A356 Aluminum Alloy Research Articles

Investigation on laser-MIG hybrid-welded joint for 5A06 aluminum alloy: effect of the laser heat input on grain size and microhardness

5A06 aluminum alloy plates with a thickness of 6.9 mm are welded by laser-metal inert gas (MIG) hybrid welding. To investigate the influence of laser heat input on grain size and microhardness, optical microscope observation, scanning electron microscope (SEM) and microhardness test are conducted. According to the microstructure distribution characteristics, the weld seam can be divided into arc-affected zone and laser-affected zone. The crystalline morphology from the weld boundary to the weld center is coarse columnar dendrites, finer columnar dendrites and equiaxed dendrites. In addition, the calculation and comparison of the grain size indicate that, the grain size Zl of the coarse columnar dendrites and the fine columnar dendrites in the laser-affected zone has increased, compared to both of the arc-affected zone. Due to the mechanical stirring effect on the upper molten pool, the finer equiaxed dendrites are formed at the center of arc-affected zone. It is worth noting that the grain size inhomogeneity has been significantly improved due to the decrease of laser heat input. The average microhardness of the arc-affected zone in case 1 is significantly lower than that of the other three cases due to the higher laser heat input. The laser line energy of 90 J/mm is more suitable for achieving the excellent microhardness property of laser-MIG hybrid welded joint for the 6.9 mm 5A06 aluminum alloy.

Effect of Sodium Tungstate on the Microstructure and Properties of Micro-Arc Oxidized Coatings Formed on 2A12 Aluminum Alloy

Effect of Sodium Tungstate on the Microstructure and Properties of Micro-Arc Oxidized Coatings Formed on 2A12 Aluminum Alloy

Effect of heat input on macro morphology and porosity of laser-MIG hybrid welded joint for 5A06 aluminum alloy

Effect of heat input on macro morphology and porosity of laser-MIG hybrid welded joint for 5A06 aluminum alloy

Dynamic mechanical behavior and microstructure evolution of 7A52-T6 alloy at elevated temperatures

Dynamic mechanical behavior and microstructural evolution of 7A52-T6 aluminum alloy were investigated at elevated temperatures ranging from 150 to 350°C and strain rates ranging from 2000s−1 to 5000s−1 using a compressive hospitalization pressure bar (SHPB) system. The results show that 7A52 aluminum alloy has obvious temperature sensitivity, but the sensitivity to strain rate is weak. The effects of temperature on the microstructure of 7A52 aluminum alloy are significant, and the dislocation density decreases with the increase of temperature. With the increase of impact temperature, some of the η’ phases are dissolved, and some of them are transformed into η phases. This study in general provides a significant understanding on the relationship between microstructure evolution and mechanical behavior of 7A52-T6 aluminum alloy under dynamic loading and at elevated temperature.

Corrosion Behavior of 3A21 Aluminum Alloy in Water-Ethylene Glycol Coolant under Simulated Engine Working Conditions

Corrosion Behavior of 3A21 Aluminum Alloy in Water-Ethylene Glycol Coolant under Simulated Engine Working Conditions

Numerical Simulation of Casting Deformation and Stress of A356 Aluminum Alloy Thin-Walled Frame Casting

One of the main reasons for the scrap of cast thin-wall frame aluminum alloy castings is deformation and cracking. It is an effective method for solving the problem by predicting the distribution of casting stress, clarifying the size of the deformation and the location of the crack, and taking necessary measures in the process. This paper uses the ProCAST software to simulate the thermal stress coupling of A356 thin-walled frame castings, analyzes the influence of pouring temperature, pouring speed and mold temperature on the stress field distribution of castings, predicts the hot cracking trend and deformation, and optimizes Casting process..

Solidification and Microstructure Simulation of A356 Aluminum Alloy Casting

To obtain an A356 aluminum alloy casting with a uniform structure and no internal shrinkage defects, ProCAST software is used to set different filling and solidification process parameters for an A356 aluminum alloy casting with large wall thickness differences, And multiple simulations are conducted to obtain optimized casting process; then, based on the process, the microstructure of the thickest and thinnest part of the casting are simulated. The size, morphology, and distribution of the simulated microstructure of the thinnest part and the thickest part of the casting are very similar. The simulated microstructure is similar to that of the actual casting. This shows that castings with uniform structure and no internal shrinkage defects can be obtained through the optimized casting process .

Effects of Different Electrolytes on Stress Corrosion Properties of 2A12 Aluminum Alloy

Effects of Different Electrolytes on Stress Corrosion Properties of 2A12 Aluminum Alloy

Effect of Process Parameters on the Hardness of Laser Surface Textured 5A06 Aluminum Alloy

Effect of Process Parameters on the Hardness of Laser Surface Textured 5A06 Aluminum Alloy

Study of corrective abrasive finishing for plane surfaces using magnetic abrasive finishing processes

On the basis of ordinary plane magnetic abrasive finishing, a finishing method is proposed that can improve the flatness of a plane workpiece. In this method, the feed speed is varied during finishing according to the profile curve of the initial surface and the material removal efficiency, to control the effective finishing time in different areas and thereby improve the surface flatness. A small magnetic pole with an end face diameter of 1 mm is designed, and a ferromagnetic plate is placed under the workpiece to improve the uniformity of the magnetic field distribution near the magnetic pole. An experiment on an A5052 aluminum alloy plate workpiece shows that after 60 min of finishing using the proposed method, the extreme difference of the workpiece surface can be reduced from 14.317 μm to 2.18 μm, and the standard deviation can be reduced from 3.322 μm to 0.417 μm. At the same time, according to the measurement results, a similar flatness can be achieved at different positions on the finishing area. Thus, the proposed variable-speed finishing method leads to obvious improvements in flatness.

Spheroidizing Process of 2A12 Aluminum Alloy Grains during Heating up and Semisolid Isothermal Treatment Stages

Spheroidizing Process of 2A12 Aluminum Alloy Grains during Heating up and Semisolid Isothermal Treatment Stages

Development of Fine-Grained Complex A356 Aluminum Alloy through Converging Die Compression

Development of Fine-Grained Complex A356 Aluminum Alloy through Converging Die Compression

Effect of Strain-Rate on Forming Limit Strain of Aluminum Alloy and Mild Steel Sheets Under Strain Path Change

The aim of this study is to show the effect of the strain-rate on the forming limit strain of an aluminum alloy A5052 sheet and a mild steel sheet SPCC. Biaxial stretching test was carried out. The prescribed strain path was linear path or that with directional change in straining. The sheet was pre-strained by uniaxial tension in the latter path. The deformation speed was set to be quasi-static or high speed whose strain-rate was about 300 /s using the dedicated high speed stretching device. The forming limit strain of the A5052 sheet for the linear strain path was larger in the high speed stretching than that under the quasi-static condition. For the case with strain path change the forming limit strain was further large. This may be due to the softening phenomenon which occurs by aging treatment, because the stretching experiment was conducted about two weeks after the pre-straining operation. On the other hand, the forming limit strain of the SPCC under the high speed condition was smaller than that under the quasi-static condition in the linear strain path. This is attributed to the decreased strain hardening exponent when the strain-rate increases. Further, in the equi-biaxial stretching of the pre-strained specimen, large difference of the forming limit strain between the deformation speeds was found. It is concluded that A5052 aluminum alloy sheet has a good adaptability to high speed forming, on the other hand, attention should be paid in increasing the forming speed of SPCC.

Reduction of Residual Quenching Stresses in 2A14 Aluminum Alloy Tapered Cylinder Forgings via a Novel Cold Bulging Process

This study combined finite element method (FEM) simulations and physical experiments to develop a novel cold bulging process, with the aim of studying and mitigating the quenching residual stresses in 2A14 tapered cylinder forgings. The samples underwent cold bulging at different ratios (0–4.0%) to evaluate the residual stress reduction performance (via the hole-drilling strain-gauge method) and the improvements in their mechanical properties. The FEM simulation and experimental results revealed that our proposed cold bulging process reduced the quenching residual stresses by up to 85–87%. The density and uniformity of the precipitated phases increased along with the extent of cold bulging, as confirmed by transmission electron microscope (TEM) observations. Furthermore, compared to the unprocessed samples, the tensile and yield strengths, and elongation of the samples with 3% cold bulging were significantly enhanced (65 MPa, 55 MPa, and 1.7%, respectively).

Dynamic plastic instability of ring-shaped aluminum alloy with different interface behaviors

Unveiling the rate-dependent shear instability mechanism is essential in evaluating the reliability and safety of materials under dynamic loadings. Herein, the strain rate-dependent plastic instability behaviors of 2A12 aluminum alloy with ring-shaped structure and different surface states were systematically investigated and analyzed. The stress softening was displayed in the stress-strain curves as the loading rate increased to a high level. The lubricated interface will induce the prominent shear instability property, followed by the fine-polished interface and coarse-polished interface. It is revealed that the initial interface state between specimen and bars not only influences the onset strain and the yield strength, but also determines the duration of plastic instability stage. The simulation results also indicated that the shear band runs through the two surfaces with different interface friction coefficients. The minor disturbance under quasi-static loading will be accelerated under dynamic loading owing to the instantaneous rising of local temperature, which eventually causes the observably plastic shear instability. The critical state of shear band formation mechanism and the modeling of the stress-softening stage were then theoretically analyzed and discussed. This work on the dynamic instability behavior of ring-shaped aluminum alloy could provide an insight in understanding the formation of adiabatic shear band with different strain rates and interfaces.

A357 Aluminum Alloy Cutting Performance Finite Element Simulation

Aiming at the problem that deformation caused by cutting force in the cutting process of A357 aluminum alloy, a two-dimension cutting simulation was established based on ABAQUS. The curves of chip, cutting force and stress under different cutting conditions were obtained by using Johnson-Cook constitutive equation. The finite element simulation was applied to further analyze the effects of different cutting conditions on chip, cutting force and stress. The simulation results show that the cutting force increases with the increase of cutting speed and increases with cutting depth in the experimental parameters range, it also leads to poor cutting quality. As the cutting length changes, the fluctuation of cutting force also increases and affects the overall quality of the workpiece.

Experimental study of grain structures evolution and constitutive model of isothermal deformed 2A14 aluminum alloy

Softening mechanism and microstructure evolution of 2A14 aluminum alloy were studied via isothermal deformation tests under the temperatures range from 573 K to 773 K and strain rates range from 10 −3 s −1 to 1 s −1 . Microstructures indicated that the grain structure was composed of massive fine sub-grains while only a small quantity of recrystallized grains formed along grain boundaries. The quantity of sub-grains increased with the decrease of deformation temperature or the increase of deformation strain rate, and the correlations between the deformation conditions and the geometrically necessary dislocation (GND) and stored strain energy were illuminated with quantification. The softening mechanism under different conditions was in compliance with the analysis of processing map. The microstructure indicated that the governing dynamic softening mechanism was the dynamic recovery for the temperature below 773 K, and dynamic recrystallization played the dominant role in the softening mechanism at low strain rates for the temperature at 773 K. The Arrhenius constitutive model and physical-based constitutive model considering lattice diffusion have been established, and both two models can well predict the flow stress and GND density of 2A14 aluminum alloy.

Properties evaluation of A356 and A319 Aluminum alloys under different casting conditions

The property evaluation of Aluminum alloys a quite a challenging task and is an essential one to achieve improved mechanical and metallurgical properties during casting. This paves the way for the present research, in which the casting of commercial A356 and A319 Al alloys have been performed under stationary and vibratory state. The vibrational recurrence has been varied between 0 Hz and 400 Hz with a constant amplitude of 15 μm during casting. Thereafter, the quality of both casted materials has been evaluated by measuring their yield strength, ultimate tensile strength and % elongation. Experimental results revealed that the higher intensity of oscillation improves mechanical properties with the reduced grain size of α-Al. It has been also observed that the fraction of nucleation sites is increased due to the vibration.

Grain-Refinement and Mechanical Properties Optimisation of A356 Casting Al by Ultrasonic-Assisted Friction Stir Processing

Conventional friction stir processing (FSP) and ultrasonic-assisted friction stir processing (Ua-FSP) were applied to modify the microstructure and enhance the mechanical properties of as-cast A356 aluminium alloy. A series of experiments with different processing parameters were conducted in these two processing methods. Forming characteristics, grain-refinement, and mechanical properties in FSP and Ua-FSP were compared to determine the effect of ultrasound. The results revealed that ultrasound improved the grain-refinement level in both grain size and grain uniformity. Further, the effect of ultrasound on microstructural evolution was more significant with relatively high processing heat-input. Ultrasonic vibration also positively affected the hardness, tensile strength, and elongation.

Microstructures and Properties of V-Modified A380 Aluminum Alloy Produced by High Pressure Rheo-Squeeze Casting with Compound Field Treatment

The melt of V-modified A380 alloy aluminum alloy was treated by compound field of ultrasonic vibration (UV) and electromagnetic stirring (ES) around liquidus temperatures. Then the high pressure rheo-squeeze casting (HPRSC) process was used to produce an ingot with the alloy melt obtained. The results indicate that the polygonal Si2V phase is precipitated after adding vanadium to the alloy. With the increasing of V content from 0 to 1.05%, the average length and volume fraction of β-Al5FeSi phase is decreased to 30 μm and 1.44%, respectively. The refinement effects of UV, ES, and UV-ES compound field on the microstructure of the gravity casting alloy are as follows: UV-ES > UV > ES. When the pressure is increased from 0 to 400 MPa, the size of primary α-Al is decreased gradually, the morphology of β-Al5FeSi phase is changed from an acicular to a fine fibrous-like one, and the polygonal Si2V phase is refined to fine particle with an average grain diameter of about 8 μm. The ultimate tensile strength (UTS), yield strength (YS), and elongation of the alloy without V are lower than that of the alloy with 0.7% V under the same pressure. When the pressure is 400 MPa, the UTS, YS, and elongation of T6 heat-treated HPRSC alloy with 0.7% V are 301 MPa, 182 MPa, and 3.3%, respectively. With the decrease in the length of β-Al5FeSi phase, the quality index of the HPRSC alloy is increased.