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.

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.

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.

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.

The Effect of Casting Speed on Sump Shape and Ingot Surface of HDC Casting 7075 Aluminum Alloy Ingot

2011 ◽  
Vol 189-193 ◽  
pp. 3785-3788 ◽  
Author(s):  
Qing Feng Zhu ◽  
Zhi Hao Zhao ◽  
Xiang Jie Wang ◽  
Jian Zhong Cui
Keyword(s):  
Aluminum Alloy ◽  
Surface Quality ◽  
Casting Speed ◽  
Direct Chill ◽  
Liquid Pool ◽  
Ingot Surface ◽  
Direct Chill Casting ◽  
7075 Aluminum Alloy ◽  
Chill Casting ◽  
Alloy Ingot

7075 aluminum alloy ingot with the diameter of 100 mm has been produced by horizontal direct chill casting in different casting speed. The effect of casting speed on the sump profile and the ingot surface quality was studied by sump profile observation. It was found that increasing the casting speed results in the deepening of the liquid pool, the adding of segregation knots and the reducing of cold shouts in the ingot surface. It is also found that the depth of the liquid pool is directly proportional to the casting speed and the squared radius of the ingot.

Sign in / Sign up

Export Citation Format

Share Document