Description:FIELD OF INVENTION
[0001] The present invention relates to the field of non-ferrous metal casting, and more particularly to a method for casting aluminum billets. Specifically, the invention pertains to a hybrid casting system that integrates ultrasonic and electromagnetic treatment to achieve high-quality, fine-grained aluminum billets through a simplified three-step process.

BACKGROUND
[0002] Casting of aluminum billets primarily involves Direct Chill (DC) casting, where molten aluminum is poured into a water-cooled mold and rapidly solidified through contact with coolant sprays. Over the years improved methods Head DC casting, Air Slip Technology, and Electromagnetic Casting (EMC) have been developed to improve surface quality, reduce segregation, and refine grain structures. Advanced techniques integrate ultrasonic melt treatment, melt stirring, or nanoparticle inoculation for enhanced microstructural control. Emerging trends include the use of recycled feedstock, hybrid furnace systems, and digital twin simulations to improve sustainability and process stability. These innovations aim to produce high-quality billets with minimal defects and tailored properties for applications in automotive, aerospace, and structural industries.
[0003] The Ultrasonic Billet Casting (UBC) System is an advanced technique that enhances the quality of aluminum billets by applying high-frequency ultrasonic vibrations to the molten metal during the casting process. These vibrations promote uniform nucleation, refine grain structures, and significantly reduce porosity and segregation by breaking up oxide films and dispersing gas bubbles. The process is particularly effective for high-performance aluminum alloys, including those used in aerospace and automotive applications, where fine microstructures and superior mechanical properties are critical.
[0004] Recent research and development in this area focusing on the integration of Ultrasonic treatment with traditional Direct Chill casting setups, providing a scalable and energy-efficient way to improve billet quality without the need for chemical grain refiners. Recent research also explores its synergistic use with nanoparticle inoculants and real-time process monitoring, positioning ultrasonic casting as a key innovation in next-generation billet production.
[0005] Electromagnetic Ultrasonic Billet Casting (EMUBCS) offers significant advantages over conventional Ultrasonic Billet Casting by combining the benefits of both ultrasonic treatment and electromagnetic stirring. While ultrasonic casting alone enhances grain refinement and removes inclusions through cavitation and acoustic streaming, EMUBCS further improves the process by introducing a rotating electromagnetic field that promotes uniform temperature distribution and controlled melt flow.
[0006] The prior art documents CN202110374278A, and CN201310227130A, describes the combined effect of Electromagnetism and Ultrasonic billet casting technology for superior grain uniformity, reduced macro segregation, and minimized porosity compared to ultrasonic treatment alone. EMUBCS enables better control over the solidification front, resulting in improved mechanical properties and a more consistent billet quality, making it especially beneficial for high-performance applications.
[0007] In the processes cited in prior art documents, grain refinement and degassing are performed as distinct operations prior to casting, each requiring dedicated equipment, handling, and additional processing time. The present invention integrates these functions directly at the casting table through in-situ electromagnetic and ultrasonic mechanisms, thereby eliminating the need for separate upstream operations. This not only simplifies the overall process but also reduces equipment footprint and energy consumption. Moreover, the in-situ treatment eliminates the possibility of grain deformation or disturbance that typically occurs during the transfer of molten metal between vessels, thus ensuring superior microstructural integrity. The invention achieves all of this while preserving the core functional characteristics of the EMUBCS (Electromagnetic-Ultrasonic Billet Casting System) process.

OBJECTS OF THE INVENTION
[0008] It is an object of the present disclosure which provides a system and method for ultra- precision aluminium parts manufacturing from the billets.
[0009] It is an object of the present disclosure which provides a hybrid system of Electromagnetic and Ultrasonic Casting.
[0010] It is an object of the present disclosure to provide an in-situ three-step casting method for aluminum billets that integrates grain refinement and degassing, minimizing defects and eliminating grain deformation during molten metal transfer.
[0011] Yet another objective of the present disclosure is to enable simultaneous application of electromagnetic and ultrasonic treatments directly at the casting table, ensuring effective in-situ grain refinement and degassing without separate processing stages or material transfer.

SUMMARY OF THE INVENTION
[0012] The present invention provides a simplified and efficient three-step method for casting aluminum billets by integrating ultrasonic treatment and electromagnetic stirring into the casting process. Unlike conventional casting methods that require multiple distinct steps such as grain refinement, degassing, filtration, and directional solidification, the disclosed method combines these functionalities into three primary steps: melting, filtration & ultrasonic degassing & grain refinement and electromagnetic stirring during casting.
[0013] In an aspect of the present disclosure, in the first step, molten aluminum alloy is subjected to high-frequency ultrasonic vibrations applied vertically. These vibrations induce acoustic streaming and cavitation within the melt, resulting in in-situ degassing and fragmentation of dendritic structures. This promotes uniform grain nucleation and eliminates the need for separate grain refiners and purging gases.
[0014] In an aspect of the present disclosure, in the second step, the ultrasonically treated melt is transferred to a casting chamber where a horizontal electromagnetic field is applied during solidification. The electromagnetic stirring ensures uniform temperature and solute distribution, minimizes segregation, and promotes the growth of fine, equiaxed grains with improved mechanical properties.
[0015] In an aspect of the present disclosure, the simultaneous application of electromagnetic and ultrasonic treatments directly at the casting table, ensuring effective in-situ grain refinement and degassing without separate processing stages or material transfer.
[0016] The invention reduces process complexity, energy consumption, and casting defects, while significantly enhancing the quality and efficiency of aluminum billet production.

BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The accompanying drawings are included to provide a further understanding of the present disclosure and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.
[0018] Figure-1 is the schematic flowchart illustrating the in-situ casting process integrating ultrasonic treatment and electromagnetic stirring within a single casting table for enhanced grain refinement, degassing, and uniform solidification.
[0019] Figure-2 is an illustration of various crystal formation during the EMUBCS

DETAILED DESCRIPTION
[0020] The following is a detailed description of embodiments of the disclosure. The embodiments are in such detail as to clearly communicate the disclosure. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure as defined by the appended claims.
[0021] As depicted in Figure-1, Molten aluminium alloy (100) is transferred from aluminium melting furnace with help of launders, into the top section of the container. Ultrasonic vibrations (102), typically at frequencies of 20 kHz or higher, are applied vertically to the molten metal. The amplitude and frequency of these vibrations are precisely controlled using a connected controller (103). The ultrasonic energy facilitates degassing, promotes grain refinement, and breaks up the melt into a more homogeneous state. The treated molten alloy is then transferred to the electromagnetic chamber (101), where it begins to crystallize due to cooling. During this stage, an electromagnetic field is applied horizontally (104) across the chamber. This induces forced convection and stirring within the melt, resulting in: Uniform temperature and composition distribution, Formation of a fine and uniform grain structure, Minimization of segregation and gas porosity, Reduction in hot tearing and surface cracks during solidification.
[0022] In the above embodiment it can be noticed that the process uniquely integrates both ultrasonic treatment and electromagnetic stirring in-situ within the same casting table, eliminating the need for separate processing stages or equipment. By applying ultrasonic vibrations vertically to the molten aluminum alloy and subsequently subjecting it to a horizontal electromagnetic field within the same casting environment, the system ensures continuous and synchronized treatment of the metal. This in-situ configuration enhances process efficiency, reduces handling and contamination risks, and ensures that degassing, grain refinement, and uniform solidification all occur in a controlled, streamlined manner during a single-stage casting operation.
[0023] Figure-2 illustrates the effect of dual mechanism of EM wave (208) and Ultrasonic vibrations (207). When ultrasonic vibrations are applied to the molten aluminium alloy (206), they generate acoustic waves (201) that travel through the liquid. These waves induce a steady flow known as acoustic streaming, which enhances mixing within the melt, distributes temperature and solute atoms uniformly, breaks up particle clusters and floating impurities, promotes a uniform composition across the casting volume. This improved mixing is crucial for eliminating macro-segregation and ensuring homogeneous grain formation.
[0024] In another embodiment of Figure-2, it depicts that ultrasound also induces cavitation (202), the formation, growth, and collapse of microscopic gas bubbles within the melt. When these bubbles violently collapse, they release localized high temperatures and pressures, shock waves that disrupt growing dendritic crystals (203), intense microturbulence, promoting nucleation of new grains. This leads to the breakdown of coarse grains and initiates the formation of fine equiaxed (isometric) grains (204).
[0025] In an embodiment of the present disclosure, in Figure-2, it can be noticed that during solidification & casting, certain elements in the alloy (e.g., Si, Cu, Mg) tend to segregate. The electromagnetic stirring caused by the EM field prevents the accumulation of solute atoms (205) at the solid-liquid interface, ensures uniform solute distribution, minimizes solute-rich regions that lead to defects. The EM field also reduces the temperature gradient, further suppressing directional solidification and promoting a globular grain structure.
[0026] In the disclosure of prior art documents, the solidification proceeds in a directional manner, leading to the growth of dendritic crystals elongated tree-like structures with high anisotropy. As it can be noticed in the embodiment of Figure-2, with the combined action of ultrasound and EM fields in a specific manner, dendrites are fragmented, and the growth of new grains is encouraged in multiple directions.
[0027] A detailed comparative study of the typical Four-Step EMUBCS aluminium billet casting with reference to the present disclosure of Three-Step EMUBCS in-situ aluminium billet casting is given below:
[0028] Four-Step Conventional Process
In the conventional four-step aluminium casting process, each treatment stage, melting, grain refinement & alloying, degassing & filtration, and casting is carried out in separate vessels or zones, often requiring transfer of molten metal between different units. Initially, raw aluminium is melted in a dedicated furnace. Grain refinement and alloying are then conducted in a separate treatment vessel, where elements like titanium and boron are added to refine the microstructure. This is followed by degassing and filtration, typically performed using external systems such as rotary degassers or argon purging units, along with ceramic filters to remove inclusions. Finally, the treated molten metal is transferred again into the casting setup, where solidification occurs often resulting in coarse, dendritic grain structures due to limited control over cooling and flow as shown in the process flow below:

 Melting – Raw aluminium is melted in a furnace.
 Grain Refinement & Alloying – Additives (e.g., Ti, B) are introduced to control grain structure.
 Degassing & Filtration – Gases and non-metallic inclusions are removed via argon purging or rotary degassing.
 Casting – The conditioned melt is poured into molds and the directional solidification usually leads to dendritic growth.
[0029] Three-Step in-situ EMUBCS Process
In contrast, the present invention eliminates these multiple and complex steps by integrating ultrasonic and electromagnetic treatments directly within the casting vessel itself. Here, ultrasonic vibrations are applied vertically to the molten aluminium in the same container where electromagnetic stirring is later introduced horizontally. This in-situ application within a unified casting table allows real-time control over grain refinement, degassing, and solidification, significantly improving process efficiency while reducing contamination, heat loss, and structural defects in the final cast product as the process flow shown below:
• Melting
• Filtration
• Casting with In-situ degassing, grain refining (ultrasonic phase) and Controlled Solidification (Electromagnetic Stirring).

[0030] WORKING EXAMPLE
In the present disclosure, 2000 series Aluminum alloy is selected from the group consisting of 2000 series Aluminum alloys containing Cu and Mg elements, 2000 series Aluminum alloys containing Cu and Mn elements, and Zr elements containing At least one of 2000 series Aluminum alloys for the Aluminium Billet Casting.The semi-continuous process is used to cast the molten Aluminum, and ultrasonic and electromagnetic waves are applied to the molten aluminum at the same time during casting. The frequency of the ultrasonic wave is 30~35kHz, the coupling parameter of the electromagnetic wave is 1.5T 25A/mm2, and the casting temperature is ~ 720°C, the casting speed is 25-30mm/min, and the casting water flow is 200-225 L/min. Large-scale 2000 series aluminum alloy slab ingots containing Cu and Mg elements are prepared.

[0031] It is a distinguishing feature of the present disclosure is that, in an embodiment, when the molten Aluminium alloy is directly treated with ultrasonic vibrations (typically >20 kHz), it replaces both grain refinement and degassing steps. It also promotes cavitation bubble collapse and creates new nucleation sites for solidification and reduces the process steps, and saving time and energy requirement for the process.

[0032] Novelty and advantages of the present invention
The three-step Electromagnetic-Ultrasonic Billet Casting System (EMUBCS) offers several advantages over the conventional four-step aluminum casting process. By integrating ultrasonic treatment and electromagnetic stirring directly into the melting and casting stages, the process eliminates the need for separate grain refinement, degassing, and filtration steps.
Ultrasonic vibrations induce acoustic streaming and cavitation within the molten metal, which effectively degasses the melt and promotes fine grain formation without the use of external purging gases or refining agents. Simultaneously, the electromagnetic field applied during casting creates forced convection, ensuring uniform distribution of solute atoms and suppressing segregation. This results in the natural formation of fine, equiaxed grains instead of undesirable dendritic structures.
The simplified in-situ three-step process reduces energy consumption, processing time, and equipment complexity, while improving billet quality and mechanical performance. It also minimizes material losses and environmental impact by avoiding chemical additives and off-gas emissions associated with traditional methods.
[0033] While the foregoing describes various embodiments of the invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof. The scope of the invention is determined by the claims that follow. The invention is not limited to the described embodiments, versions or examples, which are included to enable a person having ordinary skill in the art to make and use the invention when combined with information and knowledge available to the person having ordinary skill in the art.
, Claims:We Claim:
1. A method for casting Aluminium alloy comprising:
• melting the Aluminium alloy and transferring it to a casting table;
• applying ultrasonic vibrations vertically to the molten metal within the casting table to facilitate degassing and initiate grain refinement;
• subsequently applying a horizontal electromagnetic field to the same molten metal within the casting table to induce forced convection and homogenize the melt; and
• allowing the treated molten alloy to solidify within the casting table to form a refined solid structure;
• wherein the ultrasonic and electromagnetic treatments are performed in-situ within a single integrated casting vessel.
2. The method according to claim 1, wherein the ultrasonic vibrations are applied at a frequency of 20 kHz or higher and with a controlled amplitude using an external controller.

3. The method according to claim 1, wherein the electromagnetic field is generated by a coil system arranged to apply a horizontal magnetic field across the molten metal to promote stirring and uniform thermal distribution.

4. The method according to claim 1, wherein the ultrasonic and electromagnetic treatments occur sequentially but continuously within the same casting zone, without transferring the molten metal between different vessels.

5. The method according to claim 1, an integrated casting apparatus for Aluminium alloys comprising:
• a casting vessel configured to receive molten Aluminium alloy;
• an ultrasonic transducer assembly positioned to apply vertical ultrasonic vibrations to the molten metal in the vessel;
• an electromagnetic field generator configured to apply a horizontal electromagnetic field across the same molten metal within the vessel;
• a controller operatively connected to the ultrasonic and electromagnetic units to manage their amplitude, frequency, and timing;
• wherein the ultrasonic and electromagnetic treatments are carried out in-situ within the same vessel to refine and homogenize the molten alloy before solidification.
6. The method according to claim 1, wherein the resulting cast product exhibits a fine, equiaxed grain structure with reduced porosity, minimized segregation, and enhanced mechanical integrity.

7. The method according to claim 1, wherein the process eliminates the need for separate grain refiners, degassing agents, or gas purging.

8. The method according to claim 1, wherein the ultrasonic and electromagnetic parameters are controlled via a programmable controller.

9. The method of claim 1, wherein the molten metal comprises aluminum or aluminum-based alloys, and is optionally extendable to other non-ferrous and light metal alloys.

10. The method according to claim 1, wherein the process reduces total processing time and energy consumption as compared to conventional four-step billet casting methods.