Twin Roll Casting of Thin AZ31 Magnesium Alloy Strip with Uniform Microstructure and Chemistry

2012 ◽  
pp. 135-140 ◽  
Author(s):  
Iman Bayandorian ◽  
Ian Stone ◽  
Yan Huang ◽  
Zhongyun Fan
2005 ◽  
Vol 488-489 ◽  
pp. 419-426 ◽  
Author(s):  
Yusuke Nakaura ◽  
Koichi Ohori

Twin roll casting has been used to produce AZ31 magnesium alloy strip. The size of the cast strip is 5mm thick and 250mm wide. The microstructure of the as-cast AZ31 alloy strip consists of columnar zones from the surface to mid-thickness region and equiaxed zones in the mid-thickness region. The secondary dendrite arm spacing varies from 5.0 to 6.5 μm through the thickness and width of the strip and is much smaller than 34μm of an AZ31 alloy DC ingot used for comparison. In the temperature ranging from room temperature to 400°C, the tensile strength and elongation of the as-cast strip are higher and smaller than those of DC ingot, respectively. Elongation is evidently improved by homogenization treatment and becomes more than that of the DC ingot. Such an improvement of elongation is though to be caused by homogenization of segregation of Al and Zn atoms in the dendrite cell boundaries. The non-homogenized and homogenized strips were subsequently hot rolled. Their hot rolled sheets have much higher value of elongation with equivalent strength, compared to the hot rolled sheet of flat-bar extruded from DC ingot in the temperature ranging from 200°C to 300°C.


2013 ◽  
Vol 27 (19) ◽  
pp. 1341020
Author(s):  
YANDONG YU ◽  
KAI LIN ◽  
PENG JIANG

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.


2011 ◽  
Vol 189-193 ◽  
pp. 3844-3851
Author(s):  
Wen Ping Weng ◽  
Kang Deng ◽  
Zhong Ming Ren ◽  
Qi Chen ◽  
Zhi Dong Chi ◽  
...  

The solidification and process optimization for twin-roll casting of magnesium alloys have been studied. Effects of roll speed, roller diameter, setback length and strip thickness on the position of the solidification front and the surface quality of strip were analyzed through experiments. A kiss-point model which considers the strip thickness, set-back length and roll speed was established to optimize process and enhance the surface quality of magnesium alloy strip. Results showed that the twin-roll casting process could be effectively stabilized and optimized under the direction of the model, and the defectless magnesium alloy strip was obtained.


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