Aluminum-magnesium Alloy Research Articles

Analysis of the influence of welding parameters on defects and welding characteristics of aluminum-magnesium alloy 5052-H34 in the FSW process

Analysis of the influence of welding parameters on defects and welding characteristics of aluminum-magnesium alloy 5052-H34 in the FSW process

Sandwich composite of aluminum alloy and magnesium alloy through accumulative roll bonding technique

Aluminum and magnesium alloys are lightweight materials with outstanding technical uses. Due to their combined qualities, composites built of aluminum and magnesium alloys have surpassed the utilization of these elements individually. Accumulative Roll Bonding was used to create a three-layered sandwich composite structure made of Al-alloy/Mg-alloy/Al-alloy. The composite structure's microstructure and mechanical characteristics were studied. A fine-grained AZ31 layer was formed, according to the microstructural study. At the Al-alloy/Mg-alloy contact, a diffusion layer was also seen. On the broken surface, fractography exhibited both ductile and brittle failure characteristics.

Microscopic Studies and Application of a Stabilized Ceric Ammonium Nitrate Oxidizer in Environmentally Friendly Pyrotechnic Strobes.

The growing reservations against the use of any kind of chlorine source in pyrotechnic items revolutionize the predominantly empirical development of strobe formulations in two ways. First, a conventionally applied ammonium perchlorate oxidizer needs to be replaced. Second, visible light emissions should no longer be generated by metastable monochloride species. Moreover, until now, toxic substances such as potassium dichromate have been added in order to achieve a more pronounced strobe effect. This work evaluates the potential of stearic acid-treated ceric ammonium nitrate to serve as an oxidizing agent in next-generation strobe compositions. For this purpose, its microscopic structure, energetic properties, and stability under ambient conditions were assessed. A two-component mixture with a magnesium-aluminum alloy was investigated, which should allow for the introduction of copper-based colorants. This potentially paves the way for the first environmentally friendly blue strobe formulations.

Coupling effect of axial ultrasonic vibration and tool thread on the microstructure and properties of the friction stir lap welding joint of Al/Mg dissimilar alloys

In this study, three tools with different thread characteristics were designed for the ultrasonic-assisted friction stir lap welding (UAFSLW) of a 3-mm-thick 6061-T6 aluminum alloy and an AZ31 magnesium alloy. The coupling effect of different thread characteristics and axial ultrasonic vibrations on the size, amount, and distribution of intermetallic compounds (IMCs) and the tensile-shear strength of welded joints was analyzed. Experimental results confirmed the formation of IMCs in the stir zone (SZ) and the bottom interface in the SZ in all joints, with Al3Mg2 predominating in the Al-Mg configuration (in which the 6061-T6 aluminum and AZ31 magnesium alloys were placed at the upper and lower plates, respectively) and Al12Mg17 predominating in the Mg-Al configuration (in which the alloys on the upper and lower plates were reversed). The bottom interfaces of the joints in the Mg-Al configuration were tortuous, forming a mechanical interlocking structure; consequently, the joints welded in the Mg-Al configuration exhibited higher tensile-shear strength than those welded in the Al-Mg configuration. Furthermore, the tool with a variable-pitch thread pin achieved welds with excellent tensile-shear strength in both the configurations (223.2 and 268.3 N/mm in the Al-Mg and Mg-Al configurations, respectively). This performance improvement was attributed to the strong coupling of the tool with axial ultrasonic vibrations, which enlarged the mixing zone and increased the uniformity of the IMCs distribution in the joints.

Influence of Tool and Welding Parameters on the Risk of Wormhole Defect in Aluminum Magnesium Alloy Welded by Bobbin Tool FSW

Bobbin tool friction stir welding (BTFSW) utilizes a special tool that possesses two shoulders interconnected by a pin instead of one: the top shoulder and the pin in the conventional FSW tool. This greatly simplifies the kinematics in the otherwise complicated setup of FSW since the bottom shoulder forms the bottom surface of the weld, without the need for a backing plate. Moreover, the tool enters the base metal sideways and travels, forming the joint in a straight line while rotating, without the need for downward and upward motion at the beginning and end of the process. This paper presents a study on the BTFSW tool geometry and parameters on the risk of wormhole defect formation in the AA5005 aluminum–magnesium alloy and the wormhole effect on mechanical properties. It was shown that higher stress imposed by the tool geometry on the joint has a significant influence on heating, an effect similar to the increased rotational speed. Optimal kinematic and geometrical tool properties are required to avoid wormhole defects. Although weld tensile strengths were lower (between ~111 and 115 MPa) compared with a base metal (137 MPa), the ductile fracture was obtained. Furthermore, all welds had a higher impact strength (between ~20.7 and 27.8 J) compared with the base material (~18.5 J); it was found that the wormhole defect only marginally influences the mechanical properties of welds.

Thermal Modification of Porous Oxide Films Obtained by Anodizing of Aluminum–Magnesium Alloy

Thermal Modification of Porous Oxide Films Obtained by Anodizing of Aluminum–Magnesium Alloy

Dynamic Design and Analysis of Car Wheel Rim Using FEA Method

Abstract: The wheel rim is one of the most critical components of the vehicle. Therefore, a number tests have to be performed on it do that, it could meet the safety requirement . But physical testing of wheel rim during their devolvement is very costly and time consuming. So finite element analysis has developed as a major tool for analysis purpose. The wheel rim is designed by utilizing SOLIDEDGE software. 3-D model of wheel rim as a IGES file is imported to ANSYS for investigation work. A solver mode in ANSYS programming computes the stresses, deformation, shear stress. Here Car rim with concrete road model has made on Solid rim and simulate by ANSYS software. Through dynamic analysis find out three parameters results like deformation , Stress and Shaer stress.In this study car wheel is running 100 km/hr speed with fully loaded car.then find out variou results and compare results with exiting materials ( Steel material).Find out deformation values for Magnesium Alloy , Aluminium Alloy and Steel S-7 results are respectively like 7.99mm , 8.218 mm, 8.56 mm. here cleared seen that Magnesium Alloy has less deformation value compared to other then material deformation value so it is good for future design consideration. Find out stress values for Magnesium Alloy, Aluminium Alloy and Steel S-7 results are respectively like 102.52 MPa , 153.08 Mpa and 390.9 MPa. here cleared seen that Magnesium Alloy has less deformation value compared to other then material stress value so it is good for future design consideration. Find out shear stress values for Magnesium Alloy, Aluminium Alloy and Steel S-7 results are respectively like 59.12 MPa , 88.378 Mpa and 212.77 MPa. here cleared seen that Magnesium Alloy has less deformation value compared to other then material shear stress value so it is good for future design consideration. Keywords: ANSYS, Solid rim, Stress Analsys, Wheel Rim, Magnesium Alloy, Aluminium, Steel Material

Investigation of rolling modes, structure, and properties of aluminum-magnesium alloy plates with a reduced scandium content

Investigation of rolling modes, structure, and properties of aluminum-magnesium alloy plates with a reduced scandium content

EXPERIMENTAL INVESTIGATION ON THE EFFECT PROCESS PARAMETERS OF FRICTION STIR WELDED AL & MG ALLOYS

Friction Stir Welding is done on the Al alloy AA 5083 as well as magnesium alloy AZ31B with dimensions of 150X100X6 mm. The tool profiles used in this work are Square, Conical, Cylindrical threaded, Tapered threaded, and Hexagonal; Tool profiles are made up to certain specifications, and H13 steel is used as a tool material.The FSW tools were hardened to improve their characteristics. Tool profile plays an important role in improving welding. This study explains the essential welding parameters used in the process. Employed characteristics include traverse speed, tool rotational speed, and tool pin profile.Welded joints' mechanical characteristics were examined by conducting various tests such as tensile strength test, Impact test, Microstructure Analysis, and bending test. Following welding, the welded aluminum alloy and magnesium alloy were machined using an EDM machine following ASTM standards.At last, the test results are compared between both the aluminum and magnesium alloys

Effect of magnesium alloy compositions on the interfacial microstructure, corrosion resistance and mechanical properties of explosively welded magnesium/aluminum alloys

The effects of magnesium alloy compositions on the interfacial microstructure, corrosion resistance and mechanical properties of explosively welded magnesium alloys and aluminum alloy were investigated. The bonding interface had a periodic wavy shape. Thin interlayer consists of intermetallic compound, γ-Mg17Al12 phase, was formed at the bonding interface in all samples. When the aluminum concentration in the magnesium alloy is low, the intermediate layer at the bonding interface is thin and intermittently formed, but when the aluminum concentration in the magnesium alloy was high, the intermediate layer was relatively thick and uniformly formed, resulting in high bonding strength. In all samples, brittle fracture surface was observed and the presence of γ-Mg17Al12 phase was confirmed on the fracture surfaces.

Studies on Bending Properties of AA 6061-T6 Aluminium Alloy Joined By Friction Stir Welding

Presently for various engineering applications AA6061-T6 aluminum-magnesium alloys are widely preferred, which is due to its light weight and superior properties as compared to other aluminum alloys. The metal joining process is most complex in various industrial applications like automobile, aerospace, railway and marine. The Friction Stir Welding (FSW) of AA6061-T6 alloy has influenced substantial scientific and industrial importance, because it has a potential to transform the welded product with a good quality joint. In the present work AA6061-T6 alloy joined using FSW process. Observation has been made about material flow behavior and effect of process parameters on various mechanical properties and associated defects during FSW. From experimental results it can be concluded that FSW can be used to produce defect free welds, with better bending properties as compared to the welds produced by other conventional welding process.

Plasticity evolution of an aluminum-magnesium alloy under abrupt strain path changes

During the forming and manufacturing of engineering materials, plasticity behavior could be evolving significantly due to complex deformation history. Therefore, this study aims to characterize the plasticity evolution of an aluminum-magnesium alloy under simple monotonic and non-monotonic loading with abrupt strain path changes. Instead of focusing only on one single stress state in the first-step loading for most of the studies in the literature, the current non-monotonic strain path testing program investigates three stress states – uniaxial, plane-strain, and biaxial tension – in the first-step loading and combines them with a second-step uniaxial loading along and orthogonal to the initial loading direction. This combination generates non-monotonic stress–strain data in a quite large and distributed spectrum in terms of the Schmitt parameter. It is found that the aluminum-magnesium alloy shows a unique phenomenon with a lower yield strength at reloading compared to monotonic cases coupled with a steady increase of stress overshooting the monotonic one at large strains. This increase of stress as well as the strain hardening rate lasts till the uniform strain and is therefore referred to as permanent hardening. The comprehensive non-monotonic behavior delivered by the new experimental program in this study could further assist the development of material models and an in-depth understanding of the underlying mechanisms.

An additively manufactured magnesium-aluminium alloy withstands seawater corrosion

Magnesium, the lightest structural metal, has inherently poor corrosion resistance. In this study, we developed a magnesium-aluminium Mg-10.6Al-0.6Zn-0.3Mn alloy, additively manufactured by laser powder bed fusion. We reveal that this alloy has a record low degradation rate amongst all magnesium alloys in practically relevant corrosive solutions, and it even withstands seawater corrosion. As tested by a number of methods, the alloy shows even more enhanced passivation with longer immersion periods. The alloy surface following immersion maintained a nearly corrosion-free appearance and was determined to have a thin aluminium-containing surface film, due to surface enrichment of aluminium from the supersaturated matrix. Aluminium enrichment near the sample surface was also observed when the sample is immersed in phosphoric acid or exposed to atmosphere at room temperature. This study demonstrates the prospects for additively manufactured ultra-lightweight magnesium structure with outstanding corrosion resistance.

Enhancing corrosion resistance of hydrothermally-treated magnesium-aluminum alloys by preprocessed metallurgical microstructure

Hydrothermal treatment is one of effective methods to improve the corrosion resistance of magnesium alloys. A facile strategy is proposed in this study to control the corrosion behavior of hydrothermally-treated magnesium-aluminum alloys with aluminum content of about 9 wt. %. Prior to hydrothermal treatment, aging treatment is attempted to modify their metallurgical microstructure. After hydrothermal treatment, both the unaged and the aged alloy have a layer of dense coating mainly consisting of magnesium hydroxide on their surfaces, but the aged alloy shows better corrosion resistance according to the results of electrochemical experiments and immersion tests in 3.5 wt. % NaCl solution. This enhancement mechanism is also discussed based on the formation and redistribution of fine Mg17Al12 phases in the matrix.

Modelling the Effect of Deformation on Discontinuous Precipitation in Magnesium—Aluminium Alloy

Magnesium–Aluminium alloys can decompose from a supersaturated solid solution by either continuous or discontinuous precipitation. Deformation prior to precipitation has been shown to strongly suppress the discontinuous precipitation mode and promote continuous precipitation. In this work, a model is used to explore the interaction between deformation and precipitation in the Mg–Al system. It has been shown that accelerated nucleation of continuous precipitates on dislocations is predicted to have the dominant effect in suppressing discontinuous precipitation by reducing the solute supersaturation. A secondary effect is the direct role played by twins in the deformed structure, which act as impenetrable barriers to discontinuous precipitate growth. However, even in the deformed case, small regions of discontinuous precipitation are still observed. It is proposed that this is due to the high level of strain concentration expected in the grain boundary regions, which provides a locally enhanced driving force for the migration of grain boundaries such that limited discontinuous precipitation occurs before continuous precipitation becomes established.

Modelling the Effect of Deformation on Discontinuous Precipitation in Magnesium—Aluminium Alloy

Modelling the Effect of Deformation on Discontinuous Precipitation in Magnesium—Aluminium Alloy

Investigation of the Mechanism of Influence of Stress Corrosion on the Development of Macroplastic Instabilities of Aluminum–Magnesium Alloy

Investigation of the Mechanism of Influence of Stress Corrosion on the Development of Macroplastic Instabilities of Aluminum–Magnesium Alloy

Mechanism of the attack on metal surface in wear under ultrasonic cavtation

Two series of tests of annealed metal materials — copper, brass L60 and aluminum-magnesium alloy AMg4,0 — were carried out. The first series consists first in upsetting the cylindrical samples of the listed above alloys on a press to a different strain rate, then cutting the deformed samples and measuring the microhardness of the area adjacent to the center of the samples. The first series results in constructing the calibration plots of microhardness as a function of strain. During the second series the tests of the same materials for cavitation wear were carried out in the fresh water on the ultrasonic vibratory apparatus. The frequency and amplitude of the apparatus horn vibration amount to 22 kHz and 28 μm respectively. The microhardness of the samples surface exposed to cavitation attack was measured after the definite spans of time within the incubation period and the maximum value of the microhardness was registered. Marking the maximum microhardness value on the calibration plot yields the strain rate reached on the surface under cavitation attack before the removal of wear particles begins. On the basis of the found values of the strain the stress state rigidity of the surface layers under cavitation attack was evaluated. The obtained coefficients of stress state rigidity allowed drawing the conclusion, that cavitation attack on the material being tested on the ultrasonic vibratory apparatus occurs through the microjets impacts.

Measurement and analysis of species distribution in laser-induced ablation plasma of an aluminum–magnesium alloy

We proposed a theoretical spatio-temporal imaging method, which was based on the thermal model of laser ablation and the two-dimensional axisymmetric multi-species hydrodynamics model. By using the intensity formula, the integral intensity of spectral lines could be calculated and the corresponding images of intensity distribution could be drawn. Through further image processing such as normalization, determination of minimum intensity, combination and color filtering, a relatively clear species distribution image in the plasma could be obtained. Using the above method, we simulated the plasma ablated from Al–Mg alloy by different laser energies under 1 atm argon, and obtained the theoretical spatio-temporal distributions of Mg I, Mg II, Al I, Al II and Ar I species, which are almost consistent with the experimental results by differential imaging. Compared with the experimental decay time constants, the consistency is higher at low laser energy, indicating that our theoretical model is more suitable for the plasma dominated by laser-supported combustion wave.

Spectral quadrature for the first principles study of crystal defects: Application to magnesium

We present an accurate and efficient finite-difference formulation and parallel implementation of Kohn-Sham Density (Operator) Functional Theory (DFT) for non periodic systems embedded in a bulk environment. Specifically, employing non-local pseudopotentials, local reformulation of electrostatics, and truncation of the spatial Kohn-Sham Hamiltonian, and the Linear Scaling Spectral Quadrature method to solve for the pointwise electronic fields in real-space and the non-local component of the atomic force, we develop a parallel finite difference framework suitable for distributed memory computing architectures to simulate non-periodic systems embedded in a bulk environment. Choosing examples from magnesium-aluminum alloys, we first demonstrate the convergence of energies and forces with respect to spectral quadrature polynomial order, and the width of the spatially truncated Hamiltonian. Next, we demonstrate the parallel scaling of our framework, and show that the computation time and memory scale linearly with respect to the number of atoms. Next, we use the developed framework to simulate isolated point defects and their interactions in magnesium-aluminum alloys. Our findings conclude that the binding energies of divacancies, Al solute-vacancy and two Al solute atoms are anisotropic and are dependent on cell size. Furthermore, the binding is favorable in all three cases.