Methods for controlling the size and distribution uniformity of Al3Sc, ultrasonic devices, and water-cooled molds

Abstract

This application belongs to the field of alloy preparation technology, and particularly relates to methods, ultrasonic devices, and water-cooled molds for controlling the size and uniformity of Al3Sc. Existing technologies mostly employ single process methods, such as stirring or water-cooled molds alone, which are insufficient to simultaneously achieve Al3Sc size refinement and improved distribution uniformity. This solution organically combines refining and degassing, ultrasonic treatment, stirring, and rapid solidification casting. Ultrasonic treatment breaks down nascent Al3Sc particles to achieve size refinement; stirring achieves uniform dispersion; and rapid solidification casting inhibits particle growth, forming a complete process chain from crushing to dispersion to fixation, overcoming the limitations of single process methods.

Description

Technical Field

[0001] This application belongs to the field of alloy preparation technology, and particularly relates to methods for controlling the size and distribution uniformity of Al3Sc, ultrasonic devices, and water-cooled molds. Background Technology

[0002] Aluminum-scandium master alloys, as a key raw material for the research and development of new high-strength and high-toughness aluminum alloys and the iterative upgrading of the strategic light alloy industry, have broad application prospects in supporting the innovation of high-end manufacturing materials. The size of Al3Sc particles in aluminum-scandium master alloys and their uniformity of distribution in the aluminum matrix directly determine the application performance of subsequent high-performance scandium-containing aluminum alloys. When the Al3Sc particles are large in size and unevenly distributed, the strength-toughness balance of the alloy will be significantly deteriorated, restricting the widespread application of aluminum-scandium master alloys in high-end manufacturing fields.

[0003] However, current research on aluminum-scandium master alloys mainly focuses on their preparation methods and processes, such as using doping, metallothermic reduction, or molten salt electrolysis to obtain the aluminum-scandium master alloy melt. Research on the size and distribution uniformity of Al3Sc in the aluminum-scandium master alloy, as well as the control of scandium segregation, is still limited. In the few existing studies, single process methods are often employed, such as introducing stirring during the reaction or before casting, or using water-cooled molds during casting, in order to refine the size of Al3Sc in the aluminum-scandium master alloy and improve its distribution uniformity. However, these single process methods have significant limitations in practical applications: stirring alone is insufficient to effectively break up the already precipitated coarse primary Al3Sc particles; while water-cooled molds can increase the cooling rate and inhibit Al3Sc particle growth, they cannot solve the problem of uneven distribution of Al3Sc particles already present in the melt, and the improvement effect of single methods on scandium segregation is limited. Therefore, existing technologies cannot simultaneously achieve significant refinement of Al3Sc size and effective improvement of its uniform distribution in the aluminum matrix, resulting in a decline in the application performance of aluminum scandium master alloys and failing to meet the stringent requirements of high-end manufacturing for high-performance scandium-containing aluminum alloys. Summary of the Invention

[0004] This application provides a method, an ultrasonic device, and a water-cooled mold for controlling the size and distribution uniformity of Al3Sc, in order to solve the following technical problem: how to control the size and distribution uniformity of Al3Sc in aluminum-scandium master alloy.

[0005] In a first aspect, embodiments of this application provide a method for controlling the size and distribution uniformity of Al3Sc in an aluminum-scandium master alloy, comprising: The aluminum-scandium intermediate alloy melt is refined and degassed to remove impurities and gases from it. The aluminum-scandium intermediate alloy melt after refining and degassing is subjected to ultrasonic treatment to break up the primary Al3Sc particles precipitated in the aluminum-scandium intermediate alloy melt. The ultrasonically treated aluminum-scandium intermediate alloy melt is stirred to uniformly disperse the ultrasonically broken Al3Sc particles in the aluminum-scandium intermediate alloy melt. The aluminum-scandium intermediate alloy melt after the stirring treatment is rapidly solidified and cast to obtain an aluminum-scandium intermediate alloy ingot.

[0006] Optionally, the aluminum-scandium master alloy melt can be prepared by doping, metallothermic reduction, molten salt electrolysis, or remelting of aluminum-scandium master alloy ingots.

[0007] Optionally, the scandium content in the aluminum-scandium master alloy melt is 1 wt.%-10 wt.%.

[0008] Optionally, before the refining and degassing process, the temperature of the aluminum-scandium intermediate alloy melt is controlled at 750℃-1080℃.

[0009] Optionally, the refining agent used in the refining process is an inert refining agent, the weight of which is 1‰-3‰ of the total weight of the aluminum-scandium master alloy melt. After the refining agent is added, the mixture is allowed to stand for 5min-30min to allow impurities to float to the surface and remove the slag from the surface of the melt. The gas introduced for the degassing process is high-purity argon, and the flow rate of the high-purity argon is 0.8 m³ / s. 3 / h-2.0m 3 / h, degassing time is 10min-20min.

[0010] Optionally, the refining agent and the high-purity argon gas are simultaneously introduced into the aluminum-scandium intermediate alloy melt via a porous high-purity graphite rotor rotary injection method.

[0011] Optionally, before the ultrasonic treatment, the temperature of the aluminum-scandium intermediate alloy melt is controlled within the semi-solid temperature range of 650℃-980℃.

[0012] Optionally, the ultrasonic treatment has a power of 100W-1000W, a frequency of 10kHz-30kHz, a duration of 1min-10min, and the ultrasonic probe is inserted to a depth of 1 / 3 of the molten liquid surface.

[0013] In a second aspect, embodiments of this application provide an ultrasonic device for ultrasonic treatment of aluminum-scandium master alloy melt, applicable to the method described in any one of the first aspects, including: Multiple ultrasonic probes are used to apply ultrasonic treatment to an aluminum-scandium intermediate alloy melt. The number and arrangement of the multiple ultrasonic probes depend on the size of the graphite crucible and the total weight of the aluminum-scandium intermediate alloy melt.

[0014] Thirdly, embodiments of this application provide a water-cooled mold for casting aluminum-scandium intermediate alloy melt, applicable to the method described in any one of the first aspects, including: The mold body is a water-cooled copper mold or a water-cooled steel mold. A high-purity boron nitride coating is sprayed onto the inner surface of the mold body.

[0015] Optionally, a cooling medium channel is provided inside the mold body. The cooling medium channel is arranged in a symmetrical ring and the channel diameter is 10mm-16mm.

[0016] Optionally, the flow velocity of the cooling medium in the cooling medium channel is 2m / s-4m / s.

[0017] Optionally, the cooling medium is pure water or an aqueous solution of ethylene glycol.

[0018] The technical solution provided in this application has the following advantages compared with the prior art: The aluminum-scandium master alloy melt is refined and degassed to remove impurities and gases. Refining and degassed treatments reduce the impurity and gas content in the aluminum-scandium master alloy melt, minimizing their interference with subsequent ultrasonic treatment and ensuring that ultrasonic treatment effectively targets the primary Al3Sc particles.

[0019] The refined and degassed aluminum-scandium master alloy melt is subjected to ultrasonic treatment to break down the primary Al3Sc particles precipitated within it. Ultrasonic treatment utilizes the cavitation effect of ultrasound to generate the violent collapse of tiny bubbles within the aluminum-scandium master alloy melt, creating localized high temperatures, high pressures, and strong shock waves. This process breaks down the primary Al3Sc particles precipitated within the melt, achieving the goal of refining the Al3Sc particles.

[0020] The ultrasonically treated aluminum-scandium master alloy melt is stirred to ensure that the ultrasonically broken Al3Sc particles are uniformly dispersed within the melt. The stirring process involves applying mechanical or electromagnetic forces to drive the flow of the aluminum-scandium master alloy melt, thereby rapidly transporting the ultrasonically broken Al3Sc particles from the ultrasonic treatment area to various regions of the melt. This ensures that the Al3Sc particles are evenly distributed within the aluminum matrix, preventing them from settling and agglomerating at the bottom of the melt under gravity.

[0021] The stirred aluminum-scandium master alloy melt is rapidly solidified and cast to obtain an aluminum-scandium master alloy ingot. Rapid solidification casting allows the aluminum-scandium master alloy melt to cool and solidify quickly, thereby inhibiting the further growth of Al3Sc particles during the cooling process. This stabilizes the fine and uniformly distributed Al3Sc particles obtained after ultrasonic and stirring treatments, ultimately resulting in an aluminum-scandium master alloy ingot with fine Al3Sc particle size and uniform distribution within the aluminum matrix. This solves the technical problem of controlling the size and uniformity of Al3Sc distribution in the aluminum-scandium master alloy. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0023] The range descriptions used herein, such as numerical ranges and proportional ranges, include all possible sub-ranges and single numerical values ​​within the range. For example, a range description of 1 to 6 or 1~6 covers all sub-ranges (such as 1 to 3, 2 to 5, etc.) and single numbers (such as 1, 2, 3, 4, 5, 6) between 1 and 6. Unless otherwise specified, the terms used herein include, but are not limited to, terms such as "include"; relational terms such as "first" and "second" are used only to distinguish different entities or steps and do not imply an actual order or relationship; and / or indicate that multiple situations may exist alone or simultaneously; expressions such as "at least one," "multiple," and "at least one" refer to any combination of the corresponding objects, including combinations of single or multiple objects. Proportional relationships mentioned herein, such as mass ratios and molar ratios, should be understood as the correspondence between the antecedent and consequent terms of a proportional expression, according to the order of description. The raw materials, reagents, instruments, and equipment used herein can all be obtained through commercial purchase or prepared using existing methods.

[0024] In a first aspect, embodiments of this application provide a method for controlling the size and distribution uniformity of Al3Sc in an aluminum-scandium master alloy, comprising: S1. The aluminum-scandium intermediate alloy melt is refined and degassed to remove impurities and gases from the aluminum-scandium intermediate alloy melt; S2. The aluminum-scandium intermediate alloy melt after the refining and degassing treatment is subjected to ultrasonic treatment to break up the primary Al3Sc particles precipitated in the aluminum-scandium intermediate alloy melt. S3. The ultrasonically treated aluminum-scandium intermediate alloy melt is stirred to uniformly disperse the ultrasonically broken Al3Sc particles in the aluminum-scandium intermediate alloy melt. S4. The aluminum-scandium intermediate alloy melt after the stirring treatment is rapidly solidified and cast to obtain an aluminum-scandium intermediate alloy ingot.

[0025] Existing technologies often employ single-process methods, such as stirring or water-cooled molds, which are insufficient to simultaneously achieve both Al3Sc particle size refinement and improved uniformity of distribution. This solution organically combines refining and degassing, ultrasonic treatment, stirring, and rapid solidification casting. Ultrasonic treatment breaks down nascent Al3Sc particles to achieve particle size refinement; stirring achieves uniform dispersion; and rapid solidification casting inhibits particle growth, forming a complete process chain from crushing to dispersion to fixation, thus overcoming the limitations of single-process methods.

[0026] In some embodiments, the aluminum-scandium master alloy melt is prepared by methods including doping, metallothermic reduction, molten salt electrolysis, or remelting of aluminum-scandium master alloy ingots.

[0027] The preparation methods for aluminum-scandium master alloy melts include the doping method, the metallothermic reduction method, the molten salt electrolysis method, and the remelting of aluminum-scandium master alloy ingots. The doping method involves directly mixing and melting pure aluminum and pure scandium to prepare the aluminum-scandium master alloy melt. The metallothermic reduction method uses a metal reducing agent to reduce scandium compounds to prepare the aluminum-scandium master alloy melt. The molten salt electrolysis method uses electrolysis of a scandium-containing molten salt system to prepare the aluminum-scandium master alloy melt. The remelting of aluminum-scandium master alloy ingots involves reheating and melting the prepared aluminum-scandium master alloy ingots to prepare the aluminum-scandium master alloy melt. All of these preparation methods can yield aluminum-scandium master alloy melts suitable for subsequent refining and degassing treatments, ultrasonic treatment, stirring treatment, and rapid solidification casting. This expands the adaptability of raw material sources, allowing the control of Al3Sc size and distribution uniformity in aluminum-scandium master alloy melts obtained from different process routes.

[0028] In some embodiments, the scandium content in the aluminum-scandium master alloy melt is 1 wt.%-10 wt.%.

[0029] The scandium content in the aluminum-scandium master alloy melt is 1 wt.%-10 wt.%. When the scandium content is within this range, the aluminum-scandium master alloy melt can precipitate an appropriate amount of primary Al3Sc particles during subsequent cooling. This ensures that the aluminum-scandium master alloy has sufficient scandium content to meet the alloying requirements of high-performance scandium-containing aluminum alloys, while avoiding excessively large and numerous primary Al3Sc particles due to excessive scandium content, which would be difficult to effectively break down by ultrasonic treatment. This ensures that ultrasonic treatment can effectively break down the primary Al3Sc particles, thereby ensuring that the Al3Sc particles in the final aluminum-scandium master alloy ingot are small in size and uniformly distributed.

[0030] The scandium content in the aluminum-scandium master alloy melt is 1wt.%-10wt.%, including but not limited to 1wt.%, 2wt.%, 5wt.%, 8wt.%, 10wt.%, etc.

[0031] In some embodiments, the temperature of the aluminum-scandium master alloy melt is controlled at 750°C-1080°C before the refining and degassing treatment.

[0032] Before refining and degassing, the temperature of the aluminum-scandium master alloy melt is controlled between 750℃ and 1080℃. When the temperature of the aluminum-scandium master alloy melt is within this range, it is in a fully molten state with good fluidity. This ensures that the refining agent can fully diffuse and react with impurities within the melt, thereby ensuring that high-purity argon gas can rise fully within the melt and carry away gases and reaction products. Ultimately, the refining and degassing processes effectively remove impurities and gases from the aluminum-scandium master alloy melt.

[0033] Before refining and degassing, the temperature of the aluminum-scandium master alloy melt is controlled at 750℃-1080℃, including but not limited to 750℃, 800℃, 850℃, 900℃, 960℃, 1000℃, 1080℃, etc.

[0034] In some embodiments, the refining agent used in the refining process is an inert refining agent, the weight of which is 1‰-3‰ of the total weight of the aluminum-scandium master alloy melt. After the refining agent is added, the mixture is allowed to stand for 5min-30min to allow impurities to float to the surface and remove the slag from the surface of the melt. The gas introduced for the degassing process is high-purity argon, and the flow rate of the high-purity argon is 0.8 m³ / s. 3 / h-2.0m 3 / h, degassing time is 10min-20min.

[0035] The refining process uses an inert refining agent, with a weight of 1‰-3‰ of the total weight of the aluminum-scandium master alloy melt. After adding the refining agent, the mixture is allowed to stand for 5-30 minutes to allow impurities to float to the surface and for scum to be skimmed off. The inert refining agent does not chemically react with the aluminum and scandium in the aluminum-scandium master alloy melt; it only undergoes physical adsorption or chemical reaction with impurities. This avoids introducing new impurities or altering the composition of the aluminum-scandium master alloy melt during the refining process. The 1‰-3‰ weight of the inert refining agent ensures a sufficient quantity to adsorb and remove impurities while avoiding waste or residue due to excessive amounts. The 5-30 minute standing time after adding the refining agent provides ample time for impurities to float to the surface, forming scum that is then easily skimmed off.

[0036] The gas introduced for degassing is high-purity argon, with a flow rate of 0.8 m³ / h–2.0 m³ / h and a degassing time of 10–20 min. High-purity argon is an inert gas and does not chemically react with the aluminum-scandium master alloy melt, thus avoiding the introduction of new impurities during the degassing process. The high-purity argon flow rate of 0.8 m³ / h–2.0 m³ / h and the degassing time of 10–20 min ensure that the high-purity argon forms a sufficient number and size of bubbles in the aluminum-scandium master alloy melt, effectively carrying away harmful gases such as hydrogen from the melt. This reduces the gas content of the aluminum-scandium master alloy melt to a level that meets the requirements for subsequent ultrasonic treatment and rapid solidification casting.

[0037] The inert refining agent is added at a rate of 1‰-3‰ of the total weight of the aluminum-scandium master alloy melt, including but not limited to 1‰, 1.5‰, 2‰, 2.5‰, and 3‰. After adding the refining agent, allow the mixture to stand for 5-30 minutes, including but not limited to 5 minutes, 10 minutes, 15 minutes, 20 minutes, 25 minutes, and 30 minutes. The flow rate of high-purity argon is 0.8 m³ / h-2.0 m³ / h, including but not limited to 0.8 m³ / h, 1.0 m³ / h, 1.2 m³ / h, 1.5 m³ / h, 1.8 m³ / h, and 2.0 m³ / h. The degassing time is 10-20 minutes, including but not limited to 10 minutes, 12 minutes, 14 minutes, 15 minutes, 17 minutes, and 20 minutes.

[0038] In some embodiments, the refining agent and the high-purity argon gas are simultaneously introduced into the aluminum-scandium intermediate alloy melt via a porous high-purity graphite rotor rotary blowing method to achieve better refining and degassing effects.

[0039] The refining agent and high-purity argon gas are simultaneously introduced into the aluminum-scandium master alloy melt via a porous high-purity graphite rotor rotary injection method. This method utilizes the rotation of a porous high-purity graphite rotor within the aluminum-scandium master alloy melt to uniformly disperse the refining agent and high-purity argon gas as fine bubbles. This increases the contact area between the refining agent and impurities, as well as the contact area between the high-purity argon gas and the aluminum-scandium master alloy melt. This allows the refining agent to more effectively adsorb impurities, and the high-purity argon gas to more effectively carry away gases, thereby improving the efficiency and uniformity of the refining and degassing processes.

[0040] In some embodiments, prior to the ultrasonic treatment, the temperature of the aluminum-scandium intermediate alloy melt is controlled within the semi-solid temperature range of 650°C-980°C.

[0041] Before ultrasonic treatment, the temperature of the aluminum-scandium master alloy melt is controlled within the semi-solid temperature range of 650℃-980℃. When the temperature of the aluminum-scandium master alloy melt is within the semi-solid temperature range, both liquid and solid phases exist simultaneously in the melt. Primary Al3Sc particles precipitate from the liquid phase and exist in the environment where the solid and liquid phases coexist. As a result, the primary Al3Sc particles are in a relatively unstable state, which makes it easier for the cavitation effect and shock wave generated by ultrasonic treatment to break up the primary Al3Sc particles, ultimately improving the breaking efficiency of primary Al3Sc particles by ultrasonic treatment.

[0042] The semi-solid temperature range is 650℃-980℃, including but not limited to 650℃, 700℃, 750℃, 800℃, 860℃, 900℃, 980℃, etc.

[0043] In some embodiments, the ultrasonic treatment has a power of 100W-1000W, a frequency of 10kHz-30kHz, a duration of 1min-10min, and the ultrasonic probe is inserted to a depth of 1 / 3 of the molten liquid surface.

[0044] The ultrasonic treatment uses a power of 100W-1000W, a frequency of 10kHz-30kHz, and a duration of 1-10 minutes, with the ultrasonic probe inserted to a depth of 1 / 3 of the molten metal surface. The 100W-1000W power ensures sufficient cavitation intensity in the aluminum-scandium master alloy melt, effectively breaking up primary Al3Sc particles while avoiding excessive splashing or unnecessary energy loss due to excessive power. The 10kHz-30kHz frequency generates appropriately sized cavitation bubbles in the melt, ensuring the collapse of these bubbles effectively targets the primary Al3Sc particles. The 1-10 minute treatment time provides sufficient time for the ultrasonic waves to break up the particles while avoiding excessive energy consumption and reduced production efficiency due to prolonged treatment. Inserting the ultrasonic probe to a depth of 1 / 3 from the surface of the molten metal allows ultrasonic waves to propagate from the upper middle part of the aluminum-scandium master alloy melt to the entire melt. This ensures that the ultrasonic waves cover the main area of ​​the aluminum-scandium master alloy melt, thereby causing the primary Al3Sc particles to be broken up by ultrasonic waves throughout the entire aluminum-scandium master alloy melt.

[0045] The power of the ultrasonic treatment ranges from 100W to 1000W, including but not limited to 100W, 200W, 300W, 400W, 500W, 600W, 800W, and 1000W. The frequency of the ultrasonic treatment ranges from 10kHz to 30kHz, including but not limited to 10kHz, 15kHz, 20kHz, 25kHz, 28kHz, and 30kHz. The duration of the ultrasonic treatment ranges from 1 minute to 10 minutes, including but not limited to 1 minute, 2 minutes, 3 minutes, 4 minutes, 5 minutes, 6 minutes, 8 minutes, and 10 minutes.

[0046] In a second aspect, embodiments of this application provide an ultrasonic device for ultrasonic treatment of aluminum-scandium master alloy melt, applicable to the method described in any one of the first aspects, including: Multiple ultrasonic probes are used to apply ultrasonic treatment to an aluminum-scandium intermediate alloy melt. The number and arrangement of the multiple ultrasonic probes depend on the size of the graphite crucible and the total weight of the aluminum-scandium intermediate alloy melt.

[0047] Multiple ultrasonic probes are used to apply ultrasonic treatment to the aluminum-scandium master alloy melt. The number and arrangement of the probes depend on the size of the graphite crucible and the total weight of the melt. When the graphite crucible is large or the total weight of the melt is large, increasing the number of probes and optimizing their arrangement allows the ultrasonic waves to cover a larger area of ​​the melt, thus eliminating the attenuation and blind spots of the ultrasonic waves generated by a single probe during propagation. This ensures that the primary Al3Sc particles in each region of the melt are effectively broken up by ultrasonic waves, ultimately guaranteeing the uniform refinement of Al3Sc particle size in large-size or high-volume aluminum-scandium master alloy melts.

[0048] Thirdly, embodiments of this application provide a water-cooled mold for rapid solidification casting of aluminum-scandium intermediate alloy melt, applicable to the method described in any one of the first aspects, including: The mold body is a water-cooled copper mold or a water-cooled steel mold. A high-purity boron nitride coating is sprayed onto the inner surface of the mold body.

[0049] The mold body is a water-cooled copper mold or a water-cooled steel mold, with a high-purity boron nitride coating sprayed onto its inner surface. The water-cooled copper or steel mold has a high thermal conductivity, enabling rapid heat transfer from the aluminum-scandium master alloy melt, thus significantly increasing the cooling rate of the melt and inhibiting the growth of Al3Sc particles during solidification. The high-purity boron nitride coating on the inner surface of the mold body forms an isolation layer between the aluminum-scandium master alloy ingot and the inner surface of the mold body, preventing adhesion and facilitating demolding.

[0050] In some embodiments, a cooling medium channel is provided inside the mold body, and the cooling medium channel is arranged in a symmetrical annular pattern with a channel diameter of 10mm-16mm.

[0051] The mold body is internally equipped with cooling medium channels arranged in a symmetrical annular pattern, with a channel diameter of 10mm-16mm. This symmetrical annular arrangement ensures uniform distribution of the cooling medium within the mold body, allowing for even heat absorption. This results in uniform cooling of all areas of the aluminum-scandium master alloy melt during rapid solidification and casting, leading to consistent cooling rates across the aluminum-scandium master alloy ingot. Ultimately, this prevents internal stress or uneven microstructure caused by uneven cooling. The 10mm-16mm channel diameter ensures sufficient cross-sectional area for the cooling medium, allowing for smooth flow and effective heat removal, while avoiding excessively large channel diameters that could reduce the structural strength of the mold body.

[0052] The flow channel diameter is 10mm-16mm, including but not limited to 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, etc.

[0053] In some embodiments, the flow velocity of the cooling medium in the cooling medium channel is 2 m / s to 4 m / s.

[0054] The flow velocity of the cooling medium in the cooling medium channel is 2 m / s-4 m / s. When the flow velocity of the cooling medium is 2 m / s-4 m / s, the cooling medium has a sufficient flow velocity in the cooling medium channel, resulting in a high convective heat transfer coefficient between the cooling medium and the mold body. Consequently, the cooling medium can quickly remove the heat absorbed by the mold body from the aluminum-scandium master alloy melt, ultimately ensuring that the cooling rate of the aluminum-scandium master alloy melt meets the requirements for suppressing Al3Sc particle growth.

[0055] The flow velocity of the cooling medium in the cooling medium channel is 2m / s-4m / s, including but not limited to 2m / s, 2.5m / s, 3m / s, 3.5m / s, 4m / s, etc.

[0056] In some embodiments, the cooling medium is pure water or an aqueous solution of ethylene glycol.

[0057] The cooling medium is either pure water or an aqueous solution of ethylene glycol. Pure water has a high specific heat capacity and is inexpensive, making it effective at absorbing heat and suitable for general cooling needs. An aqueous solution of ethylene glycol has a lower freezing point than pure water, allowing it to remain liquid without freezing at lower ambient temperatures. This makes it suitable for low-temperature environments or scenarios requiring even lower cooling temperatures, thus expanding the applicable environment range for water-cooled molds.

[0058] The present application is further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the application. Experimental methods in the following embodiments that do not specify specific conditions are generally determined according to industry standards. If there is no corresponding industry standard, then generally accepted international standards, conventional conditions, or conditions recommended by the manufacturer are followed.

[0059] I. Implementation Examples Example 1 Step (1): A scandium intermediate alloy melt with a scandium content of 2 wt.% was prepared by molten salt electrolysis.

[0060] Step (2): Transfer the aluminum-scandium master alloy melt to a high-purity graphite crucible in a medium-frequency induction heating furnace, and control the temperature of the aluminum-scandium master alloy melt to approximately 850℃. Then, insert a porous graphite rotor into the bottom of the aluminum-scandium master alloy melt, and introduce a refining agent into the aluminum-scandium master alloy melt while simultaneously introducing high-purity argon gas. The gas flow rate is 0.8 m³ / h, and the weight of the refining agent is 2‰ of the total weight of the aluminum-scandium master alloy melt. After standing for 10 minutes, remove the slag from the surface of the aluminum-scandium master alloy melt.

[0061] Step (3): Control the temperature of the aluminum-scandium master alloy melt at about 750℃ using the temperature control system of the medium-frequency induction heating furnace. Then, insert the ultrasonic probe to a depth of about 1 / 3 of the depth from the surface of the aluminum-scandium master alloy melt, set the ultrasonic power and frequency to 300W and 28kHz respectively, and perform ultrasonic treatment on the aluminum-scandium master alloy melt for 1 minute.

[0062] Step (4): After ultrasonic treatment, the aluminum-scandium intermediate alloy melt is mechanically stirred at the same temperature. The stirring paddle is made of high-purity graphite, the stirring speed is 500 rpm, and the stirring time is 10 min.

[0063] Step (5): After stirring, the aluminum-scandium intermediate alloy melt is cast. The mold used is a water-cooled steel mold with an internal boron nitride coating. The mold is preheated before casting. During the casting process, the flow rate of cooling water is 2 m / s.

[0064] After preparing the aluminum-scandium master alloy ingot through the above steps, the average diameter, standard deviation, and non-uniformity coefficient of Al3Sc particles in different regions of the ingot were obtained using the above method. The results show that: the average diameter of Al3Sc particles in the edge region of the aluminum-scandium master alloy ingot is 3.9±0.3 μm, and the non-uniformity coefficient is 15±2%; the average diameter of Al3Sc particles in the half-radius region of the ingot is 5.0±0.2 μm, and the non-uniformity coefficient is 15±2%; the average diameter of Al3Sc particles in the central region of the ingot is 6.3±0.4 μm, and the non-uniformity coefficient is 15±3%.

[0065] Example 2 Step (1): A scandium intermediate alloy melt with a scandium content of 2 wt.% was prepared by molten salt electrolysis.

[0066] Step (2): Transfer the aluminum-scandium master alloy melt to a high-purity graphite crucible in a medium-frequency induction heating furnace, and control the temperature of the aluminum-scandium master alloy melt to approximately 850℃. Then, insert a porous graphite rotor into the bottom of the aluminum-scandium master alloy melt, and introduce a refining agent into the aluminum-scandium master alloy melt while simultaneously introducing high-purity argon gas. The gas flow rate is 0.8 m³ / h, and the weight of the refining agent is 2‰ of the total weight of the aluminum-scandium master alloy melt. After standing for 10 minutes, remove the slag from the surface of the aluminum-scandium master alloy melt.

[0067] Step (3): Control the temperature of the aluminum-scandium master alloy melt at about 750℃ using the temperature control system of the medium-frequency induction heating furnace. Then, insert the ultrasonic probe to a depth of about 1 / 3 of the depth from the surface of the aluminum-scandium master alloy melt, set the ultrasonic power and frequency to 600W and 28kHz respectively, and perform ultrasonic treatment on the aluminum-scandium master alloy melt for 1 minute.

[0068] Step (4): After ultrasonic treatment, the aluminum-scandium intermediate alloy melt is mechanically stirred at the same temperature. The stirring paddle is made of high-purity graphite, the stirring speed is 500 rpm, and the stirring time is 10 min.

[0069] Step (5): After stirring, the aluminum-scandium intermediate alloy melt is cast. The mold used is a water-cooled steel mold with an internal boron nitride coating. The mold is preheated before casting. During the casting process, the flow rate of cooling water is 2 m / s.

[0070] After preparing the aluminum-scandium master alloy ingot through the above steps, the average diameter, standard deviation, and non-uniformity coefficient of Al3Sc particles in different regions of the ingot were obtained using the above method. The results show that: the average diameter of Al3Sc particles in the edge region of the aluminum-scandium master alloy ingot is 3.5±0.4 μm, and the non-uniformity coefficient is 15±2%; the average diameter of Al3Sc particles in the half-radius region of the ingot is 4.3±0.2 μm, and the non-uniformity coefficient is 15±2%; the average diameter of Al3Sc particles in the central region of the ingot is 5.5±0.5 μm, and the non-uniformity coefficient is 15±3%.

[0071] Example 3 Step (1): A scandium intermediate alloy melt with a scandium content of 2 wt.% was prepared by molten salt electrolysis.

[0072] Step (2): Transfer the aluminum-scandium master alloy melt to a high-purity graphite crucible in a medium-frequency induction heating furnace, and control the temperature of the aluminum-scandium master alloy melt to approximately 850℃. Then, insert a porous graphite rotor into the bottom of the aluminum-scandium master alloy melt, and introduce a refining agent into the aluminum-scandium master alloy melt while simultaneously introducing high-purity argon gas. The gas flow rate is 0.8 m³ / h, and the weight of the refining agent is 2‰ of the total weight of the aluminum-scandium master alloy melt. After standing for 10 minutes, remove the slag from the surface of the aluminum-scandium master alloy melt.

[0073] Step (3): Control the temperature of the aluminum-scandium master alloy melt at about 750℃ using the medium-frequency induction heating furnace temperature control system. Then, insert the ultrasonic probe to a depth of about 1 / 3 of the depth from the surface of the aluminum-scandium master alloy melt, set the ultrasonic power and frequency to 300W and 28kHz respectively, and perform ultrasonic treatment on the aluminum-scandium master alloy melt for 2 minutes.

[0074] Step (4): After ultrasonic treatment, the aluminum-scandium intermediate alloy melt is mechanically stirred at the same temperature. The stirring paddle is made of high-purity graphite, the stirring speed is 500 rpm, and the stirring time is 10 min.

[0075] Step (5): After stirring, the aluminum-scandium intermediate alloy melt is cast. The mold used is a water-cooled steel mold with an internal boron nitride coating. The mold is preheated before casting. During the casting process, the flow rate of cooling water is 2 m / s.

[0076] After preparing the aluminum-scandium master alloy ingot through the above steps, the average diameter, standard deviation, and inhomogeneity coefficient of Al3Sc particles in different regions of the ingot were obtained using the above method. The results show that: the average diameter of Al3Sc particles in the edge region of the aluminum-scandium master alloy ingot is 2.8±0.3 μm, and the inhomogeneity coefficient is 15±2%; the average diameter of Al3Sc particles in the half-radius region of the ingot is 3.5±0.2 μm, and the inhomogeneity coefficient is 15±2%; the average diameter of Al3Sc particles in the central region of the ingot is 4.3±0.4 μm, and the inhomogeneity coefficient is 15±3%.

[0077] Example 4 Step (1): A scandium intermediate alloy melt with a scandium content of 2 wt.% was prepared by molten salt electrolysis.

[0078] Step (2): Transfer the aluminum-scandium master alloy melt to a high-purity graphite crucible in a medium-frequency induction heating furnace, and control the temperature of the aluminum-scandium master alloy melt to approximately 850℃. Then, insert a porous graphite rotor into the bottom of the aluminum-scandium master alloy melt, and introduce a refining agent into the aluminum-scandium master alloy melt while simultaneously introducing high-purity argon gas. The gas flow rate is 0.8 m³ / h, and the weight of the refining agent is 2‰ of the total weight of the aluminum-scandium master alloy melt. After standing for 10 minutes, remove the slag from the surface of the aluminum-scandium master alloy melt.

[0079] Step (3): Control the temperature of the aluminum-scandium master alloy melt at about 750℃ using the temperature control system of the medium-frequency induction heating furnace. Then, insert the ultrasonic probe to a depth of about 1 / 3 of the depth from the surface of the aluminum-scandium master alloy melt, set the ultrasonic power and frequency to 300W and 28kHz respectively, and perform ultrasonic treatment on the aluminum-scandium master alloy melt for 1 minute.

[0080] Step (4): After ultrasonic treatment, the aluminum-scandium intermediate alloy melt is mechanically stirred at the same temperature. The stirring paddle is made of high-purity graphite, the stirring speed is 800 rpm, and the stirring time is 10 min.

[0081] Step (5): After stirring, the aluminum-scandium intermediate alloy melt is cast. The mold used is a water-cooled steel mold with an internal boron nitride coating. The mold is preheated before casting. During the casting process, the flow rate of cooling water is 2 m / s.

[0082] After preparing the aluminum-scandium master alloy ingot through the above steps, the average diameter, standard deviation, and non-uniformity coefficient of Al3Sc particles in different regions of the ingot were obtained using the same method. The results show that the average diameter of Al3Sc particles in the edge region of the ingot is 3.8±0.3 μm, and the non-uniformity coefficient is 15±3%; the average diameter of Al3Sc particles in the half-radius region is 5.1±0.2 μm, and the non-uniformity coefficient is 15±1%; and the average diameter of Al3Sc particles in the central region is 6.2±0.2 μm, and the non-uniformity coefficient is 15±1%.

[0083] Example 5 Step (1): A scandium intermediate alloy melt with a scandium content of 2 wt.% was prepared by molten salt electrolysis.

[0084] Step (2): Transfer the aluminum-scandium master alloy melt to a high-purity graphite crucible in a medium-frequency induction heating furnace, and control the temperature of the aluminum-scandium master alloy melt to approximately 850℃. Then, insert a porous graphite rotor into the bottom of the aluminum-scandium master alloy melt, and introduce a refining agent into the aluminum-scandium master alloy melt while simultaneously introducing high-purity argon gas. The gas flow rate is 0.8 m³ / h, and the weight of the refining agent is 2‰ of the total weight of the aluminum-scandium master alloy melt. After standing for 10 minutes, remove the slag from the surface of the aluminum-scandium master alloy melt.

[0085] Step (3): Control the temperature of the aluminum-scandium master alloy melt at about 750℃ using the temperature control system of the medium-frequency induction heating furnace. Then, insert the ultrasonic probe to a depth of about 1 / 3 of the depth from the surface of the aluminum-scandium master alloy melt, set the ultrasonic power and frequency to 300W and 28kHz respectively, and perform ultrasonic treatment on the aluminum-scandium master alloy melt for 1 minute.

[0086] Step (4): After ultrasonic treatment, the aluminum-scandium intermediate alloy melt is mechanically stirred at the same temperature. The stirring paddle is made of high-purity graphite, the stirring speed is 500 rpm, and the stirring time is 20 min.

[0087] Step (5): After stirring, the aluminum-scandium intermediate alloy melt is cast. The mold used is a water-cooled steel mold with an internal boron nitride coating. The mold is preheated before casting. During the casting process, the flow rate of cooling water is 2 m / s.

[0088] After preparing the aluminum-scandium master alloy ingot through the above steps, the average diameter, standard deviation, and inhomogeneity coefficient of Al3Sc particles in different regions of the ingot were obtained using the same method. The results show that the average diameter of Al3Sc particles in the edge region of the ingot is 4.1±0.2 μm, and the inhomogeneity coefficient is 14±1%; the average diameter of Al3Sc particles in the half-radius region is 5.3±0.2 μm, and the inhomogeneity coefficient is 14±2%; and the average diameter of Al3Sc particles in the central region is 6.5±0.3 μm, and the inhomogeneity coefficient is 14±1%.

[0089] Example 6 Step (1): A scandium intermediate alloy melt with a scandium content of 2 wt.% was prepared by molten salt electrolysis.

[0090] Step (2): Transfer the aluminum-scandium master alloy melt to a high-purity graphite crucible in a medium-frequency induction heating furnace, and control the temperature of the aluminum-scandium master alloy melt to approximately 850℃. Then, insert a porous graphite rotor into the bottom of the aluminum-scandium master alloy melt, and introduce a refining agent into the aluminum-scandium master alloy melt while simultaneously introducing high-purity argon gas. The gas flow rate is 0.8 m³ / h, and the weight of the refining agent is 2‰ of the total weight of the aluminum-scandium master alloy melt. After standing for 10 minutes, remove the slag from the surface of the aluminum-scandium master alloy melt.

[0091] Step (3): Control the temperature of the aluminum-scandium master alloy melt at about 750℃ using the temperature control system of the medium-frequency induction heating furnace. Then, insert the ultrasonic probe to a depth of about 1 / 3 of the depth from the surface of the aluminum-scandium master alloy melt, set the ultrasonic power and frequency to 300W and 28kHz respectively, and perform ultrasonic treatment on the aluminum-scandium master alloy melt for 1 minute.

[0092] Step (4): After ultrasonic treatment, the aluminum-scandium intermediate alloy melt is subjected to electromagnetic stirring at the same temperature. The stirring frequency is 20Hz, the excitation current is 150A, and the time is 10min.

[0093] Step (5): After stirring, the aluminum-scandium intermediate alloy melt is cast. The mold used is a water-cooled steel mold with an internal boron nitride coating. The mold is preheated before casting. During the casting process, the flow rate of cooling water is 2 m / s.

[0094] After preparing the aluminum-scandium master alloy ingot through the above steps, the average diameter, standard deviation, and inhomogeneity coefficient of Al3Sc particles in different regions of the ingot were obtained using the same method. The results show that the average diameter of Al3Sc particles in the edge region of the ingot is 3.8±0.3 μm, and the inhomogeneity coefficient is 13±2%; the average diameter of Al3Sc particles in the half-radius region is 5.2±0.2 μm, and the inhomogeneity coefficient is 13±1%; and the average diameter of Al3Sc particles in the central region is 6.2±0.4 μm, and the inhomogeneity coefficient is 13±3%.

[0095] Example 7 Step (1): A scandium intermediate alloy melt with a scandium content of 5 wt.% was prepared by molten salt electrolysis.

[0096] Step (2): Transfer the aluminum-scandium master alloy melt to a high-purity graphite crucible in a medium-frequency induction heating furnace, and control the temperature of the aluminum-scandium master alloy melt to approximately 960℃. Then, insert a porous graphite rotor into the bottom of the aluminum-scandium master alloy melt, and introduce a refining agent into the aluminum-scandium master alloy melt while simultaneously introducing high-purity argon gas. The gas flow rate is 0.8 m³ / h, and the weight of the refining agent is 2‰ of the total weight of the aluminum-scandium master alloy melt. After standing for 10 minutes, remove the slag from the surface of the aluminum-scandium master alloy melt.

[0097] Step (3): Control the temperature of the aluminum-scandium master alloy melt at about 860℃ using the temperature control system of the medium-frequency induction heating furnace. Then, insert the ultrasonic probe to a depth of about 1 / 3 of the depth from the surface of the aluminum-scandium master alloy melt, set the ultrasonic power and frequency to 300W and 28kHz respectively, and perform ultrasonic treatment on the aluminum-scandium master alloy melt for 1 minute.

[0098] Step (4): After ultrasonic treatment, the aluminum-scandium intermediate alloy melt is mechanically stirred at the same temperature. The stirring paddle is made of high-purity graphite, the stirring speed is 500 rpm, and the stirring time is 10 min.

[0099] Step (5): After stirring, the aluminum-scandium intermediate alloy melt is cast. The mold used is a water-cooled steel mold with an internal boron nitride coating. The mold is preheated before casting. During the casting process, the flow rate of cooling water is 2 m / s.

[0100] After preparing the aluminum-scandium master alloy ingot through the above steps, the average diameter, standard deviation, and inhomogeneity coefficient of Al3Sc particles in different regions of the ingot were obtained using the same method. The results show that the average diameter of Al3Sc particles in the edge region of the ingot is 4.8±0.2 μm, and the inhomogeneity coefficient is 15±2%; the average diameter of Al3Sc particles in the half-radius region is 6.2±0.5 μm, and the inhomogeneity coefficient is 15±2%; and the average diameter of Al3Sc particles in the central region is 7.5±0.4 μm, and the inhomogeneity coefficient is 15±3%.

[0101] Example 8 Step (1): A molten aluminum-scandium intermediate alloy with a scandium content of 10 wt.% was prepared by molten salt electrolysis.

[0102] Step (2): Transfer the aluminum-scandium master alloy melt to a high-purity graphite crucible in a medium-frequency induction heating furnace, and control the temperature of the aluminum-scandium master alloy melt to approximately 1080℃. Then, insert a porous graphite rotor into the bottom of the aluminum-scandium master alloy melt, and introduce a refining agent into the aluminum-scandium master alloy melt while simultaneously introducing high-purity argon gas. The gas flow rate is 0.8 m³ / h, and the weight of the refining agent is 2‰ of the total weight of the aluminum-scandium master alloy melt. After standing for 10 minutes, remove the slag from the surface of the aluminum-scandium master alloy melt.

[0103] Step (3): Control the temperature of the aluminum-scandium master alloy melt at about 980℃ using the temperature control system of the medium-frequency induction heating furnace. Then, insert the ultrasonic probe to a depth of about 1 / 3 of the depth from the surface of the aluminum-scandium master alloy melt, set the ultrasonic power and frequency to 300W and 28kHz respectively, and perform ultrasonic treatment on the aluminum-scandium master alloy melt for 1 minute.

[0104] Step (4): After ultrasonic treatment, the aluminum-scandium intermediate alloy melt is mechanically stirred at the same temperature. The stirring paddle is made of high-purity graphite, the stirring speed is 500 rpm, and the stirring time is 10 min.

[0105] Step (5): After stirring, the aluminum-scandium intermediate alloy melt is cast. The mold used is a water-cooled steel mold with an internal boron nitride coating. The mold is preheated before casting. During the casting process, the flow rate of cooling water is 2 m / s.

[0106] After preparing the aluminum-scandium master alloy ingot through the above steps, the average diameter, standard deviation, and inhomogeneity coefficient of Al3Sc particles in different regions of the ingot were obtained using the above method. The results show that the average diameter of Al3Sc particles in the edge region of the aluminum-scandium master alloy ingot is 5.9±0.2 μm, and the inhomogeneity coefficient is 15±2%; the average diameter of Al3Sc particles in the half-radius region of the ingot is 7.6±0.5 μm, and the inhomogeneity coefficient is 15±2%; and the average diameter of Al3Sc particles in the central region of the ingot is 9.8±0.4 μm, and the inhomogeneity coefficient is 15±3%.

[0107] II. Comparative Example Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that ultrasonic treatment and stirring were not performed, and a waterless steel mold was used for casting. After preparing the aluminum-scandium master alloy ingot, the average diameter, standard deviation, and non-uniformity coefficient of Al3Sc particles in different regions of the aluminum-scandium master alloy ingot were obtained using the above method. The results show that: the average diameter of Al3Sc particles in the edge region of the aluminum-scandium master alloy ingot is 15.2±1.2 μm, and the non-uniformity coefficient is 68±2%; the average diameter of Al3Sc particles in the 1 / 2 radius region of the aluminum-scandium master alloy ingot is 24.3±2.5 μm, and the non-uniformity coefficient is 68±2%; the average diameter of Al3Sc particles in the central region of the aluminum-scandium master alloy ingot is 32.2±2.6 μm, and the non-uniformity coefficient is 68±2%.

[0108] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that no stirring treatment was performed, and a waterless steel mold was used for casting. After preparing the aluminum-scandium master alloy ingot, the average diameter, standard deviation, and non-uniformity coefficient of Al3Sc particles in different regions of the aluminum-scandium master alloy ingot were obtained using the above method. The results show that: the average diameter of Al3Sc particles in the edge region of the aluminum-scandium master alloy ingot is 10.2±2.2 μm, and the non-uniformity coefficient is 64±2%; the average diameter of Al3Sc particles in the 1 / 2 radius region of the aluminum-scandium master alloy ingot is 16.1±1.5 μm, and the non-uniformity coefficient is 64±2%; the average diameter of Al3Sc particles in the central region of the aluminum-scandium master alloy ingot is 22.4±1.6 μm, and the non-uniformity coefficient is 64±2%.

[0109] Comparative Example 3 The difference between Comparative Example 3 and Example 1 is that ultrasonic treatment was not performed, and a waterless steel mold was used for casting. After preparing the aluminum-scandium master alloy ingot, the average diameter, standard deviation, and non-uniformity coefficient of Al3Sc particles in different regions of the aluminum-scandium master alloy ingot were obtained using the above method. The results show that: the average diameter of Al3Sc particles in the edge region of the aluminum-scandium master alloy ingot is 12.5±1.2 μm, and the non-uniformity coefficient is 46±2%; the average diameter of Al3Sc particles in the 1 / 2 radius region of the aluminum-scandium master alloy ingot is 19.3±1.8 μm, and the non-uniformity coefficient is 46±2%; the average diameter of Al3Sc particles in the central region of the aluminum-scandium master alloy ingot is 26.1±2.6 μm, and the non-uniformity coefficient is 46±2%.

[0110] Comparative Example 4 The difference between Comparative Example 4 and Example 1 is that a waterless steel mold was used for casting. After preparing the aluminum-scandium master alloy ingot, the average diameter, standard deviation, and non-uniformity coefficient of Al3Sc particles in different regions of the ingot were obtained using the method described above. The results showed that the average diameter of Al3Sc particles in the edge region of the aluminum-scandium master alloy ingot was 7.5±1.4 μm, and the non-uniformity coefficient was 29±2%; the average diameter of Al3Sc particles in the half-radius region of the ingot was 11.2±1.7 μm, and the non-uniformity coefficient was 29±2%; and the average diameter of Al3Sc particles in the central region was 15.1±1.1 μm, and the non-uniformity coefficient was 29±3%.

[0111] Experimental methods for evaluating results: The average diameter and inhomogeneity coefficient of Al3Sc particles in aluminum-scandium master alloy ingots were determined by the following experimental method: Step 1: Take samples from the edge region, half-radius region, and center region of the aluminum-scandium intermediate alloy ingot to obtain edge region samples, half-radius region samples, and center region samples.

[0112] Step 2: The edge region sample, the 1 / 2 radius region sample, and the center region sample are successively subjected to grinding, polishing, and etching processes.

[0113] Step 3: Randomly capture backscattered electron images of no less than 5 fields of view in the sample at the edge, half radius, and center regions using a scanning electron microscope.

[0114] Step 4: Use Image-Pro Plus image analysis software to statistically analyze the equivalent circle diameter and area fraction of all Al3Sc particles in each field of view.

[0115] Step 5: The average diameter and standard deviation of the equivalent circle of Al3Sc particles in each field of view are used as standards to evaluate the refinement of Al3Sc particles.

[0116] Step 6: The ratio C of the standard deviation to the average value of the area fraction of Al3Sc particles in each field of view is used as the non-uniformity coefficient to evaluate the uniformity of Al3Sc particle distribution in the aluminum matrix. The non-uniformity coefficient C is calculated as shown in formula (1): C = (Standard deviation of statistical values ​​for each field of view / Average of statistical values ​​for each field of view) × 100% (1) The smaller the C value, the more uniform the distribution of Al3Sc particles in the aluminum matrix.

[0117] Table 1. Results of Examples / Comparative Examples

[0118] As shown by the examples and comparative effect data, the technical advancements of this application's technical solution include: 1. Compared with a single process (Comparative Examples 1-4), the combination of refining and degassing, ultrasonic treatment, stirring treatment and water-cooled steel mold casting reduced the Al3Sc particle size from 15.2-32.2μm to 2.8-6.5μm and the non-uniformity coefficient from 29%-68% to 13%-15%.

[0119] 2. Ultrasonic treatment breaks up nascent Al3Sc particles through cavitation effect. The power was increased from 300W to 600W (Example 2), and the average diameter of Al3Sc particles in the central region decreased from 6.3μm to 5.5μm. The time was extended from 1min to 2min (Example 3), and the average diameter of Al3Sc particles in the central region decreased from 6.3μm to 4.3μm.

[0120] 3. Stirring treatment ensures that the Al3Sc particles after ultrasonic crushing are uniformly dispersed in the aluminum-scandium intermediate alloy melt. Both mechanical stirring (Example 1) and electromagnetic stirring (Example 6) can control the non-uniformity coefficient within 13%-15%.

[0121] 4. Compared with casting without a water-cooled steel mold (Comparative Example 4), the average diameter of Al3Sc particles in the edge region decreased from 7.5 μm to 3.9 μm, and the non-uniformity coefficient decreased from 29% to 15%.

[0122] 5. Within the scandium content range of 1wt.%-10wt.%, the composite process of this application can effectively control the distribution uniformity of Al3Sc particles, and the non-uniformity coefficient is stable at 13%-15%.

[0123] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A method of regulating the size and distribution uniformity of Al3Sc in an aluminum-scandium master alloy, characterized by, include: The aluminum-scandium intermediate alloy melt is refined and degassed to remove impurities and gases from it. The aluminum-scandium intermediate alloy melt after refining and degassing is subjected to ultrasonic treatment to break up the primary Al3Sc particles precipitated in the aluminum-scandium intermediate alloy melt. The ultrasonically treated aluminum-scandium intermediate alloy melt is stirred to uniformly disperse the ultrasonically broken Al3Sc particles in the aluminum-scandium intermediate alloy melt. The aluminum-scandium intermediate alloy melt after the stirring treatment is cast to obtain an aluminum-scandium intermediate alloy ingot.

2. The method of claim 1, wherein, The preparation methods of the aluminum-scandium master alloy melt include doping, metallothermic reduction, molten salt electrolysis, or remelting of aluminum-scandium master alloy ingots.

3. The method of claim 1, wherein, The scandium content in the aluminum-scandium master alloy melt is 1 wt.%-10 wt.%.

4. The method of claim 1, wherein, Before the refining and degassing process, the temperature of the aluminum-scandium intermediate alloy melt is controlled at 750℃-1080℃.

5. The method of claim 1, wherein, The refining agent used in the refining process is an inert refining agent. The weight of the inert refining agent is 1‰-3‰ of the total weight of the aluminum-scandium master alloy melt. After the refining agent is added, the mixture is allowed to stand for 5min-30min to allow impurities to float to the surface and remove the slag from the surface of the melt. The gas introduced in the degassing treatment is high-purity argon, and the flow rate of the high-purity argon is 0.8m 3 / h-2.0m 3 / h, and the degassing time is 10min-20min.

6. The method of claim 5, wherein, The refining agent and the high-purity argon gas are simultaneously introduced into the aluminum-scandium intermediate alloy melt via a porous high-purity graphite rotor rotary injection method.

7. The method of claim 1, wherein, Before the ultrasonic treatment, the temperature of the aluminum-scandium intermediate alloy melt is controlled within the semi-solid temperature range of 650℃-980℃.

8. The method of claim 1, wherein, The ultrasonic treatment has a power of 100W-1000W, a frequency of 10kHz-30kHz, a duration of 1min-10min, and the ultrasonic probe is inserted to a depth of 1 / 3 of the molten liquid surface.

9. An ultrasonic device for ultrasonic treatment of an aluminium-scandium master alloy melt, adapted for use in the method according to any one of claims 1 to 8, characterised in that include: Multiple ultrasonic probes are used to apply ultrasonic treatment to an aluminum-scandium intermediate alloy melt. The number and arrangement of the multiple ultrasonic probes depend on the size of the graphite crucible and the total weight of the aluminum-scandium intermediate alloy melt.

10. A water-cooled mold for casting of aluminum-scandium master alloy melt, suitable for use in the method according to any one of claims 1 to 8, characterized in that include: The mold body is a water-cooled copper mold or a water-cooled steel mold. A high-purity boron nitride coating is sprayed onto the inner surface of the mold body.

11. The water-cooled mold according to claim 10, characterized in that, The mold body is provided with cooling medium channels, which are arranged in a symmetrical ring and have a diameter of 10mm-16mm.

12. The water-cooled mold according to claim 10, characterized in that, The flow velocity of the cooling medium in the cooling medium channel is 2m / s-4m / s.

13. The water-cooled mold according to claim 10, characterized in that, The cooling medium is pure water or an aqueous solution of ethylene glycol.

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