Effect of a low frequency electromagnetic field on the direct-chill (DC) casting of AZ80 magnesium alloy ingots

2006 ◽  
Vol 97 (11) ◽  
pp. 1539-1544 ◽  
Author(s):  
Shijie Guo ◽  
Qichi Le ◽  
Zhihao Zhao ◽  
Yi Han ◽  
Jianzhong Cui
Keyword(s):  
Electromagnetic Field ◽  
Magnesium Alloy ◽  
Low Frequency ◽  
Direct Chill ◽  
Az80 Magnesium Alloy ◽  
Dc Casting

Effect of Physical Fields on Solidification Structures of DC Casting AZ80 Magnesium Alloy Billets

2011 ◽  
Vol 105-107 ◽  
pp. 1616-1619
Author(s):  
Zhi Qiang Zhang ◽  
Qi Chi Le ◽  
Jian Zhong Cui
Keyword(s):  
Magnesium Alloy ◽  
Continuous Casting ◽  
Low Frequency ◽  
Direct Chill ◽  
Ultrasonic Fields ◽  
Electromagnetic Casting ◽  
Az80 Magnesium Alloy ◽  
Continuously Cast ◽  
Dc Casting ◽  
Physical Fields

AZ80 magnesium alloy was semi-continuously cast under different physical fields which were conventional direct chill (DC) casting, low frequency electromagnetic casting (LFEC), ultrasonic casting (USC) and electromagnetic-ultrasonic combined casting (ECUC), respectively. The effect of different physical fields on solidification structures of AZ80 alloys was investigated. The results show that compared with the conventional DC casting, structures of AZ80 alloys billets cast with LFEC and USC have been greatly refined. The effective refinement takes place in the edge of billets when LFEC is applied. However, the effective refinement takes place in the center of billets when USC is applied. When combination of low frequency electromagnetic and ultrasonic fields is applied during semi-continuous casting AZ80 magnesium alloy billet, structures of AZ80 alloys are refined significantly in the whole billets everywhere and more uniform.

DC Casting of Large Sized Ingot of a High Strength 7xxx Alloy under the Influence of Electromagnetic Field

2013 ◽  
Vol 765 ◽  
pp. 165-169 ◽  
Author(s):  
Jian Zhong Cui ◽  
Hai Tao Zhang ◽  
Yu Bo Zuo
Keyword(s):  
Electromagnetic Field ◽  
Flow Direction ◽  
New Technology ◽  
Low Frequency ◽  
High Strength ◽  
Direct Chill ◽  
Hot Tearing ◽  
Electromagnetic Casting ◽  
Dc Casting ◽  
7Xxx Alloy

Hot tearing and cold cracks are major defects during direct chill (DC) casting of large sized ingots of high strength aluminium alloys. In order to solve these problems, based on a low frequency electromagnetic casting (LFEC) process, a new technology, electromagnetic casting with the application of an air blade (EMA) was developed. In the present work, this new technology was used to prepare large sized AA7055 aluminium alloy ingots and the effects of the low frequency electromagnetic field and the air blade on macro-physical fields, microstructure and cracking are studied by numerical and experimental methods. The results show that applying an electromagnetic field can modify the flow direction, increase the velocity of melt flow and homogenize the distribution of temperature in the sump. Applying an air blade can homogenize the distribution of temperature and decrease the stress and strain in the solidified ingot. Furthermore, the microstructure of the ingot is refined remarkably and cracking is eliminated by simultaneously applying the electromagnetic field and the air blade during DC casting.

Effect of DC Casting Processes on Microstructure of AlCu4.5Mn0.8 Alloy

2013 ◽  
Vol 652-654 ◽  
pp. 2409-2412
Author(s):  
Li Zhou ◽  
Gen Xiang Luo
Keyword(s):  
Electromagnetic Field ◽  
Low Frequency ◽  
Direct Chill ◽  
Direct Chill Casting ◽  
Chill Casting ◽  
Dc Casting ◽  
Semi Solid

The semi-solid billets of AlCu4.5Mn0.8 alloy were cast respectively by low frequency electromagnetic, low-superheated, and conventional direct chill casting. The effect of casting processes on microstructures was investigated. The results show that due to the effect of the low frequency electromagnetic field, the coarse dentritic microstructure is gradually broken up and turned into the homogeneous, fine rosette-shaped non-dentritic microstructures with the increase of electromagnetic frequency from 10 Hz to 30 Hz. When electromagnetic frequency is 30 Hz, the homogeneous, fine non-dentritic microstructure what is suitable for semi-solid reheating and thixo-forming could be obtained successfully.

Experimental Investigation of Microsegregation in Low Frequency Electromagnetic Casting of Al-4.5%Cu Binary Alloy

2010 ◽  
Vol 152-153 ◽  
pp. 1217-1221
Author(s):  
Dan Dan Chen ◽  
Hai Tao Zhang ◽  
Xiang Jie Wang ◽  
Jian Zhong Cui
Keyword(s):  
Experimental Investigation ◽  
Electromagnetic Field ◽  
Binary Alloy ◽  
Low Frequency ◽  
Direct Chill ◽  
Solute Content ◽  
Electromagnetic Casting ◽  
Dc Casting

Al-4.5%Cu ingots were prepared by a process of low frequency electromagnetic casting (LFEC) and conventional direct chill (DC) casting, respectively. The effects of low frequency electromagnetic field on the microsegregation were investigated from eutectic analysis and electro probe microanalysis (EPMA). It was found that the amount of the nonequilibrium eutectic and the dimension of the nonequilibrium eutectic were decreasing markedly. In contrast, the solute content in the α-Al phase increased to a certain extent in the presence of the low frequency electromagnetic field, and it increased with the incerasing electromagnetic.

Investigation on Low-Frequency Electromagnetic DC Casting of AZ91 Magnesium Alloy

2005 ◽  
Vol 488-489 ◽  
pp. 345-348 ◽  
Author(s):  
Q. Le ◽  
J. Cui ◽  
Shi Jie Guo ◽  
Z. Zhao ◽  
F. Yu
Keyword(s):  
Magnesium Alloy ◽  
Low Frequency ◽  
Direct Chill ◽  
Experimental Investigations ◽  
Az91 Magnesium Alloy ◽  
The Past ◽  
Az91 Magnesium ◽  
Dc Casting ◽  
A New Technique

Direct chill (DC) casting is a dominant way of producing aluminum and copper alloy billets. In the past we developed a new technique, namely Low Frequency Electromagnetic Casting (LFEC), in which low-frequency electromagnetic field (LFEF) is incorporated to DC casting processing. In this work, LFEF was introduced to the magnesium DC casting processing. Experimental investigations and numerical simulation indicate that application of LFEF to DC casting magnesium alloy can significantly improve the surface quality of the AZ91 billets, refine microstructure and reduce both macro and micro segregations. It was also found that high casting velocity become possible for magnesium alloys through LFEC processing.

Direct Chill Casting of Φ500mm ZK60 Magnesium Alloy Billets under Low Frequency Electromagnetic Field

2011 ◽  
Vol 686 ◽  
pp. 26-29
Author(s):  
Zhi Qiang Zhang ◽  
Qi Chi Le ◽  
Jian Zhong Cui
Keyword(s):  
Electromagnetic Field ◽  
Magnesium Alloy ◽  
Surface Quality ◽  
Low Frequency ◽  
Direct Chill ◽  
Hot Tearing ◽  
Direct Chill Casting ◽  
Chill Casting ◽  
Zk60 Magnesium Alloy

Effects of low frequency electromagnetic field on surface quality, microstructure and hot-tearing tendency of direct chill casting of Φ500mm ZK60 magnesium alloy billets were investigated. The results show that with the application of the low frequency electromagnetic field, the surface quality of Φ500mm ZK60 magnesium alloy billets has been markedly improved, and the depth of cold fold is decreased. In the conventional direct chill casting, the microstructures of the billet, especially at the center, are coarse. The distribution of the grain size is non-uniform throughout the billet. From the edge to the center, the microstructure gradually changes from fine to coarse in all billets. However, under the low frequency electromagnetic casting, the microstructures of the billet is significantly refined, the distribution of the grains size is relatively uniform from the billets edge to the billets center. And it also shows that the hot-tearing tendency of direct chill casting Φ500mm ZK60 magnesium alloy billets under low frequency electromagnetic field is significantly reduced.

Effect of Electromagnetic Field on the Macrosegregation Behaviour of Al-Cu Alloy Ingot Prepared with Direct-Chill Casting Process

2016 ◽  
Vol 877 ◽  
pp. 84-89
Author(s):  
Yu Bo Zuo ◽  
Qing Feng Zhu ◽  
Lei Li ◽  
Guang Ming Xu ◽  
Jian Zhong Cui
Keyword(s):  
Electromagnetic Field ◽  
Low Frequency ◽  
Casting Process ◽  
Direct Chill ◽  
Grain Refiner ◽  
Negative Segregation ◽  
Cu Alloy ◽  
Dc Casting ◽  
Positive Segregation ◽  
Direct Chill Casting Process

A low frequency electromagnetic field was introduced into the direct chill (DC) casting process and the ingots of Al-Cu alloy were prepared to study the macrosegregation behaviour of the ingots under the influence of the electromagnetic field. The experimental results showed that there is an obvious positive segregation near to the surface and a negative segregation in the centre area of the ingot. Cu shows the highest segregation tendency among the main elements of Cu, Mg and Mn. Grain refiner element Ti shows a segregation trend opposite to that of Cu. With the application of electromagnetic field, the negative centreline segregation in the centre area of the ingot was evidently reduced although it didn’t show significant effect on the segregation near to the ingot surface. A significant grain refinement was also achieved with the application of electromagnetic field. The mechanism of the reduction of macrosegregation with electromagnetic field was also analyzed in the present work.

Effects of the Low Frequency Electromagnetic Field on the Centerline Macrosegregation of 7075 Aluminum Ingots

2011 ◽  
Vol 295-297 ◽  
pp. 1705-1708
Author(s):  
Dan Dan Chen ◽  
Hai Tao Zhang ◽  
Xiang Jie Wang ◽  
Jian Zhong Cui
Keyword(s):  
Electromagnetic Field ◽  
Steady State ◽  
Mushy Zone ◽  
Transition Region ◽  
Low Frequency ◽  
Casting Process ◽  
Direct Chill ◽  
Mushy Region ◽  
Chill Casting ◽  
Temperature Contour

The effects of the low frequency electromagnetic field on the macrosegregation of the 7075 aluminum ingots were investigated. The 7075 aluminum ingots with the diameter of 200 mm were prepared by the conventional direct chill casting and the low frequency electromagnetic field casting (LFEC) processes, respectively. The temperature during casting at steady state was measured, and the mushy region was observed from the temperature contour. The concentrations of the alloying elements were measured by the spectrograph. It was found that the transition region was broadened, but the mushy zone became narrower with presence of the low frequency electromagnetic field. The centerline macrosegregation of the ingots was alleviated by the low frequency electromagnetic casting process.

Experimental and Numerical Study of the Influence of a Low-Frequency Electromagnetic Field on the As-Cast Structure of Horizontal Direct Chill Casting Aluminum Alloy Slab

2009 ◽  
Vol 79-82 ◽  
pp. 1265-1268
Author(s):  
Zhi Hao Zhao ◽  
Jian Zhong Cui ◽  
Qing Feng Zhu ◽  
Gao Song Wang
Keyword(s):  
Electromagnetic Field ◽  
Aluminum Alloy ◽  
Temperature Field ◽  
Flow Pattern ◽  
Low Frequency ◽  
Direct Chill ◽  
Chill Casting ◽  
Cast Structure ◽  
Casting Aluminum Alloy ◽  
Casting Aluminum

The influences of low frequency electromagnetic field on the as-cast structure of horizontal direct chill casting aluminum alloy slab were experimental and numerical studied. The results of numerical analysis show that the interaction of the low-frequency electromagnetic field and the melt can generate an electromagnetically induced forced flow in the melt, which, in turn, changes flow pattern and temperature field in the mold. the as-cast structure of slab can be greatly improved by the changes of flow pattern and temperature field. The results of experimental analysis show that the grains of low frequency electromagnetic casting (LFEC) are fine, uniform, equiaxed, rosette-shaped; the surface of the slab of LFEC has no cold shut and less exudations. Moreover, the low-frequency electromagnetic field can improve the distribution of solute elements in the slab. The macrosegregation such as negative segregation and gravity segregation were reduced, which results in the homogenous distributions of the solute elements over the cross-section of the slab.

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