Effects of Al(MnFe)Si dispersoids with different sizes and number densities on microstructure and ambient/elevated-temperature mechanical properties of extruded Al–Mg–Si AA6082 alloys with varying Mn content

Rakhmonov, Jovid; Liu, Kun; Rometsch, Paul; Parson, Nick; Chen, X.-Grant

doi:10.1016/j.jallcom.2020.157937

Cited by 53 publications

(33 citation statements)

References 38 publications

(64 reference statements)

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“…Finally, the precipitation kinetics, grain size and, thus, the properties of Mn, Fe and Si containing 5xxx aluminum alloys are also strongly affected by the cooling rate in the casting process. In general, higher cooling rates during casting significantly refine the grain size, as well as constituent phases, and can further change the levels of solute Fe, Mn and Si [15][16][17][18][19]. A comprehensive overview on the details of primary and secondary phases formed in AlMg(Mn) alloys with varying Fe and Mn additions under different processing parameters, such as solidification conditions, homogenization temperature and degree of cold rolling, is given in Part I of this work [15].…”

Section: Introductionmentioning

confidence: 99%

Influence of Fe and Mn on the Microstructure Formation in 5xxx Alloys—Part II: Evolution of Grain Size and Texture

Grasserbauer

Weißensteiner

Falkinger³

et al. 2021

Materials

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In recent decades, microstructure and texture engineering has become an indispensable factor in meeting the rising demands in mechanical properties and forming behavior of aluminum alloys. Alloying elements, such as Fe and Mn in AlMg(Mn) alloys, affect the number density, size and morphology of both the primary and secondary phases, thus altering the grain size and orientation of the final annealed sheet by Zener pinning and particle stimulated nucleation (PSN). The present study investigates the grain size and texture of four laboratory processed AlMg(Mn) alloys with various Fe and Mn levels (see Part I). Common models for deriving the Zener-limit grain size are discussed in the light of the experimental data. The results underline the significant grain refinement by dispersoids in high Mn alloys and show a good correlation with the Smith–Zener equation, when weighting the volume fraction of the dispersoids with an exponent of 0.33. Moreover, for high Fe alloys a certain reduction in the average grain size is obtained due to pinning effects and PSN of coarse primary phases. The texture analysis focuses on characteristic texture transformations occurring with pinning effects and PSN. However, the discussion of the texture and typical PSN components is only possible in terms of trends, as all alloys exhibit an almost random distribution of orientations.

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Section: Introductionmentioning

confidence: 99%

Influence of Fe and Mn on the Microstructure Formation in 5xxx Alloys—Part II: Evolution of Grain Size and Texture

Grasserbauer

Weißensteiner

Falkinger³

et al. 2021

Materials

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“…In Al-Mg-Si-Mn 6xxx alloys, the typical dispersoids formed during homogenization are α-Al(FeMn)Si, appearing with either simple cubic or body-centered cubic structures [ 5 , 6 ]. These dispersoids tend to form during heating and become relatively coarse (≈200 nm in equivalent diameter) during the soaking stage of industrial homogenization treatments typically conducted above 540 °C [ 5 , 7 , 8 ]. Recent studies have focused on the nucleation and growth of α-Al(FeMn)Si dispersoids to reveal new possibilities for increasing the number density of dispersoids while ensuring that they remain reasonably small (≈40 nm) [ 7 , 9 ].…”

Section: Introductionmentioning

confidence: 99%

“…The β′-MgSi precipitates formed during heating to the homogenization temperature in an Al-Mn-Mg alloy act as effective nuclei for α-Al(FeMn)Si dispersoids [ 11 , 12 ], thus substantially increasing their number density [ 13 ]. Moreover, a new low-temperature homogenization process was established to obtain a high number density of fine α-Al(FeMn)Si dispersoids while exhibiting enhanced Orowan strengthening and Zener drag effects [ 7 , 8 , 14 ].…”

Section: Introductionmentioning

confidence: 99%

“…Extrusion is a rapid process conducted typically above 500 °C, but the continuous generation of dislocations during extrusion results in ultrafast dynamic diffusion of solutes, which can induce the coarsening of dispersoids. Our recent study [ 8 ] has shown that dispersoids become very prone to coarsening during a typical extrusion process of 6082 alloy, and their average sizes almost double after extrusion compared with that after homogenization at a relatively low temperature (400 °C). Therefore, decreasing the extrusion temperature to below 400 °C in combination with low-temperature homogenization, at which both the diffusivity of Mn in Al and the coarsening of α-Al(FeMn)Si dispersoids are rather limited [ 13 , 15 ], might further retard the coarsening of dispersoids and provide a higher Orowan strengthening effect after the final processing stage.…”

Section: Introductionmentioning

confidence: 99%

“…Incorporating fine and densely distributed α-Al(FeMn)Si dispersoids into extruded Al-Mg-Si alloys might also enhance their elevated-temperature mechanical properties and creep resistance. In our previous work [ 8 , 14 , 16 ], the positive contribution of dispersoids to the yield strength (YS) at 300 °C was proven after extrusion. For instance, the YS at 300 °C for a 1% Mn 6082 alloy improved from 36 MPa for a dispersoid-free material to ≈ 60 MPa for one that was dispersoid-rich.…”

Section: Introductionmentioning

confidence: 99%

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Enhanced Elevated-Temperature Strength and Creep Resistance of Dispersion-Strengthened Al-Mg-Si-Mn AA6082 Alloys through Modified Processing Route

et al. 2021

Self Cite

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In the present work, we investigated the possibility of introducing fine and densely distributed α-Al(MnFe)Si dispersoids into the microstructure of extruded Al-Mg-Si-Mn AA6082 alloys containing 0.5 and 1 wt % Mn through tailoring the processing route as well as their effects on room- and elevated-temperature strength and creep resistance. The results show that the fine dispersoids formed during low-temperature homogenization experienced less coarsening when subsequently extruded at 350 °C than when subjected to a more typical high-temperature extrusion at 500 °C. After aging, a significant strengthening effect was produced by β″ precipitates in all conditions studied. Fine dispersoids offered complimentary strengthening, further enhancing the room-temperature compressive yield strength by up to 72–77 MPa (≈28%) relative to the alloy with coarse dispersoids. During thermal exposure at 300 °C for 100 h, β″ precipitates transformed into undesirable β-Mg2Si, while thermally stable dispersoids provided the predominant elevated-temperature strengthening effect. Compared to the base case with coarse dispersoids, fine and densely distributed dispersoids with the new processing route more than doubled the yield strength at 300 °C. In addition, finer dispersoids obtained by extrusion at 350 °C improved the yield strength at 300 °C by 17% compared to that at 500 °C. The creep resistance at 300 °C was greatly improved by an order of magnitude from the coarse dispersoid condition to one containing fine and densely distributed dispersoids, highlighting the high efficacy of the new processing route in enhancing the elevated-temperature properties of extruded Al-Mg-Si-Mn alloys.

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Simultaneously Improved Bendability and Strength of Al–Mg–Si–Cu–Zn Alloys by Controlling the Formation and Evolution of Primary Fe‐Rich Phase

Guo

et al. 2023

Adv Eng Mater

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In present work, the formation, evolution, and distribution of the primary Fe‐rich phase in an Al–Mg–Si–Cu–Zn–Fe–Mn alloy are coupling controlled by ultrasonic melt treatment (USMT) and thermomechanical processing (TMP). It is shown in the results that the size of grains and Fe‐rich phase in the as‐cast state can be greatly reduced by the applied optimum USMT at 680 °C. Additionally, the transformation rate of β‐Fe‐rich phase to α‐Fe‐rich phase can be also enhanced. After the coupling control of USMT and TMP, the number density and distribution uniformity of multiscale Fe‐rich particles can be greatly increased or improved, which contributes to the fine‐grained recrystallization microstructure and weakened texture. Finally, compared with the 6xxx series Al alloys (such as AA6016 and AA6111), the alloy sheet in the pre‐aging state exhibits substantially improved bendability and strength (the plastic strain ratio and tensile strength are 0.67 and 304 MPa, respectively). The effect of USMT on the formation and transformation of primary Fe‐rich phase and the mechanisms of improved bendability and strength are deeply discussed.

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Effects of Al(MnFe)Si dispersoids with different sizes and number densities on microstructure and ambient/elevated-temperature mechanical properties of extruded Al–Mg–Si AA6082 alloys with varying Mn content

Cited by 53 publications

References 38 publications

Influence of Fe and Mn on the Microstructure Formation in 5xxx Alloys—Part II: Evolution of Grain Size and Texture

Influence of Fe and Mn on the Microstructure Formation in 5xxx Alloys—Part II: Evolution of Grain Size and Texture

Enhanced Elevated-Temperature Strength and Creep Resistance of Dispersion-Strengthened Al-Mg-Si-Mn AA6082 Alloys through Modified Processing Route

Simultaneously Improved Bendability and Strength of Al–Mg–Si–Cu–Zn Alloys by Controlling the Formation and Evolution of Primary Fe‐Rich Phase

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