Improvement of Casting Speed and Billet Quality of Direct Chill Cast Aluminum Wrought Alloy with Combination of Slit Mold and Electromagnetic Coil

Abstract

A mold with slits and external cooling water channels was designed for the direct chill casting processing. By imposing a high frequency magnetic field, the surface quality and microstructure of the direct chill cast billets are improved. The casting speed could be improved by the simultaneous use of mold and electromagnetic coil. In the case of one kind of Al-Cu-Mg alloy with a wide freezing range, the critical casting speed to break-out can be improved 60%. The microstructure of the billet cast with electromagnetic field is more fine and uniform than that of the conventionally cast billet, and the subsurface segregation usually observed in the conventional billets is eliminated.

Investigation structure and properties of wire from the alloy of AL-REM system obtained with the application of casting in the electromagnetic mold, combined rolling-extruding, and drawing

“…For the production of high-quality cast billets with a small cross-section, the continuous casting method using EMM has been increasingly used. At the same time, due to high cooling rates and the absence of metal contact with the walls of the mold, it is possible to obtain billets of small diameters (5-18 mm) with a fine-grained structure and increased plastic properties [6,[11][12][13][14][51][52][53][54][55]. The ingot obtained in the EMM has a dendritic parameter 100 times less than when casting into a slip mold and is comparable to the structure of granules (Table 1).…”

Microstructure as an essential aspect of EN AW 7075 aluminum alloy quality influenced by electromagnetic field during continuous casting process

“…At the very beginning, Prodhan et al [12] analyzed the solidification process of aluminum in sand molds at applying varying currents (AC/DC). Also, combinations of EMF and slit mold construction [13], and electromagnetic and ultrasonic fields [14] were explored. With the same aim, a homogenization treatment was applied on the EN AW 7075 alloy produced by EMF casting [15].…”

Effect of middle-frequency electromagnetic field on the semi-continuous casting for ZK60 billets

“…Many grain-refining methods have been developed and reviewed recently, including melt superheating [6] , rapid cooling [7] , FeCl 3 addition [8] , carbon inoculation [9] , melt stirring [10] , and addition of alloying elements such as Ca, Mn, Re, Sr, Cs, Sb and Zr [11][12][13][14] . It is an effective method to apply electromagnetic field into metal direct chill (DC) casting to improve the microstructure and properties of the billets [15,16] . Electromagnetic casting (EMC) is a technology developed by combing the magnetohydrodynamics (MHD) and DC casting [15] .…”