Effect of Low-Frequency Electromagnetic Casting on Micro-Structure and Macro-Segregation of 5A90 Alloy Ingots

Abstract

The effect of low-frequency electromagnetic fields on the micro-structure and macro-segregation of 5A90 alloy ingots during the semi-continuous casting process were quantitatively investigated. The ingots of a 5A90 alloy with a diameter 170 mm were produced by the conventional direct chill casting (DCC) process and low-frequency electromagnetic casting (LFEC) with 10 Hz/100 A. The results showed that LFEC can substantially refine the micro-structure and shorten the width of the columnar grain area of an ingot. The refinement effect came with the relieving of grain boundary segregation and an improvement in the macro-segregation of the ingot. Compared with the traditional DCC process, the tensile properties of the aged alloy prepared by the LFEC process were improved due to the effects of the increase in solid solubility and the strengthening of the grain refinement, so that the stability of the tensile properties was also improved. Meanwhile, the rate of yield increased by 2.3% with a decrease in the peeling thickness of the ingot.

Effects of Pulsed Magnetic Field Melt Treatment on Grain Refinement of Al-Si-Mg-Cu-Ni Alloy Direct-Chill Casting Billet

“…However, the details of the grain refinement mechanisms under pulse magnetic fields remain to be elucidated [22]. Some researchers have suggested that the main reason for grain refinement under pulsed magnetic fields is the strong stirring of the melt in the crystallizer due to the Lorentz force, which leads to dendrite fragmentation, and ultimately, those fragments become the nucleus, increasing the nucleation rate [23][24][25]. However, other researchers revealed that the energy of the magnetic field can reduce the energy barrier and improve the nucleation rate [26][27][28].…”

Effects of Intercooling Intensity on Temperature Field and Microstructure of Large-Scale 2219 Al Alloy Billet Prepared by Internal Electromagnetic Stirring Casting

“…A large number of studies have shown that the abovementioned problems can be solved by using electromagnetic stirring (EMS) during DCC [ 12 , 13 , 14 , 15 ]. However, the skin effect applies to conventional EMS, demonstrating that the penetration depth of the magnetic field into the melt is limited [ 16 ].…”

Correction: Wang, F., et al. Effect of Low-Frequency Electromagnetic Casting on Micro-Structure and Macro-Segregation of 5A90 Alloy Ingots. Materials 2020, 13, 2720

“…In the original article [ 1 ], there was a mistake in Figure 4 as published. The scale of vertical axis is wrong.…”

“…In the original article [1], there was a mistake in Figure 4 There was also an error in the original article. A correction has been made to Section 3.2.…”

“…The concentration of alloying elements at different positions of the 5A90 alloy ingots was detected using ICP-AES, and the degree of segregation can be expressed as the relative segregation rate as shown in Equation (1).…”