Rolled Aluminum Alloy Research Articles

Crystal Plasticity Finite Element Simulation of Grain Evolution Behavior in Aluminum Alloy Rolling.

In this study, the crystal plasticity finite element method was established by coupling the crystal plasticity and finite element method (FEM). The effect of rolling deformation and slip system of polycrystalline Al-Mg-Si aluminum alloy was investigated. The results showed that there was a pronounced heterogeneity in the stress and strain distribution of the material during cold rolling. The maximum strain and shear strain occurred at surface of the material. The smaller the grain size, the lower the strain concentration at the grain boundary. Meanwhile, a smaller strain difference existed between the grain interior and near the boundary. The rotation of grains leads to significant differences in deformation and rotation depending on their initial orientations during the rolling process. The slip system of (11-1)<-110> had a large effect on the plastic deformation, (111)<10-1> is second, and the effect of (1-11)<011> slip system on the plastic deformation is the smallest. After deformation, the grain orientation concentration was increased with deformation. Therefore, both the strength and volume fraction of texture were increased with the increase in rolling deformation. The experimental results of EBSD indicated that the large rolling reduction resulted in severe grain twisting, so the texture strength was increased. The simulation results were in close agreement with the experimental results. This study provides a theoretical basis for the rolling process, microstructure, and performance control of aluminum alloys.

Simulations of Texture Evolution in the Near-Surface Region During Aluminum Rolling

Prediction of texture changes during cold rolling is important because they affect the recrystallization and anisotropy of an aluminum sheet during successive forming steps. During cold rolling of aluminum alloys, the through-thickness textural change in the subsurface layer depends heavily on the shear stresses exerted on the material. The intensity of this shear stress is determined by the value of and change in the coefficient of friction as the contact length between the rolls and metallic sheet changes. The quality of the texture prediction under constant and variable coefficients of friction are assessed for three established texture models: the grain interaction (GIA) model, the viscoplastic self-consistent (VPSC) approach, and the full-field crystal plasticity Düsseldorf Advanced Material Simulation Kit (DAMASK) code. The simulation results are compared with subsurface layer textures obtained from conducting experimental cold-rolling trials on an aluminum alloy, which are designed to maximize shear in a single rolling pass. The formulation of a variable coefficient of friction is crucial for ensuring both the reasonable prediction of rolling forces and changes in texture. GIA and DAMASK yield the best texture prediction results for a variable coefficient of friction model.

Predicting the in-plane mechanical anisotropy of 7085 aluminum alloys through crystal plasticity simulations and machine learning

The crystallographic texture of rolled 7xxx series aluminum alloys may lead to mechanical properties anisotropy which undermines the formability and performance of the material. This article aims to explore the quantitative relationship between texture and the in-plane anisotropy of 7085 aluminum alloy. A comprehensive computational method combining crystal plasticity simulation with machine learning and experiment was used to establish an analytical model and train a machine learning model to predict the anisotropy of 7085 aluminum alloys. We first performed a full-field crystal plasticity spectral simulations using fast Fourier transformation (CPFFT) to predict the anisotropy of 7085 aluminum alloy at different annealing times. Then, based on the CPFFT simulation data, the quantitative relationship between texture and the in-plane anisotropy of the r-value was established by using the multiple linear regression and gradient boosting regressor model. The results indicate that CPFFT simulation can effectively capture the influence of texture changes on anisotropy, and the model established through the gradient boosting regressor model is in good agreement with experimental results, providing effective guidance for improving the performance of 7085 aluminum alloy sheets.

Joining Mechanism of Resistance Spot Welded Joints of Aluminum Casting Alloy and 6000 Series Rolled Aluminum Alloy

Joining Mechanism of Resistance Spot Welded Joints of Aluminum Casting Alloy and 6000 Series Rolled Aluminum Alloy

High-Temperature Tensile Mechanical Properties and Microstructure of Rolled 6082-T6 Aluminum Alloy Sheets.

The tensile properties of rolled 6082-T6 aluminum alloy were tested at a high temperature, and the influences of tensile temperature on its flow stress and anisotropy were studied. The microstructure evolution was characterized using optical microscopy (OM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). It was concluded that the tensile strength of the studied alloy decreases with increasing temperature. In higher-temperature deformation, the dislocation density decreases alongside the coarsening of precipitates, leading to a decrease in deformation resistance, and increase in the number of dimples and deepening of their sizes, exhibiting good plasticity. The alloy displays anisotropic mechanical properties at 200 °C due to the elongated grains and the orientation of the α-phase. The anisotropy becomes weaker with increasing temperature. There is no evident anisotropy at 400 °C, as the slip systems are activated more easily and the grains begin to recrystallize.

Mechanical properties and joining mechanisms of magnetic pulse welding joints of additively manufactured 316L and conventional AA5052 aluminum alloy

Magnetic Pulse Welding (MPW) is a new solid-phase welding (no heat input and no auxiliaries) technique. This results in joints with almost no brittle intermetallic compounds (IMC) and hence provides excellent joint quality. In this study, 316L fabricated by additively manufactured (AMed 316L) and conventional rolled AA5052 aluminum alloy were welded by MPW. Moreover, it was compared with conventional rolled 316L (C316L). Shear tests were used to characterize the mechanical properties of the joints. Laser confocal microscopy, Scanning Electron Microscope (SEM), and Energy Dispersive Spectroscopy (EDS) were used to characterize the microstructure and elemental diffusion of the joints. It was found that the strength of both joints was higher than that of the base material. In addition, sufficient elemental diffusion was achieved at the weld interface. No significant weld defects and IMC generation were observed at the interface of the AA5052-AMed 316L joint. Finally, Smoothed Particle Hydrodynamic (SPH) was used to analyze the formation mechanism of the transition zone morphology. This study demonstrates for the feasibility of MPW technology for welding additive manufacturing materials.

MODELING THE STRUCTURE EVOLUTION DURING HOT ROLLING OF ALUMINUM ALLOYS USING THE DEFORM SOFTWARE

The investigation of the structural evolution of aluminum alloys during hot rolling is a pertinent challenge in modern metallurgy. This study involves the modeling of the process of aluminum alloy structure formation during hot rolling using the DEFORM-3D software suite. The software allows for the replication of real rolling conditions and the prediction of changes in alloy structures. The article presents modeling of evolutionary structures during the hot rolling of aluminum alloy 5182 BT (Al-Mg 4.5%) in a five-stand continuous hot rolling mill. The DEFORM-3D software product was used for mathematical modeling, and the Johnson-Mehl-Avrami-Kolmogorov equation was employed to account for recrystallization kinetics. The results of calculations yielded the volume of recrystallized grains and their sizes throughout the entire rolling process. However, it is crucial to note that changes in grain sizes during the rolling of aluminum alloys are a complex process and do not follow a constant pattern. This is due to the influence of numerous factors related to both the metal's internal structure and the specific technological processes. Therefore, the modeling results require further verification through industrial experiments. In this context, data regarding the evolution of texture and structure obtained during forced hot rolling "2800" with subsequent thread cooling of the metal were used for comparison. In conclusion, this article contributes to a deeper understanding of processes occurring during the hot rolling of aluminum alloys and provides valuable insights into the impact of recrystallization on the final structure and material properties.

Microstructure Evolution of the Near-Surface Deformed Layer and Corrosion Behavior of Hot Rolled AA7050 Aluminum Alloy.

The current study investigates the influence of hot rolling on the microstructure evolution of the near-surface region on AA7050 aluminum alloy and the corrosion performance of the alloy. It is revealed that hot rolling resulted in grain refinement in the near-surface region, caused by dynamic recrystallization, and equiaxed grains less than 500 nm can be clearly observed. Fibrous grains were evident in the hot rolled AA7050 aluminum alloy with relatively lower rolling temperature or larger rolling reduction, caused by the more severe elemental segregation at grain boundaries, which inhibited the progression of dynamic recrystallization. The density of the precipitates in the fibrous grain layer was higher, compared with those in the equiaxed grain layer, due to the increased dislocation density, combined with more severe elemental segregation, which significantly promoted the nucleation of precipitates. With the co-influence exerted by low density of precipitates and dislocations on the improvement of the corrosion performance of the alloy, the rolled AA7050 alloy with decreased density of precipitates and dislocations exhibited better corrosion resistance.

Correlation between Mechanical Properties—Structural Characteristics and Cavitation Resistance of Rolled Aluminum Alloy Type 5083

The 5000 series aluminum alloy 5083 is distinguished by excellent processability, excellent welding characteristics, and a strong resilience to corrosion, particularly in maritime environments. It is employed in the manufacture of ships, automobiles, spacecraft, and industrial buildings. The goal of the current study is to determine whether there is any relationship between the mechanical properties, structural characteristics, and cavitation erosion properties of aluminum alloy 5083 in the H111 state (rolled from 454 °C to 399 °C and annealed at 343 °C by holding in cooled air), followed by artificial ageing at (180 °C) with three maintenance periods of 1 h, 12 h, and 24 h, and at (140 °C) with three maintenance periods of 1 h, 12 h, and 24 h. The cavitation resistance experiments of the experimental samples were performed in accordance with ASTM G32-2016. The resistance to cavitation erosion was determined by making mean erosion penetration rate (MDER) or mean depth of erosion (MDE) analytical diagrams according to the duration of the cavitation attack and by measuring the maximum depth of cavitation erosion in the samples analyzed by stereomicroscopy and scanning electron microscopy. Finally, a structural correlation between the condition of the artificially aged laminate alloy and its resistance to cavitation erosion could be achieved: ageing at 180 °C, maintained for 24 h, could lead to a maximum depth of cavitation erosion MDEmax of about 5 µm.

Effect of Final Thermomechanical Treatment on the Mechanical Properties and Microstructure of T Phase Hardened Al-5.8Mg-4.5Zn-0.5Cu Alloy.

The effect of final thermomechanical treatment (FTMT) on the mechanical properties and microstructure of a T-Mg32(Al Zn)49 phase precipitation hardened Al-5.8Mg-4.5Zn-0.5Cu alloy was studied. The as-cold rolled aluminum alloy samples were subjected sequentially to solid solution treatment, pre-deformation, and two-stage aging treatment. Vickers hardness was measured during the aging process under various parameters. Tensile tests were conducted on the representative samples based on the hardness results. Microstructural characteristics were analyzed via transmission electron microscopy and high-resolution transmission electron microscopy. The conventional T6 process was also carried out for comparison. The hardness and tensile strength are increased evidently by the FTMT process for the Al-Mg-Zn-Cu alloy, while the ductility is adversely affected to a small extent. The precipitation at the T6 state consists of a coherent Guinier-Preston zone and T″ phase in the form of intragranular, fine, and spherical particles, while a semi-coherent T' phase appears after the FTMT process as a new constituent. The distribution of dislocation tangles and isolated dislocations is another feature of FTMT samples. Enhanced precipitation hardening and dislocation strengthening account for the improved mechanical performance of FTMT samples.

Microstructure and mechanical properties of dissimilar friction stir welded joints of laser powder bed fusion processed AlSi10Mg and conventional hot rolled 6061-T6 thin sheets

In recent years, laser powder bed processed metal components have been extensively used in the aerospace and high-end automobile industries. However, this technology remains expensive in terms of the material and size limitations of the printing beds. In the present study, an alternative solution is suggested to overcome these challenges in the context to adopt the technology more effectively. For the first time, an attempt was made to join the two dissimilar materials fabricated through different technologies using friction stir welding. Laser powder bed fusion processed AlSi10Mg alloy and conventional hot rolled AA6061-T6 aluminium alloy were selected as a base material. The study aims to reveal the role of the positioning of the alloys and the effect of heat input on the microstructural characteristics and joint properties of the welded joints. The analysis of the microstructure shows the formation of the onion ring structure and thin banded patterns while positioning of AlSi10Mg material on the advancing side at high heat input. Meanwhile, the fraction of HAGBs was uniformly and highly dominated at high tool rotational speed, regardless of material positioning. Although, the dispersion of eutectic Si-particles (from the Si-rich network of AlSi10Mg) over the solid solution of Al-matrix was enhanced in the stir zone. The results of microhardness show a considerable drop in the welded zones as compared to both the base materials. The tensile properties of the welded joints were also significantly affected by the material positioning and heat input. The maximum UTS was achieved when a joint was fabricated with high tool rotational speed and AlSi10Mg positioned on the advancing side. The key findings from the present study proved a good reference for engineering applications, where the complex and large additive components are replaced by the hybrid components.

Effect of Roller Axial Position and Thickness on a Twisted Angle in the Twist Rolling of Aluminum Alloy 1050 Sheet Metal

This paper proposes a new rolling method called “twist rolling” that can continuously form a twisted shape by using taper rollers. The twisted shape of metal sheets is widely used in industrial products such as turbine blades and propellers. Such a shape is normally formed by casting or machining, but there are problems with low efficiency regarding the productivity and yield ratio. Forging processes have also been proposed, but they have problems with the surface property. The present study focuses on rolling to efficiently form a continuously twisted shape. The effect of the axial position of the taper rollers and skew angle on the average specific twisted angle were investigated by experiments and finite element analysis. The relationship between the thickness of sheet metal and the average specific twisted angle was also investigated. The average specific twisted angle decreased as the axial position increased. When the skew angle was smaller and the sheet metal thicker, the average specific twisted angle increased more. Twist rolling can form various twist angles by changing such parameters.

Evaluating the corrosion behaviour of AA6061-T6 alloy and its friction stir welded joints

ABSTRACT The cold rolled aluminium alloy (AA6061-T6) and its friction-stir welded joints (with varied tool-tilt angle and joint configuration) were investigated for their corrosion performance using a corrosion immersion test in two stages. First, the influence of corrosion conditions on the performance of base metal was investigated using the design-of-experiments approach with the central composite design of response surface methodology. Among the three input corrosion variables (namely time, temperature and NaCl-concentration) selected at three levels each, the contribution of temperature to corrode the base metal was found to the order of ≈50%, followed by time (21%) and NaCl-concentration (7%). Further, parameters were optimised to attain minimum and maximum corrosion rate conditions. In the second-stage, the optimised corrosion conditions were used to study the corrosion behaviour of the welded joints. Among all welds, the single-pass joint fabricated with 0° tilt angle showed minimum corrosion rate but possessed 96% higher mass-loss compared to the base metal. Moreover, the corrosion rate was found to increase with the increase in tool-tilt angle, as-well-as with the change in joint configuration from single-pass to double-pass. The optical and scanning electron microscopy revealed the pitting and intergranular corrosion to be the dominating corrosion mechanisms for the base metal and welded joints.

Anisotropic mechanical behavior prediction of aluminum alloy sheet based on an anisotropic GTN model: Modeling, simulation and experimental investigation

The rolled aluminum alloy sheets usually have anisotropic properties that affect its ductile fracture behavior. In order to study the plastic anisotropy and ductile fracture behavior of aluminum alloy 6016 sheet, the Hill48 anisotropic yield criterion is introduced into the Gurson–Tvergaard–Needleman (GTN) model forming an anisotropic GTN model. In this model, two groups of Hill48 anisotropic yield constants, which are respectively calculated by Lankford's coefficient in different directions and the combination of the Lankford's coefficient and yield stress in different directions, are separately used to describe anisotropic mechanical behaviors. The failure void volume fraction is identified through microstructure analysis and the other damage parameters are calibrated through a finite element (FE) inverse calibration method. The abilities of these two groups of Hill48 anisotropic yield constants in predicting anisotropic mechanical behaviors of aluminum alloy 6016 sheet are examined by performing FE simulations of 0°, 45°, and 90° plate tensile tests, deep-drawing tests and Erichsen cupping tests. Results show that the Hill48 anisotropic yield constants calculated by the Lankford's coefficient in different directions have a better ability to predict local anisotropic plastic deformation especially the earing effect in the deep-drawing test, but the Hill48 anisotropic yield constants calculated by the combination of the Lankford's coefficient and yield stress in different directions have a better prediction ability in predicting global anisotropic mechanical behaviors of the aluminum alloy 6016 sheet.

Analysis of Temperature-Deformation Conditions for Rolling Aluminum Alloy Al–Mg–Sc Based on FEM Modeling

Analysis of Temperature-Deformation Conditions for Rolling Aluminum Alloy Al–Mg–Sc Based on FEM Modeling

Analysis of temperature-deformation conditions for rolling aluminum alloy Al–Mg–Sc based on FEM modeling

The article discusses the features of Al–Mg–Sc aluminum alloy radial shear rolling (RSR). The RSR process was modeled by the finite element method in the QForm 3D program with the variable elongation ratio per pass and rolling speed. The results obtained were used as a basis for studying the temperature field of the rod in the deformation zone taking into account the cyclic nature of deformation and the configuration of flow paths. It was found that the temperature field in the deformation zone is determined by significant differences in the metal flow path geometry in surface layers and in the axial zone. When the elongation ratio is varied from 1.6 to 2.4, heating occurs inconsistently from the center to the surface. The highest temperature rise occurs for an area that is located ~0.3R from the surface. For the axial zone, temperature variation in the deformation zone occurs smoothly and with an insignificant temperature difference of 5–10 °C. Highest temperature fluctuations are observed on the rod surface, and this is explained by deformation heating and simultaneous contact with a cold roll during each deformation cycle. As the rolling speed decreases, a picture of the rod temperature field distribution in the deformation zone is observed with the temperature in central layers exceeding the surface temperature. Due to the long time of the rod contact with the roll, the surface temperature fluctuates up to 40–50 °C at each deformation cycle. As the rolling speed rises, the amplitude of temperature fluctuations on the surface decreases, and deformation heating increases. The data obtained on the relationship between control process parameters and rod temperature field variation can be useful in the design of rolling process modes.

Numerical Study on Asymmetrical Rolled Aluminum Alloy Sheets Using the Visco-Plastic Self-Consistent (VPSC) Method

Asymmetric rolling is a forming process that has raised interest among researchers due to the significant improvements it introduces to the mechanical response of metals. The main objective of the present work is to perform a numerical study on asymmetrical rolled aluminum alloy sheets to identify and correlate the effect of the additional shear strain component on the material formability, tensile strength, and texture orientations development during multi-pass metal forming. Conventional (CR), asymmetric continuous (ASR-C), and asymmetric rolling-reverse (ASR-R) simulations were carried out using the visco-plastic self-consistent (VPSC) code. For the ASR process, two different shear strain values were prescribed. Moreover, two hardening models were considered: a Voce-type law and a dislocation-based model that accounts for strain path changes during metal forming. Results showed that the ASR process is able to improve the plastic strain ratio and tensile strength. The ASR-C revealed better results, although the expected shear orientations are only evident in the ASR-R process.

Study on the anodic oxidation performance of a rolled AA5252 aluminum alloy sheet with different thicknesses

Microstructures of AA5252 aluminum alloy sheets from surface to the center were observed by use of scanning electron microscope with electron backscatter detector assembly, and treated by anodic oxidation. Results showed that changes of the grain structures and textures of the AA5252 alloy sheets occur from the surface to the center layers. The anodic oxidation surface quality of the AA5252 aluminum alloy is closely related to the area ratio and distribution uniformity of Cube texture.

An Evaluation of the Influence of Forward Slip on the Corrosion Behavior of Aluminum-Manganese Alloys

The tribological influence of hot rolling parameters, such as the work roll roughness, roll speed, and the number of rolling passes on the surface quality of rolled aluminum alloys, has been a subject of interest for the wrought aluminum industry. A hot rolling tribo-simulator was used to investigate the effect of forward slip on the surface damage induced by the rolling operation and the subsequent corrosion behavior of the Al-Mn alloys. A two-pass hot rolling schedule was conducted at 500–540 °C for forward slip levels of − 4, 1, 7, and 13% using an AISI 52100 steel work roll with a surface roughness (Ra) of 0.01 µm. Characterization of the rolled surfaces using scanning electron microscopy (SEM) revealed hot rolling-induced damage in the form of microcracks, nanocracks, and MgO coverage, which was more prominent for higher forward slips. Corrosion tests were subsequently conducted on the rolled Al-Mn specimens by immersion in a 0.5 wt.% NaCl solution. These tests showed greater corrosion-covered surface areas on samples rolled at lower forward slips. This relationship between the forward slip and corrosion behavior was due to the extent of surface damage induced at varying forward slip levels. The preferential corrosion mechanism was observed to be due to the dissolution of the MgO-rich near-surface microstructures induced during hot rolling.

Investigation of the Intermetallic Compounds Fragmentation Impact on the Formation of Texture during the as Cast Structure Thermomechanical Treatment of Aluminum Alloys

In this work, the influence of the intermetallic particle fragmentation during hot rolling of the as cast structure on the evolution of textures in aluminum alloys 8011, 5182 and 1565 was investigated. For this purpose, laboratory multi-pass rolling of the cast material was carried out. At various degrees of hot rolling deformation, the process was stopped, and the metal was quenched and sent for optical and electron microscopy to investigate the large intermetallic particles. In addition, the grain structure was studied and an X-ray analysis was carried out in order to determine the main texture components. Some of the samples were held at a temperature above the recrystallization threshold and then cooled in air; the grain structure and texture composition were also studied. In addition, the simulation of the texture evolution was carried out under various modes of rolling of aluminum alloys, taking into account the process of fragmentation of intermetallic particles. The investigation showed that intermetallic compounds with a deformation degree of 1.8, on average, decrease the particle size by 5–7 times. The large eutectic particles remaining after homogenization are drawn out in the direction of deformation and are crushed, increasing their number accordingly. Therefore, the most favorable stage for the formation of recrystallization nuclei on particles is the moment when they are already numerous and their sizes are much larger than subgrains. Simulation of hot rolling of the investigated alloys showed that considering the factor of fragmentation of intermetallic particles during hot deformation of the as-cast structure significantly increases the accuracy of the results.