Microstructure and mechanical properties of Al-7075 alloy processed by equal channel angular pressing combined with aging treatment

Shaeri, M.H.; Salehi, Mohammad Taghi; Seyyedein, S. H.; Abutalebi, M. R.; Park, Joong Keun

doi:10.1016/j.matdes.2014.01.008

Cited by 168 publications

(57 citation statements)

References 37 publications

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“…This can be due to a decreasing of the internal strains and accumulation of internal energy, therefore, increasing the possibility for crack formation, or it can be related to the increase of the strain rate sensitivity of the material, which causes resistance to neck formation. This improvement of the mechanical properties of material behavior using the ECFE process has also been reported for Al1050, Al6061, Al7075, and nickel during the ECAP process [26,27,29,30] and Al-3%Mg-0.2%Sc during the HPT process [31]. In addition, the ECAP process on the same material, reported by Tolaminejad and Dehghani [32], indicated that about 64% and 108% enhancement of the hardness value and approximately 202% and 267% improvement at the yield strength magnitude have been achieved after the first and fourth passes when compared to the annealed condition.…”

Section: Mechanical Propertiessupporting

confidence: 77%

Experimental Investigation of the Equal Channel Forward Extrusion Process

Ebrahimi

Djavanroodi

Tiji

et al. 2015

Metals

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Among all recognized severe plastic deformation techniques, a new method, called the equal channel forward extrusion process, has been experimentally studied. It has been shown that this method has similar characteristics to other severe plastic deformation methods, and the potential of this new method was examined on the mechanical properties of commercial pure aluminum. The results indicate that approximate 121%, 56%, and 84% enhancements, at the yield strength, ultimate tensile strength, and Vickers micro-hardness measurement are, respectively, achieved after the fourth pass, in comparison with the annealed condition. The results of drop weight impact test showed that the increment of 26% at the impact force, and also decreases of 32%, 15%, and 4% at the deflection, impulse, and absorbed energy, are respectively attained for the fourth pass when compared to the annealed condition. Furthermore, the electron backscatter diffraction examination revealed that the average grain size of the final pass is about 480 nm.

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Section: Mechanical Propertiessupporting

confidence: 77%

Experimental Investigation of the Equal Channel Forward Extrusion Process

Ebrahimi

Djavanroodi

Tiji

et al. 2015

Metals

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“…More recently, there is a growing interest in investigating the coupling effect of grain refinement and the introduction of dislocations and precipitation on the strength of Al alloys [13,14]. Very recent experiments showed that a UFG 7075 alloy processed by ECAP for only 4 passes achieved maximum tensile properties due to the presence of many fine η phases and minor quantities of GP zones distributed in fine grains having a size of less than 600 nm [15]. Another study showed that the yield strength of the 7005 alloy was remarkably increased after 7 ECAP passes due to a combination of precipitation strengthening, dislocation strengthening and grain boundary strengthening [16].…”

Section: Introductionmentioning

confidence: 99%

Effect of ECAP processing on microstructure evolution and dynamic compressive behavior at different temperatures in an Al-Zn-Mg alloy

Afifi

Pereira

Wang

et al. 2017

Materials Science and Engineering: A

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An artificially aged Al-Zn-Mg alloy with a grain size of ~ 1.3 m was processed by equalchannel angular pressing (ECAP) and then subjected to dynamic compression at a strain rate of 4000 s -1 in the range from room temperature to 673 K. The results show the η phase is refined and a η phase is formed during the first pass of ECAP and after further processing 8 passes the GP zones are removed. An ultrafine-grained (UFG) structure with an average grain size of ~200 nm was obtained after 4 passes. It is shown that dynamic compressive deformation assists the precipitation process through precipitate coalescence and by changing the precipitate orientations.The dynamic compressive yield strengths and flow stresses decrease gradually to different degrees with increasing temperature except after ECAP processing for 4 passes where there is thermal stability up to 473 K. The ECAP processing significantly improves the strength of the alloy at elevated temperatures by comparison with the as-received material.

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“…An important and effective way to approach the superior properties is by refining the structure, within 2 of 12 which thermal-mechanical heat treatment and severe plastic deformation have been developed in the past decade. Severe plastic deformation techniques, such as equal-channel accumulative roll bonding [12], angular pressing [13], high-pressure torsion, and friction stir processing [14], are effective approaches to refine the microstructure. However, the above techniques yield small sizes and quantities in the laboratory, but are not suitable for industrialized production [15].…”

Section: Introductionmentioning

confidence: 99%

Hot Deformation Behavior of a Spray-Deposited Al-8.31Zn-2.07Mg-2.46Cu-0.12Zr Alloy

Sheng

Lei

Xiao

et al. 2017

Metals

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Abstract:Metallic materials have a significant number of applications, among which Al alloys have drawn people's attention due to their low density and high strength. High-strength Al-based alloys, such as 7XXX Al alloys, contain many alloying elements and with high concentration, whose microstructures present casting voids, segregation, dendrites, etc. In this work, a spray deposition method was employed to fabricate an Al-8.31Zn-2.07Mg-2.46Cu-0.12Zr (wt %) alloy with fine structure. The hot deformation behavior of the studied alloy was investigated using a Gleeble 1500 thermal simulator and electron microscopes. The microstructure evolution, variation in the properties, and precipitation behavior were systematically investigated to explore a short process producing an alloy with high property values. The results revealed that the MgZn 2 particles were detected from inside the grain and grain boundary, while some Al 3 Zr particles were inside the grain. An Arrhenius equation was employed to describe the relationship between the flow stress and the strain rate, and the established constitutive equation was that: Figure 7 gives the hardness variations of the hot compressed samples aged at 120 • C fo durations. For the samples after being hot-compressed at strain rates of 1 s −1 and 0.001 s −1 , present the same trend. The initial hardness of compressed samples increased with the hot de temperature. The hardness of the hot-compressed samples increased with the aging time, a kept constant as they were aging at certain temperatures for 15 h.Metals 2017, 7, 299 deformation temperature. The hardness of the hot-compressed samples increased with the and almost kept constant as they were aging at certain temperatures for 15 h. Discussion Constitutive EquationThe constitutive relationships were used to describe the hot deformation behavior. Som are employed to reveal the hot deformation behavior, in which one of the most extended v the hot working constitutive equation is as follows [24]:where ε is the strain rate; A is a material constant which is independent of temperature true stress; Q is the activation energy; R is the gas constant (8.31); and T is the absolute tem (K). At low stress lever (ασ < 0.8):At high stress lever (ασ > 1.2):(σ) σ n F  , β and n are the material constants, α = β/n. Substituting Equations (2) and (3) (4) and (5), respectively, gives:The values of n and β are from the slopes of the lines in ln ε and σ, lnε and ln σ , Discussion Constitutive EquationThe constitutive relationships were used to describe the hot deformation behavior. Som are employed to reveal the hot deformation behavior, in which one of the most extended v the hot working constitutive equation is as follows [24]:where .ε is the strain rate; A is a material constant which is independent of temperature; σ is stress; Q is the activation energy; R is the gas constant (8.31); and T is the absolute tempera At low stress lever (ασ < 0.8):At high stress lever (ασ > 1.2): F(σ) = σ n , β and n are the material constants, α = β/n. Substit...

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Microstructure and mechanical properties of Al-7075 alloy processed by equal channel angular pressing combined with aging treatment

Cited by 168 publications

References 37 publications

Experimental Investigation of the Equal Channel Forward Extrusion Process

Experimental Investigation of the Equal Channel Forward Extrusion Process

Effect of ECAP processing on microstructure evolution and dynamic compressive behavior at different temperatures in an Al-Zn-Mg alloy

Hot Deformation Behavior of a Spray-Deposited Al-8.31Zn-2.07Mg-2.46Cu-0.12Zr Alloy

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