Microstructure Of Aluminum Alloy Research Articles

Microstructure Evolution and Mechanical Properties of Extruded AlSiCuFeMnYb Alloy

This study investigates the impact of varying extrusion ratios on the microstructure and mechanical properties of AlSiCuFeMnYb alloy. Following hot extrusion, significant enhancements are observed in the microstructure of the cast rare earth aluminium alloy. Within the cross-sectional microstructure, the α-Al phase is reduced in size, and its dendritic morphology is eliminated. The morphology of the eutectic Si phase transitions from long strips to short rods, fine fibres, or granular forms. Similarly, the Fe-rich phase changes from a coarse skeletal and flat noodle shape to small strips and short skeletal forms resembling Chinese characters. The CuAl2 phase evolves from large blocks to smaller blocks and granular forms, while the Yb (Ytterbium)-rich rare earth phase shifts from large blocks to smaller, more uniformly distributed blocks. In the longitudinal section, the structure aligns into strips along the extrusion direction, with the spacing between these strips decreasing as the extrusion ratio increases. At an extrusion ratio of 22.56, the alloy demonstrates superior mechanical properties with a tensile strength of 325.50 MPa, a yield strength of 254.44 MPa, a hardness of 143.90 HV, and an elongation of 15.47%. These represent improvements of 27.8%, 36.5%, 38.9%, and 236.4%, respectively, compared with the as-cast rare earth alloy. In addition, the fracture surface of the extruded rare earth alloy exhibits obvious ductile fracture characteristics. Additionally, the alloy undergoes dynamic recrystallisation and dislocation entanglement during hot extrusion. The emergence of a twinned Si phase and a dynamically precipitated nanoscale CuAl2 phase are critical for enhancing deformation strengthening, modification strengthening, and dynamic precipitation strengthening of the extruded alloys.

Influence of Equal Channel Angular Pressing Technique on Mechanical Properties, Corrosion Resistance, and Microstructural Behavior of Al-Alloy 5083

Introduction: During severe plastic deformation (SPD) processing, aluminum alloys exhibit moderate strength and ductility. Nevertheless, the materials' ductility, as determined by tensile testing, does not accurately represent their capacity for plastic deformation. After the tensile test, its material, aluminum alloy 5083, was observed to be super ductile. Method: The results of a more thorough plasticity analysis—applied for the first time to material following SPD processing—are presented in this paper. The aluminum alloy 5083 is examined in the patent both before and after equal channel angular pressing (ECAP). A highly effective aluminum alloy 5083 specimen preparation was suggested. Under heated temperatures, the process involves severe plastic deformation. Optical microscopy and scanning electron microscopy (SEM) were used for micro-structural research in order to look at the distribution of second-phase particles and the evolution of grain structure. Furthermore, Vickers micro-hardness testing was utilized to assess the mechanical characteristics of the alloy after processing. The outcomes showed that after ECAP processing, there was a significant decrease in grain size and an increase in micro-hardness. Result: Additionally, the production of a finer microstructure with a more uniform distribution of strengthening precipitates was clarified by electron microscopy (SEM). The micro-structural evolution and mechanical behavior of aluminum alloy 5083 under ECAP are well-explained in this patent, which may lead to improved performance in structural applications. This method can be used to forecast fractures in plastic deformation processes and estimate the final plasticity of the materials for various stress-strain states after ECAP processing, as well as the mechanical properties discussed. Conclusion: Due to its unique mechanical qualities, aluminum alloy 5083 shows great potential in a variety of structural applications. The effects of Equal Channel Angular Pressing (ECAP) on the hardness and microstructure of aluminum alloy 5083 were examined in this patent work. result: The specimen's mechanical characteristics are at their finest following a single deformation when the temperature reaches 300°C. Compared to the original specimen, the tensile strength observed enhanced after the fourth pass, and breaking elongation (28.3%) was improved. Through second-phase strengthening and fine-tuning, the recrystallized grains and second-phase particles increase the material's strength.

Effect of Ce and solidification cooling rate on the microstructure and mechanical properties of AA2017 aluminum alloy

Controlling dendritic growth and grain size in new Ce-containing Al-based alloys becomes crucial due to new envisioned applications and Ce rising demand in casting processes. In the present work Ce effect on the 2xxx Al series microstructures at various industrial-scale solidification cooling rates was investigated. The directional solidification technique is crucial in this endeavor since can generate several solidified samples related to several cooling rates. The AA2017 alloy and a modified version containing 3 wt % of Ce were both produced under directional solidification and various microstructure aspects were characterized. The mechanical behavior was analyzed by microhardness and compression tests. The Ce addition reduced primary and secondary dendritic spacing without impacting grain size. Cells were only observed to form on the Ce-containing alloy at cooling rates of approximately 19 °C/s; while dendritic configurations dominated all other conditions. While round pockets composed of Al+Al2Cu+Mg2Si ternary eutectic formed the interdendritic zones in the AA2017 alloy, the AA2017-Ce alloy microstructure was mainly constituted by elongated AlCeSi + Al8CeCu4 interdendritic phases. Finally, the addition of Ce favored an increase in the microhardness and compressive strength values of the AA2017 alloy, which is attributed to the refinement of the solidification structure, as well as the formation of a greater fraction of secondary reinforcement phases.

Effect of Aging Treatment on Microstructure and Mechanical Properties of As-Extruded AA6063 Aluminum Alloy

Effect of Aging Treatment on Microstructure and Mechanical Properties of As-Extruded AA6063 Aluminum Alloy

Influence of cooling speeds on the microstructure and properties of A356 aluminum alloy after squeeze casting

The examination focuses on the microstructural characteristics and mechanical attributes of A356 alloy subsequent to squeeze casting performed under varying cooling speeds. The findings reveal that the cooling speeds have no notable impact on the size of the grains in the A356 alloy produced through squeeze casting. However, as the cooling speeds increase, the eutectic Si phase in A356 alloy decreases, transforming it from coarse flakes to small rods or particles, thereby enhancing the mechanical characteristics of the alloy. The water-cooled alloy has the best UTS performance, whose value of A356 alloy after squeeze casting is 287 MPa.

Investigation on effect of high-efficiency solid solution and hot stamping process on microstructure evolution and mechanical properties of high-strength aluminum alloy

Aluminum alloy has become an important lightweight material in the automotive industry due to its excellent performance. The development of hot stamping technology has effectively promoted the application of high-strength aluminum alloys in auto parts. However, aluminum alloy hot stamping requires a long time for solid solution and aging heat treatment, which hinders its mass production application in the existing mature hot stamping production line. Therefore, this paper studies the effect of a high-efficiency solid solution and hot stamping process on the microstructure and mechanical property strengthening mechanism of high-strength aluminum alloy. The contact heating and hot stamping experiment device was designed. It was found that the temperature rise rate of the sheet during the contact heating process could reach 44.51 °C/s. The experiment results show that contact heating treatment with a solution temperature of 480 °C and a solution time of 20s can achieve the high-efficient solution treatment of the sheet metal. The high-temperature deformation behavior of 7075-T6 at different temperatures (300-450 °C) and different strain rates (0.01∼1/s) under the condition of high-efficiency solid solution rapid heating was studied.

Evolution of microstructure and mechanical properties of aluminum alloy induced by turning and ultrasonic surface rolling process

The microstructure and mechanical properties have a significant impact on the service performance of materials. This paper compared the microstructure and mechanical properties of 2024 aluminum alloy subjected to turning and ultrasonic surface rolling process (USRP). It was found that both turning and USRP can cause grain refinement and increased microhardness. The grain refinement induced by USRP was attributed to dislocation proliferation and T-phase fragmentation; At the same time, a quantitative relationship model between microhardness and microstructure during turning and USRP was constructed. The results showed that precipitation had the greatest impact on the microhardness induced by turning, while dislocations and grain refinement had the greatest impact on the microhardness induced by USRP; In addition, the mechanical performance response mechanism of the materials after turning and USRP was elucidated, and it was found that USRP can significantly enhance the yield strength of the materials.

Influence of Various Melt Shearing Speeds on Macrostructure, Microstructure, and Tensile Properties of A380 Aluminum Alloy

Influence of Various Melt Shearing Speeds on Macrostructure, Microstructure, and Tensile Properties of A380 Aluminum Alloy

Effect of Two-Step Solution Treatments on the Microstructure and Mechanical Properties of B357 Aluminum Alloy

AbstractThis study investigates the effect of two-step solution treatments and aging times on the microstructure and mechanical properties of B357 Al–Si alloy, part of the most widely used cast aluminum alloy. Three sets of artificial aging heat treatments were conducted on the tensile samples prepared from B357 alloy produced by low-pressure die casting. Firstly, the conventional artificial aging heat treatment (T6) was carried out by solutionizing the tensile samples at 543 °C for 8.5 h, water quenching at 60 °C, and then artificially aging for 8.5 h at 160 °C. In the two-step solution treatment, the samples were solutionized at 400, 440, 480, and 520 °C for 4 h and then solutionized at 543 °C for 8.5 h and water quenched to 60 °C and then artificially aged for 8.5 h at 160 °C. Thirdly, the samples were solutionized at 480 °C for 4 h, solutionized at 543 °C for 8.5 h, water quenched to 60 °C, and artificially aged for 3–192 h. Despite different solutioning and aging processes, no significant differences were observed in the microstructures of the samples. Si particle coarsening was observed with increasing solution temperature (400–520 °C) and aging times (3–192 h). Si-containing dispersoids and dispersoid-free zones (DFZ) were observed in the primary-α matrix. While DFZ width increased with temperature and aging, dispersoid zones in primary-α dendrites significantly decreased. Differential Scanning Calorimetry (DSC) analysis shows that two-step solution treatment in B357 alloy increases β′ precipitates for Mg2Si precipitation strengthening. The two-step solutionized and aged sample showed the best combination of strength and ductility among all aged samples. B357 alloy exhibited the highest yield and tensile strength (309.7, 366.1 MPa) with 6% elongation for two-step solutionizing and 48 h aging. All aged B357 alloys showed ductile fracture as the primary fracture mode. However, brittle fractured Si particles were observed on the fracture surfaces.

Influence of Alumina, Ferric Oxide, and Mn as Composites on the Properties of Recycled Aluminium Alloy

Recycling of aluminium alloys is gaining significant attention due to its economic and environmental benefits. However, close loop recycled aluminium alloys can be adversely affected by impurities and alloying elements present in the recycled feedstock. In this study, the influence of three composites, namely alumina (Al2O3), ferric oxide (Fe2O3), and manganese (Mn), on the properties of recycled aluminium taldon scraps was investigated to enhance the tensile behaviour of the alloys. The effects of these composites on the mechanical properties, microstructure, and corrosion behaviour of the recycled aluminium alloys were evaluated through experimental characterization techniques. The results showed that the addition of these composites had a significant influence on the properties of recycled aluminium alloys, providing insights into the potential for improving the performance of recycled aluminium alloys through composite additions. The addition of Al2O3 enhanced the tensile strength by 44.18 % and the variation can be attributed to the strengthening of the dendritic zones by the formation of α-Al.

Effects of pre-stretch on microstructure, mechanical properties and corrosion resistance of 2A14 aluminum alloy

The microstructure, mechanical properties and corrosion behaviors of the peak-aged 2A14 aluminum alloys subjected to pre-stretch prior to artificial aging were investigated. The results indicate that the hardness and strength of the peak-aged alloy can be greatly enhanced via introducing pre-stretch due to the formation of dense and finer θ′ precipitates with dispersed distribution in alloy matrix. Pre-stretch prior to peak aging evidently enhances the peak aging hardness and shortens the peak aging time of the alloy. A pre-stretching degree of 7.5% leads to a distinct inhomogeneous distribution of θ′ phase, which decreases the ultimate tensile strength. As pre-stretching degree increases, the plasticity, impact toughness and exfoliation corrosion (EXCO) resistance of the peak-aged alloy all gradually decrease, but its resistance to intergranular corrosion (IGC) increases and then decreases.

OBTAINING THE NECESSARY MECHANICAL PROPERTIES OF BLANKS OF PARTS MADE OF ALUMINUM ALLOY 7075 BY PHYSICAL MODELING

The article considers physical modeling for aluminum alloy 7075, widely used in mechanical engineering, in particular for elements of aircraft structures. This alloy differs from other rolled aluminum-based alloys not only by high values of strength properties, but also by the presence of a large number of intermetallic compounds of alloying elements. The workpiece for the parts is a round rolled product with regulated mechanical properties. Thus, the purpose of this work was to determine the effect of the deformation pattern that occurs in metal during bar rolling on the mechanical properties of blanks of parts made of aluminum alloy 7075. The present study draws attention to the importance of physical modeling in determining the characteristics of materials necessary for effective management of plastic processing processes. Analyzing the results of physical modeling, we identify the optimal parameters of material processing, such as microstructure, mechanical properties and chemical composition. The results obtained allow a deeper understanding of the physical mechanisms underlying the production of blanks (rods) from aluminum rods of alloy 7075 by rolling, as well as optimizing it to achieve the required technical characteristics of products. Thus, as a result of physical modeling of the rolling process of bars made of aluminum alloy 7075, it was found that when the samples are deformed at a temperature of 250 ° C, the value of the plasticizing stress decreases by about 18%, and a more uniform distribution of microhardness over the transverse and longitudinal sections was obtained compared with deformation at a temperature of 200 °C. The research is of practical importance for the metalworking industry, and can also be used for educational purposes to train specialists in the field of materials science and metalworking. Keywords: workpiece parts, physical modeling, aluminum alloy 7075, metalworking, aluminum alloy microstructure, deformation of samples.

Effect of Rare Earth La on Microstructure, Hardness and Corrosion Resistance of A356 Aluminum Alloy

Effect of Rare Earth La on Microstructure, Hardness and Corrosion Resistance of A356 Aluminum Alloy

Influence of different cycle strain amplitudes on the microstructure and properties of 2024 aluminum alloy

The effect of varying strain amplitudes on the tensile properties and microstructure of aluminum alloy 2024 after a solution treatment (ST) of 495 °C for 1 h followed by cyclic strengthening at room temperature in the presence of various strain amplitudes is methodically investigated. Cyclic strain treatment substantially leads to the enhancement of the strength and plasticity of the alloy. Different strain amplitudes result in distinct strengthening mechanisms in the tested specimens. The specimens treated with low strain amplitudes (Δεt/2 = 0.1–0.4%) exhibit the least changes in the dislocation cell size and the dislocation density. The strengthening is mainly attributed to the precise adjustment of solute cluster precipitation. In specimens treated with high strain amplitudes (Δεt/2 = 0.5–1.1%), various strain amplitudes result in various dislocation configurations. The S-phase precipitation occurs selectively in the dislocation cell walls, forming solute cluster-composite dislocation loops within the dislocation cells, enhancing both the strength and plasticity of the alloy. The rational cyclic strain treatment not only yields the achievement of the precise control of precipitate phases, but also regulates the dislocation configurations. The obtained results reveal that the high-density cluster-composite dislocation loops are capable of resolving the conflict between increasing dislocation density and reducing dislocation pile-up, providing new insights into alloy strengthening.

Effect of interlayer rapid cooling on the microstructure and properties of aluminum alloys produced by wire arc additive manufacturing

To reduce the impact of heat accumulation during additive manufacturing, this study used the dual-pulse GMAW-AM (Gas Metal Arc Welding-Additive Manufacturing) method for the preparation of aluminum silicon alloy components, and an interlayer rapid cooling device was designed for additive manufacturing. The results showed that the proportion of small-angle grain boundaries in the IRC-WAAM (Interlayer Rapid Cooling-Wire Arc Additive Manufacturing) component was 10.893% greater than that in the WAAM (Wire Arc Additive Manufacturing) component, and the proportion of small grains was greater. The hardness of the IRC-WAAM component in the bottom area increased by 12.65% compared to that of the WAAM component, and the hardness in the middle area increased by 15.16%.

The Influence of Cow’s Bone Calcium Concentration on the Mechanical Characteristics of a Mg-Al Alloy

Magnesium aluminium of the magnesium-alloy variety have long been extensively utilized in different technical applications and are still capturing the attention of researchers because of their cost-effectiveness and lightness. Grain fractal sizes, microstructural relationships, and sphericity, as well as their relationship with service performance, were discovered for numerous frequently employed Mg-Al alloys. As a result, the influence of cow’s bone extracts calcium on the mechanical behaviours as well as microstructure of Magnesium aluminium alloy was investigated in this work. Calcium (0.5% weight) concentration, formations with uniform and non-uniform grain boundaries led to alloy hardening. 286.537MPa and 57.3 HB are respectively the highest tensile strength and hardness gotten.

Processing, microstructural characterization, and mechanical properties of deep cryogenically treated steels and alloys – overview

Abstract Deep cryogenic treatment (DCT), a technique of deep subzero processing, is utilized after quenching and well preceding tempering. In DCT, the materials are subjected to a soaking period of typically 24 h at a temperature of −196 °C. The optimal soaking period varies depending on the material to be cryotreated. The microstructural characteristics and mechanical properties of ferrous and nonferrous materials are significantly enhanced using DCT resulting in improved durability and functional performance of the mechanical components. The DCT is generally performed on tool steel, stainless steel, aluminum alloys, and magnesium alloys to improve its mechanical properties. The complete transition of residual austenite to martensite and finer secondary carbide precipitation correlates with an increase in the mechanical properties of tool steel. The nonferrous materials such as aluminum and magnesium alloys showed improved mechanical properties owing to the precipitation of finer second phases in the matrix. The main objective of this review paper is to provide an overview on the history and theories of DCT, important processing parameters, and the effect of DCT on microstructure and mechanical properties of tool steel, aluminum alloys, and magnesium alloys.

Effect of Sc and Zr addition on microstructure and mechanical properties of high strength 7A52 aluminum alloy welded joints fabricated by double-wire gas metal arc welding

A new idea for improving the mechanical properties of medium-thickness 7A52 aluminum (Al) alloy welded joints was proposed. In this work, 40 mm 7A52 Al alloys were welded by double-wire gas metal arc welding (DW-GMAW) using Al-4.76Mg and Al-4.45Mg-0.70Sc-0.30Zr (wt%) alloy wires, respectively. The results showed that after adding 0.70Sc and 0.30Zr, the microstructure of weld metal (WM) transformed from dendritic grain to equiaxed grain, and the average grain size reduced from 45.04 µm to 5.55 µm (reduced by 87.7%). At the same time, the microstructure growth morphol-ogies of the molten pool changed from equiaxed grain + columnar grain + dendritic grain to equiaxed grain + fine columnar grain + equiaxed grain, while the microstructures significantly refined because micro-Al3(Sc, Zr) phases appeared in WM. The yield strength (YS), ultimate tensile strength (UTS), and elongation (El) of Al-4.76Mg welded joints were 155 MPa, 288 MPa, and 5.5%, respectively. After 0.70Sc and 0.30Zr were added, the YS and UTS increased to 226 MPa (an increase of about 45.8%) and 336 MPa (an increase of about 16.7%), respectively. The fine grain strengthening caused by the micron-Al3(Sc, Zr) phase and the precipitation strengthening caused by the nano-Al3(Sc, Zr) phase were the main reasons for the strength improvement. The findings of this study provided a theoretical basis for high efficiency and high quality for 7A52 Al alloys with medium thickness.

Influence of retrogression temperature and time on microstructure, mechanical properties and corrosion behaviors of cryogenically-deformed 7A85 aluminum alloy

To balance the strength, plasticity, and corrosion resistance of the alloy, the microstructure and comprehensive properties of cryogenically-deformed 7A85 aluminum alloy at various retrogression temperatures and time were investigated. The results showed that under the retrogression and re-aging (RRA) of lower retrogression temperature and time and T6 (120 °C, 24 h) tempers, the alloy had higher strength but poorer corrosion resistance. For RRA, increasing the retrogression temperature and time within a certain range reduced the strength but significantly improved the electrical conductivity and corrosion resistance of the alloy. However, excessively increasing the retrogression temperature and time led to a reduction in corrosion resistance. At the same retrogression temperature, the elongation of the alloy first decreased and then increased with the extension of retrogression time. The optimal temper matched to the three-dimensional cryogenically deformed 7A85 aluminum alloy was RRA180-0.5 ((120 °C, 24 h) + (180 °C, 0.5 h) + (120 °C, 24 h)).

Effect of Microstructure on Corrosion Behavior of Cold Sprayed Aluminum Alloy 5083

This paper investigates the effect of the microstructure on the corrosion behavior of cold sprayed (CS) AA5083 compared to its wrought counterpart. It has been shown that the microstructure of CS aluminum alloys, such as AA2024, AA6061, and AA7075, affects their corrosion behavior; however, investigations of the corrosion behavior of CS AA5083 with a direct comparison to wrought AA5083 have been limited. The microstructure and corrosion behavior of CS AA5083 were examined by scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), electron backscattered diffraction (EBSD), electrochemical and immersion tests, and ASTM G67. The CS process resulted in microstructural changes, such as the size and spatial distribution of intermetallic particles, grain size, and misorientation. The refined grain size and intermetallic particles along prior particle boundaries stimulated the initiation and propagation of localized corrosion. Electrochemical tests presented enhanced anodic kinetics with high pitting susceptibility, giving rise to extensive localized corrosion in CS AA5083. The ASTM G67 test demonstrated significantly higher mass loss for CS AA5083 compared to its wrought counterpart due to preferential attack within prior particle boundary regions in the CS microstructure. Possible mechanisms of intergranular corrosion (IGC) propagation at prior particle boundary regions have been discussed.