Effects of Low Frequency Electromagnetic Field of Multi-Physical Fields During DC Casting of 7XXX Aluminum Alloys

2012 ◽  
Vol 13 (1) ◽  
pp. 306-311
Author(s):  
Haitao Zhang ◽  
Hiromi Nagaumi ◽  
JianZhong Cui
Keyword(s):  
Electromagnetic Field ◽  
Aluminum Alloys ◽  
Low Frequency ◽  
Dc Casting ◽  
Physical Fields

The Numerical and Experimental Study on Electromagnet-Air Knife DC Casting Process of Large-Size AA 7055 Aluminum Alloys

2014 ◽  
Vol 783-786 ◽  
pp. 319-324
Author(s):  
Hai Tao Zhang ◽  
Jian Zhong Cui ◽  
Hiromi Nagaumi
Keyword(s):  
Electromagnetic Field ◽  
Flow Direction ◽  
Low Frequency ◽  
Casting Process ◽  
Stress And Strain ◽  
Large Size ◽  
Dc Casting ◽  
Physical Fields ◽  
7055 Aluminum Alloy ◽  
Air Knife

In this paper, Low frequency electromagnetic field and air knife are applied simultaneously to produce large-size AA 7055 aluminum alloy ingots during DC casting. Moreover, the effects of low frequency electromagnetic field and air knife on macro-physical fields during DC casting as well as microstructure and crack in the ingots are studied and analyzed by the numerical and experimental methods. Comparison of the calculated results indicates that applying electromagnetic field can modify the flow direction and increase the velocity of melt flow and homogenize the distribution of temperature in the sump, and applying air knife can homogenize the distribution of temperature and decrease the stress and strain in the solidified ingots. Further, the microstructure of the billet is refined remarkably and the crack is eliminated by applying electromagnetic field and air knife during DC casting because of modification of the macro-physical fields

Microstructures and Mechanical Properties of AZ31B Extruded Sheets from Different Casting Processing

2007 ◽  
Vol 546-549 ◽  
pp. 399-402
Author(s):  
Qi Chi Le ◽  
Zi Qiang Zhang ◽  
Jian Zhong Cui
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Electromagnetic Field ◽  
Deformation Process ◽  
Low Frequency ◽  
High Quality ◽  
Refined Microstructure ◽  
Plastic Deformation Process ◽  
Dc Casting ◽  
Microstructures And Mechanical Properties

A novel way producing magnesium billets, LFEC (low frequency electromagnetic casting processing), was developed in Northeastern University in China. The high-quality magnesium billets with less macrosegregation, refined microstructure, and better surface quality were achieved because the temperature field and the flow pattern of magnesium DC casting were improved significantly after applying low frequency electromagnetic field. Extrusion is an important plastic deformation process for magnesium alloys. In this research, the magnesium billets from LFEC were extruded through a special designed die into sheets. The results of investigation on AZ31B indicated that the extrusion velocity has obvious effects on their microstructures and mechanical properties and the sheets from LFEC had finer microstructure and higher mechanical properties than that from conventional DC casting.

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 low frequency electromagnetic field on casting crack during DC casting superhigh strength aluminum alloy ingots

2005 ◽  
Vol 406 (1-2) ◽  
pp. 286-292 ◽  
Author(s):  
Zuo Yubo ◽  
Cui Jianzhong ◽  
Zhao Zhihao ◽  
Zhang Haitao ◽  
Qin Ke
Keyword(s):  
Electromagnetic Field ◽  
Aluminum Alloy ◽  
Low Frequency ◽  
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.

Coupled Modeling of Electromagnetic Field, Fluid Flow, Heat Transfer and Solidification during Conventional DC Casting and Low Frequency Electromagnetic Casting of 7XXX Aluminum Alloys

2006 ◽  
Vol 15-17 ◽  
pp. 18-23 ◽  
Author(s):  
Hai Tao Zhang ◽  
Hiromi Nagaum ◽  
Yu Bo Zuo ◽  
Jian Zhong Cui
Keyword(s):  
Heat Transfer ◽  
Electromagnetic Field ◽  
Fluid Flow ◽  
Low Frequency ◽  
Casting Process ◽  
Coupled Modeling ◽  
Electromagnetic Casting ◽  
Flow Heat ◽  
Dc Casting ◽  
Heat Transfer And Solidification

A comprehensive mathematical model has been developed to describe the interaction of the multiple physics fields during the conventional DC casting and LFEC (low frequency electromagnetic casting) process. The model is based on a combination of the commercial finite element package ANSYS and the commercial finite volume package FLUENT, with the former for the calculation of the electromagnetic field and the latter for the calculation of the magnetic driven fluid flow, heat transfer and solidification. Moreover, the model has been verified against the temperature measurements obtained from two 7XXX aluminum alloy billets of 200mm diameter, cast during the conventional DC casting and the LFEC casting processes. In addition, a measurement of the sump shape of the billets were carried out by using addition melting metal of Al-30%Cu alloy into the billets during casting process. There was a good agreement between the calculated results and the measured results. Further, comparison of the calculated results during the LFEC process with that during the conventional DC casting process indicated that velocity patterns, temperature profiles and the sump depth are strongly modified by the application of a low frequency electromagnetic field during the DC casting.

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