Precipitation kinetics of AA4032 and AA6082: a comparison based on DSC and TEM

Birolia, G.; Cagliotiab, G.; Martini, Luca De; Riontino, G.

doi:10.1016/s1359-6462(98)00140-7

Cited by 24 publications

(11 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…With respect to the broad exothermic peak 2 at about 325 °C, it can be attributed to the β" precipitation. It has been reported that a second peak, usually located at about 330 °C and corresponding to β' formation, might be superimposed to a shoulder of the former peak or even completely hidden by it [39]. More precisely, it has been mentioned that the sub-peak at 325 °C is probably related to the Si-rich particles precipitation which act as motifs to form of the β'' phase and the noticeable peak at 330 °C refers to the creation of both rod-shaped β' -1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 12 phase and large Si-rich precipitates [40,41].…”

Section: Microstructurementioning

confidence: 99%

Structure and microstructure evolution of Al–Mg–Si alloy processed by equal-channel angular pressing

Khelfa

Rekik

Khitouni

et al. 2017

Int J Adv Manuf Technol

View full text Add to dashboard Cite

An ultrafine grained Al-Mg-Si alloy was prepared by severe plastic deformation using the Equal Channel Angular Pressing (ECAP) method. Samples were ECAPed through a die with an inner angle of Φ=90º and outer arc of curvature of ψ= 37° from 1 to 12 ECAP passes at room temperature following route Bc. To analyze the evolution of the microstructure at increasing ECAP passes x-ray diffraction and Electron Backscatter Diffraction analyses were carried out. The results revealed two distinct processing regimes, namely: i) from 1 to 5 passes, the microstructure evolved from elongated grains and sub-grains to a rather equiaxed array of ultrafine grains and ii) from 5 to 12 passes where no change in the morphology and average grain size was noticed. In the overall behavior, the boundary misorientation angle and the fraction of high-angle boundaries increase rapidly up to 5 passes and at a lower rate from 5 to 12 passes. The crystallite size decreased down to about 45 nm with the increase in deformation. The influence of deformation on precipitate evolution in the Al-Mg-Si alloy was also studied by differential scanning calorimetry. A significant decrease in the peak temperature associated to the 50% of recrystallization was observed at increasing ECAP passes.

show abstract

Section: Microstructurementioning

confidence: 99%

Structure and microstructure evolution of Al–Mg–Si alloy processed by equal-channel angular pressing

Khelfa

Rekik

Khitouni

et al. 2017

Int J Adv Manuf Technol

View full text Add to dashboard Cite

show abstract

“…The curve of the solution-treated alloy in Figure 4(a) agrees well with DSC traces of similar 6XXX series alloys with excess Si. [11,20,22,23] The broad exothermic peak at 130 °C to 150 °C, often interpreted as two partially superimposed subpeaks, corresponds to the formation of ␤Љ and ␤Ј metastable precipitates. More specifically, the subpeak at 130 °C could also be related to the precipitation of tiny Si-rich particles acting as precursors for the formation of ␤Љ phase, and at 150 °C, both lath shaped ␤Ј precipitates and relatively large Si precipitates are present.…”

Section: Figures 1(a) and (B)mentioning

confidence: 99%

“…Other hardening particles found in the 6082 alloy correspond to the rounded Si phase. [1][2][3]9,14,22,23] More complex intermetallics may also be present in the form of quaternary Al-Fe-Mn-Si phases, whose elements may have slightly different stoichiometric relationships. [11,20] In recent decades, the need to improve the mechanical properties of light alloys has oriented industry's attention and the research efforts toward two different, but parallel, fields.…”

Section: Introductionmentioning

confidence: 99%

Influence of severe plastic deformations on secondary phase precipitation in a 6082 Al-Mg-Si alloy

Cabibbo

Evangelìsta

Vedani

2005

Metall Mater Trans A

105

View full text Add to dashboard Cite

The role of severe plastic deformation on the second-phase stability in a 6082 Al-Mg-Si alloy was studied using differential scanning calorimetry (DSC) and transmission electron microscopy (TEM) techniques. The alloy was fully annealed prior to undergoing up to six equal channel angular pressing (ECAP) passes using route C. The Orowan strengthening mechanism was calculated on the basis of TEM inspections for the two hardening second-phase precipitates: Mg 2 Si and Si. The former had a major tendency to be cut and fragmented by dislocations, while in the latter, a dissolution process was induced by severe plastic deformation. Accordingly, the second-phase Si particles became progressively less effective with increasing deformation (i.e., additional ECAP passes). The increase in hardness with the ECAP passes was mostly due to the grain refining mechanism and to dislocation tangles within the newly formed grains. The expected, though if limited, contribution of second-phase hardening was prevalently accounted for by the Mg 2 Si particles.

show abstract

“…The age hardening response of 6xxx series alloys can be very significant, leading to remarkable improvement of strength after an appropriate heat treatment. Their precipitation sequence has been reported in numerous research works, and a satisfactory agreement on phase evolution occurring during aging has been achieved [1][2][3][4][5][6][7]. A large number of wrought Al-Mg-Si alloys contain an excess of Si, above that required to form the Mg 2 Si (β) phase, to improve the age hardening response.…”

Section: Introductionmentioning

confidence: 91%

Aging Behaviour of Al-Mg-Si Alloys Subjected to Severe Plastic Deformation by ECAP and Cold Asymmetric Rolling

Farè

Lecis

Vedani

2011

Journal of Metallurgy

View full text Add to dashboard Cite

A study was carried out on aging behaviour of a 6082 alloy processed by two different severe plastic deformation techniques: ECAP and asymmetric rolling. Both techniques were able to generate an ultrafine-grained structure in samples processed at room temperature. It was stated that severe straining promotes marked changes in the postdeformation aging kinetics. The peaks of β /β transition phases were anticipated and of progressively reduced intensity over the coarse grained alloy. A further peak accounting for onset of recrystallization also appeared in the most severely deformed samples. Full consistency in peak shape and position was found when comparing materials processed by ECAP and asymmetric rolling. Isothermal aging treatments performed at 180• C revealed that in the severely deformed samples, aging became so fast that the hardness curves continuously decreased due to overwhelming effects of structure restoration. On the contrary, aging at 130• C offers good opportunities for fully exploiting the precipitate hardening effects in the ultrafine-grained alloy.

show abstract

Precipitation kinetics of AA4032 and AA6082: a comparison based on DSC and TEM

Cited by 24 publications

References 2 publications

Structure and microstructure evolution of Al–Mg–Si alloy processed by equal-channel angular pressing

Structure and microstructure evolution of Al–Mg–Si alloy processed by equal-channel angular pressing

Influence of severe plastic deformations on secondary phase precipitation in a 6082 Al-Mg-Si alloy

Aging Behaviour of Al-Mg-Si Alloys Subjected to Severe Plastic Deformation by ECAP and Cold Asymmetric Rolling

Contact Info

Product

Resources

About