Influence of Heat-Treatment and Rolling Conditions on the Mechanical Warm Forming Properties of Twin-Roll Cast AZ31

2017 ◽  
Vol 746 ◽  
pp. 184-191 ◽  
Author(s):  
Franz Berge ◽  
Marie Moses ◽  
Rudolf Kawalla ◽  
Madlen Ullmann
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Hot Rolling ◽  
Tensile Deformation ◽  
Warm Forming ◽  
Efficient Production ◽  
Research Strategies ◽  
Component Design ◽  
Roll Casting ◽  
Twin Roll

Magnesium sheets are used for wide-ranging applications in the automotive sector. In contrast to conventional magnesium processing routes for strips, twin-roll casting (TRC) and hot rolling is a cost-efficient production process for magnesium strips and sheets. As part of previous research strategies, the optimization of the thermomechanical treatment of magnesium alloys has resulted in excellent mechanical properties for the component design. However, the previously determined results at room temperature cannot be correlated with the warm forming behaviour during the component production. This is due to different deformation mechanisms, which are active at various temperatures. For TRC material, there is a lack of knowledge about the influence of heat-treatment and rolling on the final mechanical properties at hot working temperatures. This article depicts the investigations done on the influence of heat-treatment and hot rolling conditions on the mechanical properties of AZ31 strips at tensile deformation temperatures of 20 °C and 300 °C.

Improving Mechanical Properties of Twin-Roll Cast AZ31 by Wire Rolling

2021 ◽  
Vol 1016 ◽  
pp. 957-963
Author(s):  
Marie Moses ◽  
Madlen Ullmann ◽  
Rudolf Kawalla ◽  
Ulrich Prahl
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Rolling Texture ◽  
Total Elongation ◽  
Roll Casting ◽  
Heat Treated ◽  
Heat Treated Condition ◽  
Set Up ◽  
Twin Roll Cast ◽  
Twin Roll

Since 2018, the institute of metal forming has been studying the novel twin-roll casting (TRC) of magnesium wire at the pilot research plant set up specifically for this purpose. Light microscopic and scanning electronic investigations were carried out within this work and show the unique microstructure of twin-roll cast AZ31 magnesium alloy with grain sizes of about 10 μm ± 4 μm in centre and 39 μm ± 26 μm near the surface of the sample. By means of a short heat treatment (460 °C/15 min), segregations can be dissolved and grain size changes in centre to 19 μm ± 12 μm (increase) and near the surface to 12 μm ± 7 μm (decrease). Further, the mechanical properties of the twin-roll cast and heat-treated wire were analysed by tensile testing at room temperature. By heat treatment, the total elongation could be increased by a third whereas the strength decreases slightly. In heat-treated state, no preferred orientation is evident. In addition to the twin-roll cast and the heat-treated condition, the rolled state was analysed. For this purpose, the twin-roll cast wire was hot rolled using an oval-square calibration. After hot rolling, a dynamic recrystallization and grain refinement of the twin-roll cast wire could be achieved. It can be seen, that an increase in strength as well as in total elongation occur after wire rolling. Beside this, a rolling texture is evident.

scholarly journals Effect of melt conditioning on heat treatment and mechanical properties of AZ31 alloy strips produced by twin roll casting

2015 ◽  
Vol 620 ◽  
pp. 223-232 ◽  
Author(s):  
Sanjeev Das ◽  
N.S. Barekar ◽  
Omer El Fakir ◽  
Liliang Wang ◽  
A.K. Prasada Rao ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Az31 Alloy ◽  
Twin Roll Casting ◽  
Roll Casting ◽  
Twin Roll

scholarly journals Improving element uniformity and mechanical properties of Al-Mg-Si alloy fabricated by twin roll casting with superheat melt treatment

2022 ◽  
Author(s):  
Bowen Wei ◽  
Tao Jiang ◽  
Shiju Li ◽  
Youyun Zhang ◽  
Guangming Xu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Heat Treatment ◽  
Solute Concentration ◽  
Production Cycle ◽  
Second Phase ◽  
Twin Roll Casting ◽  
Melt Treatment ◽  
Roll Casting ◽  
Twin Roll

Abstract The effect of superheat melt treatment(SMT) on microstructure and properties of Al-Mg-Si alloy fabricated by twin roll casting(TRC) was analyzed using optical microscope, scanning electron microscopy, emission electron probe micro analyzer and transmission electron microscopy. SMT increased the subcooling degree of melt during TRC. The solidification microstructure with high dendrite density and small dendrite spacing was obtained. The second phase was evenly distributed between dendrites and the solute concentration gradient was decreased. Intergranular solute aggregation caused by Reynolds’ dilatancy in TRC slab was effectively suppressed. The homogeneous solute distribution of TRC slab with SMT can be realized by short-time homogenization heat treatment. The size of insoluble particles was greatly reduced. The complete decomposition of non-equilibrium eutectic phase increased the solute concentration in α-Al, which promoted the precipitation of precipitates during aging heat treatment. The tensile strength and yield strength of T6 slab were improved, while the uniform elongation are almost not decreased. The strength and uniform of slab in T4P state were both improved. The obtained results can help further shorten the production cycle of TRC slabs and improve mechanical properties.

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 .

SUPERPLASTIC FORMABILITY OF AZ31 MAGNESIUM ALLOY SHEETS PRODUCED BY TWIN ROLL CASTING AND SEQUENTIAL HOT ROLLING

2013 ◽  
Vol 27 (19) ◽  
pp. 1341020
Author(s):  
YANDONG YU ◽  
KAI LIN ◽  
PENG JIANG
Keyword(s):  
Magnesium Alloy ◽  
Magnesium Alloys ◽  
Hot Rolling ◽  
Tensile Testing ◽  
Az31 Magnesium Alloy ◽  
Twin Roll Casting ◽  
Roll Casting ◽  
Three Stages ◽  
The Common ◽  
Twin Roll

In this paper, superplastic tensile testing and gas bulging forming of AZ31 and AZ31 + Y + Sr magnesium alloys produced by twin roll casting (TRC) and sequential hot rolling were carried out. At 673 K, the superplastic formability of the TRC AZ31 magnesium alloy sheets added Y and Sr elements has improved significantly compared to the common TRC AZ31 sheets. Formations of cavities on the bulging part go through three stages of the nucleation, growth and aggregation, finally cavities merging lead to rupture at the top of the bulging part.

scholarly journals A Novel Approach to Improve the Microstructure and Mechanical Properties of Al–Mg–Si Aluminum Alloys during Twin-Roll Casting

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1713 ◽  
Author(s):  
Yong Li ◽  
Chen He ◽  
Jiadong Li ◽  
Zhaodong Wang ◽  
Di Wu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Crystallization Front ◽  
Alloying Elements ◽  
Cast Slab ◽  
Energy Dispersion Spectroscopy ◽  
Twin Roll Casting ◽  
Roll Casting ◽  
Twin Roll Cast ◽  
Twin Roll

The main purpose of this present study was to investigate the different processing conditions on the microstructure, segregation behavior of alloying elements, and mechanical properties of Al−Mg−Si alloy twin-roll cast slab prepared using a novel twin-roll casting technology. The simulation of temperature field, distribution of alloying elements, tensile properties, hardness, and conductivity were examined by a Leica optical microscope, scanning electron microscopy, energy dispersion spectroscopy, electron probe microanalysis, and tensile tests. The results indicated that when the traditional twin-roll casting method was used to produce aluminum alloy strip, there are obvious centerline segregation defects due to the deep crystallization front depth and symmetrical solidification characteristics. When the forced-cooling technology was applied in the twin-roll casting process, by virtue of the changing of crystallization front depth and crystallization front shape, the segregation defects are obviously suppressed. Suggesting that this method can significantly improve the uniformity of alloying elements in the thickness direction of the twin-roll cast slab, ultimately improve the mechanical properties of AA6022 aluminum alloy.

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