A356 Aluminum Alloy Research Articles

Combined experimental-numerical analysis of A356 aluminum alloy friction surfacing on AA2024 aluminum alloy substrate

This study examined the influence of the rotational speed of an A356 aluminum alloy consumable rod on thermo-mechanical issues, microstructure, and the wear resistance of coating during friction surfacing on an AA2024 aluminum alloy. The study utilized a comprehensive experimental-numerical analysis to fulfill its objectives. The findings reveal that the width and thickness of the coating increase by 7 and 18% percent, respectively, as the rotational speed of the consumable rod is augmented from 600 to 800 revolutions per minute (rpm). A higher rotational speed of the consumable rod facilitates plastic deformation of the material within it, enabling softer material to be deposited on the substrate's surface under reduced axial force. Simulation outcomes display that the maximum plastic strain is experienced on the coating's upper surface, which contacts the tip of the consumable rod. Upon moving toward the interface between the coating and the substrate, the degree of plastic strain rapidly diminishes. In the coatings produced by rotational speeds of 600 and 800 rpm, a fine grain layer forms on the upper side of the coating that comes into contact with the consumable rod's tip. Friction surfacing utilizing a rotational speed of 800 rpm, a traverse speed of 125 mm/min, and an axial feeding rate of 100 mm/min, results in increases of 9 and 38% in hardness and wear resistance respectively, compared to the AA2024 substrate.

A new constitutive model and hot processing map of 5A06 aluminum alloy based on high-temperature rheological behavior and higher-order gradients

To develop a high-precision constitutive model and hot processing map for 5A06 aluminum alloy, the hot deformation behavior of the alloy was investigated through isothermal compression experiments and microstructure analysis experiments, which were conducted at temperatures ranging from 573 K to 773 K and at strain rates ranging from 0.01 to 10 s−1. Firstly, a new constitutive model, which is based on the partial derivatives of the experimental flow data and does not significantly increase the material parameters, was proposed. Secondly, a comparison and analysis of the predictive accuracies of both the new model and the classic model were conducted. Finally, the new constitutive model was used to construct the hot processing maps of the 5A06 aluminum alloy, and the optimal hot processing parameters were validated through metallographic experiments. The results show that a high-precision constitutive model can be constructed with a small number of material parameters by considering the second-order approximation between logarithmic stress and temperature, as well as the third-order approximation between logarithmic stress and logarithmic strain rate. The mean square errors of the new model were significantly lower than those of the Arrhenius model and Hense-Spittle model for all strain rates and temperatures. There were significant differences in the prediction accuracy of the AH and HS models at different temperatures and strain rates, indicating their accuracy was dependent on temperature and strain rate. The coefficients of the new model were significantly higher than those of the AH and HS models. Moreover, the proximity of predicted values to experimental values was ranked in descending order as follows: new model, AH model, and HS model. The energy dissipation rate is relatively high when the strain rate is lower than 10 s-1 and the temperature is higher than 623 K. The instability factor is larger than zero for all conditions except when the strain rate is equal to 10 s−1. The optimal hot working temperature range for 5A06 aluminum alloy is 623–700 K, and the strain rate should be in the range of 0.01 s−1 to 1 s−1. The microstructure analysis matches the predicted results from hot processing maps, which can guide the hot working process of 5A06 aluminum alloy.

The effect of rolling temperature on the microstructure and properties of multi pass rolled 7A04 aluminum alloy

The current research on 7-series aluminum alloys mainly focuses on solid solution and aging treatments, as well as the flow stress during the deformation process. There are limited researches on the influence of thermal deformation temperature on the microstructure and properties of the aluminum alloy during multi-pass hot rolling process. In this study, the as-cast 7A04 aluminum alloy was subjected to homogenization treatment, followed by multi-pass hot rolling. The effects of different deformation parameters on dislocation density were analyzed. Microstructural characterization of the deformed alloy was performed using optical microscopy (OM), scanning electron microscopy (SEM) with energy-dispersive spectroscopy (EDS), X-ray diffraction (XRD), and micro-hardness tester. The optimal microstructure of the deformed alloy was selected based on the size of recrystallization. Subsequently, the Deform–3D finite element simulation software was used to analyze the multi-pass hot rolling process. The influence of deformation parameters on the uniformity of equivalent strain distribution within the samples was investigated. The results showed that at the deformation temperature of 430 °C, a significant amount of recrystallized microstructure appeared in the alloy, resulting in the lowest dislocation density and a significant reduction in the quantity of coarse precipitates. Finite element numerical simulation revealed that the deformation temperature had a certain influence on the uniformity of strain distribution within the alloy. However, this influence was mostly eliminated when the deformation temperature exceeded 380 °C. Meanwhile, the distribution of strain within the alloy was found to be related to the temperature distribution.

Processability of A6061 Aluminum Alloy Using Laser Powder Bed Fusion by In Situ Synthesis of Grain Refiners

Despite the increasing interest in laser powder bed fusion (LPBF), only a few cast aluminum alloys are available for this process. This study focuses on improving the LPBF processability of the A6061 alloy, which is challenging due to its wide solidification range, the dendritic columnar grain growth, and consequent solidification cracking. To address these issues, in situ-synthesized grain refiners can be used to induce equiaxial grain growth and prevent crack formation. A6061 RAM2 powder—a mixture of A6061, Ti, and B4C—was characterized and processed using a low-power LPBF machine to create an in situ particle-reinforced metal matrix composite. Parameter optimization was performed to evaluate the effect of their variation on the printability of the alloy. Microstructural characterization of the samples revealed that the complete reaction and the synthesis of the ceramic reinforcement did not occur. However, TiAl3 was synthesized during the process and promoted a partial grain refinement, leading to the formation of equiaxial grains and preventing the formation of solidification cracks. The tensile tests carried out on the optimized samples exhibit superior mechanical properties compared to those of A6061 processed through LPBF.

Numerical Modelling of High-Speed Loading of Periodic Interpenetrating Heterogeneous Media with Adapted Mesostructure

A series of calculations has been conducted to study the high-speed interaction of space debris (SD) particles with screens of finite thickness. For the first time, taking into account the fracture effects, a numerical solution has been obtained for the problem of high-velocity interaction between SD particles and a volumetrically reinforced penetrating composite screen. The calculations were performed using the REACTOR 3D software package in a three-dimensional setup. To calibrate the material properties of homogeneous screens made of aluminum alloy A356, stainless steel 316L, and multilayer screens, methodical load calculations were carried out. The properties of materials have been verified based on experimental data through systematic calculations of the load on homogeneous screens made of aluminum alloy A356, stainless steel 316L, and multilayer screens comprising a combination of aluminum and steel plates. Several options for the numerical design of heterogeneous screens based on A356 and 316L were considered, including interpenetrating reinforcement with steel inclusions and a gradient distribution of steel throughout the thickness of an aluminum matrix. The study has revealed that the screens constructed as a two-layer composite of A356/316L, volumetrically reinforced composite screens, and heterogeneous screens with a direct gradient distribution of steel in the aluminum matrix provide protection for devices from both a single SD particle and streams of SD particles moving at speeds of up to 6 km/s. SD particles were modeled as spherical particles with a diameter of 1.9 mm made of the aluminum alloy Al2017-T4 with a mass of 10 mg.

Effects of pre-stretching and baking treatment on microstructural evolution and mechanical properties of 7A09 aluminum alloy subjected to pre-hardening forming

In this study, a novel pre-hardening forming process is applied to 7A09 aluminum alloy. Then, the effects of pre-stretching and baking treatment on mechanical properties and microstructural evolution are investigated. Uniaxial tensile tests are conducted to evaluate the evolution law of the mechanical properties of alloys treated using different parameters. Microstructural evolution is revealed by transmission electron microscopy (TEM), electron backscatter diffraction (EBSD), and small-angle X-ray scattering (SAXS). Results show that the yield strength (YS) of the alloys pre-aged at 110 ℃ for 12 h (PA) reaches 612–694 MPa after they are pre-stretched by 2–6 %. This strength is 26–43 % higher than that of T6-temper alloy according to the ASTM B221M-21 standard. The elongation of PA alloys with 6 % deformation increases from 2.7 % to 10 % after baking at 215 °C for 1 min. Hence, the subsequent baking treatment compensates for the loss in ductility. The TEM result shows that numerous GPII zones and few η΄ phases co-exist in the matrix of the PA alloys. Simultaneously, η΄ phases serve as the main strengthening phases after pre-stretching the PA alloys by 6 %. Moreover, pre-stretching can increase the density of dislocations and the volume fraction of precipitates. In addition, the average size of precipitates has increased from 6.4 nm to 10 nm with the increase of baking time from 1 min to 10 min, and the transformation of η΄ phases to coarse η phases has appeared during this process. All results indicate that the strength–ductility of the foregoing alloys is better than that of T6-temper alloy.

Ion bombardment induced surface microstructural modification of aluminum alloy

Surface microstructural modifications of 2A12 aluminum alloy exposed to 60 keV Ar ion bombardment with the dose of 1 × 1017 ions/cm2 under vacuum were studied in detail. The amorphous layer with the thickness of ∼130 nm accompanied with polycrystalline aluminum was formed at the surface after Ar ion bombardment. Beneath the amorphous layer, Al2CuMg precipitates were observed. Dynamic recrystallization(DRX)and grain growth were observed with the increment of texture intensity. Surface residual compressive stress and strain were enhanced characterized by electron back-scattered diffraction. After ion bombardment, the contact angles of diiodomethane and DI water on aluminum alloy were increased, and a notable decrement of surface energy of aluminum alloy was measured from 32.5 mJ/m2 to 23.4 mJ/m2. The diffusion experiments indicated that the mutual diffusion of Cu and Al was inhibited due to the bombardment-induced amorphous layer at aluminum alloy surface, which is beneficial to its application as a structure material in aerospace field.

Submicrometer analyses of the polymer flow modifier effects on metal–polymer direct joining

Polymer modification is a promising approach to improve the joining performance of injection molded direct joining (IMDJ) technology. However, the factors contributing to the improved joining strength of submicron scale surface pattern joints have not been fully elucidated. In this study, we investigated the mechanism for improving the joining performance of polyamide 6 (PA6)/aluminum alloy A5052 joints with Blast + hot water treated metal structure using a flow modifier (OSGOL MF-11). Enhanced mechanical polymer infiltration at the submicron scale was confirmed, and the hydrogen bond generation at the joint interface was characterized. These findings elucidate the reason for the joining performance improvement caused by the flow modifier in the submicron scale.

Study on corrosion protection properties of PANI/ZnO/Zn/Graphene coating on aluminum alloy

A PANI/ZnO/Zn/Graphene composite anti-corrosion coating was uniformly brushed on the surface of 2A12 aluminum alloy. The anti-corrosion performance of the coating in 3.5 % NaCl solution was studied. The potentiodynamic polarization of the 2A12 aluminum alloy coated with the PANI/ZnO/Zn/Graphene composite revealed that the anti-corrosion performance was greatly improved by prolonging the tortuosity of diffusion pathways for corrosive reactants through graphene, when compared to those with PANI/ZnO/Zn coating and 2A12 aluminum alloy. The 3.5 % NaCl solution immersion testing of PANI/ZnO/Zn/Graphene coating showed that the anti-corrosion performance of the coating was weakened by the solute immersion in the early stage of the experiment, while the pores and defects of the coating were gradually filled with corrosion products after immersion for 480 h, resulting in further improvement of corrosion resistance. The EIS results showed that the total impedance of PANI/ZnO/Zn/Graphene coating is greater than PANI/ZnO/Zn coating, and the impedance module value can reach 1.98 × 105 Ωcm2. In general, it is concluded that PANI/ZnO/Zn/Graphene coating have high protective properties.

Research on toolpath optimization of robot-assisted incremental flanging

Robot-assisted incremental flanging (RAIF), a cost-effective and promising forming technology for producing large-size open-edge flanged parts in multi-variety and small batches, is expected to be widely used in aerospace, automotive and other technological industries. As a multi-pass incremental forming technique, the forming quality of the flanged parts is dependent on the movement of the roller controlled by the robot directly. The toolpath of a certain pass is determined by the rotation velocity (to adjust the flanging angle), the revolution velocity (to complete the flanging process of the whole blank sheet) and the matching relationship between two velocities (synchronously or asynchronously). In this paper, the process principle of RAIF technology is illustrated by using the example of shrink flanging firstly, then the effects of asynchronous motion and synchronous motion on the forming quality of a 60° flanged part made of the 5A06 aluminum alloy are compared while the rotation and revolution velocity of the roller are set to 1°/s and 1.8°/s, respectively. Results show that the forming quality is improved significantly that the maximum height of edge waves is decreased from 2.1 mm to 0.19 mm when the roller is set to rotate and revolve synchronously. Based on the above comparison results, the rotation velocity is set as 1°/s, 1.33°/s, 2°/s and 4°/s respectively to further investigate the effect of different toolpaths on the forming quality under synchronous motion conditions. It can be found that the maximum stress gradually increases from 575.4 MPa to 621.6 MPa when the rotation velocity decreases from 4°/s to 1°/s.

Effect of Brazing Temperature on Microstructure, Tensile Strength, and Oxide Film-Breaking Synergy of 5A06 Aluminum Alloy Welded by TG-TLP

5A06 aluminum alloy bar was brazed by temperature gradient transient liquid phase diffusion welding (TG-TLP). The effects of brazing temperature on the microstructure and the tensile strength of the brazing joints were investigated. Three typical brazing filler alloys (1# Al-20Cu-6Si-2Ni, 2# Al-10Cu-10Si-3Mg-1Ga, and 3# Al-6Cu-10Si-2Mg-10Zn) were prepared by smelting, and TG-TLP diffusion bonding was carried out at different brazing temperatures (550 °C~590 °C). The results show that with the increase in brazing temperature, the oxide films at the brazing junction are easier to be broken and dispersed, but the oxidation extent will also increase. The oxidation products enriched were mainly Al2O3 and SiO2 at the brazing junction. There are different optimal brazing temperatures corresponding to the different filler alloys. For 1#, the optimal temperature is 570 °C; for 2# is 580 °C; for 3# is 580 °C. For 1# brazing joints, the maximum tensile strength was 113 MPa, and for 2# was 122.4 MPa. Under the experimental conditions of this study, the maximum tensile strength of the TG-TLP joint is 147.4 MPa of 3# brazing sample (at 580 °C), which has increased by 30% and 20% compared to 1# and 2# respectively. The nickel-rich phase at the interface (of 1# brazing filler) could form a brittle fracture, which was unfavorable for interface bonding. For TG-TLP brazing of 5A06, the filler alloy with high Al:Cu ratio (12:1 wt.%) needs a sufficient temperature gradient to exert the film-breaking effect, while the filler alloy with low Al:Cu ratio (3.6:1 wt.%) needs to accurately control its brazing temperature to avoid excessive oxidation. There are many research gaps in the influence of brazing material composition and brazing temperature on the microstructure and mechanical properties of 5A06 aluminum alloy TG-TLP joints. The research results can provide a theoretical basis for formulating the TG-TLP brazing specification of 5A06 aluminum alloy.

Effects of Electromagnetic Stirring process on Melt Quality of A356 Aluminum Alloy

Effects of Electromagnetic Stirring process on Melt Quality of A356 Aluminum Alloy

Simulation of Fracture Performance of Die-Cast A356 Aluminum Alloy Based on Modified Mohr–Coulomb Model

The fracture performance and damage prediction of die-cast materials are critical to guarantee the safe application of die-cast structural components in lightweight vehicles. Monotonic loading experiments were conducted on different shapes of die-cast aluminum alloy A356 specimens. Finite element simulation models of the A356 monotonic loading experiments were established, and the stress state of the specimens during the loading process was analyzed. The Modified Mohr–Coulomb (MMC) failure model of A356 was fitted by the failure strain under different stress states. Finally, the established MMC failure model was verified by a uniaxial compression experiment and bending experiment. The results show that the MMC failure model can be applied to the prediction of the fracture behavior of A356.

Corrosion and electrochemical behavior of water glass coatings embedded with graphite/titanium oxide on 2A12 aluminum alloy

Corrosion and electrochemical behavior of water glass coatings embedded with graphite/titanium oxide on 2A12 aluminum alloy

Effect of Non-Isothermal Aging on the Mechanical Properties and Corrosion Resistance of 2A12 Aluminum Alloy.

The effect of linear non-isothermal aging and composite non-isothermal aging on the mechanical properties and corrosion resistance of 2A12 aluminum alloy was investigated. Optical microscopy (OM) and scanning electron microscopy (SEM) equipped with energy-dispersive spectroscopy (EDS) were used to study the microstructure and intergranular corrosion morphology, and the precipitates were analyzed using X-ray diffraction (XRD) and transmission electron microscopy (TEM). The results showed that the mechanical properties of 2A12 aluminum alloy were improved by both non-isothermal aging techniques due to the formation of an S' phase and a point S″ phase in the alloy matrix. Linear non-isothermal aging resulted in better mechanical properties than composite non-isothermal aging. However, the corrosion resistance of the 2A12 aluminum alloy was reduced after non-isothermal aging due to the transformation of matrix precipitates and grain boundary precipitates. The corrosion resistance of the samples followed the order: annealed state > linear non-isothermal aging > composite non-isothermal aging.

Fabrication and Thermal Analysis of Hybrid A356 Aluminium Metal Matrix Composites Prepared by Stir Casting Process

Background: Electronic packaging makes use of hybrid A356 aluminium alloy MMCs (matrix metal composites). Enhanced endurance limit, increased production and energy, low maintenance cost, and benefits to the environment, such as reduced noise and airborne pollutants, are among the features that are recommended to be evaluated. Objective: This study aimed to analyze the thermal properties of A356 aluminium alloy with graphite (Gr) and boron carbide (B4C) hybrid metal matrix composites. For this purpose, the A356 hybrid composite was primed by the stir casting process with the addition of 5 wt % and 10 wt % of Gr and B4C reinforcements. In general, A356 hybrid composite material thermal analysis is crucial for electrical equipment. Methods: The liquid-in-filtration method was used to create the hybrid composites, which were then tested thermally for parameters, like melting point, thermal diffusivity, and thermal coefficient of expansion. The thermocouple sensor of a calorimeter was used to examine the disparity in the composites. A thermal analysis tool called TGA was used to visually represent the relationship between a material's weight and temperature. Results: The temperature was found to be 300oC at the 0.411 W/g maximum heat flow rate. Thermal conductivity is the ratio of the temperature difference divided by the area of the heat transfer from one substance to another. The thermal coefficient of expansion illustrates how a material's dimensions and weight change as temperature increases. Conclusion: The proportion of the weight of the hybrid composites was found to fall with a rise in the temperature. The melting point curve of the composites demonstrated a little increase in temperature to be accompanied by a sharp increase in heat flow.

Improving liquation cracks and mechanical properties of 6005A aluminum alloy MIG welded joints via a hybrid milling-friction stir processing tool

Improving liquation cracks and mechanical properties of 6005A aluminum alloy MIG welded joints via a hybrid milling-friction stir processing tool

Effects of Different Materials on Residual Stress Fields of Blade Damaged by Foreign Objects.

Foreign object damage (FOD) is a common mode of failure in high-speed rotating machinery, such as aircraft engines. Therefore, research on FOD is crucial for ensuring blade integrity. FOD induces residual stress on the surface and within the blade, impacting its fatigue strength and service life. Therefore, this paper utilizes material parameters determined by existing experiments, based on the Johnson-Cook (J-C) constitutive model, to numerically simulate impact damage inflicted on specimens, compare and analyze the residual stress distribution of impact pits, and investigate the influence law of foreign object characteristics on blade residual stress. TC4 titanium alloy, 2A12 aluminum alloy, and Q235 steel were selected as foreign objects, and dynamic numerical simulations of the blade impact process were performed to explore the effects of different types of metal foreign objects. This study analyzes the influence of different materials and foreign objects on the residual stress generated by blade impact through numerical simulation, examining the distribution of residual stress in different directions. The findings indicate that the generated residual stress increases with the density of the materials. Additionally, the geometry of the impact notch is also influenced by the density difference between the impact material and the blade. The distribution of the residual stress field reveals that the maximum residual tensile stress in the blade is related to the density ratio, and the residual tensile stress in the axial and circumferential direction is relatively large. It is important to note that a significant residual tensile stress has a detrimental effect on the fatigue strength.

Influence of pre-deformation on microstructure and mechanical properties along thickness direction of 2519A Al alloy thick plate

2519A aluminum (Al) alloy is widely employed in the military industry due to its superior strength and anti-ballistic capabilities. However, its inferior mechanical properties along the thickness direction (normal direction of the alloy, ND direction) limit its further utilization in armored vehicles. To enhance the mechanical properties along ND direction of 2519A Al alloy, the microstructure and mechanical properties in ND direction of the alloy at 7–15 % pre-deformation were investigated. The result indicated that the average aspect ratio of the grains (ARGs) of the alloy gradually increased with the increase of pre-deformation, the degree of fragmentation of the coarsen secondary phase gradually increased, and the size and number density of θ′ phase first increased and then decreased. The strength and elongation of the alloy along ND direction were increased firstly and then decreased with the increase of pre-deformation. Especially, the elongation of the alloy decreases by 55 % at 15 % pre-deformation compared to 11 % pre-deformation. The elongation of the alloy is mainly affected by the ARGs and the spacing of the secondary phase. The best mechanical properties along ND direction were obtained at 11 % pre-deformation with yield strength and tensile strength of 448 MPa and 505 MPa, and elongation of 5.99 %, respectively.

Die Design and Finite Element Analysis of Welding Seams during Aluminum Alloy Tube Extrusion

Hollow tubes are generally manufactured using porthole die extrusion. A finite element software QForm is used to analyze the material flow of aluminum alloy A6061 tubes inside a specially designed porthole die during tube extrusion. High welding pressure and shorter transverse seam length are required for a sound product. Various extrusion conditions and die geometries and dimensions affect the bonding strength of the products. In this paper, the effects of die geometries on the welding pressure are discussed using the Taguchi method. The simulation results show that a higher welding pressure is obtained with a larger porthole radius, a larger welding chamber height, and a larger bearing length, while a larger bridge width increases the welding pressure slightly. For transverse seam lengths, a shorter transverse seam length can be obtained with a smaller porthole radius and a smaller welding chamber height, and a shorter bridge width and bearing length decrease the transverse seam length slightly. The transverse seam region and flow patterns are observed. Tube expanding tests were also conducted. From the expanding test results, it is known that the fracture position did not occur at the welding line and the bonding strength could reach up to 160 MPa.