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In this investigation, AA2024 alloy was welded by tungsten inert gas welding. Access the influence of pitting corrosion on TIG weld; the joints were heat-treated after welding with different techniques. Moreover, the corrosion test was carried out with 3.5% NaCl solution under different pH values such as pH:5, pH:7, and pH: 12. From the experimental results, the joint treated with solution treatment with pH: 7 showed high corrosion resistance than its counterparts.

Aluminum alloys used for aerospace applications provide good strength to weight ratio at a reasonable cost but exhibit only limited corrosion resistance. Therefore, a durable and effective corrosion protection system is required to fulfil structural integrity. Typically, an aerospace corrosion protection system consists of a multi-layered scheme employing an anodic oxide with good barrier properties and a porous surface, a corrosion inhibited organic primer, and an organic topcoat. The present review covers published research on the anodic oxide protection layer principles and requirements for aerospace application, the effect of the anodizing process parameters, as well as the importance of process steps taking place before and after anodizing. Moreover, the challenges of chromic acid anodizing (CAA) substitution are discussed and tartaric-sulfuric acid anodizing (TSA) is especially highlighted among the environmentally friendly alternatives.

Selective laser melting (SLM) offers significant benefits, including geometric freedom and rapid production, when compared with traditional manufacturing techniques. However, the materials available for SLM production remain limited, restricting the industrial adoption of the technology. The mechanical properties and microstructure of many aluminium alloys have not been fully explored, as their manufacturability using SLM is extremely challenging. This study investigates the effect of laser power, hatch spacing and scanning speed on the mechanical and microstructural properties of as-fabricated aluminium 2024 alloy (AA2024) manufactured using SLM. The results reveal that almost crack-free structures with high relative density (99.9%) and Archimedes density (99.7%) have been achieved. It is shown that when using low energy density (ED) levels, large cracks and porosities are a major problem, owing to incomplete fusion; however, small gas pores are prevalent at high-energy densities due to the dissolved gas particles in the melt pool. An inversely proportional relationship between ED and microhardness has also been observed. Lower ED decreases the melt pool size and temperature gradients but increases the cooling rate, creating a fine-grained microstructure, which restricts dislocation movement, therefore increasing the microhardness. The highest microhardness (116 HV 0.2 ), which was obtained from one of the lowest EDs used (100 J/mm 3 ), is 45% higher than as-cast AA2024-0, but 17% lower than wrought AA2024-T6 alloy.

In the current investigation, AA2024 aluminum alloy is reinforced by alumina nanoparticles using a friction stir process (FSP) with multiple passes. The mechanical properties and microstructure observation are conducted experimentally using tensile, microhardness, and microscopy analysis methods. The impacts of the process parameters on the output responses, such as mechanical properties and microstructure grain refinement, were investigated. The effect of multiple FSP passes on the grain refinement, and various mechanical properties are evaluated, then the results are conducted to train a hybrid artificial intelligence predictive model. The model consists of a multilayer perceptrons optimized by a grey wolf optimizer to predict mechanical and microstructural properties of friction stir processed aluminum alloy reinforced by alumina nanoparticles. The inputs of the model were rotational speed, linear processing speed, and number of passes; while the outputs were grain size, aspect ratio, microhardness, and ultimate tensile strength. The prediction accuracy of the developed hybrid model was compared with that of standalone multilayer perceptrons model using different error measures. The developed hybrid model shows a higher accuracy compared with the standalone model.

The primary objective of this study is to determine the most effective solution treatment and aging temperature for AA2024 aluminum alloy to achieve superior mechanical properties. In this research, a Severe Plastic Deformation (SPD) method known as Multi-Directional Forging (MDF), which is one of the useful methods for creating Ultra-Fine Grained (UFG) microstructure, was employed on AA2024. Due to the limited studies on the effects of artificial aging on this alloy in its supersaturated state following the MDF process, the alloy was subjected to solution treatments at 480 °C, 500 °C, and 520 °C for 1 h, followed by immediate MDF. Aging was then performed at 100 °C, 140 °C, 190 °C, 240 °C, and 290 °C for 1 h each, to achieve artificial aging. To investigate the microstructure and precipitate conditions, Optical Microscopy (OM) and Field Emission Scanning Electron Microscopy (FE-SEM) were used to analyze the cross-sectional surfaces of the samples. Mechanical properties were evaluated through hardness and compression tests. The study reveals that the sample solution-treated at 520 °C exhibited the highest hardness and yield stress compared to those treated at 480 °C and 500 °C. The hardness of MDF samples increased from 82 HV to 165 HV as the aging temperature rose to 140 °C, where the highest hardness, flow stress, and yield strength were observed. At 190 °C for aging temperature, full recrystallization occurred, and at 240 °C and 290 °C, grain growth was observed, leading to a decrease in hardness, 128 HV and 97 HV, and yield strength, 505 MPa and 386 MPa, respectively. The results demonstrate that a solution treatment at 520 °C followed by artificial aging at 140 °C produces the best mechanical properties and microstructural characteristics in the AA2024 alloy, achieving the flow stress of 791 MPa and yield stress of 621 MPa.

The present work investigates the Rotary Friction Welding (RFW) of similar AA2024 and dissimilar AA2024/TA6V RFW joints. The effect of friction time on the evolution of microstructure and mechanical properties was investigated to determine the optimal friction time. It was found that the increase of friction time from 2 s to 10 s resulted in improved gradually the mechanical properties of both AA2024/AA2024 and AA2024/TA6V RFW joints and shifted the fracture location from the central zone towards the AA2024 material for the AA2024/TA6V RFW dissimilar joint. The highest tensile strength values recorded were 272.54 MPa and 254.47 MPa for the similar AA2024/AA2024 and the dissimilar AA2024/TA6V RFW joints respectively, both were achieved at 10 s friction time. Scanning electron microscopic (SEM) examination and Energy Dispersive X-ray (EDX) analysis indicated the formation of an interdiffusion band at the interface of the dissimilar AA2024/TA6V RFW joint, consisting of Cu, Al, Ti, Mg, and V atoms. Increasing the friction time enhanced the material mixing and led to the alteration of the fracture mode.

The employment of a green manufacturing process can directly save energy and materials in industrial sectors. Single Point Incremental Forming (SPIF) is an agile and flexible method of fabricating sheet material components and exempts the use of dedicated die-sets which further makes it a choice of green manufacturing. Furthermore, the customized components can be easily fabricated by SPIF economically. The surface quality of fabricated parts can greatly decide the suitability and sustainability of the process in various applications. This work investigates the impact of significant process factors on the roughness of the parts during the SPIF process. The average roughness has been considered to determine the surface quality. The increment in the value of wall angle and step size resulted in the increment in Ra value of formed components drastically. It was also observed that as the forming angle was raised from a lower level (60°) to a higher level (68°), the Ra value was found to increase significantly.

Rapid investment casting (RIC) based on additive manufacturing has been widely applied in the casting industry owing to its rapid production of patterns and components of free-form and complex geometries without tooling, which is highly desirable for multiple industries. However, high-performance Al-Cu-Mg alloys like AA2024, renowned for their exceptional strength and fatigue resistance, have traditionally posed significant challenges for investment casting. These alloys are prone to hot cracking and other shrinkage defects due to the slow solidification process involved. In this study, nanoparticles are used to enable the rapid investment casting of AA2024 without any cracks or shrinkage defects. Nanotechnology-enabled RIC of AA2024 is successfully demonstrated to offer good casting quality and extraordinary mechanical performance. This work shows great potential for nanotechnology-enabled RIC of other high-strength aluminum alloys for widespread applications.

The emphasis on dissimilar joining of aluminum alloys has increased due to the growing need for lightweight, highly durable structures in the transportation and aerospace industries. For these applications, friction stir welding (FSW), a solid‐state joining technology that offers better structural integrity than traditional fusion techniques, has proven very successful. The force‐torque behavior and mechanical characteristics of friction stir welded dissimilar aluminum alloys, AA7075 and AA2024, with and without titanium diboride (TiB 2 ) reinforcement, are investigated in this work in relation to the tool velocity ratio ( ω / v ). With a constant rotational speed of 1000 rpm and a 1.5° tilt angle, a cylindrical taper tool (3 mm tip, 6 mm length) was used. The traverse speeds were varied to 1, 2, 3, and 4 mm/s, yielding velocity ratios of 1000, 500, 333, and 250, respectively. To evaluate the impact of the TiB 2 powder on joint performance, it was injected via machined grooves at the faying surfaces. The microstructural improvement, primarily grain refinement through dynamic recrystallization and Zener pinning effects from TiB 2 particles, significantly enhanced the hardness and tensile strength of the welds. Enhanced particle dispersion and metallurgical bonding were responsible for the superior mechanical response. Because of better metallurgical bonding, grain refinement, and particle dispersion, reinforced welds demonstrated superior characteristics in microstructural, tensile, and hardness tests, particularly at higher velocity ratios (lower traverse speeds). At a velocity ratio of 1000 (1 mm/s), the reinforced samples showed the highest tensile strength (219.5 MPa), elongation (6.9%), and improved microhardness, resulting in peak joint performance. Conversely, unreinforced welds with coarser microstructures and worse mechanical properties were found at lower velocity ratios. These results provide practical advice for dissimilar alloy FSW applications in advanced engineering systems and validate that a high tool velocity ratio in conjunction with TiB 2 reinforcement is essential for maximizing weld integrity and mechanical behavior.

This study investigated the effect of the friction stir welding rotation rate and welding speed on the quality and properties of the dissimilar joints between aluminum and carbon steel. Plates of 4 mm thickness from both AA2024 and AISI 1018 were successfully friction stir butt welded at rotation speeds of 200, 250, and 300 rpm and welding speeds of 25, 50, and 75 mm/min. The joint quality was investigated along the top surface and the transverse cross-sections. Further investigation using scanning electron microscopy was conducted to assess the intermetallic layers and the grain refining in the stir zone. The mechanical properties were investigated using tensile testing for two samples for each weld that wire cut perpendicular to the welding direction and the hardness profiles were obtained along the transverse cross-section. Both the top surface and the transverse cross-section macrographs indicated defect free joints at a rotation rate of 250 rpm with the different welding speeds. The intermetallic compounds (IMCs) formation was significantly affected by the heat input, where there is no formation of IMCs at the Al/steel interfaces when higher traverse speed (75 mm/min) or lower rotation speed (200 rpm) were used, which gave the maximum tensile strength of about 230 MPa at the low rotation speed (200 rpm) along with 3.2% elongation. This is attributed to the low amount of heat input (22.32 J/mm) experienced. At the low traverse speed (25 mm/min and 250 rpm), a continuous layer of Al-rich IMCs FeAl3 is formed at the joint interface due to the high heat input experienced (79.5 J/mm). The formation of the IMCs facilitates fracture and reduced the tensile strength of the joint to about 98 MPa. The fracture mechanism was found to be of mixed mode and characterized by a cleavage pattern and dimples. The hardness profiles indicated a reduction in the hardness at the aluminum side and an increase at the steel side.