Mechanical Properties Of Aluminum Alloys Research Articles

Investigation of the Mechanical Behavior of Synthesized Al6061/TiO2 Microcomposites Using an Innovative Stir Casting Method.

Aluminum composites are preferred in many kinds of applications such as aviation, space, automotive, and marine, owing to their outstanding properties, high strength, and corrosion resistance. The main objective of the current study is to evaluate the mechanical properties of aluminum alloy 6061/titanium dioxide (micro-TiO2) microcomposite synthesized using the stir casting method. The effects of changes in stir casting parameters, such as stirring speed and tiring durations, were studied. Al6061 matrix was reinforced with micro-TiO2 particles with weight fractions of 1, 2, 3, 4, and 5 wt.%. Microstructural and chemical analyses were conducted to explore microstructural transformation resulting from the presence of the TiO2 microparticles. The mechanical characteristics were evaluated, and the results showed a considerable enhancement in the mechanical strength and hardness resulting from the incorporation of micro-TiO2 into Al606. The additions of 2 wt.% and 5 wt.% of micro-TiO2 recorded the highest ultimate tensile strength and hardness, respectively.

SIMULASI PARAMETER PENGELASAN GESEK ROTARI PADA AL ALLOY 6061 T-6 DAN AISI 1018 DENGAN FINITE ELEMENT METHOD (FEM)

Rotary Friction Welding is a welding process that is carried out to connect metal materials in the form of a cylinderby means of friction against the two materials to be joined by applying pressure. Therefore, researchers are interested in conducting simulations based on the finite element method with FEM software to solve the problem. The purpose of the simulation is to analyze the results of rotational speed, axial pressure, forging pressure and welding time. Parameters were analyzed for stress-strain values, temperature distribution and displacement visualized through contours. The parameters used are 2.5 MPa axial pressure, 4 MPa forging pressure and 1500 RPM rotational speed and welding time of 10 seconds. Simulation data shows that the stress strain analysis obtained a strain of 1.8 and a stress of 315 MPa, the displacement value was 5.2 mm and the temperature distribution value was 582ᴼC with the axial and forging pressure welding parameters 2.5 MPa, 4 MPa, rotational speed 1500 RPM with a welding time of 10 seconds. The research validation can be said to be valid because it has fulfilled the tensile strength value of 305 MPa in the tensile test based on the value of the mechanical properties of Aluminum alloy with a margin of error of 1.61%<5%. The connection results are said to be valid because they have been analyzed and then validated to meet the standard mechanical properties that have been determined by the researcher so that the welding parameters used can be recommended to be done experimentally.

Effect of the Annealing Process on the Microstructure and Performance of 5056 Aluminum Alloy Wires

Recrystallization can affect the mechanical properties of aluminum alloys by changing the grain structure, and even the secondary recrystallization will cause a sudden change in the grain size in the alloy. In this work, by choosing different annealing treatments on the cold-drawn 5056 aluminum wire, the microstructure evolution in the alloy homogenized at different annealing processes was discussed, and its influence on the mechanical properties was tested. The results demonstrated that the different annealing treatments had a great effect on the recrystallized structure in the 5056 aluminum alloy. During the annealing, it was observed that the recrystallization started at 250 °C and completed at 310 °C, leading to a significant decrease in the mechanical properties. When the temperature was further increased to 530 °C, the secondary recrystallization occurred, and the grain size of the secondary recrystallization was larger than that when the annealing temperature was 560 °C. However, there was only a minor decrease in the mechanical properties. The reasons and laws of the secondary recrystallization are analyzed and discussed in this paper.

Effect of high pressure die casting on the castability, defects and mechanical properties of aluminium alloys in extra-large thin-wall castings

The manufacturing of extra-large thin-wall castings using high pressure die casting is one of the most significant challenges for structural applications requiring excellent ductility. The present study aims to understand the effect of process parameters on the castability, defect formation and mechanical properties of aluminium alloys in extra-large thin-wall castings with a maximum flow length of 1230 mm in the 2.8 mm thick channel. Numerical simulation and experimental verification were carried out to tailor the process parameters in high pressure die casting. It is found that the process parameters can significantly affect the castability and mechanical properties of as-cast components. For a complete casting, the yield strength is slightly increased but the elongation is significantly decreased at the locations further away from runners. A new concept of effective flow length (EFL) is proposed and used to assess the castability in extra-large thin-wall high pressure die castings. Under the optimum casting condition, the EFL can reach 525 mm, at which the ratio of EFL to wall thickness is 187 and the yield strength and elongation are greater than 120 MPa and 10%, respectively. Although the extra-large thin-wall castings can be geometrically filled under several conditions, the heterogeneity of mechanical properties is the most significant concern, in which the variation of elongation is overwhelmingly important for the structural applications requiring excellent ductility under as-cast conditions. Therefore, the criteria of casting quality should consider both geometrical soundness and the homogeneity of mechanical properties in the casting body.

Increasing the efficiency of refining and modification of aluminum alloys when using electromagnetic factors

Mechanical properties of aluminum alloys and their corrosion resistance are strongly influenced by the content of non-metallic inclusions and hydrogen dissolved in the melt, therefore, the improvement of technologies for refining aluminum alloys is important. The use of electromagnetic factors for this purpose has not yet been studied enough, but theoretical studies and experiments carried out show that this direction is promising. The paper presents the results of testing a new technology in which electromagnetic factors are used to enhance the efficiency of aluminum alloy refining from non-metallic inclusions and hydrogen. A melt flow was initiated through a ceramic foam filter by an electromagnetic pump, through which an electric current with a frequency of 50 Hz passes. At the same time, argon was introduced perpendicular to the flow direction at the crucible bottom. After refining, a modifier was introduced into the liquid metal bath and electromagnetic stirring was started. Metallographic studies of the sample cast from the refined metal have shown a significant quality increase. Cast mechanical properties increased accordingly. Tables 1, Figs 1, Refs 10.

Effect of cryorolling on the microstructure and high-temperature mechanical properties of AA5083 sheets

To explore the effect of cryorolling on the high-temperature mechanical properties of aluminium alloys, AA5083 sheets were rolled at 83, 173, and 298 K, and the rolled sheets were then subjected to high-temperature tensile testing at 748 K. The elongation to failure of the 83 K cryorolled samples reached 150% at a strain rate of 1 × 10−3 s−1, which was higher than those of the 173 K cryorolled samples (92%) and 298 K rolled samples (80%). Under this condition, the strain rate sensitivity coefficient of the 83 K rolled samples was 0.36, which reached the standard of superplasticity. The enhancement of plasticity of the 83 K cryorolled samples was attributed to the finer grains, the smaller second phase, and the subgrains alleviating more stress concentration. The main deformation mechanisms during the high-temperature tensile deformation were grain-boundary sliding and dislocation slip. Compared to the 298 K rolled sample, the grain size of the 83 K cryorolled sample was smaller, which was suitable for the grain-boundary sliding mechanism. In addition, the uniform distribution of high-density dislocations prevented the dislocation slip mechanism but reduced the stress concentration and the nucleation and growth of cavities at high-temperature deformation.

Effect of Heat Treatment on the Mechanical Properties of Aluminum Alloy 2219 and its Welded Joints at Cryogenic and Elevated Temperatures

Effect of Heat Treatment on the Mechanical Properties of Aluminum Alloy 2219 and its Welded Joints at Cryogenic and Elevated Temperatures

Deterioration of Property of Aluminum Alloys (EN AW-1050A, EN AW-5754 and EN AW-6060) by Absorbed Hydrogen

The paper reports the results of research on the effect of hydrogen penetration on the variations in the mechanical properties of selected aluminum alloys. As a result of the study, it can be observed that such variations contribute to the deterioration of mechanical properties, which, in turn, contributes to shortening the reliability time associated with the operation of aluminum alloy structures. The analysis involved structural aluminum alloys: EN AW-1050A, EN AW-5754 and EN AW-6060. Tensile strength and impact strength were measured. It was demonstrated that the absorption of hydrogen by the analyzed alloys led to the deterioration of mechanical properties of aluminum alloys. The performed measurements were compared to the previous research results regarding the influence of hydrogen on the deterioration of corrosion properties. The analysis of the influence of hydrogen on both issues allowed us to notice the reasons for shortening the operational reliability time of aluminum alloy parts. The awareness of the influence of hydrogen on aluminum alloys may contribute to the development of hydrogen systems or installations in which aluminum alloys can be used as a construction material, e.g., fuel cells, hydrogen supply pipes, block of combustion engine powered by hydrogen, etc. In the era of the development of zero-emission vehicles, the use of hydrogen as fuel is gaining more and more importance, where the influence of hydrogen on the properties of materials is an important issue.

Mechanical properties and microstructural evolution of high-pressure torsion-processed Al7075 alloy at elevated temperatures

The severe plastic deformation of aluminum alloys can be advantageous for developing a unique microstructure by inducing dynamic recovery and dynamic precipitation. Because dynamic recovery and precipitation are related to temperature changes, an elevated temperature atmosphere during severe plastic deformation may accelerate microstructural changes in aluminum, resulting in different properties compared to that of the room-temperature processed sample. In the present work, the microstructural and mechanical properties of the elevated temperature high-pressure torsion-processed Al7075 alloy were investigated. Experimental results demonstrated that the elevated temperature during high-pressure torsion not only induces a dynamic recovery at a high shear strain regime but also yields coarse Mg, Zn, and Cu-rich precipitates in the aluminum matrix. Although the grain growth occurs from the shear strain of 7.8, evolved precipitates represents larger strength than matrix that result into continuous mechanical properties enhancement in the elevated temperature-processed sample. This result indicates that solute migration acceleration at an elevated temperature could be a suitable method to enhance the mechanical properties of aluminum alloys undergoing severe plastic deformation processing.

Room- and High-Temperature Mechanical Properties of Aluminum Alloys Fabricated Using Laser Powder Bed Fusion Additive Manufacturing

Room- and High-Temperature Mechanical Properties of Aluminum Alloys Fabricated Using Laser Powder Bed Fusion Additive Manufacturing

Evaluation of mechanical properties of aluminium alloy (AA 6082) reinforced with Rice husk ash (RHA) and Boron carbide (B4C) hybrid metal matrix composites using stir casting method

Aluminum alloys are commonly employed in shipbuilding and automotive manufacturing units. The mechanical properties of alloys, such as strength and hardness, can be improved by adding reinforcement to the matrix material. Stir casting is an improved method for uniform dispersion of particles over conventional casting methods. Therefore, an effort is made to fabricate aluminium alloy (AA 6082) composites with different ratios of hybrid reinforcement of Rice Husk Ash (RHA) and Boron Carbide (B4C) reinforcements.The mechanical properties of composites such as tensile strength, hardness, flexural strength, and impact strength were evaluated. The microstructural properties of composites were evaluated using a scanning electron microscope to determine the dispersion of particles in the matrix material. It is found that tensile strength, hardness were improved by 20% as well as the uniform distribution of reinforcement particles in composites.

Study of structure and mechanical properties of aluminum alloys modified by shungite after heat treatment

The results of the effect of heat treatment on the structure and mechanical characteristics of the hypereutectic silumin modified by natural fullerenes in shungite rock are presented. It is established that the modifier provides uniformity of the structure of hypereutectic silumins and improvement of mechanical properties. The structural components of the alloys return to their original unmodified state with subsequent drying of the mechanical properties after heat treatment.

Ultrasound-Assisted Liquid-Phase Synthesis and Mechanical Properties of Aluminum Matrix Nanocomposites Incorporating Boride Nanocrystals.

Incorporating boride nanocrystals could significantly impact the mechanical properties of aluminum alloys. Molten salts synthesis offers opportunities to fabricate superhard boride nanoparticles, which can sustain the harsh conditions during the liquid-phase design of metallic nanocomposites. Here hafnium diboride-aluminum nanocomposites are unveiled from molten salt-derived HfB2 nanoparticles sequentially dispersed in aluminum by ultrasound treatment. The structure and size of the nanocrystals are retained in the final nanocomposites, supporting their high chemical stability. Semicoherent interfaces between the nanoparticles and the matrix are then evidenced by TEM, suggesting that the nanocrystals could promote heterogeneous nucleation of Al and then limit the Al grain size to ≈20µm. Nanoindentation measurements reveal significant grain boundary strengthening and grain refinement effects. It is finally shown that HfB2 nanoparticles also enable a decrease in matrix grain size and an increase in the hardness of the AlSi7 Cu0.5 Mg0.3 alloy. These proof-of-concept materials are paving the way to light-weight Al matrix nanocomposites doped by molten-salt synthesized nanoparticles.

Evaluation of mechanical properties of Al-B4C and Al-SiC metal matrix composites – A comparison

This paper deals with the comparison of Mechanical properties of aluminum alloy (LM 25) with boron carbide and aluminum alloy with silicon carbide metal matrix composite. The boron carbide of particle size 35 to 40 µm and silicon carbide of similar particle size were used as reinforcements. This addition gives excellent hardness and good impact strength. The fabrication was done by using stir casting., The samples are prepared and mechanical testing like tensile, hardness, and impact was done. It was found that aluminum alloy with boron carbide showed better tensile and impact strength whereas aluminum alloy with silicon carbide showed better hardness. The structure was characterized by using optical microscope.

Optimization of process parameters of friction stir welded joints of dissimilar aluminum alloys AA3003 and AA6061 by RSM

The friction stir welding (FSW) has excellent potential compared to other welding processes for joining similar or dissimilar aluminium alloys, which operate severe plastic mixing and high temperature to enhanced the mechanical properties of aluminium alloys. In the present work, RSM was used for the mathematical modelling of the FSW input parameters to fabricate AA3003 and AA6061. The empirical correlation was developed to predict the output responses of the FSWed joints at 95% confidence interval (C.I). The developed model reveals that the tool rotational speed (TRS), and welding speed (WS) were the dominating parameters. The increase in TRS, and decrease in WS leads to increased heat input to the welded joints. The C.I reveals that the ultimate tensile strength (UTS), and microhardness increased with increasing TRS. The optimized value of UTS, % strain nad microhardness was observed as 95.8 MPa, 12.18%, and 74.47 HV, respectively, while the optimized value of TRS, WS, and tilt angle (TA) were 1172 rpm, 57.44 mm-min−1, and 1.252° respectively.

Effect of pulse frequency on weld appearance of Al alloy in pulse power ultrasonic assisted GMAW

This paper investigated the effect of pulsed power ultrasonic on the appearance, microstructure and mechanical properties of aluminum alloy using self-developed pulsed power ultrasonic wave assisted gas metal arc welding (PU-GMAW) device. The feature of the method was to combine arc and pulsed power ultrasonic field coaxially. The results indicated that, compared with conventional GMAW, the weld penetration of PU-GMAW was much increased and the melting area increased by around 49%. Further, weld melting area enlarged as pulse frequency increased. The average hardness of the weld metal of PU-GMAW was about 15 HV higher than that of GMAW. At the end, the mechanism of melting area enlargement and weld penetration enhancement was discussed, which was attributed to the increase of the welding heat input.

Fabrication of Aluminium Metal Matrix Composite by Friction Stir Processing

Friction Stir Processing (FSP) is a new approach for successful fabrication of Aluminium Metal Matrix Composites (AMCs) with required properties of Nitinol (NiTi) Shape Memory Alloys (SMA). This reinforcement agent is used for heightening the mechanical properties of aluminium alloy with Shape Memory Effect but such fabrication was not possible without defects such as critical intermetallic formation between reinforced particles and matrix. So we present a creative strategy to fabricate Al7075-T6/NiTi composites by FSP. It has been found that the groove filling method results in a more homogenous distribution compared to the multi-holes filling method. In this innovative strategy, we are going to use the groove filling method with a new FSP tool design for the linear distribution of reinforcement particles in grooves. This FSP tool will be used with the help of a Vertical Milling Machine.

Impact of Riveting Parameters on Mechanical Properties of Aluminum Alloy (LY-12) Sealant Applied Lap Joint of an Aircraft

The assembling process includes various techniques, out of which riveting has been employed most successfully in fields like construction of enormous structures, auto-motives, and most notably in the aerospace industry. This process includes marking, drilling followed by riveting. Furthermore, being a successful process, most of the aircraft structure is assembled using rivets. However, various factors contribute to the result. Therefore, the effect of riveting process parameters such as Sheet Thickness, Rivet Diameter, Rivet Type, and Riveting Sequence have been studied on responses, i.e., Deformation and Joint Load Capacity of lap joint composed of Aluminum Alloy sheets (LY-12) at T0 condition by sandwiching aerospace-grade sealant (XM-22B). Each of these parameters is studied on three levels and the experimental setup is designed using Response Surface Methodology (RSM). The main objective of this work is to demonstrate the effect of riveting parameters on lap joints with sealant and analyze the effect through careful measurement of deformation and joint load capacity of the test specimen. Finally, a variance analysis (ANOVA) is performed to identify significant factors influencing response parameters using Design Expert Software V-12.

Modelling of strains experienced by aluminium shells during machining

The study analyzes whether it is feasible to use high-strength aluminum alloys for making high-pressure cylinders. It is shown that replacing highstrength complex alloyed steel with the V95-like aluminum alloys is feasible. Aluminum alloys were not investigated for stresses and displacements occurred when workpieces are fixed in three-law grippers. The study is relevant because all the physical and mechanical properties of aluminum alloys (yield strength, ultimate strength) are about a third of the respective steel properties. Using the available references, we estimated the cutting force components and the clamping force at each jaw required to hold the workpiece in the gripper. Wide and long jaws are usually used to hold thin-wall shell workpieces in three-jaw lathe grippers. The total workpiece circumference coverage by the jaws is close to a full circle. The estimated force was applied to each jaw. A 3D model was created with SolidWorks and simulated. The simulation showed that the higher stress occurs mostly in the tooling parts amounting to 1.269...1.384 MPa. The stress in the gripper body segments contacting the jaws is 0.69...0.923 MPa. The most of the body is under a low stress: 0.015...0.023 MPa. The max stress in the workpiece is found at the lower edges of its bottom. The stress at the jaw-to-segment interface reaches 1.24 MPa. At these points, the wide jaws compress the workpiece; the segment at the center of the wide jaws is stiffer since there is a jaw and a stiffener behind its wall. There are three equally distributed stress points. Still, the stress in the rest of the segment is 0.015...0.023 MPa. The deformed workpiece has a faceted shape. The out-of-roundness is 0.0014 to 0.00165 mm. It is well below the out-of-roundness tolerance.

Effect of <i>In Situ</i> TiB<sub>2</sub> Particles on the Grain Size and Mechanical Properties of 7075 Aluminum Alloy

Light-weight and high-strength aluminum alloy drill pipes are potential and promising to replace traditional steel drill pipes. In this study, the grain size and mechanical properties of aluminum alloy drilling pipe materials reinforced by in-situ TiB2 particles were studied. The results showed when reinforced by in-situ TiB2 particles the grain size of aluminum alloy materials was refined from 155 m to 57 m and ultimate tensile strength was increased from 590 MPa to 720 MPa. Besides, the results also indicated that the friction coefficient was reduced from 0.99 to 0.50 and thus the abrasion resistance of 7075 aluminum alloy was enhanced by 34 %. This study provided theoretical basis for the application of light-weight and high-strength aluminum alloy drill pipes in directional drilling and ultra-deep wells.