Search

Hard anodizing is used to improve the anodic films' mechanical qualities and aluminum alloys' corrosion resistance. Applications for anodic oxide coatings on aluminum alloys include the space environment. In this work, the aluminum alloys 2024-T3 (Al-Cu), 6061-T6 (Al-Mg-Si), and 7075-T6 (Al-Zn) were prepared by hard anodizing electrochemical treatment using citric and sulfur acid baths at different concentrations. The aim of the work is to observe the effect of citric acid on the microstructure of the substrate, the mechanical properties, the corrosion resistance, and the morphology of the hard anodic layers. Hard anodizing was performed on three different aluminum alloys using three citric–sulfuric acid mixtures for 60 min and using current densities of 3.0 and 4.5 A/dm2. Vickers microhardness (HV) measurements and scanning electron microscopy (SEM) were utilized to determine the mechanical characteristics and microstructure of the hard anodizing material, and electrochemical techniques to understand the corrosion kinetics. The result indicates that the aluminum alloy 6061-T6 (Al-Mg-Si) has the maximum hard-coat thickness and hardness. The oxidation of Zn and Mg during the anodizing process found in the 7075-T6 (Al-Zn) alloy promotes oxide formation. Because of the high copper concentration, the oxide layer that forms on the 2024-T6 (Al-Cu) Al alloy has the lowest thickness, hardness, and corrosion resistance. Citric and sulfuric acid solutions can be used to provide hard anodizing in a variety of aluminum alloys that have corrosion resistance and mechanical qualities on par with or better than traditional sulfuric acid anodizing. [ABSTRACT FROM AUTHOR]

Microstructural stability and submerged properties of aluminium alloys are critical to their integrity and service life in corrosive environments. Submerged friction stir processing (SFSP) and friction stir processing (FSP) have become effective methods for improving the surface characteristics of these alloys, potentially mitigating corrosion-related degradation. This study provides a analysis of the corrosion behaviour of aluminium alloys post-FSP/SFSP processing. The study reveals that FSP/SFSP can significantly refine grain structure, modify the distribution of intermetallic phases, and influence the nature of the oxide film, thereby affecting the corrosion resistance. The findings suggest that optimal FSP/SFSP parameters can be engineered to develop a corrosion-resistant microstructure while preserving the mechanical attributes of the aluminium alloys. This paper contributes to the improvement of knowledge regarding the corrosion processes in FSP/SFSP-treated aluminium alloys in order to use them in various working environments. The alternation in corrosion dynamics as a function of the modified surface conditions could be identified by using electromechanical assays, surface analytical techniques, and microstructural examinations. [ABSTRACT FROM AUTHOR]

The EN AB-46000 alloy castings are widely used in automotive industry due to their relative good strength combined with a low density and an excellent conductivity. Porosity of EN AB-46000 alloys is one of the most important defects, responsible for the low strength and poor plastic properties of castings as well as their tightness. Quantitative porosity measurement were performed using quantitative metallography and image analysis methods using ImageJ. The study shows that such parameters of high-pressure die casting are the piston speed in the second casting phase and the final pressure increase in the pressing phase. It has been shown that the appropriate selection of these parameters can significantly reduce the porosity of castings made of alloy EN AB-46000. [ABSTRACT FROM AUTHOR]

AbstractDirect joining molding of metals and polymers has received increasing attention in the field of lightweight fabrication. The aluminum alloy (Al) surface was modified by secondary anodizing and a special needle-like structure was formed on the Al surface. Then, the glass fiber-filling polyphenylene sulfide (PPS) was directly joined with Al by the hot pressing technique. The relationship between the interfacial structure and mechanical properties of Al/PPS hybrids was systematically investigated and discussed. The results showed that the generation of needle-like structures could improve the surface roughness and wettability, thus effectively improving the mechanical interlocking ability of the interface and forming the Al-O-C chemical bond with PPS. The maximum tensile strength of Al/PPS hybrids was 28.34 MPa, and their impact toughness (ak) reached 9.69 J/cm2. Even though the hybrids were exposed to a salt spray environment or 200 °C, the strength could still reach 25 MPa. This study has prepared a high-performance metal/plastic hybrid by secondary anodizing method, which can be applied in harsh environments. [ABSTRACT FROM AUTHOR]

The roll bonding of an experimental Al-2%Cu-2%Mn alloy with technically pure 1050A aluminum at true deformations of 0.26, 0.33 and 0.40 has been simulated using the QForm 10.3.0 FEM software. The flow stress of the Al-2%Cu-2%Mn alloy has been measured in temperature and strain rate ranges of 350–450 °C and 0.1–20 s−1, respectively. The simulation results suggest that the equivalent strain in the cladding layer is more intense than that in the base layer, reaching 1.0, 1.4 and 2.0 at strains of 0.26, 0.33 and 0.40, respectively. The latter fact favors a decrease in the difference between the flow stresses of the rolled sheet layer contact surfaces by an average of 25% at the highest strain. The experimental roll bonding has achieved good layer adhesion for all the test samples. The average peeling strength of the samples produced at strains of 0.26 and 0.33 proves to be 12.6 and 18.4 N/mm, respectively, and at a strain of 0.40, it has exceeded the flow stress of the 1050A alloy cladding layer. The change in the rolling force for different rolling routes has demonstrated the best fit with the experimental data. [ABSTRACT FROM AUTHOR]

In order to investigate the laws of the laser peening forming process and the effects of laser peening on the surface quality and tensile properties of 5083 aluminum alloy, experiments were conducted utilizing various laser peening paths, energies, and plate thicknesses. Subsequently, laser peening forming experiments were performed on S-shaped and different shapes of aluminum alloy substrates. The impact of different laser peening durations on surface morphology and tensile properties was then analyzed. Results indicated that the largest bending deformation perpendicular to the laser peening path reached 12.5 mm. In cases where the laser peening path was inclined relative to the horizontal direction, torsional deformations were observed in the aluminum alloy plate. For laser energy levels of 5 J, 6 J, and 7 J, deformation amounts were 3.8 mm, 4.9 mm, and 5.4 mm, respectively. Plates with thicknesses of 4 mm exhibited convex deformation, while those with 2 mm thickness showed concave deformation. Furthermore, following one and two laser peening cycles, the residual stresses in the alloy plates were −80 MPa and −107 MPa, the surface hardness increased by 16 HV and 31 HV, the roughness increased by 2.495 μm and 3.615 μm, and the tensile strength increased by 9.5 MPa and 18.5 MPa, respectively. [ABSTRACT FROM AUTHOR]

Aluminum and its alloys are widely used in various applications including e-mobility applications due to their lightweight nature, high corrosion resistance, good electrical conductivity, and excellent processability such as extrusion and forming. However, aluminum and its alloys are difficult to process with a laser beam due to their high thermal conductivity and reflectivity. In this article, the two most used laser processes, i.e., laser welding and laser powder bed fusion (LPBF) additive manufacturing, for processing of aluminum have been studied. There are many common laser-material interaction mechanisms and challenges between the two processes. Deep keyhole mode is a preferred method for welding due to improved productivity, while a heat conduction mode is preferred in LPBF aiming for zero-defect parts. In LPBF, the processing maps are highly desirable to be constructed, which shows the transition zone. Presented numerical modeling provides a more in-depth understanding of porosity formation, and different laser beam movement paths have been tested including circular oscillation paths. High accuracy processing maps can be constructed for LPBF that allows us to minimize tedious and time-consuming experiments. As a result, a modeling framework is a highly viable option for the cost-efficient optimization of process parameters. [ABSTRACT FROM AUTHOR]

Laser powder bed fusion (L-PBF), one of the additive manufacturing methods, has gained an important place in several fields like aviation, space biomedical, etc., due to its advantages, such as producing complex shaped parts with high quality in shorter times. On the contrary, disadvantages such as high surface roughness, low dimensional accuracy, problems in reproducibility, and residual stress may induce difficulties during the production of the part or usage of the final product. To reduce the residual stress on the parts manufactured by the L-PBF technique, methods such as optimizing geometry-related variations and printing process parameters or applying post-processes can be implemented. This study applied different process parameters and geometry-related variations to investigate the residual stress for aluminum 7050-RAM2 (2% ceramic added) alloy prepared by L-PBF. Laser power, scanning speed, re-melting (double scan) as the process parameters and dimensional variations of the sample (surface area), and different print orientations (0°, 45°) as the geometry-related variations were examined. Minor differences in the process parameters and geometry-related variations affected the residual stress significantly. Especially up-skin scan parameters, build orientation, and size of the top surface area may entirely change the residual stress characteristics. [ABSTRACT FROM AUTHOR]

Copyright of Atomic Energy Science & Technology is the property of Editorial Board of Atomic Energy Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

For commercial processes, through-hole AAO membranes are fabricated from high-purity aluminum by chemical etching. However, this method has the disadvantages of using heavy-metal solutions, creating large amounts of material waste, and leading to an irregular pore structure. Through-hole porous alumina membrane fabrication has been widely investigated due to applications in filters, nanomaterial synthesis, and surface-enhanced Raman scattering. There are several means to obtain freestanding through-hole AAO membranes, but a fast, low-cost, and repetitive process to create complete, high-quality membranes has not yet been established. Here, we propose a rapid and efficient method for the multi-detachment of an AAO membrane at room temperature by integrating the one-time potentiostatic (OTP) method and two-step electrochemical polishing. Economical commercial AA1050 was used instead of traditional high-cost high-purity aluminum for AAO membrane fabrication at 25 °C. The OTP method, which is a single-step process, was applied to achieve a high-quality membrane with unimodal pore distribution and diameters between 35 and 40 nm, maintaining a high consistency over five repetitions. To repeatedly detach the AAO membrane, two-step electrochemical polishing was developed to minimize damage on the AA1050 substrate caused by membrane separation. The mechanism for creating AAO membranes using the OTP method can be divided into three major components, including the Joule heating effect, the dissolution of the barrier layer, and stress effects. The stress is attributed to two factors: bubble formation and the difference in the coefficient of thermal expansion between the AAO membrane and the Al substrate. This highly efficient AAO membrane detachment method will facilitate the rapid production and applications of AAO films. [ABSTRACT FROM AUTHOR]

Solidification processing of aluminum graphene composite is an attractive option for synthesis of metal matrix composites. Graphene reinforced aluminum metal matrix composites (GAMMCs) are of interest due to the low density and ultrahigh physical and mechanical properties of Graphene which can improve the properties of Al-Graphene composites. However, solidification processing of aluminum graphene composites has served challenges, including agglomeration of reinforcement and porosity resulting in decrease in properties above 0.five to three wt% graphene. Also, the graphene surface can react with molten aluminum alloys to form aluminum carbide. Challenges with particle distribution and porosity are frequently caused by the poor wetting of reinforcement by melt, requiring additions of selected wetting agents. The other problems include movement of reinforcement within the melt due to density differences and convection leading to nonuniform distribution of reinforcements. The graphene reinforcements can be pushed by solidifying interfaces under certain conditions during solidification leading to segregation of reinforcements in the interdendritic regions. The paper critically analyzes the above problems related to solidification processing of Aluminum-Graphene composites which has not been done in previous publications aluminumgraphene composites. The objective of this paper is to examine the challenges, and suggest possible solutions including addition of elements like silicon and magnesium to aluminum melt, coating graphene with metals like nickel and copper, controlling rate of advancement and nature of advancing solid liquid interface in a manner that they engulf graphene with dendrites or grains. [ABSTRACT FROM AUTHOR]

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]

Cutting forces play very important in designing the tool machine, cutting tool, and in optimization of machining processes. Modeling and prediction of cutting forces by theoretical methods are quite difficult, so, this study was focused on modeling the cutting force in face milling process using combination of theoretical and experimental methods. This study was performed to model the milling forces (MFs) and determine the milling force coefficients (MFCs) in the face milling process of aluminum alloy Al7075 using square inserts. From theoretical and experimental methods, the relationship of average milling forces (AMFs) and feed per flute (ft) were determined as the linear regression. Using experimental data, the linear regressions of AMFs and feed per flute were determined with high values of determination coefficients (larger than 95 %). MFCs were determined including shear and edge MFCs (tangential shear MFC (Ktc) of 538.127 N/mm2, radial shear MFC (Krc) of 185.967 N/mm2, axial shear MFC (Kac) of -691.297 N/mm², tangential edge MFC (Kte) of 11.253 N/mm, radial edge MFC (Kre) of 6.991 N/mm, and axial edge MFC (Kae) of -32.971 N/mm. The MF models were successfully verified by comparing the measured and predicted MFs in face milling process of Al7075. The tendency and shape of predicted MFs were quite close to the measured ones. The differences between the predicted and the measured MFs can be due to the several reasons such as the influence of vibrations, the influence of cutting heat, etc., and these are also the limitations of this study. The modeling and prediction methods of this study can be used to model and predict the cutting forces in face milling of other milling types and other pairs of cutting tool and workpiece material as well. [ABSTRACT FROM AUTHOR]

Copyright of China Mechanical Engineering is the property of Editorial Board of China Mechanical Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The aerospace industry pursues lighter, stronger, and more fuel-efficient aircraft, relying on lightweight materials. This study investigates one-shot drilling of thin hybrid stacks, including carbon fiber-reinforced polymer (CFRP, 2.2 mm thick), and aluminum alloys (Al2024-T3, 1.6 mm thick, and Al7075-T6, 1.0 mm thick), crucial in modern aircraft structures. The challenge of thin materials lies in their reduced flexural stiffness, which significantly impacts the quality of the final hole and the effects of the process parameters on torque and thrust force. The experimental approach involves drilling each material separately to analyze thrust force, torque, and hole quality, then comparing outcomes with one-shot drilling in thin hybrid stacks. The results highlight that thin hybrid stacks are challenging to drill because their reduced flexural stiffness significantly impacts the final hole quality and the effects of the process parameters on torque and thrust force differently from what typically occurs for the drilling of conventional hybrid stacks. [ABSTRACT FROM AUTHOR]

Aluminum technical alloys are well known for their outstanding mechanical properties, especially after heat treatment. However, quenching and aging, which improve the mechanical properties, by the formation of Cu-rich zones and phases that are coherent with the matrix and block the dislocation motion, cause uneven distribution of the elements in the alloy and consequently make it prone to corrosion. One method providing satisfactory corrosion protection of aluminum alloys is anodizing. On an industrial scale, it is usually carried out in electrolytes containing chromates that were found to be cancerogenic and toxic. Therefore, much effort has been undertaken to find substitutions. Currently, there are many Cr(VI)-free substitutes like tartaric–sulfuric acid anodizing or citric–sulfuric acid anodizing. Despite using such approaches even on the industrial scale, Cr(VI)-based anodizing still seems to be superior; therefore, there is an urge to find more complex but more effective approaches in anodizing. The incorporation of anions into anodic alumina from the electrolytes is a commonly known effect. Researchers used this phenomenon to entrap various other anions and organic compounds into anodic alumina to change their properties. In this review paper, the impact of the incorporation of various corrosion inhibitors into anodic alumina on the corrosion performance of the alloys is discussed. It is shown that Mo compounds are promising, especially when combined with organic acids. [ABSTRACT FROM AUTHOR]

The low-pressure die casting (LPDC) process was experimentally and numerically studied to produce AlSi7Mg0.3 components such as steering knuckles. Steering knuckles are important safety components in the context of a vehicle's suspension system, serving as the mechanical interface that facilitates the articulation of the steering to control the front wheel's orientation, while simultaneously bearing the vertical load imposed by the vehicle's weight. This work focuses on the development of a numerical model in ProCAST®, replicating the production of the aforementioned part. The model analyses parameters such as the filling dynamics, solidification process, and presence of shrinkage porosities. For the purpose of evaluating the quality of the castings, six parts were produced and characterised, both mechanically (tensile and hardness tests) and microstructurally (porosity and optical microscopy analysis). When correlating simulation results with the available experimental data, it is possible to conclude that the usage of the LPDC process is a viable alternative to the use of steels and other metals for the production of very high-quality castings while using lighter alloys such as aluminium and magnesium in more demanding applications. [ABSTRACT FROM AUTHOR]

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 formation of brittle intermetallic compounds (IMCs) at the interface between dissimilar materials causes considerable problems. In this study, a multi-material additive manufacturing technique that employs a diode laser and the hot-wire method was developed for stainless steel/aluminum alloys. An Al-Mg aluminum alloy filler wire (JIS 5183-WY) was fed on an austenitic stainless-steel plate (JIS SUS304) while varying the laser power and process speed and using paste-type flux and flux-cored wire. The effects of laser power and process speed on phenomena during manufacturing and IMC formation were investigated. Finally, the wall-type multilayer specimens were fabricated under optimized conditions. The suppression of IMC formation to a thickness of less than 2 μm was achieved in the specimens, along with a high interfacial strength of over 120 MPa on average. [ABSTRACT FROM AUTHOR]

To study the effect of calcium on the porosity, sphericity, and microstructure of Al-Cu foams, a gradient calcium content (0.5, 1.0, 1.5, and 2.0 wt%) is added into aluminum A201 alloy (Al-Cu alloy) for the cellular aluminum foam preparation via the melt foaming method (TiH2 is used as a bubbling agent). Thereafter, the porosity of the prepared Al foams and their pore size are found to increase, and the sphericity of pores tends to approach to unit with calcium addition. This phenomenon is then explained through the modified thermophysical properties (i.e., surface tension and viscosity) of A201 alloy melts caused by the calcium addition. After the microstructure analysis, a bunch of secondary phases in the A201 + Ca alloy foams, e.g., CalAl2Si2, Al2Cu, and Al20CaTi2 as well as an eutectic phase with a great copper content Al8CaCu4 are detected by means of scanning electron microscopy/energy-dispersive X-Ray spectroscopy and X-Ray diffraction analysis. [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]

This research addresses the escalating need for lightweight materials, such as aluminum and magnesium alloys, in the aerospace and automotive sectors. The study explores friction stir welding (FSW), a cost-efficient process known for producing high-quality joints in these materials. The experiment involved the welding of dissimilar aluminum alloys (AA5086-H111 to AA6061-T6) using a novel pin tool design with welding parameters such as holding time, pin tool length, tool spindle speed, and linear speed fine-tuned through a design of experiment (DOE) approach. A comparative analysis of two tool designs revealed that the newly introduced design substantially improved mechanical properties, particularly tensile strengths, by 18.2% relative to its predecessor. It is noteworthy that FSW joint efficiency is 83% when using a normal tool design in comparison with 92.2% when using a new tool design at similar FSW parameters. The new tool achieved the parameter values leading to the maximum tensile strength of 317 MPa with 3 mm thickness (Th), 25 s holding time (Tt), 0.1 mm dimension (L), 1600 rpm spindle speed (SS), and 30 mm/min feed velocity (Fr). In comparison, the normal tool achieved a maximum UTS of 285 MPa, 5 mm Th, 25 s Tt, 0.3 mm L, 800 rpm SS, and 90 mm/min Fr. The new tool design, with longitudinal and circular grooves, improves heat input for plastic deformation and alloy mixing during welding. Subsequent analysis of the joint's microstructure and microhardness shows its similarity to the original alloys. [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]

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]

In magnesium alloys with aluminum as an alloying component, zirconium loses its grain refinement effect as a grain refiner. Instead of zirconium, Mg3N2 can be used, and promising results have already been obtained. However, the duration of action of Mg3N2 has not been elucidated yet. The aim of this work is therefore to determine the grain size of the AZ80 alloy as a function of the duration of action of Mg3N2 and thus the economically reasonable duration of use. It was found that the Mg3N2 reaches its full effect from 30 min after a complete remelting and does not lose this grain refinement effect even after 90 min. It thus proves to be a stable and reliable grain refiner. A grain size of 146.3 ± 10.3 µm was achieved. Furthermore, a minimum tensile strength of 205 MPa with a break elongation of 5.99% was achieved. [ABSTRACT FROM AUTHOR]

The results of the corrosion nature of aluminum 7075 alloy in a cation-containing aqueous medium are reported by using gravimetric tests and surface analysis. The investigation showed a substantial increase in the mass of the specimens after the immersion experiments, while a minor mass change was seen in the Zn2+ containing solution. Energy dispersive spectroscopic mapping and cross-sectional pictures showed that the specimen submerged in the Zn2+ containing solution developed a zinc-linked layer. The results of X-ray photoelectron spectroscopy showed that aluminum hydroxide was deposited on the surface, and a tiny amount was deposited on the specimen that was sunk in the solution containing Zn2+. The present study suggests that the zinc-related layer prevents the alloy from corroding. [ABSTRACT FROM AUTHOR]

Introduction: The utilization of various energy sources to assist the machining process has become prominent to achieve substantial improvement in machining performance. These energy sources have also resulted in an alternative to cutting fluids which is safer for both the universe and human beings. The combined action of laser and ultrasonic vibration energies during the turning process has shown significant achievement in machining process capabilities. Moreover, the application of higher compressed air pressure has achieved substantial improvement in machinability during the turning process. Materials and methods: An attempt has been made to improve the machinability of aluminium 3003 alloy during the simultaneous application of compressed air pressure and ultrasonic-vibration-laser-assisted turning (UVLAT) process. Machining performance has been analyzed in terms of machining temperature, tool wear, machining forces, chip morphology, and surface roughness. A comparative machining performance analysis has been carried out between different compressed air pressure for the laser-assisted turning (LAT) and UVLAT processes. Results: The outcomes of the current study indicate a significant reduction in maximum machining temperature due to higher compressed air pressure. Lower tool wear was observed due to a reduction in maximum machining temperature and led to lower machining forces at higher compressed air pressure. Lesser chip segmentation and smooth chip edges were obtained which led to a reduction in surface roughness for higher compressed air pressure during the LAT and UVLAT processes. Conclusion: The presented results are important for manufacturing industries seeking to improve the machinability of aluminium alloys. [ABSTRACT FROM AUTHOR]

Aluminum and aluminum alloys are light materials with some of the preferences such as lightweight, high specific strength, good elasticity, and good workability that play an important role in today's modern and industrial world. The economic loss and environmental and safety problems are also the most concerning aspects of these materials. As a result, numerous studies are performed by the researchers to improve the overall environment throughout the materials world. That is why, in this study, the surface morphology and corrosion behavior of pure aluminum and its alloys, such as 7S10 and 7003H, were investigated in aqueous sulfuric acid medium through immersion process at different temperatures. Open‐circuit potential and potentiodynamic polarization techniques were used to evaluate the resistance to corrosion of pure aluminum and its alloys 7S10 and 7003H. The current density increased with increasing temperature in the case of the alloys, and pure aluminum showed the highest corrosion resistance properties. The surface roughness measurement was performed using atomic force microscope to find out the amount of roughness of the used materials before and after the immersion process. Surface roughness was higher on the alloys than in pure Al, which indicates that less corrosion was formed in pure Al than in the alloys. The surface morphology analysis was also carried out using scanning electron microscopic data. The results revealed that the alloy 7003H undergoes more corrosion than pure aluminum and 7S10 in sulfuric acid medium, which clearly indicates that pure aluminum has higher corrosion resistance than the alloys 7S10 and 7003H. The corrosion rate of the test materials decreased with increasing immersion time. [ABSTRACT FROM AUTHOR]

Friction stir welding is a solid-state method that is safe for the environment. Both dissimilar and similar materials have been joined using it. AAA5083 Aluminium alloy is widely utilised in many industries, including railways, automotive, and aerospace. The purpose of the study is to provide a comparative analysis of similar AA5083 friction stir welded joints while taking into account the corrosion behaviour. However, its behaviour with other aluminium alloys and other materials that were considered for corrosion behaviour was also presented. The effects of welding parameters had been demonstrated on the microstructural changes and how they may influence the strength and corrosion behaviour. Furthermore, investigating how corrosion affects the mechanical properties of AA5083 is an area that should be explored. The synergy between grain size, strength, and corrosion of AA5083 aluminium alloy and other aluminium alloys warrants more investigation. [ABSTRACT FROM AUTHOR]

Solid state sintering of cast aluminum powders by resistance heating sintering (RHS), also known as spark plasma sintering or field-assisted sintering technique, creates a very fine microstructure in the bulk material. This leads to high performance material properties with an improved strength and ductility compared to conventional production routes of the same alloys. In this study, the mechanical behavior of an RHS-sintered age-hardenable A357 (AlSi7Mg0.6) cast alloy and a SiCp/A357 aluminum matrix composite (AMC) was investigated. Aiming for high strength and good wear behavior in tribological applications, the AMC was reinforced with a high particle content (35 vol.%) of a coarse particle fraction (d50 = 21 µm). Afterwards, separated and combined effects of particle reinforcement and heat treatment were studied under compressive load both at room temperature and at 350 °C. At room temperature compression, the strengthening effect of precipitation hardening was about twice as high as that for the particle reinforcement, despite the high particle content. At elevated temperatures, the compressive deformation behavior was characterized by simultaneously occurring temperature-activated recovery, recrystallisation and precipitation processes. The occurrence and interaction of these processes was significantly affected by the initial material condition. Moreover, a rearrangement of the SiC reinforcement particles was detected after hot deformation. This rearrangement lead to a homogenized dispersion of the reinforcement phase without considerable particle fragmentation, which offers the potential for secondary thermo-mechanical processing of highly reinforced AMCs. [ABSTRACT FROM AUTHOR]

The article examines the influence of energy characteristics on the process of formation of dissimilar metals of aluminum and copper alloys during friction stir welding. The relationship between machine engine power consumption and stir welding friction regimes for a dissimilar joint of technically pure aluminum AD1 and copper M1 is studied. The influence of production regimes on weld appearance and the possibility of stabilizing power consumption during friction stir welding due to formation of a welded metal superplastic state are revealed. A relationship between capabilities of the equipment used and the permissible geometrical parameters of the welding tool is estimated. [ABSTRACT FROM AUTHOR]

Vulcanization is a process of joining the conveyor belt with high pressure and temperature. The machine consists of several components like stiffness bar, vertical supporting rod, heating plate, insulator, fasteners and particularly traverse bar which adds on to the weight of the machine. The machine consists of 5 to 10 traverse bar which is made aluminium 6061 alloy. In the present work, the weight of the vulcanization machine is reduced by reducing the weight of the traverse bar. This is achieved by choosing a less dense material. This research work mainly focused on reducing weight of the traverse bar by choosing polymer matrix composite material like epoxy carbon fiber and epoxy s-glass. A modelling and simulation work is conducted for aluminium alloy 6061 as well as composite material, deformation and stress are compared. I beam for epoxy carbon fiber deformation increased by 150 % and for epoxy s-glass increased by 366% comparing with traverse bar. In I beam with stiffener epoxy carbon fiber deformation is reduced by 38% for epoxy s-glass is increased by 6 %. Similarly, for equivalent stress composite materials for I beam is increased and for I beam with stiffener is decreased. The weight reduction from aluminium alloy to composite material is for epoxy carbon fiber is 81.70% and epoxy s-glass is 75.43%. In with stiffeners epoxy carbon fiber is 78.25% and epoxy s-glass is 70.81%. [ABSTRACT FROM AUTHOR]

Experimental and finite element studies of the rotary friction welding (RFW) process of tungsten heavy alloy (THA) with aluminium alloy 5XXX series are presented. A 2.5D torsion simulation model including the circumferential effects was developed in this study. The temperature distributions, effective stress, flash dimensions and axial shortening were calculated on un-rotated friction welding aluminium parts. The peak temperatures were measured both in the axis and at the half-radius of the specimen. The maximum interface temperature of 581 °C for the friction weld was below the melting temperature of the aluminium alloy. The experimental and numerical results of the temperature and final weld geometries show good agreement between them. The results indicate very small deviations of 4.45%, 2.96%, and 2.34% on the flash width, flash height and axial shortening of friction welds. [ABSTRACT FROM AUTHOR]

The objective of this work is to study the effect of time during the bonding process of alumina with an industrial aluminum 6060 alloy by the technique of solid-state welding at 600°C. Optical microscopy, scanning electron microscopy with energy dispersive spectroscopy, corrosion tests, and microhardness measurements were used as characterization techniques. The extended time during the bonding process had an effect on the microstructure of the interface and its mechanical properties. Oxygen diffusion was detected across the aluminum alloy/alumina interface. A recrystallization reaction developed on the aluminum side during the bonding process, which affected the aluminum alloy hardness values. By bonding metal to ceramic, it allows the use of ceramics in automotive engines to reduce weight, increase thrust-to-weight ratio and operating temperature, and improve working efficiency. [ABSTRACT FROM AUTHOR]

Friction Stir Spot Welding (FSSW) has emerged as a promising alternative to traditional riveting in the automotive industry. In this study, we explore the application of doublesided FSSW, a solid-state joining method, as an innovative approach to overcome the limitations of conventional resistance spot welding. Our focus is on welding 2 mm thick sheets of aluminum alloy AA6061-T4. To improve the strength and quality of welded joints, we employed the double-sided FSSW technique, which utilizes a revolving anvil and a pin-less tool. This approach not only enhances the tensile strength of the connections but also mitigates potential defects such as keyholes. Intriguingly, our numerical analysis reveals the complexity of material flow between the rotating anvil and the pin-less tool during the welding process. This complexity underscores the suitability of using a rotating anvil and a pin-less tool in FSSW operations, particularly when welding larger sheets. In conclusion, our study underscores the potential of double-sided FSSW with a rotating anvil and pin-less tool for achieving robust weld connections in the context of aluminum alloy AA6061-T4. These findings contribute to the ongoing efforts to advance solid-state joining methods in the automotive industry, offering a more efficient and reliable alternative to traditional riveting. [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]

The microstructure and mechanical properties of electrically assisted brazing (EA-brazing) joints of aluminum alloy 6061-t6 (AA6061-t6) and S45C steel are experimentally investigated. During the EA-brazing process, an electric current is directly applied to the cylindrical specimen assembly (S45C and AA6061-t6) and fillers of 88% Al and 12% Si (in the middle of the specimen assembly). The temperature of the specimen assembly rises rapidly to the melting point of the filler and remains nearly constant for a period of time using a pulsed electric current. Two types of EA-brazing joints are fabricated, namely Joint-0s (no temperature holding time) and Joint-12s (12 s temperature holding time). The characteristics of the intermetallic compounds (IMCs) formed at the EA-brazing joint interface are analyzed using scanning electron microscopy and energy dispersive spectrometer. Compared to Joint-0s, the Fe-rich IMCs (FeAl) are observed at the interface of Joint-12s due to the 12 s temperature holding time. In addition, the microstructural analysis shows that the thickness of the diffusion layer increases with increasing temperature holding time. The mechanical properties of the EA-brazing joints are evaluated using bending tests. The results of the mechanical test show that the strength of Joint-12s is higher than that of Joint-0s. [ABSTRACT FROM AUTHOR]