Numerical and Experimental Study on Melt Treatment for Large-Volume 7075 Alloy by a Modified Annular Electromagnetic Stirring

This study presents a modified annular electromagnetic stirring (M-AEMS) melt treatment suitable for a large-volume and high-alloyed aluminum alloy. A 3D computational model coupling an electromagnetic model with a macroscopic heat and fluid-flow model was established by using Ansoft Maxwell 3D and Fluent from ANSYS workbench, and the effects of the electromagnetic shielding ring, the height of the magnet yoke, the shape of the iron core, and the internal cooling mandrel on the electromagnetic, thermal and flow fields were studied numerically. Based on the optimal technical parameters, the effectivity of the M-AEMS process by using 7075 alloy was validated experimentally. The results show that a favorable electromagnetic field distribution can be achieved by changing the magnet yoke height, the iron-core shape and the electromagnetic shielding ring, and the melt temperature of the 7075 alloy can drop rapidly to the pouring temperature by imposing the internal cooling mandrel; compared with ordinary annular electromagnetic stirring, the M-AEMS process creates a lower magnetic strength near the melt top, beneficial for stabilizing the melt surface; meanwhile, it yields a higher magnetic strength near the melt bottom, which increases the shear rate and ensures an optimal stirring effect. Therefore, M-AEMS works more efficiently because the thermal and composition fields become uniform in a shorter time, which reduces the average grain size and the composition segregation, and a more stable melt surface can be obtained during treatment, which reduces the number of air and oxide inclusions in the melt.

Download Full-text

Liquid and Semisolid Melt Treatment: Electromagnetic Stirring

Al-Si Alloys ◽

10.1007/978-3-319-58380-8_5 ◽

2017 ◽

pp. 111-132

Author(s):

Francisco C. Robles Hernandez ◽

Jose Martin Herrera Ramírez ◽

Robert Mackay

Keyword(s):

Electromagnetic Stirring ◽

Melt Treatment

Download Full-text

Effect of Annular Electromagnetic Stirring on Microstructure and Mechanical Property of 7075 Aluminium Alloy

Materials Science Forum ◽

10.4028/www.scientific.net/msf.749.75 ◽

2013 ◽

Vol 749 ◽

pp. 75-81 ◽

Cited By ~ 4

Author(s):

Zhi Hua Gao ◽

Jun Xu ◽

Zhi Feng Zhang ◽

Meng Ou Tang

Keyword(s):

Liquid Metal ◽

Heat Dissipation ◽

Skin Effect ◽

Melt Processing ◽

Processing Technology ◽

Electromagnetic Stirring ◽

Solidification Structure ◽

Ferrous Metals ◽

7075 Alloy ◽

Microstructure And Mechanical Property

Annular electromagnetic stirring (A-EMS) process, developed by General Research Institute for Non-Ferrous Metals, is an advanced processing technology for conditioning liquid metal prior to solidification processing. A-EMS can avoid skin effect effectively, impose a higher shear rate and a higher intensity of turbulence to the liquid metal, and increase the area of the melt heat dissipation by means of innovatively combining noncontact electromagnetic stirring and an annular chamber with specially designed profiles. The solidification structure, composition macro-segregation and property of 7075 alloy were investigated under the conditions of the conventional casting, the conventional electromagnetic stirring casting and A-EMS casting. The results indicated that A-EMS melt processing technology had significant effects on grain refinement, reduction of composition macro-segregation and improvement of mechanical properties.

Download Full-text

Effects of Annular Electromagnetic Stirring Melt Treatment on Microstructure and Mechanical Properties of 7050 Rheo-Casting

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.285.219 ◽

2019 ◽

Vol 285 ◽

pp. 219-223 ◽

Cited By ~ 1

Author(s):

Tian Yang Guan ◽

Zhi Feng Zhang ◽

Min He ◽

Yue Long Bai ◽

Ping Wang

Keyword(s):

Mechanical Properties ◽

Casting Process ◽

Hot Cracking ◽

Electromagnetic Stirring ◽

Solidification Structure ◽

Alloy Casting ◽

Melt Treatment ◽

Microstructure And Mechanical Properties ◽

Strength And Ductility

The microstructure and mechanical properties of 7050 alloy rheo-castings after treated by Annular Electromagnetic Stirring (A-EMS) melt treatment were investigated. The results revealed that, under A-EMS, the refinement and homogeneity of the solidification structure could be improved greatly and the slurry was suitable for the following rheo-casting; and also the hot-cracking defects in the casting process were significantly alleviated, meanwhile, the strength and ductility of the alloy casting were found to be comparable to those of conventionally forged 7000 series alloys.

Download Full-text

Application Research on DC Casting Process by Annular Electromagnetic Stirring for a Modified 7075 Alloy

Materials Science Forum ◽

10.4028/www.scientific.net/msf.765.175 ◽

2013 ◽

Vol 765 ◽

pp. 175-179 ◽

Cited By ~ 5

Author(s):

Jun Xu ◽

Hai Jun Wang ◽

Meng Ou Tang ◽

Zhi Feng Zhang

Keyword(s):

Casting Process ◽

Electromagnetic Stirring ◽

Solidification Structure ◽

Application Research ◽

Treatment Technology ◽

Composition Segregation ◽

Continuously Cast ◽

Dc Casting ◽

7075 Alloy ◽

Metallurgy Industry

The annular electromagnetic stirring (A-EMS) process, as an advanced melt treatment technology, is increasingly applied in metallurgy industry. DC casting by A-EMS was applied in this study to investigate the solidification behaviour of a modified 7075 alloy. The effects of DC casting without EMS, with normal electromagnetic stirring (N-EMS) and with annular electromagnetic stirring (A-EMS) on microstructure, composition segregation and mechanical properties of continuously cast billets were compared. Research results showed that the billets with higher performance, lower macro-segregation, more uniformly fine solidification structure were obtained in the case of A-EMS.

Download Full-text

Study on Grain Refinement and Homogenization of Large-Sized DC Casting Ingot by A-EMS Melt Treatment

Materials Science Forum ◽

10.4028/www.scientific.net/msf.850.653 ◽

2016 ◽

Vol 850 ◽

pp. 653-658 ◽

Cited By ~ 6

Author(s):

Ya Jun Luo ◽

Zhi Feng Zhang ◽

Ming Wei Gao ◽

Jun Xu ◽

Shao Ming Zhang

Keyword(s):

Casting Process ◽

Direct Chill ◽

Electromagnetic Stirring ◽

Solidification Structure ◽

Treatment Technology ◽

Melt Treatment ◽

Composition Segregation ◽

Continuously Cast ◽

Dc Casting ◽

Metallurgy Industry

Electromagnetic stirring (EMS) process, as an advanced melt treatment technology, is increasingly applied in metallurgy industry. Direct chill (DC) casting process by annular electromagnetic stirring (A-EMS) was applied in this study to investigate the solidification behavior of a modified 7N01 alloy, and the effects of DC casting process without EMS, and A-EMS casting process on microstructure, composition segregation and mechanical properties of continuously cast billets were compared. The research results showed that the billets with higher performance, lower macro-segregation, more uniformly fine solidification structure were obtained in case of A-EMS.

Download Full-text

Enhanced Refinement of Al-Zn-Mg-Cu-Zr Alloy via Internal Cooling with Annular Electromagnetic Stirring above the Liquidus Temperature

Materials ◽

10.3390/ma12142337 ◽

2019 ◽

Vol 12 (14) ◽

pp. 2337 ◽

Cited By ~ 2

Author(s):

Tianyang Guan ◽

Zhifeng Zhang ◽

Yuelong Bai ◽

Bao Li ◽

Ping Wang

Keyword(s):

Experimental Study ◽

Grain Refinement ◽

Liquidus Temperature ◽

Electromagnetic Stirring ◽

Homogeneous Distribution ◽

Internal Cooling ◽

Grain Refining ◽

Refined Grains ◽

Nucleation Sites ◽

Zr Alloy

There are two critical stages of grain refinement during solidification: above and below the liquidus temperature. The key to improve the refinement potential is ensuring the nucleation sites precipitate in large quantities and dispersed in the melt above liquidus. In this work, internal cooling with annular electromagnetic stirring was applied to an Al-Zn-Mg-Cu-Zr alloy at a temperature above liquidus. A systematic experimental study on the grain refining potential was performed by combining different melt treatments and pouring temperatures. The results indicate that internal cooling with annular electromagnetic stirring (IC-AEMS) had a significantly superior grain refining potency for the alloy compared to traditional electromagnetic stirring (EMS). In addition, homogeneous and refined grains were achieved at high pouring temperatures with IC-AEMS. The possible mechanisms for the enhanced grain refinement above the liquidus temperature are explained as the stable chilling layer around the cooling rod in IC-AEMS providing undercooling for the precipitation of Al3Zr nucleant particles and the high cooling rate restraining the growth rate of these particles. At the same time, forced convection promotes a more homogeneous distribution of nucleant particles.

Download Full-text

Effect of Internal Electromagnetic Stirrings DC Casting on Grain Refinement and Segregation of Large-Sized Billet of 2219 Alloy

Materials Science Forum ◽

10.4028/www.scientific.net/msf.1035.227 ◽

2021 ◽

Vol 1035 ◽

pp. 227-234

Author(s):

Hao Dong Zhao ◽

Zhi Feng Zhang ◽

Bao Li ◽

Ming Wei Gao ◽

Yue Long Bai

Keyword(s):

Grain Refinement ◽

Process Condition ◽

Electromagnetic Stirring ◽

Coarse Grain ◽

Internal Cooling ◽

Composition Distribution ◽

Mean Grain Size ◽

Engineering Problems ◽

The Mean ◽

Dc Casting

An advanced method called internal electromagnetic stirring (I-EMS) was investigated to resolve the engineering problems like coarse-grain, inhomogeneous structure and macrosegregation. The electromagnetic stirrer functioned with internal-cooling was inserted in the melt during DC casting. In this study, a round billet of 2219 alloy DC cast with a diameter of 880mm under I-EMS process condition was produced, and its structure and composition distribution were comparatively characterized. The results show that the mean grain size decreased from the range of 872, 1023, 332 μm to the range of 317, 438, 271 μm at different billet positions with I-EMS. I-EMS consequently produce superior grain refinement and homogeneity. The effect of I-EMS on the grain-refinement and macrosegregation was also discussed.

Download Full-text

Application Research on Annular Electromagnetic Stirring Casting Process of Al-Zn-Mg-Cu Alloy

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.192-193.466 ◽

2012 ◽

Vol 192-193 ◽

pp. 466-469

Author(s):

Jun Xu ◽

Zhi Hua Gao ◽

Zhi Feng Zhang ◽

Men Gou Tang ◽

Wei Dong Yu

Keyword(s):

Mechanical Properties ◽

Casting Process ◽

Electromagnetic Stirring ◽

Application Research ◽

Solidification Behavior ◽

Treatment Technology ◽

Technology Application ◽

Cu Alloy ◽

Melt Treatment ◽

Fine Microstructure

Annular electromagnetic stirring (A-EMS) process is verified an advanced metal melt treatment technology. Application research was performed to investigate the solidification behavior of Al-Zn-Mg-Cu alloy in this study. The results indicated that uniformly fine microstructure, less composition macro-segregation and improved mechanical properties were achieved.

Download Full-text

Selected Abstracts of Recent Research in Stuttering

Perspectives on Fluency and Fluency Disorders ◽

10.1044/ffd9.1.5 ◽

1999 ◽

Vol 9 (1) ◽

pp. 5-6

Author(s):

Carrie Bain ◽

Nan Bernstein Ratner

Keyword(s):

Large Volume ◽

Clinical Relevance

Due to the large volume of fluency-related publications since the last column, we have chosen to highlight those articles of highest potential clinical relevance.

Download Full-text