits of velocity, bullet radius, and interlayer spacing by using the machine learning model. An empirical equation for the impact limit of interlayer spacing was established. The results showed that non-zero interlayer spacing can significantly improve the impact resistance of the hybrid structure; to fully exploit the superior impact resistance of this Whipple structure, the number of graphene layers should be at least 3. Furthermore, at high impact velocities and large bullet radii, the impact limit of the interlayer spacing exhibits a substantial correlation with the number of graphene layers. These results provide valuable information for the design of the impact resistance of the graphene/aluminum alloy composites. [ABSTRACT FROM AUTHOR]

To efficiently enhance the bonding performance of aluminum lithium alloy, the surface morphology characteristics of the samples were constructed by copper chloride rapid etching method. The microstructure, roughness characteristics, wetting performance, and bonding joint strength performance of different modified surfaces were compared and analyzed. The results show that compared to the original surface and sandpaper grinding method, rapid etching can effectively enhance the surface wettability and adhesive strength of the sample. When the etching time is 5,10, and 15s, the strength of the adhesive joint of the untreated sample is increased by 217. 6%,245. 9%, and 270. 3 %, respectively. The Increase of etching time contributes to the construction of concave convex stepped morphology and the increase of surface roughness, thereby improving the actual contact area and mechanical interlocking of the bonding interface, promoting the penetration and adhesion of the adhesive on the substrate surface, and thereby improving the strength performance of the bonding joint. [ABSTRACT FROM AUTHOR]

This work investigates temperature's effect on the critical energy release rate using damage mechanics material models and the element deletion method. The energy release rate describes the decrease in total potential energy per increase in crack surface area. The critical energy release rate is widely used as the failure criterion for various elastic and plastic materials. In real-life scenarios, fractures may occur at different temperatures. The temperature dependency of the critical energy release rate for aluminum 2024-T351 and titanium Ti-6Al-4V is studied in this work. We utilized test-data-based advanced material models of these two alloys, considering the strain rate, temperature, and state of stress for plasticity and failure. These material models are used to simulate a three-dimensional fracture specimen to find the critical energy release rate at different temperatures. A new method to calculate the critical energy release rate with the element deletion method is introduced and verified with the virtual crack opening method. This method enables the calculation of the energy release rate in a classical damage mechanics simulation for dynamic cack propagation. The simulation result indicates that the critical energy release rate increases with rising temperatures for these alloys. [ABSTRACT FROM AUTHOR]

Electromagnetic treatment (EMT) plays a critical role in the manipulation of microstructures and properties in aluminum alloys. This study aims to investigate the impact of EMT on stress corrosion cracking (SCC) resistance in 7075 aluminum alloy and to reveal the underlying mechanisms from both thermodynamic and kinetic perspectives. The results demonstrate that EMT has a significant positive effect on the stress corrosion resistance of the aluminum alloy. It effectively reduces the elongation loss from 11.2 to 2.6% and the SCC susceptibility index from 3.9 to 1.4%. This improvement can be attributed to two primary mechanisms: (1) the energy supplied by the electromagnetic field lowers the thermodynamic barriers for the dissolution of precipitates, even at temperatures below the critical threshold. This facilitates the dissolution and coarsening of precipitates, ultimately reducing the alloy's susceptibility to stress corrosion in various environments. (2) The activation energy provided by the electron wind force facilitates the movement and annihilation of dislocations, leading to a reduction in residual stresses and further enhancing the aluminum alloy's resistance to stress corrosion. [ABSTRACT FROM AUTHOR]

Melting, solidification, and viscosity properties of multicomponent Fe-Cu-Nb-Mo-Si-B alloys with low aluminum addition (up to 0.42 at.% Al) were studied using an oscillating cup viscometer. It is shown that melting and solidification are divided into two stages with a knee point at 1461 K. The temperature dependences of the liquid fraction between the liquidus and solidus temperatures during melting and solidification are calculated. It has been proven that aluminum accelerates the processes of melting and solidification and leads to an increase in liquidus and solidus temperatures. In the liquid state at temperatures above 1700 K in an alloy with a low aluminum content, the activation energy of viscous flow increases. This growth was associated with the liquid–liquid structure transition, caused by the formation of large clusters based on the metastable Fe23B6 phase. Aluminum atoms attract iron and boron atoms and contribute to the formation of clusters based on the Fe2AlB2 phase and metastable phases of a higher order. [ABSTRACT FROM AUTHOR]

Direct water spraying (DWS) is an approach similar to ablation casting using direct impingement of water spray on the solidifying casting but is modified in that it no longer relies on eroding removal of the sand bound by water-soluble binders. A removable part of the sand mold is withdrawn during the process, and water is directly sprayed on the exposed casting surface. Two commercial casting Al alloys, i.e., A413 with short to zero and A356 with a wider freezing range, were processed by the DWS method. Comparison of the conventional and DWS-processed castings with respect to the microstructure and mechanical properties was evaluated via computer-aided thermal analysis, metallography, and tensile testing. The average ultimate tensile strength (UTS) increased from 126 to 193 MPa in A356 and 139–159 MPa in A413 by applying the DWS method. The elongation was increased from 2.8 to 11% in the DWS A356 and from 1.8 to 5% in the DWS A413. The secondary dendrite arm spacing (SDAS) was decreased from 80 µm in A356 to 44 µm and from 68 µm in A413 to 32 µm in the respective DWS-processed counterparts. The experimental results confirmed that a longer freezing range is more favorable with the DWS process, producing improved castings with higher tensile properties. [ABSTRACT FROM AUTHOR]

A laser-electromagnetic acoustic transducer (Laser-EMAT) Rayleigh wave (RW) detection based on surface constraint mechanism and its optimisation design are proposed to solve the low signal-to-noise ratio (SNR) of its application in aluminium alloy detection at high-temperature. We established a finite element (FE) model of aluminium alloy's Laser-EMAT RW detection process based on the surface constraint mechanism and investigated the effect of the surface constraint mechanism on laser-excited RW. We also studied the effects of laser parameters and meander-line coil (MLC) EMAT parameters on the ultrasonic wave amplitude and spectral composition. Finally, the enhancement effect of the surface constraint mechanism on RW amplitude was analysed by Laser-EMAT RW detection experiments on aluminium alloy at room temperature and high temperatures. The results show that the optimised MLC-EMAT can increase the RW amplitude by 1.97 times. When the laser line source width equals the MLC-EMAT turn spacing, the echo SNR is the highest. The enhancement effect of the surface constraint mechanism on the RW amplitude gradually decreasesas the specimen temperature increases. The RW amplitude can increase by 1.43 times when the surface constraint mechanism is applied at room temperature, and for the aluminium alloy specimen at 430°C, the RW amplitude can increase by 32%. [ABSTRACT FROM AUTHOR]

This article describes the changes in the microstructure, cooling curve characteristics and mechanical properties of cast Nickel Aluminium Bronze alloy (NAB) alloy that were produced by the addition of various amounts of Tin (Sn). The solidification parameters were recorded using a computer-aided cooling curve analysis setup, and optical and scanning electron microscopes were utilised to study the evolution of the microstructure. The chemical composition of different phases generated in the NAB alloy with and without Tin was investigated using an X-ray diffraction technique. With the addition of tin, the alloy's microstructure changed from columnar to equiaxed grain structures, and the ideal microstructure was produced at a Tin concentration of roughly 1.0 weight percent. The formation of the high temperature α and the grain boundary Sn rich phases across the alloy microstructure as a result of further addition has a considerable impact on the alloy's increased hardness (upto 69%) and tensile strength (upto 28.4%) compared to untreated NAB alloy. Influence of Sn on microstructure transformation is confirmed by the decline in alloy nucleation temperatures, the reduction in undercooling intensity, and the decrease in cooling rate during solidification. The addition of Tin to the NAB alloy caused morphological changes in the kappa (K) phases, which are also reported in the this article. In addition to this, the research makes an attempt to describe the mechanism underlying the formation of equiaxed grains and phase transformations in Sn-treated NAB alloys. [ABSTRACT FROM AUTHOR]

Corrosion is a serious problem that affects several industries and causes significant economic losses. In recent years, the transportation industry has replaced several ferrous parts with aluminum or magnesium alloys to produce lighter vehicles. Due to this, galvanic corrosion has been more frequent in that industry. In this work, a colorimetric sensor for the detection of Al(III) species during galvanic corrosion is presented. The sensor was made of a chromophore immobilized on a gel electrolyte based on NaCl and agar. The sensor developed a red coloration proportional to the Al(III) concentration under the pH interval studied (3.2–4.5). A galvanic couple consisting of an aluminum alloy and carbon steel was used to test the capacity of the sensor to develop the production of Al(III) into the gel electrolyte and over the whole aluminum surface. Through image processing, it was possible to construct 2D Al(III) concentration maps over time using a commercial aluminum alloy (AA7075) and a castable aluminum alloy from a steering rack as a real sample. [ABSTRACT FROM AUTHOR]

In this paper, we studied the effects of a series of alloying atoms on the stability and micromechanical properties of aluminum alloy using a machine learning accelerated first-principles approach. In our preliminary work, high-throughput first-principles calculations were explored and the solution energy and theoretical stress of atomically doped aluminum substrates were extracted as basic data. By comparing five different algorithms, we found that the Catboost model had the lowest RMSE (0.24) and lowest MAPE (6.34), and this was used as the final prediction model to predict the solid solution strengthening of the aluminum matrix by the elements. Calculations show that alloying atoms such as K, Na, Y and Tl are difficult to dissolve in the aluminum matrix, whereas alloy atoms like Sc, Cu, B, Zr, Ni, Ti, Nb, V, Cr, Mn, Mo, and W exerted a strengthening influence. Theoretical studies on solid solutions and the strengthening effect of various alloy atoms in an aluminum matrix can offer theoretical guidance for the subsequent selection of suitable alloy elements. The theoretical investigation of alloy atoms in an aluminum matrix unveils the fundamental aspects of the solution strengthening effect, contributing significantly to the expedited development of new aluminum alloys. [ABSTRACT FROM AUTHOR]

This article describes the changes in the microstructure, cooling curve characteristics and mechanical properties of cast Nickel Aluminium Bronze alloy (NAB) alloy that were produced by the addition of various amounts of Tin (Sn). The solidification parameters were recorded using a computer-aided cooling curve analysis setup, and optical and scanning electron microscopes were utilised to study the evolution of the microstructure. The chemical composition of different phases generated in the NAB alloy with and without Tin was investigated using an X-ray diffraction technique. With the addition of tin, the alloy's microstructure changed from columnar to equiaxed grain structures, and the ideal microstructure was produced at a Tin concentration of roughly 1.0 weight percent. The formation of the high temperature α and the grain boundary Sn rich phases across the alloy microstructure as a result of further addition has a considerable impact on the alloy's increased hardness (upto 69%) and tensile strength (upto 28.4%) compared to untreated NAB alloy. Influence of Sn on microstructure transformation is confirmed by the decline in alloy nucleation temperatures, the reduction in undercooling intensity, and the decrease in cooling rate during solidification. The addition of Tin to the NAB alloy caused morphological changes in the kappa (K) phases, which are also reported in the this article. In addition to this, the research makes an attempt to describe the mechanism underlying the formation of equiaxed grains and phase transformations in Sn-treated NAB alloys. [ABSTRACT FROM AUTHOR]

The drive to lower the carbon footprint of the automotive industry has led to the development of high efficiency diesel engines. The materials used for diesel engine components must withstand greater thermomechanical loading, as compared to gasoline engines. Thus, to determine the feasibility of using conventional aluminum-based powertrain alloys for next generation high efficiency engines, the present study evaluates the elevated temperature (250 and 300 °C) tensile and creep performance of a T7 319-type alloy. To represent real-world conditions, the 319 samples used in this study were extracted from the cylinder bridges of a sand cast engine block and then conditioned at their respective test temperatures for 200 hours. The results indicate that at 250 °C (~30–50 °C above current engine operating temperatures), the tensile strength and creep resistance of the T7 319 alloy will be able to withstand current cylinder pressures (i.e., 22 MPa) and may allow for an increase up to 30–35 MPa. However, at 300 °C, the strength decreases by more than 50% and tertiary creep initiates at 40 MPa. As such, the inherent evolution of residual stress during current engine block manufacturing technologies prevents the safe use of the 319 alloy in engine applications operating at 300 °C. [ABSTRACT FROM AUTHOR]

Polymer-metal hybrids were prepared by using the ultrasonic-assisted hot-press molding process. The surface of the aluminum alloy is anodized to produce nano-pores with a pore size distribution of 60 to 210 nm. The surface of the anodized aluminum alloy is soaked with a silane coupling agent solution to alter its surface polarity. In addition, PP-g-MAH was used to alter the polarity of polypropylene. The structure and properties of the composites were investigated by tensile shear tests, the microstructure of the bonding interface, and elemental analysis. The results show that adding silane coupling agents can create a chemical connection based on the mechanical interlocking structure of the composite bonding interface, leading to an increase in tensile shear strength. When the aluminum alloy surface was treated with a silane coupling agent with a volume fraction of 4%, the tensile shear strength reached 21.02 MPa, increasing by 20.32% compared to the specimen without the silane coupling agent treatment. [ABSTRACT FROM AUTHOR]

Serious requirements are put forward for aircraft electric machines (EMs) in terms of weight and size indicators. To reduce the mass of EMs, it is possible to consider aluminum windings, the density of which is 3 times less than that of copper windings. However, due to the much lower electrical conductivity of aluminum (40% less than that of copper), the overall performance of EMs with the same output parameters with aluminum windings is higher. In this regard, there is an interest in the electrical industry in increasing the electrical conductivity of aluminum windings. This problem can theoretically be solved by using carbon nanotubes (CNTs) together with aluminum. This article presents the results of a study of additive windings of aircraft EMs from a powder alloy based on aluminum with CNTs. Visual inspection shows that aluminum windings with CNTs have a 7.4 times more porous structure. The results of experimental studies show that after adding CNTs, the electrical conductivity of aluminum windings became 35% lower and the resistance 50% higher compared to aluminum windings without CNTs. Thus, in the presented work, additive aluminum windings with CNTs exhibit much worse electromagnetic properties compared to aluminum windings without CNTs. [ABSTRACT FROM AUTHOR]

This paper presents comparative characteristics of the aluminum and magnesium alloys in the context of their utilization in the metallurgical and automotive industry. The studies carried out in our work help to solve the problem of reducing the weight of automotive devices to reduce fuel consumption through the use of aluminum-magnesium alloys. The originality of our article lies in a comprehensive study of the stated problem: development of a research methodology, testing of the alloys under study for uniaxial tension, quantitative analysis of the Portevin-Le Chatelier effect, development of a mathematical model for optimizing parts, computer simulation of the viscoplastic properties of a model sample. Analysis of the obtained strength parameters demonstrates that the flow characteristics of the two-phase alloy of aluminum and magnesium exceed the ultimate tensile strength by 50 %. Rate of extension was inversely proportional to the intensity of the Portevin-Le Chatelier effect. [ABSTRACT FROM AUTHOR]

Machining with the textured cutting tool is an emerging sustainable method to improve the cutting performance of the tool. In this work, an attempt has been made to improve the cutting performance of HSS cutting tool by fabricating the protruded surface textures on the rake surface of HSS cutting tool. A triangular-shape protruded textures were fabricated on HSS cutting tool by radium masking followed by chemical etching process (CEP). Protruded textured (PT) cutting tools are used in the dry machining of aluminium 6063 alloy, and these tools were compared with the cutting performance of non-textured (NT) cutting tool. Experimental results showed that protruded textured (PT) tool has significantly impact on reduction of chip-tool tool contact area it leads to improved the cutting performance as compared to NT cutting tool. [ABSTRACT FROM AUTHOR]

The first Principle calculations are made to study the structural electronic and optical properties of indium-doped aluminum antimonide. The most appropriate method of density functional theory (DFT) naming Full Potential Linearized Augmented Plane Wave (FP-LAPW) is used. The structural properties like Lattice constant (a), pressure derivative, and bulk modulus (B) of Al1−xInxSb (x = 0, 0.25, 0.5, 0.75) are examined with generalized gradient approximation (GGA). Generalized gradient approximation along with TB-mBJ is used to determine electronic parameters like band structure along and density of states. According to the computed results the binary compound AlSb is optically inactive and exhibits an indirect (Γ-L) band gap. By increasing the concentration of indium with different percentages, the indirect band gap shifted to the direct (Γ-Γ) band gap which shows the material is optically active. The optical properties of the material including dielectric (Real and imaginary parts) constant, reflectivity, refractive index, energy loss, absorption coefficient, and optical conductivity have changed significantly. Electronic and optical properties are modified by (TB-mBJ) approach. The results obtained are examined with experimental data and utilized as a starting point to propose that the material is the superlative choice for the manufacturing of p-n junctions, photo-detectors, laser, photo-diodes, transistors and solar spectrum absorptions in the visible, infrared and ultraviolet energy ranges. [ABSTRACT FROM AUTHOR]

Additive manufacturing technologies; It includes methods based on the principle of manufacturing the part layer by layer until the final geometry is obtained according to the threedimensional (3D) digital model data of the objects using plastic, ceramic and metal materials. Today by using this method can be manufactured in the art, building sector, medical, energy, automotive aviation and space industries, without the need for additional (assembly, welding, etc.) processes of very complex geometry products. Its use has increased gradually thanks to its advantages such as weight reduction (topology optimization) by creating porous and cavitied structures. Aluminum and aluminum alloys are highly preferred among the powder materials used in the additive manufacturing sector. In this study, parts manufactured by using additive manufacturing technologies and topology optimization methods of aluminum alloys used in the automotive, aerospace and aerospace industries are examined. [ABSTRACT FROM AUTHOR]

Aluminum and its alloys are widely used in packaging, transportation, electrical materials, and many other fields because of their abundance, light weight, good mechanical properties, suitable corrosion resistance, excellent electrical conductivity, and other advantages. Grain refinement achieved by adding inoculant is important not only to reduce the segregation and thermal cracking of alloy castings but also to improve the mechanical properties of alloy castings. Therefore, fine equiaxed grain structure has always been one of the goals pursued by the aluminum alloy casting industry. For this reason, the selection and development of effective inoculants for aluminum alloy is a key technology in the aluminum processing industry. This paper summarizes the development history of inoculants for aluminum alloy, including Al-Ti-C, Al-Ti-B, Al-Ti, Al-Ti-B-(C)-Ce, Al-Sc, and the Fe-rich phase of Al-Si alloy. At the same time, the advantages and disadvantages of common inoculants are introduced and prospective future applications are reviewed. [ABSTRACT FROM AUTHOR]

The results of the experimental study of the effect of sodium on the anodic behavior of AlTi0.1 aluminum conductor alloy in a medium of NaCl electrolyte are presented. Studies have been carried out using the potentiostatic method in the potentiodynamic mode at a potential sweep rate of 2 mV/s. It has been shown that sodium modification of the AlTi0.1 aluminum conductor alloy contributes to the shift of the potentials of free corrosion, pitting formation, and repassivation to the positive range of values. The corrosion rate of AlTi0.1 aluminum conductor alloy when modified with 0.01–0.5 wt % sodium is reduced by 10–20%. Depending on the concentration of chloride ions in the NaCl electrolyte, the corrosion rate of the alloys increased and the electrochemical potentials shifted to the region of negative values. [ABSTRACT FROM AUTHOR]

Metal additive manufacturing techniques typically operate using powders with limited particle size ranges, but atomisation processes produce significant amounts of particles outside these ranges, resulting in an accumulation of out-of-size specification metal powders without a clear use case. Field-assisted sintering technology (FAST) can provide an alternative, solid-state processing route to consolidate these powders into billets for subsequent processing, or directly into near-net shape components. In this study, surplus powders of A20X, an aerospace approved aluminium alloy developed by Aluminium Materials Technologies (ECKART GmbH), were processed using FAST and subsequently hot rolled to produce sheet material. Tensile properties were similar to hot rolled conventional cast material and comparable to additively manufactured product. This indicates that FAST is an effective option for converting surplus metal powders into useful products, while improving sustainability in the additive supply chain. [ABSTRACT FROM AUTHOR]

Air entrainment is a well-known phenomenon that plays an important role in the quality of aluminum castings. This phenomenon negatively affects mechanical properties, attributed to double oxide films with low bonding forces between layers, leading to higher volume fractions of shrinkage and gas porosity. A previous measuring system developed by our research group required applying temperature corrections to the volumes of entrained air, introducing some degree of uncertainty, motivating the design of this new and precise measuring system. The present study shows the quantification of the volume of entrained argon and air through this new measuring system which, to the authors' knowledge, has not been used in any other study. This new system provides highly accurate values for the volume of entrained gas. Furthermore, it was demonstrated that entrained volumes are considerably lower than volumes measured in water experiments, mainly due to temperature and surface tension differences. In addition, it allows measuring a critical velocity of 2.71 m/s for entrainment, which is an important parameter for designing filling systems and reducing the entrainment damage to the microstructure and the negative effect on mechanical properties. Results show a notable reduction in tensile strength, ductility, and impact energy with the increase in the air entrainment volume, highlighting the importance of controlling the pouring variables to reduce the adverse effects of air entrainment. On the other hand, the higher the volume of argon entrainment, the lower the porosity volume fraction compared with the samples taken from the ladle before pouring. This effect was attributed to a degassing effect produced by the entrained bubbles of argon. Quantification of argon and air entrainment volumes performed in the present study shows the great importance of the amount of gas entrained on the porosity and mechanical properties of an aluminum A356 alloy. [ABSTRACT FROM AUTHOR]

To systematically and comprehensively analyze the effects of different aging environments on the aging failure of aluminum alloy/CFRP (Carbon Fiber Reinforced Plastics) composite bonded shear and butt joints, seven typical aging environments of room temperature (23°C/20%RH, RT), high-temperature (80°C/20%RH, HT), low temperature (−40°C, LT), temperature cycles (−40 ~ 80°C/20%RH, TC), immersed in water at room temperature (IRT), high temperature and high humidity (80°C /95%RH, HTHH), and hygrothermal cycles (−40°C ~ 80°C /95%RH, HC) were selected to perform aging tests. The composition analysis revealed that the adhesive underwent the most significant post-curing in HT, followed by TC, while LT had almost no effect on the adhesive. It was also found that the degree of moisture absorption and hydrolysis of the adhesive in IRT, HTHH and HC decreased sequentially. A single temperature or humidity environment had small effect on the failure strength of bonded joints less than 20%, increasing temperature or humidity could further reduce the failure strength by about 30%, and periodically changing the temperature or humidity had the greatest effect on the failure strength by more than 40%. ANOVA (Analysis of Variance) shows that all the single factors of aging time, load type, or aging environment had significant effects on the failure strength, but the aging environment had the greatest effect. Multifactor coupling effects on the failure strength was not significant, except for the coupling effects of aging environment and aging time. [ABSTRACT FROM AUTHOR]

An effort to understand the corrosion characteristics of aluminium Al3102 alloy in a neutral medium in the presence of Desulfovibrio desulfuricans was made. The corrosion rate increased up to tenfold in the bacterial medium in comparison to the control (abiotic) medium. Scanning electron microscopy (SEM) studies showed substantial sulfate-reducing bacteria (SRB) adhesion on the alloy surface and pit formation. Supplementation of 1000 ppm Azadirachta indica leaves extract decreased corrosion by 82%. Sulfide analysis, SEM, and X-ray photoelectron spectroscopy (XPS) studies showed a significant effect of neem leaf extract (NLE) on bacterial metabolic activity and confirmed the adsorption of the inhibitor molecules on Al3102 surface. Electrochemical impedance spectroscopy studies showed that the NLE formed a highly resistive external layer which protected the alloy surface from the corrosive effects. The gas chromatography-mass spectroscopy studies (GC-MS) showed appreciable amount of esters, terpenoids, heterocyclic nitrogen, sulfur compounds, and organic bromine compounds in NLE. [ABSTRACT FROM AUTHOR]

Results are given for studies of the structure and properties of semi-finished products made of aluminum and alloys of the Al-REM system, prepared using ingotless rolling-extrusion and equal-channel angular extrusion. It is established that rods obtained by high-speed crystallization-deformation technology using the method of ingotless rolling-extrusion have a stable ultrafine subgrain structure, which makes it possible to use deformed semi-finished products from them as modifier rods and electrical wire for cable products. Experimental studies are conducted confirming the assumption that the initial structure of a modifying rod has an effect on the melt. At the same time, it is found that sizes and distribution density of additional cluster-based crystallization centers formed within the melt volume are inherited from the initial subgrain structure of the modifying rod made of aluminum or its alloys. At the same time, it is found that the introduction of 3–4% of such a master alloy rod with a diameter of 8–9 mm into a crystallizing aluminum ingot at a melt temperature of 700–720°C and a melt standing time of at least 5 minutes provides a stable modifying effect. Production parameters for manufacture of bars from aluminum alloys by the ingotless rolling-extrusion method are established: melt temperature 720°C; degree of deformation during rolling is not less than 50%, roll rotational speed is 8 rpm. Metallographic studies also show that subsequent severe plastic deformation by equal-channel angular extrusion of bars prepared by ingotless rolling-extrusion from an experimental alloy of the composition Al–0.2Zr–0.2Fe–0.4Mg makes it possible to achieve additional metal hardening due to grain size and structure refinement. and to obtain wire for electrical purposes with a high level of physical and mechanical properties. [ABSTRACT FROM AUTHOR]

Corrosion resistance of aluminum and aluminum-based alloys is analyzed from the standpoint of their use for railroad transport (freight and passenger) in aggressive environments. The effect of alloying elements on the operating characteristics of the aluminum alloys is considered. The advantages of aluminum-based alloys with expected high corrosion resistance for replacing container and car steels are presented. [ABSTRACT FROM AUTHOR]