scholarly journals Hot Rolling of the Twin-Roll Cast and Homogenized Mg-6.8Y-2.5Zn (WZ73) Magnesium Alloy Containing LPSO Structures

Metals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1771
Author(s):  
Madlen Ullmann ◽  
Kristina Kittner ◽  
Ulrich Prahl
Keyword(s):  
Magnesium Alloy ◽  
Dynamic Recrystallization ◽  
Hot Rolling ◽  
Texture Evolution ◽  
Strain Rates ◽  
Zn Content ◽  
Increased Strength ◽  
Twin Roll Cast ◽  
Twin Roll ◽  
Strength And Ductility

In this study, hot rolling trials were conducted on a twin-roll cast and homogenized magnesium alloy Mg-6.8Y-2.5Zn (WZ73). The WZ73 contains long period stacking ordered (LPSO) structures due to the ratio of Y and Zn content. Microstructural and texture evolution depending on the different strain and strain rates were investigated, and the resulting mechanical properties were also considered. Therefore, samples were quenched in water directly after hot rolling. The results revealed that the rolling parameters significantly influence dynamic recrystallization (DRX), while continuous and twin-induced dynamic recrystallization are assumed to be the main DRX mechanisms. It was also found that high strains and strain rates are required to proceed the DRX. The resulting textures revealed that the non-basal slip of <a>-dislocations and <c+a>-dislocations is activated during hot rolling. Hot rolling results in increased strength and ductility compared to the initial twin-roll cast and homogenized state.

MICROSTRUCTURAL EVOLUTION AND FLOW BEHAVIOR OF TWIN-ROLL CAST AZ41 MAGNESIUM ALLOY DURING HOT COMPRESSION

2012 ◽  
Vol 26 (32) ◽  
pp. 1250181
Author(s):  
ZHIYI LIU ◽  
XU CHEN ◽  
YANHUI HOU ◽  
SUKBONG KANG
Keyword(s):  
Elevated Temperature ◽  
Magnesium Alloy ◽  
Dynamic Recrystallization ◽  
Strain Rate ◽  
Microstructural Evolution ◽  
Flow Behavior ◽  
Hot Compression ◽  
Dislocation Slip ◽  
Twin Roll Cast ◽  
Twin Roll

Microstructural evolution and flow behavior of twin-roll cast AZ41 magnesium alloy during hot compression were characterized by employing deformation temperature of 300°C, 350°C and 400°C, and strain rate ranging from 10-3 to 10-2 s -1. When compressed at different temperature (300°C, 350°C and 400°C) and strain rate (10-3 and 10-2 s -1) all stress strain curves showed a flow softening behavior before strained to 0.51 due to dynamic recrystallization, even though concurrent twinning was quite active. Twinning contributed to the flow hardening behavior appeared during the end of hot compression (ε > 0.51) at a strain rate of 10-2 s -1 and elevated temperature (300°C, 350°C and 400°C) in spite of the softening effect of concurrently occurred dynamic recrystallization. TEM image showed that discontinuous recrystallization occurred when deformed at elevated temperature as high as 400°C and the strain rate ranging from 10-2 to 10-3 s -1. It is suggested that dislocation slip, twinning and recrystallization develop in a cyclic mode from initial stage to the end of hot compression.

Dynamic Recrystallization Behaviour of Twin Roll Cast AZ31 Strips during Hot Deformation

2014 ◽  
Vol 622-623 ◽  
pp. 569-574 ◽  
Author(s):  
Madlen Ullmann ◽  
Matthias Schmidtchen ◽  
Rudolf Kawalla
Keyword(s):  
Dynamic Recrystallization ◽  
Hot Deformation ◽  
Volume Fraction ◽  
Az31 Alloy ◽  
Rolling Process ◽  
Recrystallization Process ◽  
Strain Rates ◽  
Compression Tests ◽  
Twin Roll Cast ◽  
Twin Roll

The recrystallization behaviour of a Twin Roll Cast AZ31 alloy, under deformation conditions corresponding to the initial stands of a magnesium hot rolling process, has been investigated. A set of strain levels, beginning at the critical strain for the onset of dynamic recrystallization has been studied. The dynamic recrystallization, taking place during hot deformation of magnesium alloy AZ31 is analyzed with help of plane strain compression tests conducted together with microscopic examination. Dynamically recrystallized volume fraction and size of dynamically recrystallized grains increase with increasing strain. When the strain is constant, the dynamically recrystallized volume fraction is higher at higher deformation temperatures or lower strain rates. Furthermore, it has been found out that deformation temperature plays a major role, rather than strain rates, in activating the dynamic recrystallization process during deformation. The results were used to identify the coefficients for the JMAK-model approach on the dynamic recrystallization of an AZ31 TRC-sheet.

scholarly journals Analysis of defects in a twin roll cast Mg‐Y‐Zn magnesium alloy

2021 ◽  
Author(s):  
Kristina Kittner ◽  
Madlen Ullmann ◽  
Falko Arndt ◽  
Susanne Berndorf ◽  
Thorsten Henseler ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Twin Roll Cast ◽  
Twin Roll

An XPS Study of Native Oxide and Isothermal Oxidation Kinetics at 300 °C of AZ31 Twin Roll Cast Magnesium Alloy

2013 ◽  
Vol 81 (5-6) ◽  
pp. 529-548 ◽  
Author(s):  
H. Saleh ◽  
T. Weling ◽  
J. Seidel ◽  
M. Schmidtchen ◽  
R. Kawalla ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Oxidation Kinetics ◽  
Isothermal Oxidation ◽  
Native Oxide ◽  
Cast Magnesium Alloy ◽  
Cast Magnesium ◽  
Xps Study ◽  
Twin Roll Cast ◽  
Twin Roll

Microstructures and Mechanical Properties of AZ31+Sr+Y Magnesium Alloy Sheets Produced by Twin-Roll Casting and Sequential Hot Rolling

2013 ◽  
Vol 765-767 ◽  
pp. 3176-3179 ◽  
Author(s):  
Yan Dong Yu ◽  
Qiong Hu ◽  
Peng Jiang
Keyword(s):  
Magnesium Alloy ◽  
Hot Rolling ◽  
Room Temperature ◽  
Dominant Role ◽  
Boundary Slip ◽  
Twin Roll Casting ◽  
Roll Casting ◽  
Deformation Properties ◽  
Increasing Temperature ◽  
Twin Roll

In this paper, the deformation properties of AZ31+Sr+Y magnesium alloy sheets produced by twin-roll casting (TRC) and sequential hot rolling were studied by the tensile testing at a strain rate of 7×10-4s-1and various temperatures: room temperature (RT), 200°C, 300°C and 400°C, respectively. The result shows that the microstructure of AZ31+Sr+Y alloy was refined obviously by adding elements Sr and Y, the elongation of the alloy increased with increasing temperature, and the fracture behavior of the alloy changed from brittle fracture to ductile fracture with increasing temperature. During the process of plastic deformation of AZ31+Sr+Y alloy, the twin plays a leading role at room temperature; the dislocation movement is regarded as the main deformation mechanism at 200° C; at the higher temperature (above 300°C) the grain boundary slip (GBS) plays a dominant role .

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