Phase transformation and microstructure evolution of an ultra-high strength Al-Zn-Mg-Cu alloy during homogenization

Xu, Da; Li, Zhihui; Wang, Guojun; Li, Xiwu; Lv, Xinyu; Zhang, Yongan; Fan, Yunqiang; Xiong, Baiqing

doi:10.1016/j.matchar.2017.07.011

Cited by 84 publications

(25 citation statements)

References 29 publications

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“…High strength 7xxx series (Al-Zn-Mg) alloys are widely used in the aerospace and automobile industries as structural materials [1,2]. Processing by severe plastic deformation (SPD) as in equal-channel angular pressing (ECAP) [3][4][5][6] is recognized as an effective strategy to enhance the mechanical properties of Al alloys by producing ultrafine-grained (UFG) microstructures with high densities of dislocations.…”

Section: Introductionmentioning

confidence: 99%

Characterization of precipitates in an Al-Zn-Mg alloy processed by ECAP and subsequent annealing

Afifi

Wang

Pereira

et al. 2018

Materials Science and Engineering: A

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Experiments were conducted to examine the influence of equal-channel angular pressing (ECAP) and post-ECAP annealing on the microstructures of an Al-Zn-Mg alloy. The results show that precipitates, mainly of the η', η (MgZn 2), T (Al 20 Cu 2 Mn 3) and E (Al 18 Mg 3 Cr 2) phases, are fragmented to fine spherical precipitates during ECAP processing for 4 and 8 passes. After post-ECAP annealing at 393 and 473 K for 20 h, precipitates with larger sizes lie primarily along the grain boundaries and finer particles are evenly distributed within the grains. Increasing the numbers of ECAP passes from 4 to 8 leads to an increase in the volume fraction of the finer precipitates in the ECAP-processed and annealed alloy. After 4 passes and heat treatment at 473 K, the precipitates are slightly larger compared with the alloy processed under identical conditions and annealed at 393 K. Nevertheless, significant coarsening is evident after processing for 8 passes and increasing the annealing temperature from 393 to 473 K. Different types of precipitates are effective in impeding grain growth during the post-ECAP annealing even at 473 K for 20 h. In addition, η precipitates form within the T and E phases after both ECAP and post-ECAP annealing.

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Section: Introductionmentioning

confidence: 99%

Characterization of precipitates in an Al-Zn-Mg alloy processed by ECAP and subsequent annealing

Afifi

Wang

Pereira

et al. 2018

Materials Science and Engineering: A

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“…The white, gray, and dark gray second phase precipitates are shown in the matrix. The research results of Xu [43] and Wen [44] showed that the precipitates of as-cast Al-Zn-Mg-Cu alloy are mainly composed of Mg(Zn,Cu,Al) 2 -, S(Al 2 CuMg)-, θ(Al 2 Cu)-, and iron-rich-phases. The primary precipitates in the syntactic foam matrix were analyzed by EDS ( Fig.…”

Section: Quasi-static Compression Testingmentioning

confidence: 99%

“…This result is closely related to the microstructure of the matrix. The S(Al 2 CuMg)-phase in the eutectic structure of (α + S) is a brittle phase [43,44,52]. At 800 • C, the amount of S(Al 2 CuMg)-phase is less, and the size of the eutectic group is small.…”

Section: Compressive Propertiesmentioning

confidence: 99%

Microstructure and compressive properties of aluminum matrix syntactic foams containing Al2O3 hollow particles

Rao¹,

Yang²,

Huang³

et al. 2021

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“…As a key technology for U.S. Low Cost Manufacturing System, the cost of Al-Cu-Li alloys microalloying Mg and Zn is lower than that of rare earths and their recyclability is higher due to the addition of Zn and Mn elements [11]. The addition of Mg and Zn to 7XXX series alloys can lead to the formation of η (MgZn 2 ) phase during heat treatment [12,13], besides, the addition of Zn can also promote the precipitation of T 1 phase as Ag-like effect in 2198 alloy [14,15]. However so far, the specific mechanism of the influence of Zn on the microstructure and properties of the alloy during solidification, deformation and heat treatment is still unclear.…”

Section: Introductionmentioning

confidence: 99%

Investigation on Microstructural Evolution and Properties of an Al-Cu-Li Alloy with Mg and Zn Microalloying during Homogenization

Wang

et al. 2018

Metals

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The microstructural evolution and properties of an Al-Cu-Li alloy with Mg and Zn microalloying (Al-3.5Cu-1.5Li-0.5Mg-0.4Zn-0.3Mn-0.12Zr-0.06Ti) ingot subjected to homogenization (second-step annealing at 500 °C for 24 h following first-step annealing at 400 °C for 8 h) were investigated. Mg-Zn atom clusters were enriched at the end of dendrites as well as low-melting eutectic phases such as S (Al2CuMg), T2 (Al6CuLi3), TB (Al7.5Cu4Li) and T1 (Al2CuLi) in the as-cast alloy. During homogenization, Mg-Zn atom clusters diffused from the segregation to the vacancies, leading to the dissolution of the low-melting eutectic phases. Not only Al3Zr particles were observed at 500 °C, but more fine and uniform spherical dispersoids appeared, which were assumed as Al3(ZrxTiyLi1−x−y). Mg and Zn microalloying can promoted the nucleation of Al3Zr and Al3(ZrxTiyLi1−x−y) dispersoids, as well as T (Al20Cu2Mn3) phases, which all inhibited recrystallization effectively and improve the uniformity of the grains due to the strong pinning effect. The yield ratio was decreased from 0.81 to 0.52 with the yield strength decreased from 172 MPa to 61 MPa, which showed better plastic deformation ability of the alloy subjected to homogenization. In addition, the dissolution of low-melting eutectic phases and formation of Al3(ZrxTiyLi1−x−y) dispersoids resulted in the significant improvement on thermal stability.

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Phase transformation and microstructure evolution of an ultra-high strength Al-Zn-Mg-Cu alloy during homogenization

Cited by 84 publications

References 29 publications

Characterization of precipitates in an Al-Zn-Mg alloy processed by ECAP and subsequent annealing

Characterization of precipitates in an Al-Zn-Mg alloy processed by ECAP and subsequent annealing

Microstructure and compressive properties of aluminum matrix syntactic foams containing Al2O3 hollow particles

Investigation on Microstructural Evolution and Properties of an Al-Cu-Li Alloy with Mg and Zn Microalloying during Homogenization

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