A356 Aluminum Alloy Research Articles

Research on wrinkling in rubber forming of the convex flange with 2A12 aluminum alloy sheet

Research on wrinkling in rubber forming of the convex flange with 2A12 aluminum alloy sheet

Investigating the mechanical properties of A356 (Sr doped) using mechanical stirring

The Aluminium alloy A356 alloy is primarilyusually used for automobile and aerospace components owing to its high strength to weight ratio, and its relatively good corrosion resistance. The effectiveness of the economical stir casting method was investigated by adding the strontium (Sr) metal uniformly to aid in the modification of the alloy’s eutectic morphology for improved mechanical properties. The addition of ̴0.63 wt% Sr addition resulted into grain refinement which improved the mechanical properties whereby the ultimate tensile strength (UTS) increased from 200 MPa to 250 MPa, Yield strength increased from 85 MPa to 100 MPa and the microhardness was increased from 74.94 Hv to 87.10 Hv.

Investigation of microstructure, mechanical properties, and wear behavior of A380 aluminum nanocomposite reinforced with SiC nanoparticles produced by powder metallurgy

In this study, the effect of adding SiC nanoparticles and heat treatment on the mechanical properties and wear behavior of A380 aluminum alloy was investigated. Al A380 aluminum powder and SiC nanoparticles with values (0, 0.5, 1, and 2% wt%) were milled in a planetary ball mill with balls of different diameters (4–10 mm) in an argon atmosphere for 10 hours. After the milling process, a hot press (510°C) was used to produce the samples. The microstructure, mechanical properties, and wear behavior of the samples were examined using an optical and scanning electron microscope (SEM), micro Vickers hardness test, and pin-on-disk test, respectively. To investigate the effect of heat treatment, the samples were placed in a furnace at 530°C for 3 hours, then the sample was quenched with boiling water, then placed in a furnace at 175°C for 16 hours, and then by micro Vickers hardness device, the hardness of the samples were measured. The best hardness of the samples was related to aluminum alloy with 0.5 wt% of SiC nanoparticles. Also, after heat treatment, the hardness of the samples increased significantly. Al A380 2wt% SiC nanocomposite sample represents the greatest wear properties when compared with the other experiment samples.

Research on hydroforming of 5A06 aluminum alloy semi-ellipsoid shell with differential thickness

For the purpose of eliminating the annular welding seams in welding structures with differential thickness, a hydroforming method using a circular 5A06 aluminum alloy plate with a radial differential thickness in coupling with a flexible polyurethane auxiliary plate was proposed to form an integrated semi-ellipsoid shell. The circular 5A06 aluminum alloy plate had a smaller in the middle and a larger thickness in the periphery. In the forming process of such aluminum alloy plates, concentrated deformation and fracture might have occurred in the thin zone. According to the size of the target specimen, the testing plates with two types of thickness ratios were obtained by mechanical processing. Furthermore, the thickness and strain of the drawn specimens with different thickness ratios were analyzed under different hydraulic pressure by means of deep drawing experiments. Compared to the conventional deep drawing, the formability of 5A06 aluminum alloy plates with differential thickness could be effectively improved by hydroforming. The integrated semi-ellipsoid shells with the thickness ratios of 2/3 and 1/2 were obtained under the hydraulic pressure of 10 MPa with maximum thinning ratios of 8.5% and 10.9%, respectively. In a word, the increase in hydraulic pressure could effectively reduce the maximum thinning ratio in the thin zone, and improve the thickness distribution uniformity.

A study on Fe removal in aluminum scrap to make A356 aluminum alloy

The domestic demand for A356 raw material is increasing, so the price is often very high. The goal of this study is to sort the scrap, then reduce Fe from about 1 % to less than 0.15 %. The reducing Fe by Na2B4O7 to refine aluminum scrap has been conducted under laboratory conditions. The results showed that the iron reduction rate increased with the addition of Na2B4O7 and the heat retention time and obeyed the first-order exponential law. The addition of flux containing Na2B4O7 can reduce the iron content from 1% to less than 0.1% and reach an optimal rate of 77 %. The XRD, SEM and EDS analyzes of aluminum samples described the microstructure and morphology of the obtained aluminum products. This product is a good raw material for making Al alloy group A356.

Differential flow velocities control method for push-bending of the thin-walled tube with a 0.9D bending radius by differential lubrication

The smaller the relative bending radius of the bent tube, the more difficult the tube blank is to be bent. In this paper, the push-bending process for the aluminum tube with a relative bending radius of 0.9D was analyzed through simulation. There was tangential tensile stress concentration occurring at the front endpoint of tube intrados, which increased the risk of cracking. That is because the bending tube’s extrados moves less angular distance than its intrados by the uniform lubrication method, causing excessive deformation of the cross-section. Therefore, a differential lubrication method using the lubricant with a larger friction coefficient at intrados and the lubricant with a smaller friction coefficient at extrados was proposed to increase the angular velocity of the tube’s extrados. It was found that the differential lubrication method helped avoid excessive thinning at the front endpoint of tube intrados through simulations. Furthermore, push-bending experiments of 5A02 aluminum alloy with a relative bending radius of 0.9D were carried out to investigate this effect. The experimental results showed that the differential lubrication method effectively avoided cracking, which agreed with the simulation results.

Pengaruh variasi laju aliran dan preheating cetakan pada investment casting terhadap sifat fisis dan mekanis prototipe aluminium cylinder head engine

This research studies the effect of flow rate on the pouring of molten metal into the mould so that the flow rate into the mould can be controlled. Furthermore, this research studies the effect of mould preheating so that the temperature inside the cavity can be maintained, especially for narrow holes. The process starts with making the engine cylinder head pattern and gating system using a three-dimensional printer with polylactic acid resin. The mould pattern and gating system are combined and coated with a layer of cement plaster, silica sand and kaolin. After the coating is dry, the mould is heated until the mould pattern evaporates and there is no residue. The casting process was carried out at pre-heating moulds of 300 0C and 350 0C and a pouring temperature of 800 0C with pouring speeds of 20, 30, and 40 rpm. The final stage of the research is manufacturing test objects and testing mechanical properties. The results showed that the higher the pouring speed, the less perfect the casting results, especially in the cylinder head fins. The best casting results occurred in the pre-heat condition of the 300 0C mould with a pouring speed of 20 rpm, with a Maximum Tensile Strength of 105 N/mm2, Hardness 53 hardness Brinell test (HBN), Density and Porosity of 2.43 gr/cm3. The material used in this study refers to the reference is A356 Aluminum Alloy.

Influence of Stress Field and Temperature Field on Residual Stress of 2A14 Aluminum Alloy Based on In Situ SAXS Method.

In this paper, based on in situ synchrotron radiation SAXS technology, the effects of stress field, temperature field and thermo-mechanical coupling conditions on the evolution of residual stress are discussed, respectively. The results show that the continuous increase of the external load led to the increase of the residual stress perpendicular to the tensile direction of the 2A14 aluminum alloy, and when the external load closed to the yield strength, the change of the residual stress was no longer significant. Under the action of temperature, the residual stress of 2A14 aluminum alloy reduced after the process of heating-holding-cooling. Under the action of thermo-mechanical coupling, the recovery effect of aluminum alloy was triggered, the energy storage of deformation was released, the lattice strain was reduced and the residual stress introduced by external load was reduced.

Microstructure evolution in semi-solid A356 aluminium alloy treated by ICTE process

ABSTRACT The effects of parameters of a novel internal cooling thermal equilibrium (ICTE) process on microstructure evolution in semi-solid A356 aluminium alloys were investigated. The results indicated that a low predetermined temperature (T P), a higher mechanical stirring intensity for the thermal equilibrium body (TEB) and a reduced melt mass contributed to obtaining fine grained semi-solid structures. The cooling effect of TEB combined with dendritic remelting fractures of solidified shells formed on surface of TEB at room temperature promoted massive nucleation in alloy melt and contributed to obtaining numerous fine primary solid phases. The ICTE process, which regulated stirring time of TEB, obtained numerous spherical grains and simplified the operational process.

Effect of the Addition of Steel Fibers on the Bonding Interface and Tensile Properties of Explosion-Welded 2A12 Aluminum Alloy and SS-304 Steel

First of all, the explosion-welding method was adopted to prepare steel fiber-reinforced steel-aluminum composite plates. Secondly, the smooth particle hydrodynamic (SPH) method was used to investigate the effect of introducing steel fibers to a vortex region created at the bonding interface of the steel-aluminum composite plate. Thirdly, the following conclusions were drawn through an analysis of the vortex region with the assistance of scanning electron microscopy and energy-dispersive X-ray spectroscopy. A brittle intermetallic compound FeAl was produced in the vortex region in an environment characterized by high temperature, high pressure, and high strain rate, resulting in cracks, holes and pores. In addition, the hardness of the vortex area was less than the estimated value, which is mainly because the main element in the vortex area was 2A12 aluminum with low hardness, and there were cracks, holes, pores and other defects that caused hardness reduction. Although the addition of steel fibers caused defects at the bond interface, the addition of steel fibers was effective in improving the tensile resistance performance of steel-aluminum composite panels to a certain extent. In addition, the larger the fiber diameter, the more significant the increase in tensile resistance.

Creep Behavior of A356 Aluminum Alloy Reinforced with Multi-Walled Carbon Nanotubes by Stir Casting.

Lightweight aluminum alloy components are often used to manufacture a variety of engineering components in many industries. In recent years, researchers have studied the effect of improving the mechanical properties of metal alloys by incorporating nano-carbon into its structure. In this study, the effect of the addition of 0.2, 0.5, and 1 wt% of multi-walled carbon nanotubes (MWCNTs) on the stress-strain behavior and creep phenomenon of an A356 aluminum alloy were studied. The effect of nickel coating on 0.2 wt% MWCNTs was also investigated. Samples were prepared using the stir-casting method. The results revealed that the grain size became finer when MWCNT nano-particulates were introduced. Although the MWCNTs were distributed homogeneously in the A356 matrix, as confirmed by FESEM analysis, there were some agglomerations observed in a specific area with dimensions smaller than 100 nm. Nevertheless, the addition of MWCNTs was found to be beneficial in enhancing the hardness of alloys containing 0.2 wt%, 0.2 wt% nickel-coated, 0.5 wt%, and 1 wt% MWCNTs by 9%, 24%, 32%, and 15%, respectively, as compared with the unreinforced A345 matrix. It was also found that the 0.5 wt% MWCNT-A356 matrix exhibited an improvement in the creep lifetime by more than two orders of magnitude.

The Effect of Interrupted Homogenization on β-Al5FeSi → α-Alx (Fe and Mn) Si Transformation in the A6063 Aluminum Alloy

The aluminum alloys corresponding to the 6000 series are mainly manufactured by mechanical forming processes. Their properties are enhanced by the homogeneous distribution of intermetallic phases such as β-Al5FeSi or α-Alx (Fe, Mn) Si. By thermal homogenization treatment, the intermetallic compound β-Al5FeSi changes its morphology from a needle type with a monoclinic structure to an acicular form known as α-Al12(Fe, Mn)3Si with an fcc structure. In the present study, samples of the 6063 alloy were subjected to different temperatures of homogenization (798, 823, and 848 K) and treatment times from 0 to 660 min (in intervals of 30 min) to evaluate their effects on the microstructures and morphologies of the intermetallic phases. For the kinetic study, the microstructures of the β and α intermetallic phases were quantified using the Image-Pro software. The results indicate that as the temperature and homogenization time increase, the percentage of phase α also increments. The results of the kinetic analysis revealed that the β → α transformation is controlled by two stages; the first corresponds to the diffusion of Mn atoms from the matrix to the interface of reaction for the formation of the intermetallic phases, while the second corresponds to the nucleation and growth of the iron- and manganese-rich intermetallic phases.

Effect of CMT Welding Heat Input on Microstructure and Properties of 2A14 Aluminum Alloy Joint

Cold metal transfer (CMT) welding is an attractive welding technology for thin sheet aluminum alloys because of its low heat input, arc stability and spatter-free behavior during the welding process. The present research is mainly concerned with the effect of different heat input on microstructure and mechanical properties of CMT welding 2A14 aluminum alloy in 3 mm thickness. The results indicate that a welded joint with good quality can be achieved when the welding current is 105 A and welding speed is 8 mm/s. The weld width and porosity gradually increase along with the constantly increasing welding heat input. The center of the welded joint consists of a large number of fine equiaxed dendrites, and the gray matrix is uniformly distributed accompanied by a large number of dots and blocks as a white second phase, corresponding to the composition of the Al2Cu phase. The microhardness of welded joints under different welding heat input maintains relative stability and presents a certain softening degree; the base material is the highest, followed by the heat-affected zone.

NDT of Residual Stress in Thick Aluminum Alloy Plates under Different Aging Conditions Using Multiple Techniques.

In this paper, a portable residual stress tester and synchrotron radiation diffraction technique were used to measure the residual stress distribution of thick 2A14 aluminum alloy plates under different aging conditions after solution treatment. The stress changes after solution and aging were analyzed using metallographic structure observation, electron backscattered diffraction (EBSD), X-ray diffraction (XRD), and other characterization methods. The results show that after solution treatment at 500 °C and aging at 170 °C, the second phase precipitates, lattice distortion is released, and the stress level gradually decreases with aging time. The residual stress of the plate comprises compressive stress; there is stress concentration in the central area. The stress distribution obtained by the two residual stress calculation methods, cosα and sin2ψ, under different process conditions was consistent.

Measurement of Air Entrainment and its Effect on the Microstructure and Mechanical Properties of a A356 Aluminum Alloy

Measurement of Air Entrainment and its Effect on the Microstructure and Mechanical Properties of a A356 Aluminum Alloy

MICROSTRUCTURE, MECHANICAL PROPERTIES AND WEAR BEHAVIOR OF NI-COATED CONTINUOUS CARBON FIBER-REINFORCED A356 ALUMINUM MATRIX COMPOSITES FABRICATED BY SQUEEZE CASTING

In this research, aluminum matrix composites reinforced with continuous carbon fibers (CFs) were fabricated using A356 aluminum alloy and PAN-based CFs by squeeze casting. For this purpose, CFs were first coated with a nickel layer using the electroless method and then the microstructure of the nickel–phosphorus (Ni–P) electroless coating was investigated. In the next step, composite samples reinforced with volume fractions of 5, 10, and 15 vol.% CFs coated with Ni–P coating were fabricated by squeeze casting at 60 MPa, and then microstructure and mechanical properties were examined. The results of the bending test on the composite samples indicated that the nickel coating had a significant effect on the flexural strength of the composite and increased the flexural strength by up to 30%. In addition, with the increase in the volume percentage of the fibers, the hardness of the samples increased while both the wear rate and the coefficient of friction decreased. Moreover, the best wear resistance was observed in the sample containing 15 vol.% as-coated carbon fibers. The Ni coating led to the formation of a mechanically mixed layer (MML) containing a fine mixture of metallic oxides and carbon thus enhancing the wear resistance.

Effect of Cyclic Stress on Corrosion Behavior of 7A09 Aluminum Alloy in Tropical Coastal Atmosphere

Effect of Cyclic Stress on Corrosion Behavior of 7A09 Aluminum Alloy in Tropical Coastal Atmosphere

Effects of interlayer on the interfacial microstructures and thermomechanical kinetics of explosive welded 2A14 aluminum alloy-niobium composite

The explosive welding of 2A14 aluminum alloy and niobium with and without a 1060 Al interlayer is investigated by experiments and a two-step numerical simulation. Microstructure observations revealed a continuous molten layer with plenty of micro-defects at the joint interface by direct welding, and for the welding situation with an interlayer, straight and curled joints devoid of imperfections were obtained at the upper and lower interfaces, respectively. The tensile-shear strength for the direct welded samples was 84.4 MPa, while a rise of 38.2% was achieved for the composite with an interlayer. The coupled Lagrange-Eulerian simulation showed a dramatic decline in impact velocity and an obvious increase in collision area and duration due to the insertion of the interlayer, the resulting less kinetic energy loss at the joint interfaces eliminates the formation of the intermetallic compounds. In addition, the smoothed particles hydrodynamics simulation demonstrated that the distribution of strain, temperature, and pressure is more pronounced at the lower interface, and different bonding processes were elucidated for these two interfaces. The introduction of the interlayer strengthened the weldment by adjusting the way the interface accommodates the impact-induced strain.

Microstructure and fatigue behavior of MIG-welded joints of 6005A aluminum alloy with trace amounts of scandium

Extruded plates of 6005A aluminum alloy with 0.07 wt% Sc (referred to as M6005A alloy) was metal-inert-gas-welded (MIG-welded) with ER5087 filler wire. The microstructure, mechanical properties, and fatigue behavior of the joints were studied. Compared with the base material (BM), recrystallization occurred and the formation of the coarse β' phase was evident in the heat-affected zone close to the weld zone (HAZ 2), which resulted in a significant decrease in the mechanical properties of HAZ 2. However, trace Sc inhibited the growth of the recrystallized grains in the HAZ 2, strengthening the α-AlFeSi and β'′ phases in the BM, which drastically improved the mechanical properties of the BM. In the weld zone (WZ), grains were significantly refined since the presence of Al3(Sc, Zr) particles promoted the nucleation of such grains in the WZ, and the particles also promoted the non-uniform nucleation of the α-AlFeSi phase, which significantly improved the mechanical and fatigue properties of the WZ. The hardness distribution of the MIG-welded joint shows a double-W shape. The lowest hardness is 55 HV, observed in the HAZ 2. The ultimate tensile strength (UTS) and conditional fatigue strength (107 cycles) of the MIG-welded joint of M6005A-T6 are 238.5 MPa and 108.2 MPa, respectively, 38 MPa and 13 MPa higher than the those of the MIG-welded joint of 6005A-T6 alloy, respectively.

Preventing Crack in an Aluminum Alloy Complex Structure during Welding Process Based on Numerical Simulation Technology

Aluminum alloy structures are widely used for weight reduction in aviation, shipbuilding, rail vehicles and automotive industries. Fusion welding technology is one of the most important joining methods for lightweight structure assembly due to its advantages such as flexibility in design, high production efficiency, and low cost. However, the local centralized heating during fusion welding inevitably produces residual stress and welding deformation. For actual engineering structures, if the product design is unreasonable or the external restraint is inappropriate, the transient stress or residual stress become a key factor resulting in cracking during the assembly process. In the current study, an effective computational approach was developed based on the MSC Marc software to simulate transient and residual stress fields for complex aluminum alloy structures during the welding process. In the developed computational approach, according to the location and arrangement of welding lines, an instantaneous heat source model was used to replace the traditional moving heat source model, and as a result significanlty improved the calculation efficiency to meet actual engineering needs. The welding stresses, including transient and residual stress, of an A6061 aluminum alloy complex structure were calculated by the developed numerical simulation technology. The simulation results indicated that the cracking was produced by excessive transient stress during welding process. Subsequently, the effect of external restraint intensity on welding stress at the key location was examined numerically. Based on the simulation results, measures to reduce welding stress and cracking risk were put forward based on adjusting the external restraint intensity.