Microstructures and mechanical characteristics of electromagnetic casting and direct-chill casting 2024 aluminum alloys

2002 ◽  
Vol 327 (2) ◽  
pp. 133-137 ◽  
Author(s):  
Cao Zhiqiang ◽  
Jia Fei ◽  
Zhang Xingguo ◽  
Hao Hai ◽  
Jin Junze
2010 ◽  
Vol 97-101 ◽  
pp. 991-994
Author(s):  
Zhi Hao Zhao ◽  
Jian Zhong Cui ◽  
Jing Wang ◽  
Gao Song Wang

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.


2007 ◽  
Vol 561-565 ◽  
pp. 995-998 ◽  
Author(s):  
Dmitry G. Eskin ◽  
Laurens Katgerman

Hot tearing is a significant problem upon direct-chill casting of high-strength aluminum alloys. The occurrence of hot cracks is related to the thermal contraction of the solid phase and to the lack of feeding by the liquid phase during solidification. It has been identified that structure features such as grain size and amount of nonequilibrium eutectics influence both phenomena involved in hot tearing. Experimental and computer-simulation results are presented for a range of model and commercial aluminum alloys. The results are obtained both during special small-scale experiments and during industrial-scale direct-chill casting. It is shown that grain refinement reduces hot tearing susceptibility of aluminum alloys through the related decrease of the temperature of thermal contraction onset and increased permeability of the mushy zone. The effects of process parameters on hot tearing are also discussed.


2008 ◽  
Vol 39 (5) ◽  
pp. 1206-1212 ◽  
Author(s):  
Dmitry G. Eskin ◽  
Qiang Du ◽  
Laurens Katgerman

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