Description: TITLE
Method and System for Manufacturing High-Strength Aluminium Alloy with Enhanced Microstructure and Mechanical Properties

FIELD OF INVENTION
The present invention relates to the field of metallurgy and materials science, specifically to the synthesis and characterization of aluminium alloys. More particularly, it pertains to the method and system for manufacturing ADC12 aluminium alloy with enhanced mechanical properties through microstructural refinement techniques. The invention is particularly relevant to the automotive, electronics, and aerospace sectors, where ADC12 alloy is widely used for its excellent castability, strength, corrosion resistance, thermal conductivity, and electrical conductivity. The invention aims to improve the performance and reliability of components made from ADC12 alloy by refining its microstructure, resulting in increased hardness, tensile strength, and ductility.

BACKGROUND
Aluminium alloys are widely used in automotive, electronics, and aerospace industries due to their favourable properties, including low density, good thermal conductivity, and corrosion resistance. ADC12, a commonly used aluminium alloy, is especially valued for its excellent castability, high strength-to-weight ratio, and durability. However, as typically manufactured, the conventional ADC12 alloy exhibits limitations in its microstructural properties, particularly in the form of coarse a-Al dendrites and acicular eutectic silicon particles. These structural characteristics can reduce mechanical performance, lower hardness, tensile strength, and elongation and impede thermal and electrical conductivity.
Refining these microstructural elements, primarily through grain refinement and eutectic silicon modification, has significantly enhanced the alloy’s strength and conductivity. Traditionally, modifications are achieved by adding elements like strontium (Sr) and titanium (Ti), often as part of master alloys. When properly introduced and held at specific temperatures, Sr and Ti refine the eutectic silicon phase into a fine, fibrous structure and transform coarse dendrites into equiaxed grains, improving both mechanical and conductivity properties.
Current methods, however, face challenges in optimizing these modifications without compromising other desirable properties. Additionally, achieving uniform distribution of modifiers and maintaining consistency in the die-casting process can be challenging, often resulting in casting defects or inconsistent mechanical characteristics. Therefore, there is a need for an improved manufacturing method and apparatus that can provide reliable microstructural refinement of ADC12, ensuring enhanced strength, ductility, and conductivity suitable for demanding applications. This invention addresses these needs by introducing an optimized process and system for incorporating Sr and Ti-based master alloys in ADC12, providing consistent enhancements in the alloy’s properties.

SUMMARY
The present invention provides a novel method and system for manufacturing a high-strength ADC12 aluminium alloy with refined microstructure and enhanced mechanical, electrical, and thermal properties. By integrating specific alloying elements, optimal temperature control, and an advanced high-pressure die-casting process, the invention effectively transforms the microstructure of ADC12 alloy to achieve superior performance in applications demanding lightweight, high-strength, and corrosion-resistant materials.
According to a preferred embodiment, the method involves melting a selected combination of raw materials, including aluminium, silicon, copper, magnesium, manganese, iron, and zinc, to produce a homogeneous molten ADC12 alloy, degassing the alloy to remove impurities and adding Sr and Ti-based master alloys as modifiers at precise concentrations. These master alloys refine the eutectic silicon phase into a fine, fibrous structure and convert the a-Al dendrites into a more equiaxed form, enhancing the alloy’s mechanical and conductive properties. The molten alloy is maintained at an optimal temperature range of 730 ± 10°C for a specific holding time to ensure complete microstructural modification before it is poured into a steel die under high pressure (approximately 1000 bar) using a high-pressure die-casting (HPDC) process. After solidifying within the die, the alloy undergoes post-processing operations such as machining, sanding, and surface finishing. The resulting ADC12 alloy demonstrates improved hardness, tensile strength, elongation, and significantly higher electrical and thermal conductivity.
A preferred embodiment of the system includes a furnace for melting ADC12 raw materials, a degassing unit, and a modifier addition unit designed to introduce Sr and Ti-based master alloys in specific concentrations. A die-casting machine injects the modified molten alloy into a steel die under high pressure, and an integrated cooling mechanism solidifies the alloy in the die. The system also features a post-processing unit for machining and surface treatments to achieve desired final properties. The optimized system controls temperature, alloy composition, and pressure, leading to the consistent production of high-performance ADC12 alloys with uniform microstructure and minimal casting defects.
Finally, this invention yields a modified ADC12 alloy with exceptional improvements in electrical conductivity, thermal conductivity, and mechanical properties, making it highly suitable for applications in the automotive, electronics, and aerospace industries. The refined microstructure enhances conductivity by reducing electron scattering, while the modified grain structure increases strength, elongation, and hardness, thus addressing the limitations of conventional ADC12 alloys and expanding its range of applications.

BRIEF DESCRIPTION OF DRAWING
To further clarify the advantages and features of the present disclosure, a more particular description of the disclosure will be rendered by reference to specific embodiments thereof, which are illustrated in the appended drawings. It is appreciated that these drawings depict only typical embodiments of the disclosure and are therefore not to be considered limiting of its scope. The disclosure will be described and explained in additional specificity and detail in the accompanying drawings.
The subject matter that is regarded as the invention is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other aspects, features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:
Figure 1 illustrates Scanning Electron Microscopy (SEM) / Energy Dispersive Spectroscopy (EDS) elemental mapping of the unmodified ADC12 alloy. Further, (a) and (b) illustrate the Elemental distribution of Aluminium (Al) and Silicon (Si) at 250x magnification. Similarly, (c) and (d) illustrate the Elemental distribution of Aluminium (Al) and silicon (Si) at 1000x magnification.
Figure 2 illustrates Scanning Electron Microscopy (SEM) / Energy Dispersive Spectroscopy (EDS) elemental mapping of the modified ADC12 alloy. Further, (a) and (b) illustrate the Elemental distribution of Aluminium (Al) and Silicon (Si) at 250x magnification. Similarly, (c) and (d) illustrate the Elemental distribution of Aluminium (Al) and silicon (Si) at 1000x magnification. This figure demonstrates the refined microstructure achieved by adding Sr and Ti-based master alloys. The eutectic silicon phase is modified into a fine, fibrous form, and the a-Al dendrites are broken down into finer, more equiaxed grains.
Figure 3 illustrates the Scanning Electron Microscopy (SEM) microstructures of ADC12 alloy. Wherein (a) illustrates the Microstructure of unmodified ADC12 alloy, showing long needle-shaped ß-AlFeSi phases and coarse Al2Cu intermetallic compounds. Similarly, (b) shows the Microstructure of modified ADC12 alloy, illustrating refined ß-AlFeSi phases with a fishbone or Chinese script morphology and a finer, uniformly distributed Al2Cu phase. This figure highlights the microstructural changes that enhance the mechanical properties of the alloy.
Figure 4 illustrates the schematic of electron transport in unmodified and modified ADC12 alloys. Shows the effect of microstructural refinement on electrical and thermal conductivity. The unmodified alloy exhibits large eutectic silicon strips that impede electron flow, while the modified alloy shows an increased electron pass rate due to finer silicon particles, enhancing electrical and thermal conductivity.
Figure 5 illustrates the graph of electrical conductivity (% IACS) of ADC12 alloy with varying wt% of Sr and Ti-based modifiers. It shows the increase in electrical conductivity with different concentrations of Sr and Ti- based master alloys, with a peak conductivity of 0.5 wt%.
Figure 6 illustrates the graph of thermal conductivity (W/mK) of ADC12 alloy with varying wt% of Sr and Ti-based modifiers. The thermal conductivity improvements were demonstrated with the addition of Sr and Ti- based modifiers, with the highest thermal conductivity achieved at 0.5 wt%.
Figure 7 illustrates the graph of mechanical properties of ADC12 alloy with varying wt% of Sr and Ti-based modifiers. It presents data on hardness, yield strength (YS), ultimate tensile strength (UTS), and % elongation of ADC12 alloy. The optimal mechanical properties are observed at 0.05 wt% in addition to Sr and Ti-based master alloys.
These figures collectively illustrate the impact of Sr and Ti-based master alloy modification on the microstructure, electrical and thermal conductivity, and mechanical properties of ADC12 alloy.

DETAILED DESCRIPTION OF INVENTION
For the purpose of promoting an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings, and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended. Such alterations and further modifications in the illustrated system and such further applications of the principles of the invention as illustrated therein would be contemplated as would usually occur to one skilled in the art to which the invention relates. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. The system, methods, and examples provided herein are illustrative only and are not intended to be limiting.
Figure 1 illustrates Scanning Electron Microscopy (SEM) / Energy Dispersive Spectroscopy (EDS) elemental mapping of the unmodified ADC12 alloy. Further, (a) and (b) show the SEM/EDS elemental mapping of aluminium (Al) and silicon (Si) in the unmodified ADC12 alloy at 250x magnification. The mapping reveals a coarse a-Al dendritic structure with large grain sizes, indicative of the unmodified alloy's lack of refinement. Similarly, (c) and (d) display the elemental mapping of aluminium (Al) and silicon (Si) in the unmodified ADC12 alloy at 1000x magnification. This mapping highlights the presence of eutectic silicon in long, acicular, or strip-like formations, which negatively affect the alloy's electrical and thermal conductivity as well as its mechanical properties. This figure serves as a baseline, showing the coarser and less refined microstructure of the ADC12 alloy without any modification by Sr and Ti-based master alloys.
Figure 2 illustrates Scanning Electron Microscopy (SEM) / Energy Dispersive Spectroscopy (EDS) Elemental Mapping of Modified ADC12 alloy. Further, (a) and (b) present the SEM/EDS elemental mapping of aluminium (Al) and silicon (Si) in the modified ADC12 alloy at 250x magnification. After modification with Sr and Ti-based master alloys, the a-Al grains are transformed into a finer, more equiaxed dendritic structure and demonstrate significant grain refinement. Similarly, (c) and (d) show the elemental mapping of aluminium (Al) and silicon (Si) in the modified ADC12 alloy at 1000x magnification. The eutectic silicon phase is modified into a fine fibrous form, with the long strip-like silicon particles broken down into shorter, finer fibers. This modification enhances the alloy’s electrical and thermal conductivity by reducing electron scattering and improving mechanical properties. This figure illustrates the significant transformation in microstructure resulting from the addition of Sr and Ti-based master alloys, showing finer, homogenized grains and a refined eutectic silicon structure.
Figure 3 illustrates Scanning Electron Microscopy (SEM) microstructures of Unmodified and Modified ADC12 Alloy. Figure 3 (a) depicts the SEM microstructure of the unmodified ADC12 alloy, showing long, needle-shaped ß-AlFeSi intermetallic phases and coarse Al2Cu phases. These coarse ß-AlFeSi needles are detrimental to mechanical properties, particularly elongation, as they create weak points within the matrix. Figure 3 (b) Illustrates the SEM microstructure of the modified ADC12 alloy after the addition of Sr and Ti-based master alloys. The ß-AlFeSi phase is refined into a more desirable fishbone or Chinese script morphology, while the Al2Cu intermetallic compounds are also broken down into finer and more uniformly distributed particles. This refinement results in improved mechanical properties, including enhanced strength and ductility. This figure visually demonstrates the transformation of critical intermetallic phases in the ADC12 alloy, leading to a more refined and robust microstructure, which contributes to increased durability and strength.
Figure 4 illustrates a schematic of electron transport in unmodified and modified ADC12 alloys. The unmodified ADC12 alloy of the schematic illustrates how large eutectic silicon strips impede electron flow in the unmodified ADC12 alloy, resulting in low electrical and thermal conductivity. The long, acicular silicon particles cause significant electron scattering, reducing electron transport efficiency. The modified ADC12 alloy of the schematic demonstrates the improved electron pass rate in the modified alloy, where the eutectic silicon phase has been transformed into finer, shorter fibers. The refinement of the silicon structure reduces obstacles to electron flow, thus enhancing electrical and thermal conductivity. This schematic provides a conceptual view of how microstructural refinement affects the alloy's electrical and thermal properties, emphasizing the importance of a fine silicon structure for higher conductivity.
Figure 5 illustrates the electrical conductivity (% IACS) graph of ADC12 alloy with varying wt% of Sr and Ti-based modifiers. This graph shows the relationship between the electrical conductivity (% IACS) and different weight percentages (wt %) of Sr and Ti-based master alloy additives. As the concentration of Sr and Ti-based modifiers increases from 0% to 0.5%, the electrical conductivity of the ADC12 alloy improves significantly, reaching a peak conductivity of 33 % IACS at 0.5 wt%. This figure highlights the role of Sr and Ti-based modifiers in enhancing the electrical conductivity of ADC12 alloy by optimizing the eutectic silicon structure.
Figure 6 illustrates the graph of thermal conductivity (W/mK) of ADC12 alloy with varying wt% of Sr and TI-based modifiers. This graph illustrates the thermal conductivity (W/mK) of ADC12 alloy as a function of different weight percentages of Sr and Ti-based modifiers. The thermal conductivity increases from 113.7 W/mK in the unmodified state to a maximum of 142.7 W/mK at 0.5 wt% addition. This improvement is attributed to the refined silicon morphology that reduces electron scattering and increases thermal conduction. This figure demonstrates how modifying the ADC12 alloy with Sr and Ti-based master alloys positively impacts thermal conductivity, making it suitable for applications requiring efficient heat transfer.
Figure 7 shows the mechanical properties of ADC12 alloy with varying wt% of Sr and Ti-based modifiers. This graph presents the mechanical properties, including hardness, yield strength (YS), ultimate tensile strength (UTS), and % elongation, of ADC12 alloy with different concentrations of Sr and Ti-based modifiers. The graph shows that the optimal mechanical properties—such as a hardness of 40 HRB, yield strength of 199 MPa, ultimate tensile strength of 251 MPa, and elongation of 2.96%—are achieved with a 0.05 wt% addition of the modifiers. Beyond this concentration, the properties tend to decrease, likely due to the coarsening of microstructural phases. This figure emphasizes the effectiveness of Sr and Ti-based master alloys in achieving an optimized balance of mechanical properties in the ADC12 alloy at a specific concentration, which is crucial for applications requiring high strength and durability.

Method for manufacturing ADC12 Aluminium alloy
The present embodiment provides a detailed method and system for manufacturing an improved version of ADC12 Aluminium alloy, which is particularly advantageous for applications requiring high-performance materials with refined microstructures and enhanced mechanical properties. The ADC12 alloy, part of the Al-Si series, is known for its thermal and electrical conductivity, strength-to-weight ratio, and corrosion resistance. Embodiments disclosed introduce a system and method to significantly improve the mechanical characteristics of ADC12 by refining its microstructure, resulting in higher electrical conductivity, better strength-to-weight ratio, higher corrosion resistance, better hardness, and greater tensile strength.
Composition and Raw Material Selection
The process begins with carefully selecting and measuring raw materials to achieve the desired alloy composition. The composition of the ADC12 aluminium alloy in this invention is carefully chosen to optimize its mechanical, thermal, and electrical properties while ensuring excellent castability and structural integrity for demanding applications. The alloy is primarily composed of:
Aluminium (Remainder): Aluminium serves as the primary base metal, providing lightweight characteristics and a high strength-to-weight ratio. It offers excellent corrosion resistance and good thermal and electrical conductivity, making it suitable for automotive and electronic applications.
Silicon (9.6-12%): Silicon enhances the alloy’s fluidity during casting, enabling complex shapes to be formed precisely. It also contributes to the alloy's hardness and wear resistance, which is essential for components subject to mechanical stress.
Copper (1.5-3.5%): Copper is added to increase the alloy’s strength and hardness. It improves the alloy’s response to heat treatment and enhances thermal and electrical conductivity, which are key properties in high-performance environments.
Magnesium ( 0.3 max%): Magnesium strengthens solid solution, increasing the alloy’s tensile strength and elongation. Its presence also supports the alloy's overall corrosion resistance.
Manganese (0.5 max%): Manganese stabilizes the iron content, preventing the formation of brittle phases and improving toughness and impact resistance.
Iron (1.3 max%): Iron is added to increase the strength and hardness of the alloy, but its content must be controlled to avoid brittleness. While iron improves strength, excessive amounts can lead to the formation of brittle phases, which can negatively impact the alloy's toughness.
Zinc (1.0 max%): Zinc contributes to strength and provides additional corrosion resistance. Zinc helps enhance the mechanical strength of the alloy and works synergistically with aluminium to improve the alloy’s resistance to environmental degradation.
Nickel (0.5% max): Nickel helps in providing the high-temperature strength and heat resistance to the alloy.
Tin (0.2% max): Tin is added to Al alloys to improve the casting properties of the alloy.
Lead (0.2% max): Lead is added to Al alloys to enhance the machinability of the alloy.
Titanium (0.3% max): Titanium contributes to grain refinement and improves the mechanical property of the alloy.
Embodiments disclosed include, in addition to these primary elements, Sr and Ti-based master alloys, which are introduced in concentrations ranging from 0.01% to 0.5% by weight. These modifiers play a crucial role in refining the microstructure by transforming the eutectic silicon phase into a fine, fibrous form and converting the coarse a-Al dendrites into an equiaxed grain structure. The optimal concentration of Sr and Ti-based master alloys are found to be around 0.05%, which maximizes the mechanical improvements, including increased hardness, tensile strength, and elongation while minimizing adverse effects on casting fluidity and structural integrity. This alloy composition provides a foundation for high castability, corrosion resistance, and strength-to-weight ratio. Sr and Ti-based master alloys are added in concentrations ranging from 0.01% to 0.5% by weight, with an optimum concentration of 0.05% to achieve maximum refinement of the microstructure.
The selection of these raw materials and their precise composition ensures that the ADC12 alloy achieves a desirable balance of strength, durability, and conductivity. This combination allows the alloy to meet rigorous performance requirements in the automotive, aerospace, and electronics industries, where components are subject to thermal cycling, corrosion, and mechanical stress. The controlled addition of each element and modifier is critical to enhancing the alloy’s properties without compromising its castability, resulting in a refined, and high-performance aluminium alloy.
Melting
The melting process is a critical step in manufacturing the high-strength ADC12 aluminium alloy, as it sets the foundation for achieving a homogeneous and defect-free alloy with enhanced microstructural and mechanical properties. According to an embodiment, the melting procedure comprises heating a carefully selected combination of raw materials in a temperature-controlled furnace to achieve a molten state. For ADC12 alloy, the melting temperature is maintained at approximately 730°C (1346°F) to ensure that all alloying elements dissolve uniformly into the aluminium matrix, creating a homogeneous molten alloy with minimal segregation.
The selected raw materials, comprising 9.6-12% silicon, 1.5-3.5% copper, 0.3% max magnesium, 0.5% max manganese, 1.3% max iron, and 1% max zinc, 0.5% max nickel, 0.2% max tin, 0.2% max lead, 0.3% max titanium, and remainder aluminium are carefully weighed and loaded into the furnace. To promote efficient melting and minimize oxidation, the raw materials are typically added in layers, with aluminium as the base layer, followed by the other elements. The furnace is heated to approximately 730°C (1346°F), a temperature that ensures the complete dissolution of all alloying elements. This temperature is carefully controlled to maintain a consistent melt, preventing element segregation or forming undesirable phases. As the materials melt, they are stirred periodically to promote homogenization of the molten alloy. This step is crucial for ensuring that the final alloy has a uniform composition, which is critical to achieving the desired mechanical properties.
In addition, the melting process is designed to ensure the complete dissolution of the Sr and Ti-based master alloys, which are added during the subsequent modification stage. By achieving a homogeneous molten alloy in this stage, the modifier elements introduced later can effectively interact with the alloy matrix, facilitating grain refinement and modification of the eutectic silicon phase. This melting process provides a solid foundation for the degassing, modification, and die-casting steps that follow, ultimately contributing to the enhanced mechanical, thermal, and electrical properties of the ADC12 alloy.
According to an embodiment, the temperature of the molten alloy is continuously monitored using thermocouples or infrared sensors to ensure it remains within the optimal range. Any deviations are promptly corrected to prevent issues such as overheating or incomplete melting. Periodic samples of the molten alloy may be taken and analysed to verify the composition and homogeneity. This real-time feedback allows for adjustments to be made if necessary, ensuring that the final product meets the required specifications.
In some embodiments, during melting, dross (oxidized impurities) forms on the surface of the molten alloy. This dross is skimmed off regularly to prevent it from being into the melt, which could compromise the quality of the final casting. In some cases, fluxing agents may be added to the melt to help remove additional impurities and reduce the viscosity of the dross, making it easier to remove.
The melting process is critical in determining the quality and properties of the alloy. Proper control of temperature, homogenization, and impurity removal are all essential for producing a molten alloy that will yield high-quality castings with the desired mechanical characteristics. Any inconsistencies or errors during the melting process can lead to defects in the final product, such as porosity, segregation, or variations in mechanical properties.
Degassing
Embodiments disclosed include a post-melting degassing to remove impurities and dissolved gases from the molten alloy. Degassing is a crucial step in the manufacturing process of ADC12 aluminium alloy, as it removes impurities and dissolved gases, mainly hydrogen, which can form during the melting process. Hydrogen gas, if left in the alloy, can cause porosity and other structural defects, compromising the alloy's mechanical integrity, electrical conductivity, and thermal conductivity. The degassing process ensures a homogeneous and defect-free alloy, enhancing the final quality and performance of the ADC12 alloy. The degassing step typically involves the following:
Degassing Agent Introduction: A degassing agent, often in the form of argon or nitrogen gas, is introduced into the molten ADC12 alloy through a lance or rotary impeller. This degassing agent bubbles through the molten alloy, binding with dissolved gases and impurities, which are then carried to the surface.
Removal of Impurities: The action of the degassing agent removes hydrogen gas, oxides, and other non-metallic inclusions from the melt. These impurities float to the surface and are then skimmed off, resulting in a purer molten alloy.
Temperature Control: Throughout degassing, the molten alloy is maintained at approximately 730 ± 10°C, ensuring that the degassing agent functions effectively without altering the alloy’s composition or causing oxidation of the molten metal.
Refinement of Microstructure: The removal of impurities creates a cleaner matrix that improves the efficiency of the subsequent modification step, allowing for optimal incorporation of Sr and Ti-based master alloys. This cleaner environment enhances the interaction between the modifiers and the alloy matrix, promoting a finer and more uniform grain structure.
According to an embodiment, the molten alloy is often stirred during the degassing process to ensure that the inert gas bubbles are uniformly distributed throughout the melt. This stirring action helps break more giant bubbles into smaller ones, increasing the contact between the bubbles and the molten metal, thus improving gas removal efficiency. After degassing, molten metal samples may be taken and analysed for gas content and impurities to ensure that the degassing process has been effective. If the gas content is still above the desired level, additional degassing may be required, or the process parameters may need to be adjusted. After degassing, any remaining dross (oxidized impurities) on the surface of the molten metal is skimmed off. This ensures that the molten alloy is as clean as possible before casting, reducing the likelihood of defects in the final product.
By implementing an effective degassing process, the ADC12 alloy achieves reduced porosity and inclusions, resulting in improved mechanical properties, such as increased strength and elongation, as well as better conductivity. This step is vital in ensuring the high quality and consistency required for ADC12 alloy applications in automotive, aerospace, and electronic components, where structural integrity and reliability are essential.
Modifier Addition
Embodiments disclosed include the modifier addition step, which is a key part of the manufacturing process for ADC12 aluminium alloy, as it enhances the alloy’s microstructure and significantly improves its mechanical, thermal, and electrical properties. In this step, Sr (strontium) and Ti (titanium)-based master alloys are introduced to the molten ADC12 alloy at a precise concentration and temperature, targeting grain refinement and eutectic silicon modification. These modifiers play a crucial role in transforming the alloy’s microstructure, refining the silicon particles, and modifying the a-Al dendrites, leading to improved alloy performance in applications requiring high strength and durability. The modifier addition process typically involves the following:
Controlled Modifier Addition: Sr and Ti-based master alloys are added to the molten ADC12 alloy in a concentration range of 0.01% to 0.5% by weight. The optimal concentration, usually around 0.05%, provides the best balance of mechanical properties, including increased hardness, tensile strength, and elongation, without adversely affecting the alloy’s castability.
Temperature and Holding Time: The modifier addition is performed at a controlled temperature, typically between 730 ± 10°C, and maintained for a specified holding time, usually 10 to 30 minutes. This controlled environment allows the Sr and Ti modifiers to dissolve fully into the alloy, ensuring uniform distribution and complete modification of the microstructure.
Grain Refinement and Eutectic Silicon Modification: The addition of Sr and Ti-based master alloys leads to two main microstructural improvements:
Refinement of a-Al Dendrites: The modifiers transform the coarse, elongated a-Al dendrites into a fine, equiaxed grain structure, which increases the alloy's strength and ductility.
Modification of Eutectic Silicon Phase: The acicular (needle-like) eutectic silicon phase is broken down into a fine, fibrous structure. This refined silicon morphology enhances the alloy’s thermal and electrical conductivity and reduces brittleness, leading to improved toughness and elongation.
Enhanced Conductivity and Mechanical Properties: The modified alloy exhibits superior properties, such as an increase in electrical conductivity from 25.7 %IACS to 33 %IACS and thermal conductivity from 113.97 W/mK to 142.7 W/mK. Additionally, mechanical properties improve substantially, with hardness increasing from 22.5 HRB to 40 HRB, tensile strength from 181 MPa to 251 MPa, and elongation from 2.44% to 2.96%.
According to an embodiment, the modifier addition step ensures a refined, uniform microstructure, which is crucial for high-performance applications in the automotive, electronics, and aerospace industries. The Sr and Ti-based master alloys provide consistent, reliable modification, enhancing both the structural integrity and conductivity of the ADC12 alloy. This process leads to a significant improvement in the mechanical properties of the ADC12 alloy. The refined microstructure, characterized by fine fibrous silicon and equiaxed a-Al grains, results in higher tensile strength, better ductility, and improved fatigue resistance. Components made from the modified ADC12 alloy are better suited for high-stress applications, such as in the automotive and aerospace industries, where reliability and durability are critical.
High-Pressure Die-Casting (HPDC)
According to an embodiment, the refined molten alloy is poured into a steel die using a high-pressure die-casting (HPDC) machine, operating at approximately 1000 bar once the modification is complete. High-pressure die-casting (HPDC) is a key manufacturing process used to produce precise, high-quality components from ADC12 aluminium alloy. This process is particularly favoured in automotive, electronics, and aerospace industries due to its ability to create complex shapes with excellent dimensional accuracy and surface finish. The HPDC process also ensures the rapid solidification of the alloy, which is crucial for maintaining the refined microstructure achieved through previous modification steps. HPDC is comprised of forcing molten alloy into a steel mold or die under high pressure. The process is characterized by high-speed injection and significant pressure to ensure the molten metal fills the mold cavity completely, capturing every intricate detail of the die. This results in components with tight tolerances, minimal porosity, and a high-quality surface finish.
According to an embodiment, the steel die used in HPDC is custom-designed to match the exact specifications of the component being produced. The die is typically made in two halves, which come together to form the mold cavity. Before casting, the die is coated with a release agent. This coating prevents the molten aluminium from sticking to the die, ensuring easy ejection of the solidified part and prolonging the life of the die. The die is preheated to a specific temperature to reduce thermal shock and help maintain the molten alloy's temperature as it is injected.
Additionally, the refined and degassed ADC12 alloy, modified with Sr and Ti-based modifiers, is maintained at the appropriate casting temperature. The molten alloy is then transferred to the HPDC machine's injection system. The molten alloy is injected into the die cavity at high speed, typically under 1000 to 2000 bar pressures. The high pressure ensures that the alloy fills every part of the die cavity, including thin sections and complex geometries, with minimal air entrapment.
Due to rapid solidification and the compaction effect of high-pressure injection, the die-cast ADC12 alloy exhibits increased strength, hardness, and elongation, with tensile strength reaching up to 251 MPa, hardness up to 40 HRB, and elongation up to 2.96%. Die-casting preserves the modified eutectic silicon phase, resulting in improved thermal conductivity (up to 142.7 W/mK) and electrical conductivity (up to 33 %IACS).
High-Pressure Die Casting (HPDC) is well-suited for mass production, offering high throughput rates and consistent quality, which is crucial for industries with high-volume demands. The high-pressure injection ensures that even complex and thin-walled components are produced with tight tolerances, reducing the need for post-casting machining. The rapid cooling in HPDC helps retain the fine microstructure of the modified ADC12 alloy, resulting in components with superior mechanical properties such as strength, ductility, and wear resistance. Despite the initial investment in die design and setup, HPDC becomes highly cost-effective in large-scale production due to reduced material waste and minimal need for secondary machining.
Cooling and Ejection
The cooling and ejection stages/steps are critical components of the High-Pressure Die-Casting (HPDC) process, ensuring the integrity and quality of the final alloy component. Proper management of these stages/steps is essential for achieving the desired mechanical properties, minimizing defects, and ensuring efficient production.
After the molten alloy is injected into the die under high pressure, it begins to solidify. Rapid cooling is crucial in HPDC as it helps to preserve the fine microstructure achieved through the modification process (with Sr and Ti-based master alloys), leading to enhanced mechanical properties such as strength and toughness. The cooling rate in HPDC is significantly higher than in other casting methods due to the excellent thermal conductivity of the steel die and the thin-walled sections typically designed into HPDC components. This rapid cooling results in a finer microstructure with reduced dendrite arm spacing and smaller silicon particles, which contributes to the superior properties of the alloy.
Preferably the die is equipped with a network of internal cooling channels that circulate water or another cooling fluid. These channels are strategically placed to control the cooling rate across different sections of the casting, ensuring uniform solidification and minimizing thermal gradients that could lead to internal stresses or warping. By adjusting the flow rate and temperature of the cooling fluid, the cooling process can be fine-tuned to optimize the solidification time and reduce the likelihood of defects such as hot spots, cold shuts, or shrinkage porosity.
In an embodiment, sensors may be used to monitor the temperature within the die and the cooling rate of the molten alloy to provide real-time feedback. This real-time feedback allows for adjustments to be made during the process, ensuring consistent quality in each casting cycle. The total solidification time varies depending on the complexity of the part, the thickness of the sections, and the alloy's thermal properties. The goal is to achieve complete solidification quickly while avoiding defects that could compromise the part's performance.
According to an embodiment, once the alloy has solidified, the two halves of the die are separated. The timing of this step is critical; the die must be opened only after the alloy has fully solidified to avoid deformation or damage to the casting. Ejector pins, which are integrated into the die, are activated to push the solidified casting out of the mold cavity. These pins are strategically placed to apply uniform pressure and prevent warping or cracking of the component during ejection.
According to an embodiment, the die coating (release agent) is applied before casting to ensure that the component is easily released from the die without sticking. This coating also helps to prolong the life of the die by reducing wear and tear. The ejected component is carefully handled to prevent damage. Depending on the size and shape of the part, automated systems or manual handling methods may be used to transfer the component to the next stage of production. Although the part is mostly solidified within the die, it may still retain some residual heat. After ejection, the part is often allowed to cool further in ambient air or in a controlled environment to reach room temperature before any post-processing steps, such as trimming or machining, are performed.
The cooling and ejection stages in High-Pressure Die-Casting (HPDC) are crucial for producing high-quality ADC12 alloy components with superior mechanical properties. Proper cooling ensures rapid and uniform solidification, preserving the refined microstructure achieved through earlier process steps. When carefully managed, the ejection process ensures that the components are released from the die without damage, maintaining the integrity and dimensional accuracy required for high-performance applications. Together, these stages play a vital role in the efficiency and success of the HPDC process in the production of alloy components.
Post-Processing
According to an embodiment, post-processing operations are performed on the cast component to achieve the final product specifications. Post-processing operations are critical in refining and enhancing aluminium alloy components' final properties after being cast using the High-Pressure Die-Casting (HPDC) process. These operations ensure that the cast parts meet their intended applications' stringent dimensional, surface, and mechanical requirements. Post-processing can involve a variety of steps, depending on the complexity and final use of the component. The post-processing of ADC12 alloy typically involves several operations:
Machining: After die-casting, the alloy undergoes machining to remove any residual material, such as flash or excess metal, ensuring that the component meets precise dimensional tolerances. Machining processes, including milling, drilling, and turning, are used to refine the part’s geometry and add specific features required for its final application.
Sanding and Polishing: Sanding and polishing operations are performed to smooth and finish the surface of the alloy. These processes help remove minor surface irregularities, enhance the alloy's aesthetic appeal, and prepare the component for further surface treatments. Smoother surfaces also improve the component’s resistance to wear and corrosion.
Surface Finishing Treatments: To further protect against corrosion and extend the component’s lifespan, surface treatments such as anodizing and powder coating can be applied.
Anodizing: This electrochemical process increases the thickness of the natural oxide layer on the surface of the aluminium alloy, enhancing its resistance to corrosion and wear. Anodizing also improves surface hardness and can provide an attractive finish.
Powder Coating: In powder coating, dry powder is applied to the surface and cured, creating a protective and durable coating. Powder coating provides additional protection against harsh environments, making it suitable for outdoor or automotive applications.
Quality Inspection and Testing: After completing all post-processing steps, each component undergoes quality inspections to verify its mechanical properties, dimensions, and surface finish. Standard tests include hardness testing, tensile strength testing, and dimensional analysis to ensure that the alloy meets specifications. Conductivity tests may also be performed to confirm the alloy’s enhanced electrical and thermal conductivity.
Embodiments disclosed include systems and methods to produce an alloy that exhibits significantly enhanced mechanical properties, including an improved microstructure, hardness, tensile strength, ductility, wear resistance, corrosion resistance, thermal stability, and conductivity. These enhancements make the alloy particularly well-suited for demanding applications in the automotive, aerospace, and electronics industries, where high-performance materials are essential. The combination of microstructural refinement, optimized alloy composition, and tailored post-processing treatments ensures that the alloy can meet the rigorous demands of modern engineering applications.

System for manufacturing ADC12 Aluminium alloy
According to an embodiment, the system configuration for manufacturing the aluminium alloy is designed to efficiently produce high-quality components with refined microstructures and enhanced mechanical properties. The system for manufacturing the aluminium alloy comprises a furnace for melting the raw materials, a degassing unit for removing impurities and gases, a high-pressure die-casting machine for casting the molten alloy, a mold die for cooling and solidification, and a mechanism for adding Sr and Ti-based master alloys during the melting process.
Embodiments disclosed include systems and methods in a comprehensive and integrated setup designed to produce high-quality aluminium components with superior mechanical properties. From the melting furnace and degassing unit to the high-pressure die-casting machine and post-processing equipment, each component of the system is carefully designed to work in harmony, ensuring precise control over the entire manufacturing process. These systems and methods not only enhance the performance of the alloy but also improves efficiency, consistency, and reliability in producing components for demanding applications such as automotive, electronics, and industrial machinery. The system comprises the following components:
Furnace
The furnace is a critical component in the manufacturing of ADC12 aluminium alloy, serving as the primary unit for melting the raw materials to create a homogeneous molten alloy. For ADC12, the furnace operates at a controlled temperature of approximately 730 ± 10°C. This temperature range ensures complete melting and uniform distribution of alloying elements, such as aluminium, silicon, copper, magnesium, and trace elements like iron, manganese, and zinc.
Temperature precision is essential in the furnace to avoid excessive oxidation and to retain volatile elements, preserving the alloy’s composition and quality. The furnace is often equipped with a temperature control system to maintain a steady heat level, which is particularly important when introducing Sr and Ti-based master alloys for modification. This consistent temperature control enables effective modifier dissolution, ensuring the alloy's desired grain refinement and eutectic silicon modification.
In addition to providing a consistent melting environment, the furnace is designed to minimize impurities, setting the stage for subsequent degassing, modification, and casting steps, which ultimately enhance the alloy's mechanical, thermal, and electrical properties.
Degassing Unit
Embodiments disclosed comprise the degassing unit, essential in manufacturing the ADC12 alloy, as it removes dissolved gases, primarily hydrogen and other impurities from the molten alloy. Hydrogen gas, if left in the alloy, can lead to porosity and weaken the final product. The degassing unit operates by introducing an inert gas, such as argon or nitrogen, into the molten metal, which binds with dissolved gases and carries them to the surface where they can be removed.
The inert gas is injected into the molten alloy through a lance or rotary impeller, creating fine bubbles that rise through the molten metal, attracting hydrogen and other impurities. As the gas bubbles rise, they trap dissolved gases and bring them to the surface. These impurities are then skimmed off, resulting in a cleaner, purer alloy. During degassing, the molten alloy’s temperature is maintained at around 730 ± 10°C to ensure the alloy’s stability and prevent oxidation.
By effectively reducing impurities, the degassing unit improves the alloy's density, strength, and overall quality, setting a solid foundation for the subsequent modification and die-casting stages. This step is critical for ensuring the high performance and consistency of ADC12 alloy components, making them more resistant to structural defects and suitable for demanding applications.
Modifier Addition Unit
According to an embodiment, the modifier addition unit is a specialized component in the ADC12 alloy manufacturing system designed to introduce Sr (strontium) and Ti (titanium)--based master alloys into the molten alloy. This unit enables precise control over the concentration and distribution of these modifiers, which play a crucial role in enhancing the alloy’s microstructure and, consequently, its mechanical, thermal, and electrical properties.
According to an embodiment, the unit introduces Sr and Ti-based master alloys at a concentration of 0.01% to 0.5% by weight of the alloy, with an optimal concentration of around 0.05%. This precise dosage refines the eutectic silicon phase into a fine, fibrous structure and transforms the a-Al dendrites into a uniform, equiaxed form, which enhances the alloy’s strength, ductility, and conductivity. Modifiers are added at a temperature between 730 ± 10°C, maintained for a specific holding time, preferably 10 to 30 minutes, to allow full dissolution of the modifiers and uniform microstructural modification. The modifier addition unit ensures that Sr and Ti are evenly distributed throughout the molten alloy, allowing consistent grain refinement and silicon modification across the alloy matrix. This uniformity is crucial for achieving reliable mechanical properties in the final product.
The modifier addition unit plays a critical role in achieving a refined and consistent microstructure, contributing to significant improvements in the ADC12 alloy’s hardness, tensile strength, elongation, and conductivity. By controlling modifiers' concentration and distribution, the unit ensures a high-quality alloy suitable for applications requiring durability, strength, and conductivity.
Die-Casting Machine
Embodiments disclosed comprise a die-casting machine, which is a core component in the ADC12 aluminium alloy manufacturing system, configured to shape the modified molten alloy into precise, high-quality components. In this process, high-pressure die-casting (HPDC) is used, where the alloy is injected into a steel die at high pressure to ensure dimensional accuracy, surface quality, and structural integrity of the cast part. The machine injects the modified molten ADC12 alloy into a steel die at a pressure of approximately 1000 bar. This high pressure forces the alloy into intricate mold cavities, ensuring a complete fill with minimal voids, enabling complex shapes with fine surface finishes.
High-pressure injection and rapid solidification lead to increased hardness, tensile strength, and elongation in the final product, as the refined microstructure is preserved. The system maintains the modified silicon structure, boosting the alloy’s thermal and electrical conductivity. The die-casting machine is crucial for producing high-performance ADC12 alloy components with a balance of strength, conductivity, and precision, and it is ideal for applications in automotive, aerospace, and electronics where durability and exact tolerances are required.

Cooling Mechanism
The cooling mechanism in the ADC12 aluminium alloy manufacturing system is essential for controlling the solidification of the molten alloy within the die after die-casting. This mechanism is configured to achieve the desired cooling rate, which directly impacts the alloy’s microstructure and, consequently, its mechanical properties. Proper cooling is crucial for maintaining the refined grain structure introduced by the Sr and Ti-based modifiers, which enhances the alloy's strength, hardness, and conductivity.
According to a preferred embodiment, the cooling mechanism is configured to provide adjustable cooling rates, allowing fine control over the solidification process. By tuning the cooling rate, the system ensures that the refined, fibrous eutectic silicon structure and equiaxed a-Al dendrites are preserved, leading to improved mechanical and thermal properties. It ensures uniform cooling throughout the casting, preventing localized overheating or uneven solidification, which could result in residual stresses or structural defects. The cooling mechanism thus plays a vital role in preserving the refined microstructure and ensuring high performance of ADC12 alloy components, making them suitable for demanding applications in the automotive, aerospace, and electronics industries.
Ejection Mechanism
Embodiments disclosed comprise the ejection mechanism in the ADC12 alloy die-casting system, configured to safely and efficiently remove the solidified casting from the die after the cooling process. This step is crucial for maintaining the cast part's structural integrity and surface quality, ensuring that the refined microstructure achieved during die-casting and cooling is not compromised.
The ejection mechanism applies controlled force to release the solidified casting from the die, ensuring that the part is extracted without damaging its shape, surface, or microstructure. The mechanism is designed to eject the casting smoothly, preventing scratches, dents, or warping that could compromise the alloy’s properties and aesthetic finish. This precision is essential for high-quality components that require minimal post-processing. The ejection mechanism works in alignment with the die to ensure that force is evenly distributed across the casting. This precision helps avoid residual stresses that could affect the alloy’s mechanical properties. Therefore the machine is vital to preserving the quality and properties of the ADC12 alloy components, ensuring that each casting meets the high standards required for performance-driven applications.
Post-Processing Unit
A preferred embodiment of the system includes the post-processing unit, which is a crucial part of the ADC12 alloy manufacturing system and is configured to refine the surface finish, dimensional accuracy, and corrosion resistance of the cast parts after ejection from the die. This unit ensures that the final components meet the necessary quality and performance standards for high-demand applications in the automotive, aerospace, and electronics industries.
Additionally, the post-processing unit performs machining operations such as milling, drilling, and turning to remove any excess material, flash, or imperfections from the casting. This step ensures that each part meets precise dimensional tolerances and enhances its fit and functionality in its intended application.
Sanding and polishing processes are applied to smooth the surface of the alloy, removing minor surface irregularities and achieving a high-quality finish. These processes improve the alloy’s aesthetic appeal and prepare it for additional surface treatments.
Additionally, surface treatments such as anodizing or powder coating are performed to enhance corrosion resistance and extend the component's lifespan. This electrochemical process increases the thickness of the oxide layer on the aluminium surface, enhancing corrosion resistance, wear resistance, and surface hardness while also providing a range of colour options. A durable powder coating protects the alloy from corrosion, especially in harsh environments, and improves its aesthetic appearance.
The post-processing unit is integral to preparing ADC12 alloy components for final use, providing enhanced functionality, durability, and appearance that meet the stringent demands of industries such as automotive, aerospace, and electronics.

Advantages of modified ADC12 alloy
The modified ADC12 aluminium alloy offers several distinct advantages over its unmodified counterpart, making it suitable for high-performance applications in the automotive, aerospace, and electronics industries. Key benefits include:
Refined and Uniform Microstructure
The addition of Sr and Ti-based master alloys transforms the ADC12 alloy’s microstructure by refining the eutectic silicon into a fine, fibrous form and converting the a-Al dendrites into a uniform, equiaxed structure. This refined microstructure reduces brittleness, enhances durability, and provides consistency throughout the material, improving its overall performance in high-stress applications.
Better Castability and Fluidity
The modified ADC12 alloy exhibits improved castability and fluidity, essential for complex shapes and precise die-casting. The fine, consistent microstructure reduces the likelihood of defects such as porosity and shrinkage, ensuring more reliable casting results and increasing the efficiency of production processes.
Superior Electrical and Thermal Conductivity
The electrical and thermal conductivity of ADC12 alloy are crucial properties, particularly for applications in electronics and automotive components, where efficient heat dissipation and electrical performance are required. In its modified form, ADC12 alloy exhibits significantly improved conductivity due to microstructural refinements. In the unmodified ADC12 alloy, electrical conductivity is approximately 25.7 %IACS (International Annealed Copper Standard). However, with the addition of Sr and Ti-based modifiers, the conductivity increases to around 33 %IACS. Thermal conductivity also sees a marked improvement in the modified ADC12 alloy, rising from approximately 113.7 W/mK to 142.7 W/mK. Overall, the modifications to the ADC12 alloy result in enhanced electrical and thermal conductivity, which are beneficial for components requiring heat dissipation and electrical efficiency, such as engine parts, electronic housings, and heat sinks in automotive and electronics applications.
According to research, thermal conductivity can be characterized by the conductivity measuring method; hence, the modified Widman-Franz law was used to compute thermal conductivity:
k_e=L_0 Ts+c ….(1)
Where k_e is the thermal conductivity, T is the temperature in Kelvin (300 K), s is the electrical conductivity, L_0 is the Lorentz number, and c = 10.5 to 12.6 W/m K. L_0 value for Al-Si alloys is accepted as 2.1 × 108 + 0.021×10-8 [Si]b V2/K-2, where [Si]b denotes Si wt% in the alloy.
Table 1. Electrical and thermal conductivity of ADC12 alloy with different wt% addition of Sr and Ti-based master alloys
Wt% ELECTRICAL CONDUCTIVITY (%IACS) THERMAL CONDUCTIVITY (W/mK)
0 25.7 ± 0.3 113.97 ± 1.25
0.01 26 ± 0.5 115.12 ± 2.3
0.05 26.2 ± 0.5 116 ± 1.74
0.1 31.65 ± 0.5 137.43 ± 3.42
0.25 32 ± 0.4 138.79 ± 2.8
0.5 33 ± 0.5 142.7 ± 3.6
Superior Mechanical Properties
The modified ADC12 alloy demonstrates significantly enhanced mechanical properties. By adding master alloys, the eutectic Si phase is modified, and the a-Al and ß-AlFeSi phases are refined, improving the mechanical properties of the alloys. The alloy containing 0.05 wt% master alloy has the best hardness and tensile characteristics due to the entirely modified structure formation. The hardness (40 ± 1 HRB), YS (199 ± 10 MPa), UTS (251 ±13 MPa), and %Elongation (2.96 ± 0.15%) are increased by 77%, 18.5%, 39%, and 21%, as compared to the unmodified ADC12 alloy, respectively. After 0.05 wt% addition of Sr and Ti-based master alloys in ADC12 alloy, the mechanical properties declined, which can be partially attributed to the coarsening of a-Al phase, Si phase, and ß-AlFeSi phase.
Table 2. Mechanical properties with different wt% addition of Sr & Ti-B modifiers
Wt% YS (MPa) UTS (MPa) %ELONGATION (%) HARDNESS, HRB
0 168 ± 8.4 181 ± 9 2.44 ± 0.12 22.5 ± 1
0.01 177 ± 8.9 190 ± 10 2.48 ± 0.12 25 ± 0.5
0.05 199 ± 10 251 ±13 2.96 ± 0.15 40 ± 1
0.1 198 ± 9 242 ± 12 2.88 ± 0.14 26 ± 1
0.25 194 ± 8.6 237 ± 11.8 2.76 ± 0.13 23.5 ± 0.5
0.5 193 ± 8.2 233 ± 11.5 2.68 ± 0.13 24 ± 0.5

In summary, the modified ADC12 alloy offers a combination of refined microstructure, improved castability, superior conductivity, and enhanced mechanical strength, making it an optimal choice for high-performance and precision-engineered applications.
Since various possible embodiments might be made of the above invention, and since various changes might be made in the embodiments above set forth, it is to be understood that all matter herein described or shown in the accompanying drawings is to be interpreted as illustrative and not to be considered in a limiting sense. Thus, it will be understood by those skilled in the art of metallurgy and materials science, manufacturing alloys with enhanced mechanical properties using die-casting technique-based method and system, and more particularly, for Manufacturing High-Strength Aluminium Alloy with Enhanced Microstructure and Mechanical Properties superior to ADC12 alloys, that although the preferred and alternate embodiments have been shown and described in accordance with the Patent Statutes, the invention is not limited thereto or thereby.
The figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present invention. It should also be noted that, in some alternative implementations, the functions noted/illustrated may occur out of the order noted in the figures.
The terminology used herein is for the purpose of describing embodiments only and is not intended to be limiting to the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
The present invention and some of its advantages have been described in detail for some embodiments. It should be understood that although the system and process are described with reference to systems and methods for Manufacturing High-Strength Aluminium Alloy with Enhanced Microstructure and Mechanical Properties superior to ADC12 alloys, the system and method are highly reconfigurable and may be used in other systems as well. It should also be understood that various changes, substitutions, and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims. An embodiment of the invention may achieve multiple objectives, but not every embodiment falling within the scope of the attached claims will achieve every objective. Moreover, the scope of the present application is not intended to be limited to the embodiments of the process, machine, manufacture, and composition of matter, means, methods, and steps described in the specification. A person having ordinary skill in the art will readily appreciate from the disclosure of the present invention that processes, machines, manufacture, compositions of matter, means, methods, or steps presently existing or later to be developed are equivalent to and fall within the scope of, what is claimed. Accordingly, the appended claims are intended to include processes, machines, manufacture, and compositions of matter, means, methods, or steps within their scope.
, Claims:CLAIMS
1. A method for manufacturing a high-strength ADC12 aluminium alloy with enhanced microstructure and mechanical properties comprising:
melting a selected plurality of raw materials in a furnace at approximately 730 ± 10°C to form a homogeneous molten alloy, wherein the selected plurality of raw materials comprise 9.6-12% silicon, 1.5-3.5% copper, 0.3% max magnesium, 0.5% max manganese, 1.3% max iron, and 1% max zinc, 0.5% max nickel, 0.2% max tin, 0.2% max lead, 0.3% max titanium, and remainder aluminium;
degassing the melted plurality of raw materials to remove impurities and dissolved gases from the homogeneous molten alloy;
adding a master alloy to the homogeneous molten alloy at a specific temperature and holding time for eutectic modification and grain refinement;
maintaining the molten alloy at a temperature for a particular holding time to ensure uniform modification of the microstructure;
pouring the molten alloy into a steel die using a high-pressure die-casting (HPDC) process at approximately 1000 bar;
cooling the cast alloy until it solidifies within the die;
ejecting the solidified cast alloy from the die; and
performing post-processing operations comprising machining, sanding, and surface finishing on the cast alloy.
2. The method of claim 1, wherein the degassing further comprises introducing a degassing agent into the plurality of molten aluminium alloy to remove entrapped gases and impurities from the homogeneous molten alloy.
3. The method of claim 1, wherein the Sr and Ti-based master alloys are added in a concentration of 0.01% to 0.5% by weight of the ADC12 alloy, enhances the refinement of eutectic silicon and a-Al dendrites.
4. The method of claim 3, wherein the optimum concentration of the Sr and Ti-based master alloys is 0.05% by weight to improve mechanical properties, including increased hardness, tensile strength, and elongation.
5. The method of claim 1, wherein the holding temperature of the molten alloy during the addition of the modifier is maintained between 730 ± 10°C for a period of 10 to 30 minutes to ensure complete modification of the microstructure and resulting in the transformation of coarse a-Al grains into fine dendritic structures and eutectic silicon from long acicular forms into delicate fibrous forms.
6. The method of claim 1, wherein the die-casting process is carried out at a pressure of approximately 1000 bar to achieve precise casting and minimize casting defects.
7. The method of claim 1 further comprising adjusting the cooling rate of the casting in the die to control the microstructure and improve the mechanical properties of the final product.
8. The method of claim 1, wherein performing post-processing operations further comprise surface finishing techniques such as anodizing or powder coating to enhance corrosion resistance.
9. The method of claim 1, wherein the modified ADC12 alloy exhibits an increase in electrical conductivity from 25.7 %IACS to 33 %IACS and an increase in thermal conductivity from 113.97 W/mK to 142.7 W/mK due to the refinement of the eutectic silicon phase.
10. The method of claim 1, wherein the mechanical properties of the modified ADC12 alloy include an increase in hardness from 22.5 HRB to 40 HRB, tensile strength from 181 MPa to 251 MPa, and elongation from 2.44% to 2.96%.
11. A system for manufacturing a high-strength ADC12 aluminium alloy with enhanced microstructure and mechanical properties comprising:
a furnace for melting a selected plurality of raw materials at approximately 730 ± 10°C to form a homogeneous molten alloy, wherein the selected plurality of raw materials comprise 9.6-12% silicon, 1.5-3.5% copper, 0.3% max magnesium, 0.5% max manganese, 1.3% max iron, and 1% max zinc, 0.5% max nickel, 0.2% max tin, 0.2% max lead, 0.3% max titanium, and remainder aluminium;
a degassing unit for removing impurities and gases from the molten alloy;
a modifier addition unit for introducing Sr and Ti-based master alloys into the molten ADC12 alloy, which causes the refinement of the a-Al dendrites and eutectic silicon phases;
a die-casting machine configured to inject the molten alloy into a steel die under high pressure of about 1000 bar;
a cooling mechanism for solidifying the molten alloy in the die;
an ejection mechanism for removing the solidified alloy from the die; and
a post-processing unit for machining, sanding, and surface finishing the cast product to achieve desired final properties.
12. The system of claim 11, wherein the degassing unit is configured to introduce a degassing agent into the molten alloy.
13. The system of claim 11, wherein the modifier addition unit is configured to introduce Sr and Ti-based master alloys in a concentration ranging from 0.01% to 0.5% by weight of the molten ADC12 alloy.
14. The system of claim 13, wherein the system is optimized for adding 0.05% by weight of Sr and Ti-based master alloys to achieve maximum refinement of the eutectic silicon and a-Al dendritic structure.
15. The system of claim 11, wherein the furnace is equipped with a temperature control system to maintain the molten alloy at a temperature range of 730 ± 10°C for 10 to 30 minutes during the modification process.
16. The system of claim 11, wherein the die-casting machine is designed to operate at a pressure of approximately 1000 bar to ensure precise casting and uniform distribution of the modified microstructure.
17. The system of claim 11 further comprises a cooling unit configured to adjust cooling rates to control the solidification of the cast alloy and improve its final microstructure and properties.
18. The system of claim 11, wherein the post-processing unit is configured to perform additional surface treatments, including anodizing or powder coating, to enhance the corrosion resistance of the cast alloy.
19. The system of claim 11, wherein the system is configured to produce a modified ADC12 alloy with enhanced electrical conductivity of up to 33 %IACS and thermal conductivity of up to 142.7 W/mK.
20. The system of claim 11, wherein the cast product from the modified ADC12 alloy exhibits a hardness of up to 40 HRB, tensile strength of 251 MPa, and elongation of 2.96%.