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.

Combined Effect of Electromagnetic Field and Grain Refiner on Microstructure of Φ310 Mm 7050 Aluminium Alloy Ingot

2011 ◽  
Vol 399-401 ◽  
pp. 1708-1711 ◽  
Author(s):  
Yu Bo Zuo ◽  
Zhi Hao Zhao ◽  
Hai Tao Zhang ◽  
Ke Qin ◽  
Jian Zhong Cui
Keyword(s):  
Electromagnetic Field ◽  
Aluminum Alloy ◽  
Aluminium Alloy ◽  
Grain Refinement ◽  
Large Scale ◽  
Low Frequency ◽  
Combined Effect ◽  
Grain Refiner ◽  
Alloy Ingot ◽  
7050 Aluminum Alloy

Grain refinement is quite important for producing 7050 alloy ingot especially in large scale. Low frequency electromagnetic casting (LFEC) process was used to make 7050 aluminum alloy Φ310 ingots and study the effect of electromagnetic field and grain refiner on the microstructure of 7050 alloy ingots. The results showed that both grain refiner and low frequency electromagnetic field can result in some grain refinement of 7050 alloy. However, the low frequency electromagnetic field shows more remarkable grain refinement. For the grain refined alloy by grain refiner, further significant grain refinement can be achieved with the application of low frequency electromagnetic field. The finest microstructure was achieved by combining the applications of both grain refiner and electromagnetic field.

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.

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.

Grain Refinement of Direct Chill Cast 7050 Aluminium Alloy with Low Frequency Electromagnetic Field

2011 ◽  
Vol 402 ◽  
pp. 850-853 ◽  
Author(s):  
Yu Bo Zuo ◽  
Zhi Hao Zhao ◽  
Jian Zhong Cui
Keyword(s):  
Electromagnetic Field ◽  
Grain Refinement ◽  
Low Frequency ◽  
Direct Chill ◽  
Current Intensity ◽  
Field Frequency ◽  
7050 Aluminum Alloy ◽  
Microstructure Effects ◽  
Chill Cast ◽  
Direct Chill Cast

Low frequency electromagnetic casting (LFEC) process was used to make 7050 aluminum alloy 162mm ingots and study its effect on the as-cast microstructure. Effects of electromagnetic field parameters such as frequency and current intensity on microstructures were systemically investigated. The results showed that LFEC has a significant grain refining effect on 7050 alloy. The microstructures of LFEC ingot from the border to the center of the cross section are all equiaxed or nearly equiaxed grains which are much finer and more uniform than those of DC cast ingot. It was also found that electromagnetic field frequency and current intensity play important roles on the microstructure refinement. The discussion was mainly focused on the mechanism of grain refinement by LFEC process.

Homogenization Behaviors of Low Frequency Electromagnetic Casting and Direct Chill Casting 7050 Aluminum Alloy

2010 ◽  
Vol 97-101 ◽  
pp. 991-994
Author(s):  
Zhi Hao Zhao ◽  
Jian Zhong Cui ◽  
Jing Wang ◽  
Gao Song Wang
Keyword(s):  
Aluminum Alloy ◽  
Low Frequency ◽  
Eutectic Structure ◽  
Optical Microscope ◽  
Direct Chill ◽  
Direct Chill Casting ◽  
Chill Casting ◽  
Electromagnetic Casting ◽  
7050 Aluminum Alloy ◽  
Dsc Analyses

7050 aluminum alloy ingots were produced by low frequency electromagnetic casting (LFEC) and direct chill casting (DC) respectively. As-cast microstructures and homogenization behaviors of LFEC and DC ingots were investigated experimentally. The optical microscope and DSC analyses shown that the grain size of LFEC ingot was finer and the content of constituents and eutectic structure was less than that of DC ingot. Accordingly, the homogenization behaviors of the LFEC and DC ingots were significantly different. The remnant constituents of LFEC ingot were less in content and smaller in size than that of DC ingot after homogenization at 480°C for various lengths of time. Similar to the dissolving of constituents, the LFEC ingot exhibited faster diffusion kinetics of alloying elements from grain boundary to inner. The concentrations of Cu, Mg and Zn inside grain of LFEC ingot after homogenization for 12 h were 2.4%, 2.2% and 6.5% respectively, but the DC ingots had not reach the level even for 48 h.

scholarly journals New high-strength casting aluminum alloy based on the Al–Zn–Mg–Ca–Fe system without requirement for heat treatment

2020 ◽  
pp. 48-58
Author(s):  
P. K. Shurkin ◽  
N. A. Belov ◽  
A. F. Musin ◽  
A. A. Aksenov
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Aluminum Alloy ◽  
Base Alloy ◽  
High Strength ◽  
Hot Tearing ◽  
Grain Structure ◽  
Casting Aluminum Alloy ◽  
Casting Aluminum ◽  
Alloy Properties

The paper substantiates the composition and prospects of using high strength Al–Zn–Mg–Ca–Fe casting aluminum alloy without heat treatment based on the study on the structure, technological and mechanical properties. Alloys of the base composition Al–5.5%Zn–1.5%Mg (wt.%) jointly and separately doped with 0.5–1.0 % Ca and 0.5 % Fe were obtained as the objects of research. Standard casting alloys according to GOST 1583-93: AK12M2, AMg6lch, AM4,5Kd were the objects of comparison. A hot tensile test using a cast test bar was conducted to check the tendency to form hot cracks due to hindered contraction. It was shown that separate alloying with calcium and iron does not contribute to the improvement of crack resistance and adversely affects mechanical properties. Combined alloying with 1 % Ca and 0.5 % Fe improves the hot tearing resistance to the level of the AMg6lch alloy properties. This effect is due to calcium-containing phases of eutectic origin formed and a favorable grain structure created that is free from columnar grains. Iron in the alloy structure is bound in compact Al10CaFe2 phase particles as a result of the non-equilibrium crystallization during permanent mold casting. The formation of this phase allowed to reduce the amount of zinc in the (Al, Zn)4Ca phase and mostly retain the (Al) solid solution composition as evidenced by similar hardness values of the Al–5.5%Zn–1.5%Mg base alloy and Al–5.5%Zn–1.5%Mg–1%Ca–0.5%Fe alloy, and the superiority of the values over the hardness of alloys separately alloyed with calcium and iron. Also the cast hardness of the promising alloy more than 20 HV higher than the cast hardness of commercial cast alloys. The new alloy in the as-cast condition exhibited competitive mechanical tensile properties: UTS ~ 310 MPa, YS ~ 210 MPa, El ~ 4 %.

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