scholarly journals Effect of Artificial Aging Temperature on Mechanical Properties of 6061 Aluminum Alloy

Author(s):  
Mukesh Kumar ◽  
Muhammad Moazam Baloch ◽  
Muhammad Ishaque Abro ◽  
Sikandar Ali Memon ◽  
Ali Dad Chandio

Aluminum alloys have been attracted by several engineering sectors due to their excellent strengthweight ratio and corrosion resistant properties. These are categorized into 1, 2, 3, 4, 5, 6, 7and 8xxx on the basis of alloying elements. Among these 6xxx series contains aluminum–magnesium–silicon as alloying elements and are widely used in extruded products and automotive body panels. The major advantages of these alloys are good corrosion resistance, medium strength, low cost, age hardening response no yield point phenomenon and Ludering. 6xxx series alloys generally have lower formability than other aluminum alloys which restrict their utilization for wide applications. Keeping in view of the shortcomings in the set of mechanical properties of 6xxx series the efforts were made to improve the tensile strength and toughness properties through age hardening. In present study heat treatment cycles were studied for 6061 aluminum alloy. Three different age hardening temperatures 160, 200 and 240oC were selected. The obtained results showed that 17.26, 7.69, and 10.51% improvement in tensile strength, toughness and hardness respectively was achieved with solution treatment at 380oC followed by an aging 240oC. Microstructural study revealed that substantial improvements in the mechanical properties of 6061 aluminum alloy under heat treatment were achieved due to precipitation of Mg2Si secondary phase.

2006 ◽  
Vol 114 ◽  
pp. 91-96 ◽  
Author(s):  
Maxim Yu. Murashkin ◽  
M.V. Markushev ◽  
Julia Ivanisenko ◽  
Ruslan Valiev

The effects of equal channel angular pressing (ECAP), further heat treatment and rolling on the structure and room temperature mechanical properties of the commercial aluminum alloys 6061 (Al-0.9Mg-0.7Si) and 1560 (Al-6.5Mg-0.6Mn) were investigated. It has been shown that the strength of the alloys after ECAP is higher than that achieved after conventional processing. Prior ECAP solution treatment and post-ECAP ageing can additionally increase the strength of the 6061 alloy. Under optimal ageing conditions a yield strength (YS) of 434 MPa and am ultimate tensile strength (UTS) of 470 MPa were obtained for the alloy. Additional cold rolling leads to a YS and UTS of 475 and 500 MPa with 8% elongation. It was found that the post-ECAP isothermal rolling of the 1560 alloy resulted in the formation of a nano-fibred structure and a tensile strength (YS = 540 MPa and UTS = 635 MPa) that has never previously been observed in commercial non-heat treatable alloys.


Author(s):  
Mohammad W. Dewan ◽  
Muhammad A. Wahab ◽  
Khurshida Sharmin

Friction Stir Welding (FSW) offers significantly better performance on aluminum alloy joints compared to the conventional fusion arc welding techniques; however, plastic deformation, visco-plastic flow of metals, and complex non-uniform heating cycles during FSW processes, result in dissolution of alloying elements, intrinsic microstructural changes, and post-weld residual stress development. As a consequence, about 30% reduction in ultimate strength (UTS) and 60% reduction in yield strength (YS) were observed in defect-free, as-welded AA2219-T87 joints. PWHT is a common practice to refine grain-coarsened microstructures which removes or redistributes post-weld residual stresses; and improves mechanical properties of heat-treatable welded aluminum alloys by precipitation hardening. An extensive experimental program was undertaken on PWHT of FS-welded AA2219-T87 to obtain optimum PWHT conditions and improvement of the tensile properties. Artificial age-hardening (AH) helped in the precipitation of supersaturated alloying elements produced around weld nugget area during the welding process. As a result, an average 20% improvement in YS and 5% improvements in UTS was observed in age-hardened (AH-170°C-18h) specimens as compared to AW specimens. To achieve full benefit of PWHT, solution-treatment followed by age-hardening (STAH) was performed on FS-welded AA2219-T87 specimens. Solution-treatment (ST) helps in the grain refinement and formation of supersaturated precipitates in aluminum alloys. Age-hardening of ST specimens help in the precipitation of alloying elements around grain boundaries and strengthen the specimens. Optimum aging period is important to achieve better mechanical properties. For FS-welded AA2219-T87 peak aging time was 5 hours at 170°C. STAH-170°C -5h treated specimens showed about 78% JE based on UTS, 61% JE based on yield strength, and 36% JE based on tensile toughness values of base metal.


2014 ◽  
Vol 566 ◽  
pp. 409-414 ◽  
Author(s):  
Yuki Kitani ◽  
Keitaro Horikawa ◽  
Hidetoshi Kobayashi ◽  
Kenichi Tanigaki ◽  
Tomo Ogura ◽  
...  

The effect of impact compression on age hardening behavior was examined for Meso20 and 6061 aluminum alloys using a single stage gun. The hardness of Meso20 and 6061 aluminum alloy applied with an impact compression (about 5.0GPa) after the solution treatment increased with the aging time. The cluster of point defects like stacking fault tetrahedral (SFT) was observed in the 6061 aluminum alloys with the impact compression (5.3GPa) after the solution treatment. Even after the impact compression, distribution of the aging precipitates was clearly identified.


2013 ◽  
Vol 829 ◽  
pp. 62-66 ◽  
Author(s):  
Alireza Fallahi ◽  
Hossein Hosseini-Toudeshky ◽  
Seyed Mahmoud Ghalehbandi

It is the objective of this study to investigate the effect of ECAP processing and heat treatment on the mechanical properties of the UFG 7075 alloy. Also the effect of post ECAP heat treatment is investigated. The alloy is processed by ECAP after annealing as well as solution treatment to produce an UFG structure. Furthermore mechanical properties and their variations during annealing and aging are investigated. The hardness of the pre-ECAP annealed and the pre-ECAP solutionised 7075 aluminum alloy has increased significantly compared with that of the CG sample. Also hardness of ECAPed specimen has not experienced significant changes in post-ECAP heat treatment and indicated that the alloy had approximately good thermal stability.


Metals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 790 ◽  
Author(s):  
Changping Tang ◽  
Kai Wu ◽  
Wenhui Liu ◽  
Di Feng ◽  
Xuezhao Wang ◽  
...  

The effects of Gd, Y content on the microstructure and mechanical properties of Mg-Gd-Y-Nd-Zr alloy were investigated using hardness measurements, X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), and uniaxial tensile testing. The results indicate that the alloys in as-cast condition mainly consist of α-Mg matrix and non-equilibrium eutectic Mg5.05RE (RE = Gd, Y, Nd). After solution treatment, the non-equilibrium eutectics dissolved into the matrix but some block shaped RE-rich particles were left at the grain boundaries and within grains. These particles are especially Y-rich and deteriorate the mechanical properties of the alloys. Both the compositions of the eutectic and the block shaped particle were independent of the total Gd, Y content of the alloys, but the number of the particles increases as the total Gd, Y content increases. The ultimate tensile strength increases as the total Gd, Y content decreases. A Mg-5.56Gd-3.38Y-1.11Nd-0.48Zr alloy with the highest ultimate tensile strength of 280 MPa and an elongation of 1.3% was fabricated. The high strength is attributed to the age hardening behavior and the decrease in block shaped particles.


Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4157 ◽  
Author(s):  
Isidro Guzmán ◽  
Everardo Granda ◽  
Jorge Acevedo ◽  
Antonia Martínez ◽  
Yuliana Dávila ◽  
...  

Precipitation hardening aluminum alloys are used in many industries due to their excellent mechanical properties, including good weldability. During a welding process, the tensile strength of the joint is critical to appropriately exploit the original properties of the material. The welding processes are still under study, and gas metal arc welding (GMAW) in pulsed metal-transfer configuration is one of the best choices to join these alloys. In this study, the welding of 6061 aluminum alloy by pulsed GMAW was performed under two heat treatment conditions and by using two filler metals, namely: ER 4043 (AlSi5) and ER 4553 (AlMg5Cr). A solubilization heat treatment T4 was used to dissolve the precipitates of β”- phase into the aluminum matrix from the original T6 heat treatment, leading in the formation of β-phase precipitates instead, which contributes to higher mechanical resistance. As a result, the T4 heat treatment improves the quality of the weld joint and increases the tensile strength in comparison to the T6 condition. The filler metal also plays an important role, and our results indicate that the use of ER 4043 produces stronger joints than ER 4553, but only under specific processing conditions, which include a moderate heat net flux. The latter is explained because Mg, Si and Cu are reported as precursors of the production of β”- phase due to heat input from the welding process and the redistribution of both: β” and β precipitates, causes a ductile intergranular fracture near the heat affected zone of the weld joint.


2013 ◽  
Vol 690-693 ◽  
pp. 44-48
Author(s):  
Feng Wang ◽  
Zhi Wang ◽  
Zheng Liu ◽  
Ping Li Mao

In this paper, developed a non-aluminum die casting magnesium alloys were studied based on Mg-xGd-Y-Zr(x=6, 8, 12 wt.%)alloys in cold chamber press. The microstructures and mechanical properties of die casting GWK alloys have been investigated using OM, SEM, XRD, EDS and mechanical property test. The experimental results show that with increasing Gd content of Mg-xGd-Y-Zr alloys, the tensile strength increase, but elongation decrease. In particular, die casting GWK alloys after short-term and low-temperature solid solution treatment (T4) have a small variation in grain size and more uniform microstructures, and the second phases distribute at the grain boundaries in form of discontinuous rod shape or granule shape, which result in an obvious improvement in tensile mechanical properties of alloys. The Mg-12Gd-3Y-0.5Zr die casting alloy exhibit maximum tensile strength after solution heat treatment, and the value is 269MPa at room temperature. The effect of solution heat treatment on die casting Mg-xGd-Y-Zr alloys was also discussed.


2017 ◽  
Vol 67 (2) ◽  
pp. 109-116
Author(s):  
Branislav Vanko ◽  
Ladislav Stanček ◽  
Roman Moravčík

AbstractBy using the wrought aluminum alloys can be created castings with higher mechanical properties than the castings made of standard foundry aluminum alloys, but it is necessary to handle the process of making sound castings without any defects such as hot tears and shrinkage porosity. In experiments, we have been studied of wrought aluminum alloy EN AW-2024 which has been processed by the casting with crystallization under pressure with forced flow. Castings were heat treated by standard T6 heat treatment.


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