6061-T6 Aluminum Research Articles

Enhance forming properties of 7075-T6 aluminium alloy by two-step electromagnetic forming and electrical pulse treatment

Enhance forming properties of 7075-T6 aluminium alloy by two-step electromagnetic forming and electrical pulse treatment

An Investigation on Laser Machining of 7075 T6 Aluminium Alloy and Effect of Thermal Treatment on its Mechanical Property

An Investigation on Laser Machining of 7075 T6 Aluminium Alloy and Effect of Thermal Treatment on its Mechanical Property

Investigation of The Fatigue Behavior of Gyrocopter Propellers Produced From 6061 T6 Aluminium Alloy

In the aviation sector, the production of propeller-driven aircraft is being accelerated due to the increase in passenger numbers, the possibility of transportation for shorter distances, and the reduction in costs in aircraft designs. Gyrocopter vehicles, which have recently begun to be used in aviation, have significant potential in the near future. The demand for these air vehicles in the aviation sector is growing due to their ability to operate in relatively short ranges, their low operational and maintenance costs. Generally, the systems that most significantly reduce costs in these aircraft are propellers. The technological advancements in material science have facilitated innovative solutions in the design and manufacturing of propellers from a wide range of materials. The combination of nanotechnology and materials science has been achieved alongside ongoing innovations in these two evolving technologies. In this study, samples of propellers produced from 6061 T6 Aluminium Alloy, were produced with a special extrusion model and were then subjected to fatigue, tensile, and hardness tests. The mechanical standards of the produced propellers were examined to determine whether the desired flight configurations could be achieved.

Theoretical and experimental research on the critical buckling pressure of the thin-walled metal liner installed in the composite overwrapped pressure vessel

Composite overwrapped pressure vessels (COPVs) are widely used in the field of high-pressure gas storage and transportation because of their light weight and high strength. In engineering, autofrettage is usually used to improve the fatigue life of composite pressure overwrapped vessels with metal liners. However, excessive pressure of autofrettage could cause buckling damage to the metal liner. In order to determine the upper limit of autofrettage (critical buckling pressure) and analyze its influence on the safety factor of COPVs, a theoretical calculation model of the critical buckling pressure about the metal liner was established based on classical laminated plate theory and the confined buckling theory. Then, a COPV with thin-walled welded metal liner was prepared by fiber winding process. In order to monitor and judge the buckling damage mode of the liner, the circumferential strain of the COPV's cylinder was measured by loading and unloading step-by-step. Finally, the influence of materials and dimensions of the metal liner on the pressure ratio (the ratio of the first layer failure pressure to the critical buckling pressure of the COPV's metal liner) was discussed. When the diameter to thickness ratio (R/t) of the metal liner was greater than 35, the pressure ratios of the 6063-T5 aluminum alloy liner and the S30408 stainless steel liner both exceeded 2.25. However, the pressure ratio of 6061-T6 aluminum alloy liner with R/t ≤ 60 was lower than 1.85, which shows that the metal liner with higher yield strength and lower elastic modulus has higher utilization rate of fiber winding layers. Due to the fact that the current design standards only ensure the reliability of COPVs through safety factors and various type testing with their evaluation methods, the proposed theoretical calculation method can reduce the uncertainty of COPVs during the design and testing rounds.

Characterization of surface integrity of 7075-T6 aluminum alloy subjected to microbiologically induced corrosion during high-speed machining

Microbiologically Influenced Corrosion (MIC) is one of the primary causes of corrosion damage and equipment failure in industrial environments. This paper aims to investigate the impact of microbiologically influenced corrosion on the surface integrity of 7075-T6 aluminum alloy. Through experiments involving cryogenic treatment and machining, the study systematically compares the effects of different microbiologically influenced corrosion environments on 7075-T6 aluminum alloy. Techniques such as X-ray Diffraction (XRD), surface roughness measurement, Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), and work hardening were used to elucidate the influence of natural seawater (Planktonic microorganisms, PM) and marine sediment (Benthic microorganisms, BM) corrosion on the surface integrity of 7075-T6 aluminum alloy.The results indicate that, compared to PM corrosion, BM corrosion results in a smaller surface roughness of 7075-T6 aluminum alloy. Specifically, the BM-10d specimen exhibits the smallest roughness at 0.353 μm. XRD and EDS analyses show that the corrosion products after microbiological corrosion are primarily a mixture of Al2O3, AlO(OH), and Al(OH)3. The peak intensity of AlO(OH) in the (200) crystal plane of the BM-5d corrosion product is notably higher than that of the 7075-T6 aluminum alloy under other conditions. In the PM environment, the corrosion products fully cover the entire surface of the workpiece and are accompanied by significant cracking. In contrast, in the BM environment, the corrosion products mainly exhibit a granular structure, are scattered across the workpiece surface, and the exposed substrate can be observed.The microhardness of the aluminum alloy after microbiological corrosion shows a trend of increasing initially, then decreasing, and finally stabilizing. The maximum depth of the hardened layer for PM-10d is 120 μm, with a maximum hardness of 178.74 HV. Compared to PM corrosion, BM corrosion results in a significantly greater hardened layer depth for 7075-T6 aluminum alloy, with the BM-10d hardened layer depth reaching approximately 140 μm and the peak hardness at 185.36 HV. Additionally, in the BM environment, the precipitates are fewer compared to those in the PM environment and exhibit a non-continuous, non-grain-boundary precipitation band.

Data-driven modeling and optimization of a robotized multi-needle ultrasonic peen-forming process for 2024-T3 aluminum alloy

Data-driven modeling and optimization of a robotized multi-needle ultrasonic peen-forming process for 2024-T3 aluminum alloy

Study on the friction and wear properties of 7075-T6 aluminum alloy enhanced by milling and ultrasonic impact treatment

This study investigates the effects of milling parameters on the surface friction behavior of 7075-T6 aluminum alloy subjected to ultrasonic impact treatment. A three-dimensional milling and friction-wear model was developed using ABAQUS finite element analysis, examining the influence of milling speed, depth, and feed rate on the coefficient of friction, wear volume, and surface morphology through single-factor experiments. Results indicate that milling parameters affect the friction coefficient in the following order: Vc > f > ap. Specifically, increasing milling speed from 35 m/min to 59 m/min raises the average friction coefficient from 0.305 to 0.387, a 26.88 % increase. At a milling speed of 83 m/min, the friction coefficient and wear volume reach their lowest values of 0.305 and 0.977 mm³, respectively. The wear volume decreases with increasing milling speed and feed rate, while milling depth has a minor effect. The most significant reduction in wear volume, from 5.76 mm³ to 0.977 mm³ (an 83.04 % decrease), occurs as milling speed increases from 35 m/min to 83 m/min. Maximum longitudinal slip during the reciprocating motion primarily occurs at the ends, with both positive and negative peak offsets. Surface damage from 304 stainless steel balls against the 7075-T6 alloy involves adhesive and abrasive wear. At a milling depth of 35 μm, friction-induced compounds in the transfer film mainly consist of Al, C, Fe, Zn, Mg, and Cr.

Effect of repair patch nature on J-integral reduction in notched plates

PurposeThe purpose of this research is to evaluate the effectiveness of different repair patch materials in reducing the stresses at the crack tip of a 2024-T3 aluminum plate. This involves a numerical analysis using the finite element method (FEM) to estimate the reduction in the J-integral value, with the goal of identifying how various parameters related to the patch materials, adhesive properties and loading conditions influence the structural integrity of the repaired plate.Design/methodology/approachThe methodology of this research involves conducting a numerical analysis using the FEM to estimate the reduction in the J-integral value at the crack tip of a 2024-T3 aluminum plate. Three types of patches – metal, composite and functionally graded material (FGM) – were examined under tensile loading conditions, and Adekit-A140 adhesive was used to bond these repair patches to the aluminum plate.FindingsThe analysis considered various parameters, including crack length, the nature of fibers in the composite material, the gradation exponent for FGM patches and the nature of the face in contact with the adhesive for the FGM patch. Additionally, stress analysis was conducted, examining the J-integral values for the plate, shear stress in the adhesive layer and peel stress in the composite patch. The findings highlight that modifying the nature of the repair patch used can significantly enhance the structural integrity of the repaired plate.Originality/valueThe study analyzed J-integral values, shear stress in the adhesive and peel stress in the composite patch. Various parameters, including crack length, fiber type, gradation exponent and adhesive contact face nature, were considered. Results demonstrate that the J-integral value can be significantly reduced by altering the repair patch type, highlighting the effectiveness of customized patch materials in enhancing structural integrity.

Synergistic Effects of Pre-charged Hydrogen and Tensile Stress on the Stress Corrosion Cracking of 2024-T351 Aluminum Alloy

Synergistic Effects of Pre-charged Hydrogen and Tensile Stress on the Stress Corrosion Cracking of 2024-T351 Aluminum Alloy

Synergistic Effects of Surface Texture and Cryogenic Treatment on the Tribological Performance of Aluminum Alloy Surfaces

In order to improve the tribological properties of the 7075-T6 aluminum alloy used on the rotor surface, a combined method of cryogenic treatment and laser surface texture treatment was applied. Various tests, including metallographic microscopy, scanning electron microscopy, elemental analysis, microhardness measurements, were conducted to examine the wear morphology and modification mechanism of the treated 7075-T6 aluminum alloy surface. A numerical simulation model of surface texture was established using computational fluid dynamics to analyze the lubrication characteristics of V-shaped texture. The research finding that the 7075-T6 aluminum alloy experienced grain refinement during the cryogenic treatment process, enhancing the wear resistance of the V-shaped textures. This improvement delayed the progression of fatigue wear, abrasive wear, and oxidative wear, thereby reducing friction losses. The designed V-shaped texture contributes to reducing contact area, facilitating the capture and retention of abrasives, and enhancing oil film load-bearing capacity, thereby improving tribological performance. The synergistic effect of cryogenic treatment reduced the friction coefficient by 24.8% and the wear loss by 66.4%. Thus, the combination of surface texture and cryogenic treatment significantly improved the tribological properties of the 7075-T6 aluminum alloy.

Efficient evolution mechanism of electrolytic gas products from laser-assisted electrolyte jet machining

Efficient evolution of electrolytic gas products is one of the mechanisms for increased material removal rate in laser-assisted electrolyte jet machining. However, the evolution mechanism of electrolytic gas products with multiple energy fields in laser-assisted electrolyte jet machining is not clear. In order to quantitatively characterize the laser-assisted facilitation of the evolution of electrolytic gas products, a gas quantification and detection device was designed and built in this paper. Compared to traditional electrolyte jet machining, laser-assisted electrolyte jet machining of 2024-T3 aluminum alloy increased the gas production by 52 % in 180 s. For the anode, the surface modification induced by laser texturing reduces the oxygen evolution potential and surface free energy and promotes gas nucleation and detachment. In addition, laser-induced conductive plasma can enhance transient currents for electrolyte jet machining and cause machining vibrations. The cathodic gas discharge phenomenon was characterized in conjunction with interelectrode gap visualization experiments and cathodic nozzle damage. Experimental results show that cathodic gas discharge depends on strong electric field and high laser pulse fluence. In summary, laser temperature rise, anode surface modification, laser-induced plasma, plasma recoil and cathode gas discharge can all contribute to the evolution of electrolytic gas products.

A New Continuous Strength Method for Prediction of Strain-Hardening Performance of High-Strength Aluminum Alloy Cylindrical Columns

This paper aims to develop a new continuous strength method (CSM) to more accurately predict the strain-hardening characteristics of high-strength aluminum alloy circular hollow sections (CHSs) under axial compression. A total of 11 stub column specimens made of 7A04-T6 and 6061-T6 aluminum alloys underwent testing. Additionally, 16 sets of experiment data were gathered from open sources, encompassing various aluminum alloy types such as 6082-T6, 6061-T6, and 6063-T5. Validated by experimental result, the finite element (FE) model was applied in a series of comprehensive parameter studies, supplementing the limited test result of high-strength aluminum alloy stub columns. Based on the experiment and FE results, this paper proposes a new CSM relation to determine the cross-sectional resistance of high-strength non-slender CHS aluminum alloys under compression. The cross-sectional resistance obtained from tests are compared with predicted strengths determined using the European code, as well as the solution of the CSM proposed in a previous study and in this paper. The comparison illustrates that the strength predictions in the European code and the previous study are conservative. Compared with the European code and the previous study, the strength prediction formula proposed in this paper improves accuracy by 11% and 5%, respectively, while reducing scatter by 8.4% and 2%, respectively.

Crack Growth Patterns of Aluminum Tubular Specimens Subjected to Cyclic Tensile Loads

This study presents a detailed analysis of a fatigue test campaign in order to identify different crack patterns. It was conducted on 6061-T6 aluminum tubular specimens featuring an internal diameter of 10 mm and different thicknesses (2, 3 and 4 mm). These specimens were subjected to cyclic tensile loads with a load ratio of R = 0.1, utilizing a sinusoidal load function at a frequency of 3 Hz. The investigation examines the crack growth rates, the stress intensity factor, and the final and intermediate fracture zones by applying overloads in some cases. The differences with two-dimensional specimens and the importance of this study for the interpretation of results with biaxial loading states are highlighted. The different states of crack growth detected are analyzed using artificial vision techniques. The differences between the exterior and interior faces of the specimen are revealed, and a series of states prior to the formation of the radial crack front expected in these specimens are identified.

Experimental and Numerical Investigation of the Ballistic Response of Alumina 99.7% Covered with Aluminum 6061-T6 Face Sheets

Experimental and Numerical Investigation of the Ballistic Response of Alumina 99.7% Covered with Aluminum 6061-T6 Face Sheets

Multiphysics computational modelling and experimental analysis of friction stir welding of aluminium alloy metal matrix composites (AAMMCs)

Friction stir welding is a modern method for fabricating aluminium alloy metal matrix composites (AAMMCs) that significantly enhance the properties of the parent materials. In this study, Al2O3 particles were incorporated into a 6061-T6 aluminium matrix. Experimental and numerical modeling provided in-situ observations of particle-aluminium matrix mixing in the weld stir zone (SZ). Two different pin profiles, threaded and square, were used to fabricate the AAMMC joints. The threaded pin profile resulted in uniform dispersion and a homogeneous distribution of Al2O3 particles within the aluminium matrix. In contrast, the square pin profile led to defects in the SZ and a non-homogeneous particle distribution. The volume fraction mixing of the AA6061-T6 matrix and Al2O3 at the workpiece/tool interface from top to bottom was analyzed using a level set technique. Experimental results showed effective mixing of Al2O3 particles in the AA6061-T6 matrix with the threaded pin profile, resulting in a defect-free joint, uniform particle distribution, and ultra-fine grain refinement, with grain sizes reduced to 4.19 µm. The main shear texture components observed in the threaded pin joints included B/B̅ and C, along with deformed and recrystallized texture components such as Copper {112} 〈111〉, Brass {110} 〈112〉, Goss {011} 〈100〉, Cube {001} 〈101〉, and P {011} 〈112〉 . Additionally, joints fabricated using threaded pin profiles exhibited significantly higher tensile strength (up to 270 MPa) and microhardness (average of 120 HV0.2) compared to those with square-shaped pin profiles, which showed lower values of 240 MPa and 105 HV0.2, respectively. Thus, AAMMC joints made with threaded pins demonstrate ultra-fine grain refinement, increased high-angle grain boundaries, enhanced recrystallized texture components, and improved mechanical properties, resulting in superior overall joint performance.

Orthogonal cutting of 3D printed multi-material workpiece: numerical investigation of machining forces, stress, and temperature distribution

AbstractWith the development of 3D metal printers for rapid prototyping and industrial component production, heightened attention was directed towards post-processing operations for achieving precise surface quality and geometrical tolerances for these components. This paper investigated the orthogonal cutting of multi-material 3D printed workpieces using a coated cutting tool through finite element simulation. The workpieces featured different horizontal and vertical arrangements of layers composed of aluminum 7075-T6 alloy (Al), stainless steel 316 low alloy (SS), and Ti6Al4V alloy (Ti). The study explored the impacts of multi-material composition, coating thickness, and the rake angle of the cutting tool on machining forces, stress distribution, temperature distribution, and chip formation geometry. The results revealed a bimodal chip morphology in the machining process of horizontally arranged SS layers combined with other alloys. The SS layer resulted in a relatively uniform chip formation, while layers with two other materials exhibited a serrated chip formation. In contrast, a discontinuous chip formed when combining Al and Ti materials, as well as in the horizontally arranged layers made of Al, SS, and Ti alloys. The cutting force increased by 2.26 times when cutting workpieces with the horizontal arrangement of SS and Al layers compared to those with a single Al material. For the horizontal and vertical arrangement of layers made of Al and SS, von Mises stress values over the edge of the coated cutting tool significantly increased where the tool contacted the SS layer. Additionally, the horizontal arrangement of layers made of Al and SS materials caused the coated cutting tool to exhibit an extensive temperature distribution, with the maximum recorded temperature reaching 1448 °K. Increasing coating thickness led to a decrease in maximum principal stress at the surface of the tool and a rise in temperature at the cutting edge of the insert.

Friction stir welding of AA2024-T3 and SS304 alloys: microstructural analysis, microhardness evaluation, and tensile performance

This study examines the feasibility of friction stir welding (FSW) for dissimilar butt joints formed between 3 mm thick 2024-T3 aluminum alloy and AISI 304 stainless steel. It explores the impact of operational parameters, particularly traverse speeds of 20 and 40 mm min−1, a fixed tool rotation speed of 450 rpm, a tool pin offset of 1.5 mm, and a tool shoulder diameter of 18 mm, on microstructure, microhardness, and tensile strength. A traverse speed of 40 mm min−1 resulted in a lower peak temperature of 257.75 °C, while optimal conditions at a speed of 20 mm min−1 led to peak temperatures of 356.5 °C. This higher temperature facilitated material deformation, improved flow, enhanced mixing, and contributed to grain refinement, with an average grain size of 4.2 μm. Vickers microhardness tests revealed a maximum hardness of 339 Hv at a traverse speed of 40 mm min−1 and 413 Hv at 20 mm min−1. The ultimate tensile strength (UTS) reached 338 MPa, resulting in a joint efficiency (JE %) of 76.81% for the weld performed at optimal conditions.

Fatigue performance of a fastener hole treated by a novel electromagnetic strengthening process

In this study, a novel non-contacting electromagnetic cold expansion process was proposed to improve the fatigue performance of hole component using a single power supply and a single coil. The stress state and deformation of the 6063-T6 aluminum alloy hole component during the electromagnetic strengthening process were investigated through numerical simulation. The residual stress around the hole edge was measured using XRD. Fatigue testing was performed to verify the effectiveness of the process on improving the fatigue life of the hole component. Results showed that the proposed electromagnetic strengthening process could effectively improve the fatigue life of the hole component. Fatigue life of the specimen via electromagnetic treatment is 3.42 times of that of the original specimen at a maximum stress of 120 MPa. Simulation results indicated that the generation of compressive residual stress was attributed to the falling stage of the pulse current, and the maximum compressive residual stress was −102 MPa.

Evaluating the Plastic Anisotropic Effect on the Forming Limit Curve of 2024-T3 Aluminum Alloy Sheets Using Marciniak Tests and Digital Image Correlation

This study thoroughly investigates the influence of anisotropy on the formability of 2024-T3 aluminum alloy sheets using advanced techniques such as digital image correlation (DIC) and Marciniak tests. A key finding is the relatively small variation in anisotropy values across different strain paths and orientations, contrasting with more significant variations reported in other studies. Tests were conducted on nine samples with various geometries to induce specific strain paths, including uniaxial, plane, and balanced biaxial strains, oriented in different directions relative to the rolling direction. The study also provides a detailed analysis of microstructural and mechanical characteristics, such as precipitate distribution and anisotropy behavior, which are crucial for understanding the relationship between microstructure and material formability. The results show that while anisotropy impacts deformation capacity, the differences in formability among the directions were minimal, with slightly greater formability observed in the diagonal direction. These findings are compared with forming limit curves (FLCs), offering an integrated view of how relatively uniform anisotropic properties influence formability. These insights are essential for optimizing the processing and application of 2024-T3 alloy in industrial contexts, emphasizing the importance of understanding anisotropy in the design of metal components.

Experimental Investigation of Hardness and Surface Roughness in the Friction Stir Welding of the 6061-T6 Aluminum Alloy

Experimental Investigation of Hardness and Surface Roughness in the Friction Stir Welding of the 6061-T6 Aluminum Alloy