Aluminum Alloy Plates Research Articles

Investigation on dynamic deformation behavior of 7A75 aluminum alloy over wide strain rates and constitutive model establishment

The aluminum alloy components on automobile often experience high strain rate deformation during accidents. The dynamic deformation behavior and constitutive model are crucial for analysis of vehicle body collisions and failures. In this work, the 7A75 aluminum alloy plate was heat treated according to standard body manufacturing procedures. Quasi-static and dynamic tensile experiments were conducted on the aged 7A75 alloy in a wide strain rate range from 0.001 s−1 to 500 s−1. The dynamic deformation behavior of the alloy was revealed, and the constitutive models were established. It was found that the 7A75 alloy has strong strain rate sensitivity, and its mechanical properties can be significantly improved with the increase of strain rate. As the strain rate increases, the necking instability strain shifts towards higher values, which leads to a larger uniform deformation ability and fracture elongation. This behavior results in a better energy absorption capacity at high strain rates, thus providing a good collision protection property. The constitutive models, including Johnson-Cook (J-C) and Zerilli-Armstrong (Z-A) types, were established and compared. Note that the conventional J-C and Z-A models exhibit severe prediction distortion. Therefore, a modified J-C model incorporating strain rate compensation was introduced, which decrease the errors by 149% and achieves accurate predictions of both dynamic and static deformation behaviors over a wide range of strain rates.

MFC-PINN: A method to improve the accuracy and robustness of acoustic emission source planar localization

Aluminum alloys used in aerospace can be monitored for cracks using acoustic emission (AE) technology, ensuring structural safety. However, data-driven deep learning models for AE source planar localization of defects in aerospace aluminum alloy plates suffer from poor prediction ability for unknown data and require a large amount of data. Additionally, physical models are heavily influenced by noise. To address these challenges, this paper proposes a multimodal fusion convolutional physical information neural network (MFC-PINN) model that considers numerical-type and image features, improving the model’s comprehensive performance and generalization ability. The model also uses physical equations as constraints, reducing the dependence on large amounts of data and improving the prediction ability for unknown data. MFC-PINN performs well on datasets in complete, incomplete, and noisy conditions, especially in predicting unknown data in high-noise conditions. The study ensures the reproducibility of experiments and the validity of modules through sub-sampling cross-validation and ablation study.

Investigation of the Additional Powder Effect on the Strength of Joined Aluminum Alloy Plates in Friction Stir Welding Using the Topsis-Game Theory Model

Friction stir welding (FSW) is a process that can join many materials by causing minimal internal stress without the need for a direct electric current, contrary to traditional welding methods. The effects of SiC and Al2O3 reinforcing powders on the joining of AA6061-T6 and AA7075-T6 plates, which are difficult to join with conventional welding methods by FSW, are investigated in this study. The metallurgical properties of the combined samples are examined in terms of strength characteristics to investigate the effects of the reinforcement powder. In addition, elemental analysis is carried out for the mixing behavior of the powders. Finally, we used the TOPSIS method to select the most appropriate powder types to improve welding quality. Furthermore, a game theory application is presented to determine which powder type is suitable considering the joined aluminum plate’s strength expectations.

Study of Anisotropic Behavior in Sheet Metal Forming.

Since sheet metal exhibits significant anisotropy in processing and forming, which has a significant impact on its performance during processing, forming, and use, we explore the anisotropic behavior of materials in the forming process of sheet metal. The ability of the Yld2000-2d criterion to describe anisotropic behavior is analyzed, and its accuracy for characterization of the anisotropic behavior of metal plates is improved, based on which anisotropic behavior is predicted in three-dimensional space. Theoretical and experimental results on the anisotropy of sheet metal are compared, and two materials, 5754O aluminum alloy and DP980 steel plate, are tested and analyzed, and the anisotropic behaviors, such as three-point bending and cylindrical deep-drawing, are well predicted.

Dislocation configuration on the fatigue fracture behavior of a solution-treated 7005 aluminum alloy plate

In the present study, the dislocation configuration in 7005 aluminum alloy plate stored at room temperature for 96 h following solution quenching was changed by pre-stretch at room temperature for various deformations, to reveal its influence on the tensile properties, especially fatigue life and fatigue fracture characteristics of alloy plate. The results show that with the increase in pre-strain deformation to 16%, the thickness of the thin strip grains decreases from 7.70 to 6.31 μm, the dislocation density in the matrix of the plates gradually increases, especially the changing law of dislocation distribution inside a grain and among grains is “nonuniform-uniform-nonuniform”. The plate exhibits an obvious hardening effect, the strength and hardness increase, but the elongation decreases monotonically. However, the fatigue performance of the alloy plates under the conditions of a maximum stress of 180 MPa and a stress ratio of R = 0 is improved by 3∼16% pre-strain deformation, the alloy plates underwent 12% pre-strain deformation have the longest fatigue life that is (1.10 ± 0.16) × 106 cycles, due to the higher dislocation density and the uniform dislocation distribution inside a grain and among grains, which is 169% longer than that of the alloy plates without pre-strain. The results provide an important theoretical basis and some experimental data for improving the fatigue performance of 7005 aluminum alloy plate used in high-speed railway and aviation industries.

Computational studies on hyper velocity impact of spherical projectiles on whipple shield with hybrid Newtonian fluid-filled core

Satellites orbiting in low Earth orbits face potential threats from space debris. To mitigate this risk, a Whipple shield is employed to shield satellites from potential hyper-velocity impacts caused by debris of varying sizes and speeds. Typically, these protective systems use spaced aluminum plates affixed to the satellite’s exterior. Ongoing advancements in this field include exploring alternative materials such as foam, cellular cores, and ceramics to replace aluminum in plate construction. This study introduces a hybrid configuration featuring a Newtonian fluid-filled, high-performance fiber-reinforced polymer core positioned between the aluminum alloy plates, aiming to enhance the Whipple shield’s overall shielding effectiveness. The analysis of hyper-velocity impacts was performed numerically using ANSYS Autodyn® computational software. Spherical projectiles made of stainless steel, ranging in diameter from 2 mm to 4 mm, were selected for direct collision simulations with the Whipple shield at velocities of 5 km/s, 7 km/s, and 9 km/s. The front and rear plates, each 1 mm thick, were constructed using AA6061-T6. The core, measuring 10 mm in thickness, incorporated multiple plies of Kevlar fiber-reinforced polymer (KFRP), with interplay spacing between successive KFRP plies filled with a Newtonian fluid (water). It was observed that spherical projectiles made of stainless steel with diameter ≥ 3 mm penetrated the rear plate of the whipple shield at the lower velocity of 5 km/s, with enhanced damage as the initial velocity of the projectile was increased from 5 km/s to 9 km/s. The debris cloud was found to scatter the fluid droplets, rupture the successive KFRP layers, with the initial kinetic energy playing a significant role in the severity of the damage.

Characterizing boiling behaviors in water/ethanol binary droplet impact on a heated plate

This work experimentally investigates the transition boiling behaviors of water/ethanol binary droplets impact on a heated smooth aluminum alloy plate with a high-speed imaging system, forming a more finely defined impact behavior regime map. The dynamic Leidenfrost point temperature exhibits a non-monotonic variation trend with ethanol fraction. Binary droplets exhibit two characteristic boiling behaviors at specific temperatures (Ts) and droplet compositions (Φe), including corona boiling and prompt boiling, distinguished by the elevation of a crown-shaped thick liquid lamella and the prompt generation of numerous secondary droplets from the contact line, respectively. Both boiling behaviors are featured with the violent breakup of parent droplet into about 10 or more fragment droplets (secondary droplets with D ≥ 0.3 mm) and the short residence times on the wall, while exhibiting different splash angle distributions of satellite droplets (secondary droplets with D < 0.3 mm). Characteristic parameter analysis of the two boiling behaviors is conducted to provide qualitative mechanistic explanations. Corona boiling occurs at Φe = 25% & 50% with a lower temperature range (Ts ≤ 200 ℃), the liftoff of the liquid layer is attributed to the combined effect of decelerated wetting speed caused by evaporation and the vapor-induced lift. Prompt boiling occurs at Φe = 25% & 50% with Ts ≥ 220 °C and Φe = 75% with Ts < 200 °C, the intensity of the bubble cloud determines whether the central part of the droplet forms a jet or a liquid bulk filled with microbubbles. This work will provide some new insights into the boiling behaviors and the regulation of secondary atomization of binary solution droplets impact studies.

Dynamic failure behavior of 7B52 laminated aluminum alloy subjected to deformable projectile impact

The ballistic response and failure mechanisms during the impact of a 304 steel-core projectile on a 7B52 laminated aluminum alloy plate were investigated. The impact resistance of the target plate was obtained through ballistic testing, and a detailed analysis of the fracture mechanism was conducted using microstructure characterization. Furthermore, an enhanced Gurson-Tvergaard-Needleman (GTN) model was employed to simulate the ballistic impact process, as well as the initiation and propagation of fractures. The results revealed significant deformation following the impact of the 304 steel-core projectile on the 7B52-T6 laminated plate. The target plate exhibited spalling failure, shear failure, and ductile hole expansion, with spalling failure being caused by intergranular fracture mechanisms. In the high stress triaxiality regions of the 7A62 alloy, intergranular cracks are prone to occur, and shear stress influences the expansion of the cracks. Fragments following layer cracking adhere to the 7A52 layer, thereby increasing the ballistic resistance surface area. The 7A52 layer on the rear side of the target plate effectively absorbed the projectile's energy through bending and stretching deformation, thereby offering enhanced protection. Furthermore, the spall resistance of the 7B52 laminated plate eliminate secondary damage caused by spall fragments.

Numerical study on enhancing shear performance of RC beams with external aluminum alloy plates bonded using steel anchors

This article compromises a three-dimensional numerical study employing the Abaqus program to investigate the behavior of reinforced concrete (RC) beams externally strengthened in shear using aluminum alloy (AA) plates bonded utilizing steel anchors. Based on previous experimental tests, a numerical validation study was conducted in two parts. The first part modeled the interaction behavior using different bonding methods between steel plates and the surface of the RC beams, whether utilizing epoxy adhesive only, steel anchors only, or a dual system between them. The second part modeled the performance of shear-defected RC beams that externally strengthened by the AA plates using epoxy adhesive. To take into account debonding collapse due to epoxy adhesive bonding, the interaction between the AA plates and beam surface was simulated with a cohesive-damage interaction. Comparing the numerical results with previous experimental studies shows the success of the numerical model in simulating the performance of different bonding methods, as well as the behavior of the RC beams defected in shear and strengthened by the AA plates, which qualified it to study some additional variables. From the study it was found that by utilizing only epoxy adhesive, the strengthening technique using the AA plate over the entire shear span zone (AASP method) was capable of increasing the ultimate capacity of the defected beam by 104%, which represents 77% of the load of the non-defected beam. It was also demonstrated that the AA plates were susceptible to collapse by the out-of-plane buckling when bonded using the steel anchors only. By utilizing a dual system for bonding the AA plates consisting of epoxy adhesive and steel anchors, the AASP method was capable of enhancing the ultimate capacity of the defected beam by 164% and changing its failure pattern to the preferred ductile bending pattern.

Simulations and experimental study on imaging of thick defect in reusable thermal protective system using microwave NDT

Reusable thermal protective system (TPS) plays a key role for protecting space vehicles against the aerothermal heating. Thus the characterization of TPS performance becomes an important issue in their production, processing and applications. This paper demonstrates the detection and imaging of inner disbond and thick defect, which considerably compromises the performance of TPS materials within a two-layer TPS configuration (a special designed thick heat insulation tile backed by an aluminum alloy plate). The methodology employed for this investigation is a near-field microwave non-destructive testing (NDT), encompassing both simulations and experimental study. A 3D microwave model for the two-layer TPS structure containing the specified defects was established, and the magnitude and phase of the waveguide input impedance (i.e. S11 parameters) for each node within the X-band (8.2 ∼ 12.4 GHz) frequency range were obtained in the work. The simulation results reveal distinct featured amplitude and phase images of defects at various frequencies. Correlation processing algorithms were employed to make the images dimensionally reduction and featured enhancement. Finally, the results were verified by experimental measurements using an open-ended rectangular waveguide. Interestingly, the disbond defect between the two layers could be clearly identified by the phase information after correlation processing algorithms. The proposed method appears to offer a contactless, intuitive, and effective approach for characterizing defects within TPS materials.

Microstructure and mechanical properties of laser-MIG hybrid multi-layer welded joints for 20-mm thick aluminum alloy plates

Microstructure and mechanical properties of laser-MIG hybrid multi-layer welded joints for 20-mm thick aluminum alloy plates

Hydrophilic properties of the aluminum alloy induced by femtosecond laser structuring

This study explored the changes in wetting property and surface morphology in aluminum alloy plates due to femtosecond laser structuring. The laser scanning produced a hierarchical micro- and nano-scale structure consisting of microchannels decorated by irregular shape particles. The surface morphology was controlled by laser power and scanning line density. The surface wettability gradually changed from hydrophilic to hydrophobic one due to various chemical reactions for low laser power and scanning line density. However, femtosecond laser structuring with appropriate laser power and scanning line density was demonstrated to maintain strong and stable hydrophilic properties of aluminum alloy surfaces.

Thermal and mechanical characterisation of friction stir welded dissimilar aluminium alloys

The influence of thermal properties on the friction stir welded (FSW) dissimilar aluminium alloys at different tool rotational speeds and tool pin profiles was studied. AA 5083 H111 and AA 6082 T6 of 6 mm aluminium alloy plates are welded by varying the process parameters. The influence of heat generation and heat transfer in the joint efficiency of the weldments are characterised. Heat flow and heat flux for various tool rotation speeds generated between the tool shoulder and workpiece are calculated and analysed. The rate of heat distribution during welding is evaluated by calculating the thermal diffusivity of AA5083 H111 and AA6082 T6. Microhardness test helps to comprehend the influence of the parameters over the mechanical property of the weldments. The results revealed that the thermal characterisation clearly illustrates that an increase in tool rotation speed directly amplifies the heat flow and heat flux in weldments. However, AA 5083 H111 and AA 6082 T6 for varying temperature and reveals that 580°C possessed higher thermal conductivity for AA 6082 T6 (260 W/m°C) and AA 5083 5083 H111 (160 W/m°C), thermal conductivity for AA 6082 T6 (1260 J/Kg°C) and AA 50835083 H111 (1225 J/Kg°C) and thermal Diffusivity was 5.2029 × 10−5 (m2/s) for AA 5083 H111 and 7.61819 × 10−5 (m2/s) for AA 6082 T6.

TOFD detection of shallow subsurface defects in aluminum alloy thin plates by half-skip mode-converted wave

Aluminum alloy is widely applied to the aerospace field. However, the inspection of thin plates using Time-of-Flight Diffraction (TOFD) technique is restricted by the near-surface dead zone because of the coupling between diffracted longitudinal wave and lateral wave. The half-skip mode-converted wave is introduced to decrease dead zone and detect defects in aluminum alloy thin plates by increasing ray path and propagation time. The quantitative correlation for the diffracted shear wave from longitudinal back-wall wave is deduced in combination with the acoustic path, realizing the accurate location of shallow subsurface defects. Simulated and experimental results indicate that the dead zone is decreased by 38% by the half-skip mode-converted wave, and the location errors are within 5% for the aluminum alloy plate with a thickness of 7.0 mm. Compared to other alternative TOFD techniques, half-skip mode-converted wave has better response amplitude and positioning accuracy, demonstrating strong applicability in TOFD inspection of thin plates.

Effects of impact location on the dynamic response of repeatedly impacted aluminum alloy plates

This paper presents a numerical investigation of the effects of impact location on the dynamic response of aluminum alloy plates to repeated mass impacts. The numerical model was developed and validated against relevant test data. In the simulation, the strain hardening was adopted using existing published equations. A parametric study was performed by considering different impact locations while keeping impact energy (mass and velocity) identically for each impact. The results showed that the plate was deformed progressively, and the resulting impact forces increased, while its duration decreased when the plate was impacted repeatedly. While changing in impact location after each impact remarkably affected the response of impacted plates, i.e., less damage was observed. The study results are expected to be helpful for the design of marine structures including fishing boats subjected to repeated impacts arising from collisions or dropped objects. Keywords: Numerical simulation, aluminum alloy plate, repeated impacts, residual deformation.

Micro-adhesive wear and microhardness behavior of friction stir welded 2524-T3 aluminium alloy

Friction Stir Welding (FSW) emerges as a compelling solid-state welding technique for aluminium alloy components used as aircfrat materials. Despite being a solid-state process and mitigating numerous solidification challenges, it retains its thermomechanical nature, affecting the material's microstructure and, consequently, its mechanical properties. This concise communication sought to assess the impact of the FSW process on the micro-adhesive wear and microhardness properties of the 2524-T3 alloy. The results showed that the FSW process was executed successfully on 2524-T3 aluminium alloy plates as well as the great influence of intermetallic particles on hardness and micro-adhesive wear.

Analysis on Evaporation Characteristics of Palm Oil Biodiesel using a HSDT Method

The purpose of this study is to investigate the evaporation characteristics of different types of fuels by applying the hot surface deposition test (HSDT). Generally, HSDT method is a simplified method to simulate fuel deposition in diesel engines. In this study, diesel fuel (DF) and palm oil biodiesel with different blend ratios (B10-B50) were used to evaluate the fuel droplet evaporation behavior on a heated aluminum alloy plate surface. Single fuel droplet was impinged on the heated plate at various surface temperatures (Ts). Important data from the evaporation characteristics was the maximum evaporation point (MEP), which is the temperature point where a droplet evaporates in the shortest lifetime (tlife). MEP is referred to identify the surface temperature range in which fewer deposits will be produced by the test fuel. Furthermore, MEP is also used to determine the appropriate droplet interval to create wet and dry conditions in the fuel deposition test. The obtained MEP was 360°C (DF), 365°C (B10, B50), 375°C (B20, B40), and 385°C (B30).

Laser metal deposition of AlSi10Mg for aeroengine casing repair: Microhardness, wear and corrosion behavior

Laser metal deposition (LMD) based remanufacturing leverage of the flexibility of additive manufacturing and provides an attractive and cost-effective means for repairing or remanufacturing high value engineering components. In this work, AlSi10Mg alloy was cladding on the surface of cast aluminum alloy plate for aeroengine casing, AlSi10Mg repair layer with porosity of only 0.19% was obtained when the laser power P = 1800 W, powder feeding rate f = 1.6 g/min, scanning speed v = 8 mm/s. Microhardness, wear and corrosion resistance tests were used to evaluate the repair feasibility of the AlSi10Mg repair layer. The results indicated that the microhardness of the AlSi10Mg repair layer was more than 80% of aeroengine casing, the ultimate tensile strengthen and elongation of the repair layer are 215 ± 12 MPa and 5.79 ± 0.1%, respectively, while the tensile strength of the substrate is 225 MPa. The mechanical properties of the repair layer basically meet the repair requirements of the aeroengine casing. The coefficient of friction (COF) and wear rate ω of the repair layer were comparable to the level of aeroengine casing. Moreover, the corrosion behavior test results showed that the corrosion potential of as-build AlSi10Mg repair layer was −0.90 V, which was higher than that of substrate (−0.92 V), indicating that the AlSi10Mg repair layer has better corrosion resistance than substrate, and the Al9Si phase is the important factor that effecting the corrosion performance of AlSi10Mg repair layer. This work can provide reference for the potential application of the LMD technology in the field of high-quality repair of aeroengine casing.

Effect of welding mode on selected properties of additively manufactured AA5087 aluminium alloy parts

Wire and arc additive manufacturing (WAAM) is a popular direct energy deposition (DED) method for producing large-scale metallic components. The main advantages of the technique are a high deposition rate and low cost. Furthermore, the utilization of the WAAM is prevalent in the aerospace industry. The AA5087 aluminium alloy with 4.5 wt.% of magnesium has been investigated because of its excellent properties. The present research deals with the study of thermal cycles and fields developed in the alloy during additive manufacturing with two different Cold metal transfer (CMT) modes, namely conventional (CMT) and cycle-step (CMT-CS). The welding system was equipped with a Fronius TransPulse Synergic 3200 CMT power source, a Fanuc Arc Mate 1000iC 6-axes robot with an R 30iA control unit, a welding torch, and a 1-axis positioner. The AA5087 aluminium alloy welding wire with a diameter of 1.2 mm was deposited onto the AA5083 aluminium alloy plate with dimensions of 70 mm x 200 mm x 3 mm during the experiment. The thermal cycles were documented using an Ahlborn Almemo 5690-2 measuring station equipped with K-type thermocouples. The thermal fields were monitored with a FLIR E95 thermography camera. The results showed the evident influence of arc mode on the temperatures developed in manufactured aluminium alloy parts during the process of WAAM.

A combination of properties of welded joints made in 1565chM aluminium alloy plates

A combination of properties of welded joints made in 1565chM aluminium alloy plates