A New Approach of Casting Aluminium Alloy Bar by Applying Low Frequency Electromagnetic Field

2014 ◽  
Vol 794-796 ◽  
pp. 167-171
Author(s):  
Xiang Jie Wang ◽  
Gang Sun ◽  
Li Juan Wang ◽  
Peng Wei Li ◽  
Jian Zhong Cui
Keyword(s):  
Electromagnetic Field ◽  
New Technology ◽  
Low Frequency ◽  
High Strength ◽  
Casting Process ◽  
Lower Surface ◽  
Growth Direction ◽  
Direct Chill ◽  
Cast Aluminum ◽  
Low Efficiency

Aluminum is the richest metallic element in the earth, the ingots cast by DC casting process are usually extruded into aluminum bars. When the final products do not require high strength, this process appears to be low efficiency and high cost. We try to design a new technology to cast aluminum bar by horizontal direct chill (HDC) casting process directly. An electromagnetic field is applied during the horizontal continuous casting of 6061 aluminium bar with a diameter of 30mm. The experimental results show the asymmetry of the sump can be overcome by electromagnetic field. Ingot with good upper and lower surface quality is obtained. The structure of ingot is refined and the angle between growth direction and horizontal direction becomes small with increasing casting speed.

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.

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.

Effects of Low Frequency Electromagnetic Field on Segregation Layer during Hot-Top Casting of Aluminium Alloy

2011 ◽  
Vol 189-193 ◽  
pp. 3795-3798
Author(s):  
Xiang Jie Wang ◽  
Jian Zhong Cui ◽  
Hai Tao Zhang ◽  
Hui Xue Jiang ◽  
Gao Song Wang
Keyword(s):  
Electromagnetic Field ◽  
Aluminium Alloy ◽  
Surface Segregation ◽  
Low Frequency ◽  
Casting Process ◽  
Direct Chill ◽  
Direct Chill Casting ◽  
Chill Casting ◽  
Direct Chill Casting Process

Surface segregation layer are frequently encountered during aluminium alloy direct chill casting process, and the removal of the surface segregation layer before further processing of the ingot decreases the ingot yield. In this work, the low frequency electromagnetic field was applied to study the effects of low frequency electromagnetic field on segregation layer during the direct chill casting process. The results show that under the effect of the low frequency electromagnetic field, the surface quality of ingot is improved, the structure of the ingot is refined, and the thickness of segregation layer is decreased.

Preparing Large Sized Billet of High Strength Aluminum Alloy with the Application of Low Frequency Electromagnetic Field

2012 ◽  
Vol 472-475 ◽  
pp. 723-726
Author(s):  
Yu Bo Zuo ◽  
Zhi Hao Zhao ◽  
Qing Feng Zhu ◽  
Xiang Jie Wang ◽  
Jian Zhong Cui
Keyword(s):  
Electromagnetic Field ◽  
Aluminum Alloy ◽  
Large Scale ◽  
Low Frequency ◽  
High Strength ◽  
Direct Chill ◽  
Hot Tearing ◽  
Grain Structure ◽  
Grain Refiner ◽  
7050 Aluminum Alloy

Grain refinement is quite important for producing 7050 alloy billet especially in large scale. Low frequency electromagnetic casting (LFEC) process was used to make 7050 aluminum alloy Φ500 mm billets and study the effect of electromagnetic field on the microstructure. The sound Φ500 mm billets of 7050 alloys without any grain refiner can be successfully prepared by the LFEC process. The results show that low frequency electromagnetic field has a significant grain refining effect on 7050 alloy and can effectively eliminate feather grain structure. The microstructures of LFEC ingot from the border to the center of the cross section are all equiaxed grains and are finer and more uniform than that of conventional direct chill (DC) cast billets. The LFEC process also shows a strong power to eliminate hot tearing during casting large sized billet of high strength aluminium alloy.

Effect of Low Frequency Electromagnetic Field on Microstructures and Macro-Segregation of Direct Chill Casting Al-19.2%Si Alloys

2007 ◽  
Vol 546-549 ◽  
pp. 953-956
Author(s):  
Ke Qin ◽  
Jian Zhong Cui
Keyword(s):  
Electromagnetic Field ◽  
Low Frequency ◽  
Casting Process ◽  
Primary Silicon ◽  
Direct Chill ◽  
Direct Chill Casting ◽  
Optimum Frequency ◽  
Chill Casting ◽  
Solid Region ◽  
Spherical Structures

The influences of low frequency electromagnetic field on microstructures and macro-segregation in direct chill casting process were investigated in the experiments，Al-19.2%Si alloys were semi-continuously cast into ingots with 100 mm in diameter. Microstructures and macrostructures of samples taken from different part of the cast with different electromagnetic field conditions were characterized by optical microscopy. The results showed that low frequency electromagnetic field refines the microstructures and reduces macro-segregation. Unlike casting without electromagnetic field, the primary Si grains were homogeneous with fine dimensions and the morphology of the primary silicon exhibited small blocky structures or near-spherical structures. Further more, decreasing frequency is beneficial to the improvement. In the range conditions in the experiments, the optimum frequency is found to be 15Hz. During casting, the temperature of the liquid metal in the sump was monitored. The results shown, under LFEC the width of the liquid-solid region became narrowed and the temperature field in the sump also became homogeneous.

Low-Frequency Electromagnetic Field Influencing Horizontal Direct Chill Casting of Aluminum Alloy Rods

2007 ◽  
Vol 546-549 ◽  
pp. 691-696
Author(s):  
Zhi Hao Zhao ◽  
Jian Zhong Cui ◽  
Qing Feng Zhu
Keyword(s):  
Electromagnetic Field ◽  
Aluminum Alloy ◽  
Low Frequency ◽  
Casting Process ◽  
Gravitational Effect ◽  
Direct Chill ◽  
Cooling Condition ◽  
Chill Casting ◽  
Alloy Ingot ◽  
Production Route

The horizontal direct chill (HDC) casting process is a well-established production route for an aluminum alloy ingot; however, the ingot may suffer from inhomogeneous microstructures and serious macrosegregation due to the unbalanced cooling condition and gravitational effect. In order to control the defect, a low frequency electromagnetic field has been applied in the HDC casting process and its influences on microstructures and macrosegregation have been studied. The results show that the low frequency electromagnetic field can improve macrostructures, reduce inhomogeneous microstructures and macrosegregation in HDC product; and two main parameters of the electromagnetic field—density and frequency influence the microstructures and solution distribution along the diameter of the ingot significantly. In the range of ampere-turns and frequency employed in the experiments, the optimum ampere-turns and frequency have been found to be 10000At, 30Hz.

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.

Research on causes of hot-tearing of AA3003 aluminum billet during DC casting process

2021 ◽  
Vol 95 ◽  
pp. 29-37
Author(s):  
Bach Dao Hong ◽  
◽  
Trung Trinh Van
Keyword(s):  
Chemical Composition ◽  
Casting Process ◽  
Direct Chill ◽  
Hot Tearing ◽  
Cast Aluminum ◽  
Allowable Limit ◽  
Chemical Composition Distribution ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes ◽  
Direct Chill Casting Process

AA3003 aluminum alloy made from raw scrap materials that have the advantage of economical use, but hottearing often occurs in the product billets of the direct chill casting process. This study used ANOVA analysis method for determination of chemical composition of AA3003 aluminum billet products to show influence of chemical composition on hot-tearing ability. The evaluation of the microstructure and chemical composition distribution of the elements by optical and scanning electron microscopes combined with energy dispersive spectroscopy showed the existence of impurities such as Cu, Zn, Fe, Pb exceeding the allowable limit in aluminum billets, especially at grain boundary, which can be the main reason for the hot-tearing of cast aluminum billets.

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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