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Al-Zn-Mg-Cu alloys are the strongest aluminum alloys which have been widely used for aerospace applications. They are usually machined from the wrought state usually with a high waste percentage. To reduce waste, it is important to thixoform these alloys in near net shape. In this work, the thixoformability of a commercial high performance Al-Zn-Mg...
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... shown in Fig. 3, the microstructure consists of elongated and fibroid grains with some dispersed particles, indicating the alloy has not recrystal- lized even after T6 heat treatment. Figure 4 shows the longitudinal SEM image and EDS patterns of as-received 7075 alloy. As shown in Fig. 4, some intermetallic compound particles are distributed along the extru- sion direction, which contain much Cu, Fe and Mn ( Fig. Fig. 2. Thixoformed wheel-shaped components. ...
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... optical micrograph of the extruded 7075 aluminum alloy. As shown in Fig. 3, the microstructure consists of elongated and fibroid grains with some dispersed particles, indicating the alloy has not recrystal- lized even after T6 heat treatment. Figure 4 shows the longitudinal SEM image and EDS patterns of as-received 7075 alloy. As shown in Fig. 4, some intermetallic compound particles are distributed along the extru- sion direction, which contain much Cu, Fe and Mn ( Fig. Fig. 2. Thixoformed wheel-shaped components. (Fig. 4(c)). Figure 5 shows the longitudinal microstructures of 7075 alloy partially remelted at 620 ° C for different holding times. As shown in Fig. 5, the alloy ...
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... the alloy has not recrystal- lized even after T6 heat treatment. Figure 4 shows the longitudinal SEM image and EDS patterns of as-received 7075 alloy. As shown in Fig. 4, some intermetallic compound particles are distributed along the extru- sion direction, which contain much Cu, Fe and Mn ( Fig. Fig. 2. Thixoformed wheel-shaped components. (Fig. 4(c)). Figure 5 shows the longitudinal microstructures of 7075 alloy partially remelted at 620 ° C for different holding times. As shown in Fig. 5, the alloy recrystallized at 620 ° C with liquid penetrating the recrystallized boundaries. Some elongated unrecrystallized grains still exist in the microstructure after remelting for 10 min ...
Citations
... The ER5356 joint shows more severe and higher pit contents in both passes relative to the AW condition owing to dispersion of the anodic β-Al 2 Mg 3 at the grain boundaries and within the grains (Figure 4d). Figure 11 illustrates the pitting corrosion in detail for both the AW and PWHT joints. The BM pits are elongated in the extrusion direction (Figure 11a) owing to the distribution of intermetallics in the extrusion direction (Figure 4a) [54]. The intermetallics, such as Q-AlMgSiCu and the Fe-rich phases, act as cathodes relative to the matrix; hence, the material around such phases is dissociated. ...
... Figure 11e illustrates a case of aggressive corrosion observed in the AW ER5356 joint, where the pits are found not only at the dispersed β-Al 2 Mg 3 phase but also throughout the matrix, leading to coalescence of the pits and severe damage of the FZ. to the AW condition owing to dispersion of the anodic β-Al2Mg3 at the grain boundaries and within the grains (Figure 4d). Figure 11 illustrates the pitting corrosion in detail for both the AW and PWHT joints. The BM pits are elongated in the extrusion direction (Figure 11a) owing to the distribution of intermetallics in the extrusion direction (Figure 4a) [54]. The intermetallics, such as Q-AlMgSiCu and the Fe-rich phases, act as cathodes relative to the matrix; hence, the material around such phases is dissociated. ...
In this study, the welding performance of three filler wires, ER4043, ER5356, and the newly developed FMg0.6, were systematically investigated in the gas metal arc welding of high-strength AA6011-T6 plates. An extensive analysis of the microstructural evolution, mechanical properties, fatigue resistance, and corrosion behavior of different weldments was conducted. The ER4043 and FMg0.6 joints exhibited finer grain sizes in the fusion zone (FZ) than the ER5356 joint. The as-welded ER5356 and FMg0.6 joints exhibited higher hardness and tensile strength values than the ER4043 joint. The FMg0.6 joint demonstrated the highest mechanical strength among all of the joints with superior fatigue resistance under both the as-welded and post-weld heat treatment (PWHT) conditions. In the as-welded state, the ER5356 joint exhibited the lowest corrosion resistance, attributed to the precipitation of β-Al2Mg3 at the grain boundaries. The FMg0.6 joint, characterized by a high-volume fraction of eutectic Mg2Si in the as-welded state, exhibited a higher corrosion rate than that of the ER4043 joint. However, the PWHT effectively improved the corrosion resistance of the FMg0.6 joint. Given its excellent tensile properties, superior fatigue properties, and satisfactory corrosion resistance, particularly with PWHT, the newly developed FMg0.6 filler has emerged as a promising candidate for welding high-strength 6xxx alloys.
... Nicolas (2002) stated in his dissertation that this phase can be presented as MgZn 2 , but there is a strong possibility for copper to be present in this so-called η' phase. Many authors have focused their research on the mechanical properties of the EN AW-7075 aluminium alloy during different heat treatments (Panigrahi and Jayaganthan, 2011;Fallahi et al., 2013;Kacar and Guleryuz, 2015;Chen et al., 2015;Ozer and Karaaslan, 2017;Ku et al., 2018;Kilic et al., 2019;Cai et al., 2020). Kacar and Guleryuz (2015) showed that the quench rate, pre-straining as well as the ageing temperature and time, play an important role in the precipitation hardening. ...
... Dos Santos et al. (2021) stated that this phase appears in a white colour after etching the sample with Dix-Keller solution as in this investigation. Similar results were obtained by Chen et al. (2015) and Ku et al. (2018). The S2 spectrum in Fig. 6a ( Table 2) may indicate the presence of the Al 7 Cu 2 Fe phase, which remained undissolved in the solid solu- tion by previous annealing. ...
The influence of the ageing temperature on the hardness, electrical conductivity, thermal diffusivity and thermal conductivity of the EN AW-7075 aluminium alloy was studied in this paper. After solution treating the alloy at 480 °C for 1 h and quenching it in ice water, the investigated alloy was characterized using Differential Thermal Analysis (DTA) in order to determine the optimal temperatures for the isochronal ageing treatments. Afterwards, isochronal ageing was conducted at the temperature range of 110 °C-250 °C for 30 min The hardness, electrical conductivity, thermal diffusivity, thermal conductivity and microstructural features were investigated during the ageing treatments. Hardness had a peak value after ageing at 150 °C, while other properties gradually increased with the ageing temperature. Microstructural investigation of the aged alloy by SEM-EDS revealed the existence of precipitated phases that appear homogenously distributed in the microstructure.
... Both of the kinds and quantities of process parameter are the same in all BDS and TDS samples. Fig. 9 Comparison of ultimate tensile strength and elongation of high-strength aluminum alloy 6,[38][39][40][41][42][43][44][45][46][47][48][49][50] . CP is the conventional industrial production process, SD is the spray deposition process, PM is the powder metallurgy process, and SPD is the severe plastic deformation process. ...
One of the challenges in material design is to rapidly develop new materials or improve the performance of materials by utilizing the data and knowledge of existing materials. Here, a rapid and effective method of alloy material design via data transfer learning is proposed to efficiently design new alloys using existing data. A new type of aluminum alloy (E2 alloy) with ultra strength and high toughness previously developed by the authors is used as an example. An optimal three-stage solution-aging treatment process (T66R) was efficiently designed transferring 1053 pieces of process-property relationship data of existing AA7xxx commercial aluminum alloys. It realizes the substantial improvement of strength and plasticity of E2 alloy simultaneously, which is of great significance for lightweight of high-end equipment. Meanwhile, the microstructure analysis clarifies the mechanism of alloy performance improvement. This study shows that transferring the existing alloy data is an effective method to design new alloys.
... The E2 alloy is prepared through the same process as the CP process in conventional industrial production, breaking through the performance boundary of the existing high-strength aluminum alloy and achieving a significant improvement in its strength and ductility. Fig. 9 Comparison of ultimate tensile strength and elongation of high-strength aluminum alloy [6,[40][41][42][43][44][45][46][47][48][49][50][51][52]. CP is the conventional industrial production process, SD is the spray deposition process, PM is the powder metallurgy process, and SPD is the severe plastic deformation process. ...
One of the challenges in material design is to rapidly develop new materials or improve the performance of materials by utilizing the data and knowledge of existing materials. Here, a novel method of alloy material design via data transfer learning is proposed to efficiently design new alloys using existing data. A new type of aluminum alloy with ultra strength and high toughness (so-called E2 alloy) previously developed by the authors is used as an example, and an optimal three-stage solution-aging treatment process (which is very difficult to design by trial-and-error method, T66R process for short) was rapidly designed based on 1053 pieces of heat treatment process data of AA7xxx series commercial high-strength aluminum alloy and a total of 29 groups of experimental data of E2 alloy. It overcomes the bottleneck of expensive theoretical calculations and more than millions of possible process combinations in the experimental trial-and-error space in the process design of complex alloy heat treatment. Compared with the common T6 process in the aluminum industry, the T66R process can increase the ultimate tensile strength and elongation of the E2 alloy simultaneously, from 715 ± 6 MPa and 8.4 ± 0.4% to 767 ± 6 MPa and 13.4 ± 0.5%, respectively. The results of microstructure characterization indicate that employing the optimal T66R process, the amount of micron-scale insoluble phases in the E2 alloy is sharply reduced, and the number of nano-precipitates is significantly increased, which leads to the simultaneous improvement of the strength and plasticity of the alloy. This study shows that transferring the existing alloy data is an effective method to design new alloys.
... Under the influence of the rotating tool, friction is induced which increases the temperature of the sheet material in contact with the drilling tool. The temperature reaches 750 °C and 380 °C during thermal drilling of austenitic stainless steels and Al-alloys respectively [9,10]. The induced temperature softens the material in front IOP Publishing doi:10.1088/1757-899X/1172/1/012026 2 of the tool drill. ...
... The details of the friction drilling tool were discussed in our previous work [10]. The friction angle (is also defined as the tool cone angle) and the length of the conical region are referred as β and h n respectively. ...
... On the other hand, the maximum temperature during friction drilling of S8 and S21 recorded 292 ⁰C and 376 ⁰C respectively [10]. It seems that the higher the induced temperature during the friction drilling process, the lower the hardness of the induced bush of the 7075 Al-alloy. ...
The thickness of sheet metal parts can be locally increased by friction drilling technology via forming of a hole with a bush by a special drilling tool. Here, a 7075 Al-alloy was drilled by friction using tool cone angles with values of 40, 45 and 50° under different feed rates (100, 200 and 315 mm/min) and rotational speeds (1000, 1250 and 1600 rpm). The present study investigates the hardness distribution in the thermally-formed bush and in the heat-affected zone around the bush. It was found that the hardness of the bush was slightly increased with increasing of the tool cone angle and reduction of the tool rotational speed. However, the hardness of the thermally-induced bush showed values lower than the parent metal. The hardness near the drilling surface was approximately 65±10 HV, while it recorded hardness values of 75±10 HV at 5 mm away from the drilling surface. In addition, the microstructure of the friction drilled specimens showed a very fine structure in the drilling zone due to crushing of the original structure during the friction drilling process.
... The presence of defects and imperfections on the control alloys surface is noticeable, indicating the need for surface treatments to prepare for further deposition [16,33,34]. ...
Experiments reported in this paper issue on the behavior of two types of aluminum alloys (A2014 and A7075) before and after surface treatments. Each sample of alloys was cleaned and degreased in acetone by ultrasound, and the chemical roughening process involves two steps: etching in NaOH solution and desmutting in HNO3 solution, followed by washing with deionized water to remove the secondary reaction products.
The microstructural characterization and morphological analysis of the alloys surface before and after treatment processes were investigated by OM, FE-SEM, EDX and FTIR. Also, the effect of solutions on surface roughness of aluminum alloys was determined by variation of weight and thickness according to the applied process, and the hydrophilic or hydrophobic character was measured by determining the contact angle. The obtained results highlight the need for the alloy surface processing steps in order to ensure adhesion and good compatibility with different types of composite materials.
... In the mid-1990s, the mechanical assembly of automotive heat exchangers started using brazed Al alloys, and this trend is currently applied in the heat exchangers of air conditioners [7]. In air conditioners, AA 1xxx and AA 3xxx series alloys are used because automotive heat exchangers do not require high mechanical properties and these series have higher thermal transfer efficiency and are economic advantages [8]. ...
The multi-galvanic effect of an Al fin-tube heat exchanger was evaluated using polarization tests, numerical simulation, and the seawater acetic acid test (SWAAT). Determination of the polarization state using polarization curves was well correlated with numerical simulations using a high-conductivity electrolyte. However, the polarization results did not match those of the low-conductivity electrolyte due to the lower galvanic effect. Although the polarization state is changed by electrolyte conductivity, the total net current of the tube is decreased in the case of the anodic joint. From SWAAT results, the leakage time of Al fin-tube heat exchanger assembled by anodic joint was longer than the case with cathodic joint.
... Al-Si alloys are widely used in the aerospace, military, and automobile industries due to their superior castability and good balance of strength, ductility, and corrosion resistance. [1][2][3][4] However, under the conditions of traditional casting processes, Al-Si alloys usually contain massive coarse, or long needle or lamellar shape eutectic Si phases, which degrades the microstructure of alloy, and reduces the mechanical properties and decreases corrosion resistance. 5 The addition of rare earth (RE), Sr, Al 2 O 3 or ceramic elements, and the heat treatment 6 is an effective way to change the morphology and distribution of eutectic silicon phase in Al-Si alloys. ...
Aluminum matrix composites reinforced with SiC particles (SiCp) were prepared by electromagnetic stirring. This article aims to study the effects of SiCp addition on microstructure and mechanical properties of SiCp/ZL105, finally leading to expended range for ZL105 alloy application. Microstructural studies were carried out by optical microscope, scanning electron microscopy, and energy dispersive spectrometer. Tensile and hardness tests were conducted in order to identify mechanical properties. It was found that addition of 1.5 wt% SiCp causes the refined microstructure (including primary α-Al and eutectic Si) and reduced secondary dendrite arm spacing of α-Al matrix (12.6 μm). Compared to the ZL105 alloy, the ultimate tensile strength, elongation, and hardness of the composite with 1.5 wt% SiCp were increased by 24.6%, 37.3%, and 27.0%, respectively. The improved mechanical properties can mainly be attributed to the refinement of primary α-Al and eutectic Si, and uniformed dispersion of SiCp. Furthermore, the effects of voltage and agitation frequency of magnetic field on microstructure of composites were discussed.
... Applications of aluminum (Al) alloys have expanded across numerous industries due to their desirable properties, including their light weight, high heat conduction, and favorable electrical and mechanical characteristics [1]. One typical applications for an Al alloy is as a heat exchanger in an air conditioner [2][3][4][5]; notably, Al is a commonly used material for heat exchange because of its high formability, good specific strength, low density, and high thermal conductivity [6,7]. In addition, it is a more economical material than copper, which is the original material that is used in heat exchanger applications. ...
Corrosion resistance of Zr that has been added to an Al alloy (U1070) is higher than that of a commercial Al alloy (A1070). A decreasing number and size of Al3Fe intermetallic particles (IMPs) were observed by electron microprobe analysis and transmission electron microscopy. Based on the numerical corrosion simulation, it was confirmed that decreasing the number and size of IMPs was favorable for improving the corrosion resistance of the Al alloy due to the reduction of the galvanic effect. In addition, Al3Zr was found to be insignificant in promoting galvanic corrosion within the Al matrix. Thus, Zr is an advantageous alloying element for improving the corrosion resistance of the Al alloy
... Nowadays, the attention of the researchers is focused on the investigation of the properties of less conventional alloys for SSM processing, like AlSi8 [82], Al5Fe4Cu [83], Al-Zn-Mg-Cu [84], AlZnMg alloys with Sc addition [85], etc., in order to evaluate the advantages in their application as semi-solid manufactured products. ...
Semi-solid processing of aluminum alloys is a well-known manufacturing technique able to combine high production rates with parts quality, resulting in high performance and reasonable component costs. The advantages offered by semi-solid processing are due to the shear thinning behavior of the thixotropic slurries during the mold filling. This is related to the microstructure of these slurries consisting of solid, nondendritic, near-globular primary particles surrounded by a liquid matrix. This paper presents a review on the formation of this nondendritic microstructure, reports on the different proposed mechanisms that might be responsible, and illustrates the relationship between microstructure and properties, in particular, tensility, fatigue, wear, and corrosion resistance.
