Segregation in twin-roll cast Mg alloy and its suppression through alloy design

Bae, Jun Ho; Shim, Myeong-Shik; Suh, Byeong-Chan; Kim, D.W.; Park, S.H.; Kim, Nack J.

doi:10.1016/j.matlet.2014.06.113

Cited by 26 publications

(6 citation statements)

References 14 publications

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“…Hence, the strips cast by an industrial scale caster should suffer from the centreline segregation similar to both lab scale and pilot scale TRC cast strip. 36 This is in good agreement with the study performed by Dunar et al 39 Their study shows that increasing the roll diameter from 650 to 1100 mm for TRC of AA3003 aluminium alloy does not eliminate the centreline segregations.…”

Section: Resultssupporting

confidence: 91%

“…The calculated solute profile presented here is not the exact solute distribution during TRC; however, it qualitatively represents what occurs. 9,35,36 The SEM energy dispersive spectroscopy analysis of the as cast samples shows that the amount of Al and Zn in the bulk material is 2?11-2?51 wt-% and 0?39-0?46 wt-%, respectively. In the segregation zones (both centreline and inverse), the amounts of Al and Zn were detected as 4?17-4?50 wt-% and 2?11-2?23 wt-% respectively.…”

Section: Thermodynamics Of Segregation Formationmentioning

confidence: 99%

“…The appearance of a deeper mushy zone represents higher propensity of the strip to centreline segregation, which is in agreement with the trend observed in previous studies. 11,25,[36][37][38] Moreover, increasing the setback distance reduces the mushy zone thickness. Effect of final thickness on the mushy zone thickness is more pronounced than the nozzle opening height.…”

Section: Modellingmentioning

confidence: 99%

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Inverse and centreline segregation formation in twin roll cast AZ31 magnesium alloy

Hadadzadeh

Wells

2015

Materials Science and Technology

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Two microstructure defects formed in the twin roll cast AZ31 strips were investigated: inverse and centreline segregations. A two-dimensional finite element thermal–fluid–stress model was employed to study the thermomechanical response of the AZ31 strip during twin roll casting process. The results showed that the key parameter for centreline segregation is the mushy zone thickness at centreline. For inverse segregation, the interaction between the yy peak stress at the centreline in the mushy zone and the solidified shell on the roll surface is the determinant parameter. The modelling results suggested increasing the setback distance decreases the risk of both defects. Moreover, scaling up the caster reduces the propensity to inverse segregation but appears to have a minor effect for centreline segregation formation.

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Section: Resultssupporting

confidence: 91%

Section: Thermodynamics Of Segregation Formationmentioning

confidence: 99%

Section: Modellingmentioning

confidence: 99%

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Inverse and centreline segregation formation in twin roll cast AZ31 magnesium alloy

Hadadzadeh

Wells

2015

Materials Science and Technology

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“…Furthermore, irregularities such as segregation can occur in twin-roll cast magnesium-aluminum-zinc alloys (AZ alloy system), which must be avoided to achieve high component qualities. As the twin-roll cast wire passes through the rolls, the presence of the mushy zone can influence the degree of segregation [19][20][21].…”

Section: Microstructure Of Twin-roll Cast and Annealed Alloymentioning

confidence: 99%

Microstructure and Hot Deformation Behaviour of Twin-Roll Cast AZ31 Magnesium Wire

et al. 2022

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Due to their low density and high specific strength, magnesium alloys offer great potential as a design material for lightweight construction. An economical and energy-efficient method for the production of magnesium wire is the technology of twin-roll casting. In this work, the deformation behaviour of twin-roll cast and heat-treated AZ31 wire pre-profile is investigated for the first time during the compression test at different temperatures (250–400 °C) and forming speeds (0.01–10 s−1). To obtain optimal parameters, a processing map is created, and the microstructural changes during the hot forming processes are determined by accompanying microstructure characterization through an optical microscope and scanning electron microscope. The heat treatment causes a reduction in segregation and a homogeneous microstructure. The average activating energy for plastic deformation of twin-roll cast and heat-treated magnesium alloy AZ31 is 159.008 kJ·mol−1. The instability region of the process map starts at a forming temperature of 250 °C and extends into the range of high forming speeds (1–10 s−1). In this area, cracks in the microstructure can be detected during hot forming. At high temperatures (300–350 °C), dynamic recrystallization at the grain boundaries is observed as the main forming mechanism. Based on these results and observations, existing models for describing the hot forming behaviour of magnesium alloys can be extended and validated.

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“…Con- * corresponding author; e-mail: m.zimina@seznam.cz ventional TRC Mg-3Al-1Zn alloy exhibits severe inverse and central segregation of solute Al and Zn atoms due to its rather wide solidification range. The role of the segregation on tensile properties of magnesium alloys was studied by several authors [7,8]. Thus, an exact characterization of the segregation of secondary-phase particles becomes more important for the alloys production and can help to optimize casting conditions.…”

Section: Introductionmentioning

confidence: 99%

Center Line Segregation in Twin-Roll Cast AZ31 Magnesium Alloy

Zimina

Šlapáková

Bohlen³

et al. 2018

Acta Phys. Pol. A

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A three-dimensional approach to microstructural investigations was for the first time applied to a continuous cast material in order to understand solidification processes and liquid flow during casting. A twin-roll cast AZ31 magnesium alloy strip was subjected to observations by light optical microscopy, electron microscopy, and X-ray microtomography. The last one is found to be the only suitable for the 3D characteristic of the segregation channels containing Mn and Al-rich primary phases located in the central zone of the strip. It was shown that a reliable three-dimensional image of the volume containing central line segregation cannot be obtained using conventional metallographic methods, whereas X-ray microtomography allows the complete reconstruction of major features of the central segregation in the alloy.

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Segregation in twin-roll cast Mg alloy and its suppression through alloy design

Cited by 26 publications

References 14 publications

Inverse and centreline segregation formation in twin roll cast AZ31 magnesium alloy

Inverse and centreline segregation formation in twin roll cast AZ31 magnesium alloy

Microstructure and Hot Deformation Behaviour of Twin-Roll Cast AZ31 Magnesium Wire

Center Line Segregation in Twin-Roll Cast AZ31 Magnesium Alloy

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