Scientific principles of the development of technologies for melting and casting aluminum and titanium-based alloys in an alternating electromagnetic field are considered. In the 21st century, innovative technologies for melting and casting light alloys in an alternating electromagnetic field can hardly be developed and implemented unless being supported with digital technologies, and methodology of digital twins and numerical models combining closely interconnected electromagnetic, thermodynamic, hydrodynamic and mechanical processes. A unique technology for continuously casting small-diameter round ingots into an electromagnetic crystallizer with the crystallizing metal surface directly cooled with water has been developed. By applying the newly developed technology it becomes possible to simultaneously achieve a number of unique effects that alter significantly the quality and properties of the resulting billets (reduction in the amount of undesirable impurities and inclusions in the metal structure, uniform distribution of phases and grains in the metal ingot structure, and uniform distribution of chemical elements and compounds in the metal matrix). The occurrence of a titanium alloy liquid phase inside the cylinder was predicted using a numerical model and confirmed by experimental studies. Owing to a unique combination of the titanium thermophysical properties with the action of an alternating electromagnetic field in an inductor, up to 90% of the total mass of a titanium cylindrical billet can be obtained in the liquid phase. Magnetohydrodynamic effects that come into picture after the start of melting play a special role in achieving this result.

The effect of equal-channel angular pressing (ECAP) and subsequent cold drawing (CD) on the microstructure and properties of the Al-0.5Fe-0.3Cu (wt. %) alloy produced by electromagnetic casting (EMC) is examined. The high rate of crystallization of the alloy ensured the formation of a solid solution of copper in the aluminum matrix, while iron was completely bound in intermetallic particles of the Al-Fe and Al-Fe-Cu types. A distinctive feature of ECAP processing followed by CD is the presence of signs of both ECAP and CD in the structure of the processed alloy. Moreover, the syncretic effect of two deformation methods, implementing different deformation schemes, led to the appearance of features that were absent in the alloy structures after ECAP or after CD. Presence of the unique ultra-fine grained (UFG) microstructure, formed as a result of the combined ECAP+CD treatment, led to an increase in the tensile strength of wires made of the Al-0.5Fe-0.3Cu alloy to 342 MPa while maintaining a relatively high electrical conductivity of 55.5 % IACS. Compared to the commercial scale alloys, the wire (with a UFG structure) from the Al-0.5Fe-0.3Cu alloy demonstrates either equal (6000 series alloys) or improved (8000 series alloys) mechanical strength and electrical conductivity. Introduction of copper into Al-0.5Fe alloy, obtained using the EMC method, allows to even further improve the strength-conductivity combination of this alloy.

The effect of alloying with 0.3 wt

The addition of the 0.3 wt. % copper to the Al-0.5 wt.% Fe alloys was studied. The initial billets of the alloy were produced via electromagnetic casting (EMC) with the subsequent cold drawing (CD). Further annealing at 230˚C for 1h was carried out as a thermal stability test. The microstructure of the alloy with and without Cu is similar with the slight variation in intermetallic particles distribution. The addition of copper resulted in the two-fold increase of the yield stress (YS) of the alloy in as-cast state and increase of the ultimate tensile strength (UTS) after CD (by 60 MPa). The electrical conductivity of the Cu-containing alloy is lower by 1.5-2 %IACS in both all states. Such difference in properties is attributed for the Cu presented in both solid solution in aluminium matrix, and in the intermetallic particles.

The paper explores the microstructure, mechanical properties and heat resistance of the piston alloy AL30 (AK12MMgN) for the first time produced via continuous casting into an electromagnetic mold (electromagnetic casting, EMC). The study demonstrates that casting into EMC allows for the formation of a homogeneous dispersed microstructure in both the peripheral and central zones of the ingot, consisting of a blend of aluminum's solid solution and eutectic, which contains lamellar silicon (Si). The volume fraction of compact primary Si particles does not exceed 1 %. In addition to Si, the aluminum matrix contains the phases of crystallization origin such as epsilon-Al3Ni, pi-Al8FeMg3Si6, Q-Al4Cu2MgSi7 and S-Al2CuMg. The analysis of the evolution of microstructure and properties of a cast alloy after conventional heat treatment (HT) reveals that microstructural changes induced by HT lead to the AL30 alloy having mechanical properties that far exceed the properties of its counterparts obtained through traditional casting methods. The research analysis shows that mechanical properties and heat resistance of the AL30 alloy produced via EMC with subsequent T6 treatment are comparable to the deformable piston alloys such as the AK12D alloy after similar heat treatment.

В работе представлены многодисциплинарная численная модель процесса литья алюминиевых слитков в электромагнитное поле и результаты, полученные при ее применении для анализа процессов литья алюминиевых слитков диам. 25–30 мм. Численная модель основана на расчете электромагнитного поля посредством решения дополнительного уравнения во Fluent с совместным моделированием процессов, связанных со свободной поверхностью и кристаллизацией. Найденные источники электромагнитного поля используются в уравнениях движения и энергии для решения задачи магнитной гидродинамики. Представлены результаты решения задачи на определение совокупности технологических параметров, обеспечивающих стабильное формирование слитка требуемого диаметра, а также результаты моделирования аварийных режимов. Также представлены результаты применения найденных режимов на лабораторной установке литья в электромагнитный кристаллизатор по технологии ElmaCast® для производства слитков из опытных сплавов Николин и Альцимак. The paper presents a multidisciplinary numerical model of the process of casting aluminum ingots in an electromagnetic field and the results obtained by using it to analyze the processes of casting aluminum ingots with a diameter of 25–30 mm. The numerical model is based on the internal calculation of the electromagnetic field by solving an additional equation in Fluent with joint modeling of the processes associated with the free surface and crystallization. The solution of the problem of magnetohydrodynamics is carried out through the use of electromagnetic sources of motion and energy. The results of solving the problem of determining the set of technological parameters that ensure the stable formation of an ingot of the required diameter, as well as the results of simulation of emergency modes are presented. The results of the application of the found modes on a laboratory installation for casting into an electromagnetic mold using ElmaCast® technology for the production of ingots from experimental Nikolin and Alcimak alloys are also presented.

The article represents a multidisciplinary numerical model for electromagnetic casting of aluminum ingots, as well as the results of its application when casting aluminum ingots diam. 25–30 mm. The numerical model is based on a calculation of the electromagnetic field by solving an additional equation in Fluent combined with the modeling of processes connected with free surface crystallization. The obtained electromagnetic field sources are used in motion and energy equations for solving the magneto-hydrodynamics problem. A solution to the problem of determining the set of technological parameters for ensuring the stable formation of an ingot with the required diameter is provided along with the results of emergency mode modeling. In addition, the article presents the results of applying the established emergency modes at the laboratory casting unit with the electromagnetic mold for the production of ingots using Nikolin and Altsimak experimental alloys as part of ElmaCast® technology.

A calculation technique (Thermo-Calc software code) and experimental methods (scanning and transmission electron microscopy and X-ray spectral analysis) have been used to study the effect of thermodeformation treatment on the structure and strengthening of the Al–7.1

This paper presents a proposed numerical model of casting process into electromagnetic crystallizer mold and results obtained when applying it to the analysis of the processes of casting aluminum ingots with a diameter of 25 to 30 mm. The numerical model is based on the calculation of the electromagnetic field by means of user-defined function (UDF) in Fluent software combined with the simulation of processes related to free surface using volume of fluid (VOF) method and crystallization on Kozeny-Carman method. The results of solving the search problem on the determination of a set of parameters ensuring the stable formation of an ingot of the required diameter as well as the results of simulation of emergency and special modes are shown. The article also presents application results of the modes identified on the laboratory installation of casting into electromagnetic crystallizer using ElmaCast® technology for the production of ingots from experimental alloys "Nikalin" and "Alcimac".

A calculation technique (Thermo-Calc software code) and experimental methods (scanning and transmission electron microscopy and X-ray spectral analysis) have been used to study the effect of thermodeformation treatment on the structure and strengthening of the Al–7.1% Zn–2.8% Mg–1.4% Ni–1.1% Fe alloy produced via casting in an electromagnetic crystallizer (EMC). It has been shown that at a cooling rate higher than 10 3 K/s, the entire amount of iron, which exceeds its content in the grade AZ6NF alloy (GOST 4784–2019) by two times, is bound into eutectic inclusions of the Al 9 FeNi phase of a submicron size. The combination of high hardness (more than 190 HV) and ductility indicates the advantages of applying the EMC technology to this alloy.

A calculation technique (Thermo-Calc software code) and experimental methods (scanning and transmission electron microscopy and X-ray spectral analysis) have been used to study the effect of thermodeformation treatment on the structure and strengthening of the Al–7.1% Zn–2.8% Mg–1.4% Ni–1.1% Fe alloy produced via casting in an electromagnetic crystallizer (EMC). It has been shown that at a cooling rate higher than 103 K/s, the entire amount of iron, which exceeds its content in the grade AZ6NF alloy (GOST 4784–2019) by two times, is bound into eutectic inclusions of the Al9FeNi phase of a submicron size. Thecombination of high hardness (more than 190 HV) and ductility indicates the advantages of applying the EMC technology to this alloy.

The Al-3.3Cu-2.5Mn-0.5Zr (wt%) alloy was manufactured by electromagnetic casting and further subjected to processing including cold rolling, drawing and annealing. Excellent processability of the alloy at cold rolling and drawing was observed due to the ultrafine as-cast structure. Annealing of the cold-rolled strip at 350 degrees C for 48 h insignificantly reduces the hardness, but the electrical resistivity (ER) decreases by almost 3 times (from 115 to 40 nOm). The large deformation during rolling (reduction 98.4%) and high fraction of the Zr- and Mn-bearing nano dispersoids (Al20Cu2Mn3 and Al3Zr-L1(2) ) stipulated the high set of mechanical properties and electrical conductivity after annealing at 400 degrees C (UTS-330 MPa, YS, 250 MPa, EL-7%, 42.5 IACS). A model of ER dependence on the phase composition was proposed. While at above 400 degrees C there is a good agreement between the calculated and experimental values, the scatter at lower temperatures is attributed to exposure times insufficient for achieving the equilibrium (Al) composition. Atom probe tomography was employed for observation of Cu, Mn and Zr concentrations in (Al) after annealing at 350-450 degrees C. According to the experimental results and root-mean-square calculations, annealing at between 350 and 400 degrees C allows achieving (Al) compositions close to the equilibrium in reasonable time while with decreasing temperature the diffusion of Zr in (Al) decreases and thus it requires extremely long exposures, e.g. at 300 degrees C it is about 23,000 h. From this viewpoint annealing at below 350 degrees C is unreasonable for achieving lower ER. (C) 2021 Elsevier B.V. All rights reserved.

The Scientific and Production Center for Magnetic Hydrodynamics Ltd has developed an innovative technology for casting long ingots of small diameter (8–12 mm) into an electromagnetic mold (EMM) and manufacturing thin wire (0.5 mm in diameter) from them for onboard wires from 01417 alloy. Crystallization of liquid metal occurs under the influence of electromagnetic forces in an electromagnetic mold with direct supply of coolant to the ingot, due to which cooling rates are achieved that ensure the dispersion of the eutectic phases of rare earth metal aluminides, similarly to how it takes place during the crystallization of granules (~1.103...1.104 K/s). It has been established that the determining parameters in casting ingots are the power supplied to the inductor and the level of the melt above the crystallization front. For the casting to reach a steady state (the process of stabilizing the diameter of the ingot after the start of casting), it is necessary to regulate the melt level for some time. The surface quality of the ingot depends on ensuring stability of the current in the inductor during casting. Fluctuations in the current in the inductor lead to changes in the ingot`s diameter. Casting speed and metal temperature have a great influence on the structure of ingots. In contrast to the method of producing granulated wire with a thin (less than 1 mm) cross-section, which turned out to be problematic due to numerous breaks during drawing associated with the presence of oxide and foreign inclusions, the casting technology in the electromagnetic mold does not require preliminary metal filtration, since oxide and solid non-metallic inclusions are intensively squeezed out by electromagnetic forces onto the ingot`s surface. It has been established that hot deformation of a billet cast in the EMM at the Conform facility provides higher strength characteristics of the wire from the 01417 alloy after drawing compared to the cast annealed billet. Pressing provided an increase in the yield strength and relative elongation of the 01417 alloy by 2 and 2.5 times, respectively, compared with the cast state. As a result, the billet was obtained with high technological plasticity for further drawing. Electron microscopic studies of the wire have been carried out, which have shown that dispersed REM aluminides are rather uniformly distributed over the cross section of the wire with a diameter of 0.5 mm. Determination of the particle size of aluminides at ×50000 magnification showed that their size is ~96–214 nm. Wire from 01417 alloy is used by JSC “Special Design Bureau of the Cable Industry” (JSC “OKB KP”) for the manufacture of conductive cores of installation wires, providing a significant reduction in their weight.

The application of the electromagnetic casting (EMC) to aluminum alloys is capable of producing structures, hardly obtainable by the conventional methods of casting due to the constant stirring of the crystallizing alloy and high cooling rate (∼103 K/s). For the first time we study EMC high purity binary Al-0.5Fe and Al-2.5Fe (wt.%) alloys in the as-cast state as well as after equal-channel angular pressing (ECAP) and cold rolling (CR). We demonstrate that EMC process leads to formation of metastable Al2Fe-alike intermetallic phase which does not decompose by further straining and annealing. Combined deformation by ECAP and CR results in the formation of ultrafine grained structure in which providing the increase in ultimate tensile strength up to 200 MPa in Al-0.5Fe and up to 340 MPa in Al-2.5Fe. Electrical conductivity level of Al-0.5Fe alloy increases up to 58.5% IACS, while the conductivity of Al-2.5Fe alloy decreases to 47.9% IACS. Both alloys demonstrate thermal stability of microstructure, mechanical and electrical properties under annealing up to 230 °C for 1h. These effects are discussed in terms of as-cast and strain-induced microstructures.

A three-dimensional mathematical model was developed to analyze the magnetohydronamic (MHD) processes and migration of discrete non-conductive particles in molten aluminium within an induction channel device. The particles’ trajectories and dynamics of their distribution in metal were determined using the Lagrange approach with account of the gravitational forces, drag forces, lift forces, added mass and electromagnetic force. The results indicate complex turbulence flows being present in the channels of the induction device caused by electromagnetic forces. The trajectories of particles and their dynamic distribution within the device channels are determined by the structure of hydrodynamic flows. The results show that the electromagnetic force present in the vertical channels of the device has a significant impact on removal of particles from the metal (especially of coarse particles). The study demonstrated that particles with the diameter of $50 \mu \mathrm{m}$ and more can be efficiently removed at 3 kW power in metal. Increase in power also has a positive effect on fine particles removal efficiency. For instance, the increase of power from 3 kW to 5 kW causes a 25 percent increase in $5 \mu \mathrm{m}$ particles removal efficiency.

n the paper numerical modeling of the process of conduction refining in the casting launder is carried out. The behavior of non- conductive particles in aluminum melt during conduction refining is investigated. Numerical calculation is performed using the MAXWELL and FLUENT software packages. For calculation of non-conductive particle trajectories and distributions the Discrete Phase Model is used. It is shown that electromagnetic forces strong affect the process of particle migration to the surface. The effective current value for refining the melt in the casting launder is determined.

The electromagnetic processes in an apparatus for electromagnetically refining aluminum melt with conduction excitation of current in the melt are simulated. The numerical calculation is carried out using the Maxwell finite element software package. Based on numerical calculations, the equivalent circuit parameters and the main electromagnetic characteristics of the apparatus are determined. From the distribution of bulk electromagnetic forces in the melt, the terminal velocities for particles of different diameters are obtained. It is shown that the operating voltages are in the range from 0.1 to 6.0 V depending on the current and contact resistance values. The preheating of metal in the trough by conductive supply of electricity in the system under study can only be used jointly with another kind of heating. With the operating currents in the secondary circuit higher that 2000 A, the terminal velocities of particles 30—50 m in diameter are in the range 1—4 mm/s. This means that efficient removal of impurity particles with a diameter of 30 m or larger can be achieved in the apparatus under study. With the secondary circuit current less than 1500 A, the particle migration direction is governed by the buoyancy force, which also governs the (inefficient) natural particle sedimentation process.

This study deals with numerical simulation of electromagnetic refining using a conduction method of in-melt current excitation. The ANSYS and FLUENT software packages were applied to numerically compute trajectories and distribution of non-conducting particles. The distribution of in-melt electromagnetic forces, hydrodynamic flows and non-conducting particles cloud has been analyzed.