A method for preparing an al-ti-b grain refiner

Abstract

The application relates to the technical field of grain refiners, and discloses a preparation method of an Al-Ti-B grain refiner, which comprises the following steps: S1, adding fluoroborate and fluorotitanate into aluminum liquid, carrying out alloying treatment, removing slag, and obtaining aluminum melt; during the alloying treatment, TiB2 and TiAl3 are generated, and the first mechanical vibration treatment is adopted to refine and disperse the TiB2 and TiAl3; S2, after the aluminum melt is refined and degassed, the second mechanical vibration treatment is carried out, slag is removed, and continuous casting is carried out to obtain the Al-Ti-B grain refiner; the second mechanical vibration treatment is used for forming a TiAl3-coated TiB2 structure of the TiB2 and TiAl3 refined and dispersed after the first mechanical vibration treatment. The first mechanical vibration and the second mechanical vibration are used in combination, so that the refining capacity of the Al-Ti-B grain refiner can be effectively improved.

Description

Technical Field

[0001] This invention relates to the field of grain refiner technology, specifically to a method for preparing an Al-Ti-B grain refiner. Background Technology

[0002] With the increasing application of aluminum alloys in high-speed rail, aerospace, and other fields, the requirements for their comprehensive performance are becoming increasingly stringent. To meet the performance demands of aluminum alloys in industrial production, grain refinement is often employed, which involves adding grain refiners to refine the microstructure and improve performance. Currently, Al-Ti-B grain refiners have become a widely used and relatively mature method. Adding Al-Ti-B grain refiners can reduce defects in aluminum alloy materials, such as shrinkage cavities, porosity, and hot cracking, thus improving the internal quality of the aluminum alloy. Furthermore, it can eliminate coarse columnar and feather-like structures, refining the grains. The finer the grains, the better the strength and toughness of the alloy, thereby improving product performance and service life.

[0003] Research on grain refiners for aluminum alloys in my country started relatively late. Current preparation processes typically involve adding different salts and other materials to molten aluminum, followed by aluminothermic reaction, slag removal, and then casting, rolling, or extrusion to produce grain refiner filaments. However, the salts produce a large amount of molten slag during the high-temperature reaction. This slag has a similar specific gravity to the molten aluminum and is difficult to remove effectively. The remaining slag easily becomes inclusions, leading to casting defects. Furthermore, during the grain refiner smelting process, TiB2 particles are prone to precipitation, segregation, or internal clustering. These clustered TiB2 particles not only scratch the product surface during subsequent rolling but also reduce the grain refiner's refining effect.

[0004] Therefore, how to achieve uniform dispersion of TiB2 in the refining agent and improve its refining ability has become an important technical indicator for the preparation of high-quality aluminum alloy refining agents. Summary of the Invention

[0005] This invention proposes a method for preparing an Al-Ti-B grain refiner, which uses a combination of first and second mechanical vibrations to obtain an Al-Ti-B grain refiner with uniform internal structure and high refining ability.

[0006] The specific technical solution of the present invention is as follows: According to one aspect of the present invention, a method for preparing an Al-Ti-B grain refiner is provided, comprising the following steps: S1. Fluoroborate and fluorotitanate are added to the aluminum melt, alloyed, and slag is removed to obtain the aluminum melt. During the alloying process, TiB2 and TiAl3 are generated. A first mechanical vibration treatment is then applied to refine and disperse the TiB2 and TiAl3. S2. After refining and degassing the aluminum melt, it undergoes a second mechanical vibration treatment to remove slag and is then continuously cast to obtain the Al-Ti-B grain refiner. The second mechanical vibration treatment is used to refine and disperse the TiB2 and TiAl3 after the first mechanical vibration treatment, forming a TiAl3-coated TiB2 structure.

[0007] In the above technical solution, the vibration frequency of the first mechanical vibration treatment is 40~60Hz, the amplitude is 0.8~1.2mm, and the vibration time is 5~180s; The vibration frequency of the second mechanical vibration treatment is 40~60Hz, the amplitude is 0.8~1.2mm, and the vibration time is 5~180s.

[0008] In the above technical solution, the vibration directions of the first mechanical vibration and the second mechanical vibration are each independently one of the X direction and the Y direction; Wherein, the X direction is the horizontal left-right direction and the Y direction is the horizontal front-back direction.

[0009] In the above technical solution, the amount of fluoroborate added is 30% to 50% of the total mass of the fluoroborate and the fluorotitanate.

[0010] In the above technical solution, the mass ratio of the fluoroborate and the fluorotitanate to the molten aluminum is 3~6:10.

[0011] In the above technical solution, the fluoroborate and fluorotitanate are added in one step or in stages. When adding fluoroborate and fluorotitanate, add them while stirring, and the total addition time is 5~30 minutes.

[0012] In the above technical solution, in step S1, the alloying treatment is carried out at a temperature of 700~900℃ for a time of 10~60min.

[0013] In the above technical solution, in step S1, before adding fluoroborate and fluorotitanate to the aluminum liquid, the aluminum liquid is heated to 700~800℃ to degas and remove slag.

[0014] In the above technical solution, during step S1, when removing slag, light calcium carbonate is sprinkled 5-10 mm onto the surface of the alloyed melt.

[0015] In the above technical solution, during step S2, argon gas is introduced during the refining and degassing process. The argon gas pressure is 0.1~0.5MPa, and the argon gas introduction time is 5~15min.

[0016] According to another aspect of the present invention, the present invention also provides an Al-Ti-B grain refiner prepared by the above-mentioned method for preparing Al-Ti-B grain refiner, wherein the Al-Ti-B grain refiner is one of Al-Ti5-B1 ​​and Al-Ti3-B1.

[0017] Compared with existing technologies, this invention provides a method for preparing an Al-Ti-B grain refiner, employing a combination of first and second mechanical vibrations. The synergistic effect of these two vibrations refines and disperses TiB2 and TiAl3 particles, forming a TiAl3-coated TiB2 structure. This avoids precipitation, segregation, or internal clustering of TiB2 particles and increases the number of nucleation sites, thereby improving the stability of the refiner's internal structure. Furthermore, it offers advantages such as simple processing and short preparation time, effectively improving production efficiency. Ultimately, the Al-Ti-B grain refiner significantly enhances its refining ability. When added to aluminum alloys, it effectively eliminates coarse structures, refines grains, improves the internal quality of the aluminum alloy, and enhances its wear resistance.

[0018] First, fluoroborate and fluorotitanate are added to molten aluminum for alloying treatment, followed by an initial mechanical vibration to obtain molten aluminum. This vibration operation not only avoids incomplete reaction caused by fluoroborate and fluorotitanate sticking to the aluminum walls, but also avoids the introduction of oxides and impurities during stirring. Simultaneously, the initial mechanical vibration helps improve the dispersion rate and uniformity of fluoroborate and fluorotitanate in the molten aluminum, thereby increasing their contact area with the aluminum, improving alloying reaction efficiency, shortening reaction time, and resulting in finer and more dispersed TiB2 and TiAl3 particles formed by alloying, laying the foundation for enhancing the refining ability of the refining agent.

[0019] Secondly, after refining and degassing the aluminum melt, a second mechanical vibration is performed. This vibration further enhances the effect of the first vibration: it promotes better gas escape from the aluminum melt, causes oxides and salt deposits in the aluminum melt to float to the surface, and further disperses TiB2 and TiAl3 particles. This increases the contact probability between the alloyed product TiAl3 and TiB2, promoting the formation of a TiAl3-coated TiB2 structure. This ensures that the Al-Ti-B grain refiner has a high refining ability. At the same time, the application of the Al-Ti-B grain refiner in aluminum alloys can also effectively hinder the movement of dislocations in the internal structure of aluminum alloys, producing a significant dispersion strengthening effect and improving its wear resistance. Attached Figure Description

[0020] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0021] Figure 1The optical microstructure of the Al-Ti-B grain refiner prepared in Example 1 of this invention is shown in Figure 1. Figure 2 The optical microstructure of the Al-Ti-B grain refiner prepared in Example 6 of this invention is shown in Figure 6. Figure 3 The optical microstructure of the Al-Ti-B grain refiner prepared in Example 7 of this invention is shown in Figure 7. Figure 4 The optical microstructure of the Al-Ti-B grain refiner prepared in Example 8 of this invention is shown in the image. Figure 5 This is a transmission electron microscope (TEM) image of TiAl3-coated TiB2 in the Al-Ti-B grain refiner prepared in Example 1 of this invention. Figure 6 The figure shows the cooling curves of pure aluminum added to the Al-Ti-B grain refiner prepared in Examples 1 and 6-8 of this invention; in the figure, Example 1 is the cooling curve of Example 1, Example 2 is the cooling curve of Example 8, Example 3 is the cooling curve of Example 7, and Example 4 is the cooling curve of Example 6; ΔT is the supercooling, which is the difference between the theoretical crystallization temperature and the actual nucleation temperature. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention more apparent, the invention is described in detail below. It should be understood that the invention is not limited to the description herein.

[0023] Fluoroborates and fluorotitanates In this invention, the fluoroborate is KBF4 (potassium fluoroborate), which serves as a raw material for introducing boron in the preparation of the Al-Ti-B grain refiner. Boron acts as a grain refiner in aluminum alloys, forming compounds such as AlB2 with aluminum. Introducing a titanium source facilitates the formation of TiB2. These compounds can act as heterogeneous nucleation sites, promoting the nucleation process in aluminum alloys and thus refining the grains. The fluorotitanate is K2TiF6 (potassium hexafluorotitanate), which, when added to molten aluminum, introduces titanium, thereby forming TiAl3 and TiB2 with aluminum and boron, further refining the grains.

[0024] In this invention, the amount of fluoroborate added is 30% to 50% of the total mass of fluoroborate and fluorotitanate, for example, it can be any point value or any range between any two points from 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, 50%; the amount of fluorotitanate added is 50% to 70% of the total mass of fluoroborate and fluorotitanate, for example, it can be any point value or any range between any two points from 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, 60%, 61%, 62%, 63%, 64%, 65%, 66%, 67%, 68%, 69%, 70%.

[0025] In this invention, the mass ratio of fluoroborate and fluorotitanate to molten aluminum is 3~6:10, for example, it can be 3:10, 3.5:10, 4:10, 4.2:10, 4.3:10, 4.5:10, 5:10, 5.5:10, or 6:10, preferably 4~5:10, and more preferably 4.3~5:10.

[0026] Light calcium carbonate In this invention, light calcium carbonate is sprinkled on the surface of the alloyed molten metal. The light calcium carbonate can adsorb impurities in the molten metal and form a slag layer that is easy to remove, thereby improving the purity of the aluminum melt.

[0027] In this invention, the thickness of the light calcium carbonate layer sprinkled on the surface of the molten liquid is 5~10mm, for example, it can be any point value or the range between any two point values ​​from 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 8.5mm, 9mm, 9.5mm, 10mm, preferably 5~8mm, more preferably 5mm.

[0028] Al-Ti-B grain refiner In this invention, after adding fluoroborate and fluorotitanate to molten aluminum, alloying, mechanical vibration, and continuous casting are performed to prepare an Al-Ti-B grain refiner with an internal structure containing TiAl3 coated TiB2. Adding this to aluminum alloy materials can, on the one hand, reduce defects such as shrinkage cavities, porosity, and hot cracking tendency, thus improving the intrinsic quality of the aluminum alloy material; on the other hand, it can eliminate coarse columnar and feathery structures in the aluminum alloy material, resulting in finer grains, which in turn improves the strength and toughness of the aluminum alloy material, thereby enhancing the performance and service life of aluminum alloy products.

[0029] In this invention, the Al-Ti-B grain refiner is one of Al-Ti5-B1 ​​and Al-Ti3-B1.

[0030] In this invention, when the Al-Ti-B grain refiner is Al-Ti3-B1, the mass of K2TiF6 required to produce Al-Ti3-B1 is 60% of the mass of K2TiF6 required to produce Al-Ti5-B1.

[0031] Preparation method of Al-Ti-B grain refiner This invention provides a method for preparing the Al-Ti-B grain refiner as described above, comprising the following steps: S1. Fluoroborate and fluorotitanate are added to the aluminum melt, alloyed, and slag is removed to obtain the aluminum melt. During the alloying process, TiB2 and TiAl3 are generated. The first mechanical vibration treatment is used to refine and disperse TiB2 and TiAl3. S2. After refining and degassing the aluminum melt, a second mechanical vibration treatment is performed to remove slag and then continuous casting to obtain Al-Ti-B grain refiner. The second mechanical vibration treatment is used to refine and disperse TiB2 and TiAl3 after the first mechanical vibration treatment to form a TiAl3-coated TiB2 structure.

[0032] In this invention, a three-dimensional vibration platform is used for the first and second mechanical vibrations. Driven by its own motor, it achieves three-dimensional vibration in the up-down, left-right, and forward-backward directions. The three-dimensional vibration platform uses a stationary base as the absolute reference, and its vibration direction is referenced to a fixed rectangular coordinate axis established by the platform itself, having vibration directions in the X, Y, and Z directions. The X direction is a horizontal left-right direction, parallel to the width of the platform surface, and reciprocates left and right; the Y direction is a horizontal forward-backward direction, parallel to the length of the platform surface, and reciprocates forward and backward; the Z direction is a vertical up-down direction, perpendicular to the plane of the vibration platform surface, and reciprocates up and down. In this invention, the vibration direction of the first mechanical vibration is either the X or Y direction; the vibration direction of the second mechanical vibration is also either the X or Y direction. For example, the vibration directions of the first and second mechanical vibrations can be X-X-X; X-Y-X; Y-X-X; Y-Y-Y; preferably X-X-X; Y-Y-Y. In this invention, when the vibration directions of the first and second mechanical vibrations are both X or Y, the single-direction horizontal vibration in the first mechanical vibration generates a continuous and stable vibration wave along that direction within the molten aluminum. This directional vibration promotes the full diffusion of the fluorine-containing mixed salt in the molten aluminum along the same direction, allowing Ti and B elements to be more uniformly incorporated into the molten aluminum. Compared to vibration in random directions, single-direction vibration is more conducive to achieving highly uniform mixing of components in a specific direction, and more conducive to forming a uniform and effective grain-refining phase, thereby improving the refining ability of the grain refiner and also improving the wear resistance of the aluminum alloy material. In the second mechanical vibration, the single horizontal vibration can further apply vibration force based on the horizontal vibration direction of the first mechanical vibration, which is more conducive to forming a TiAl3-coated TiB2 structure, ultimately further improving the refining ability of the Al-Ti-B grain refiner and the wear resistance of the aluminum alloy material.

[0033] In this invention, the grain-refining ability of the Al-Ti-B grain refiner can be further improved when the vibration directions of the first and second mechanical vibrations are both X-direction or both Y-direction. The speculated reason is that when the vibration directions of the first and second mechanical vibrations are the same, it is more conducive to optimizing the crystal structure of the heterogeneous nucleation core. Adding it to aluminum alloy materials can provide better attachment sites for aluminum alloy atoms, promote the crystallization process of aluminum alloy, improve the grain-refining effect, and at the same time, the fine grain structure improves the wear resistance of aluminum alloy.

[0034] In this invention, the vibration frequency of the first mechanical vibration treatment is 40~60Hz, for example, it can be any point value or any range between two points of 40Hz, 45Hz, 50Hz, 55Hz, and 60Hz, preferably 50Hz; the amplitude is 0.8~1.2mm, for example, it can be 0.8mm, 0.9mm, 1.0mm, 1.1mm, and 1.2mm, preferably 1.0~1.1mm, more preferably 1.0mm; the vibration time is 5s~3min, for example, it can be 5s, 10s, 20s, 40s, 1min, 1.5min, 2min, 2.5min, and 3min, preferably 10s~2min, more preferably 10s.

[0035] The vibration frequency of the second mechanical vibration treatment is 40~60Hz, for example, it can be any point value or any range between two points of 40Hz, 45Hz, 50Hz, 55Hz, and 60Hz, preferably 50Hz; the amplitude is 0.8~1.2mm, for example, it can be 0.8mm, 0.9mm, 1.0mm, 1.1mm, and 1.2mm, preferably 1.0~1.1mm, more preferably 1.0mm; the vibration time is 5s~3min, for example, it can be 5s, 10s, 20s, 40s, 1min, 1.5min, 2min, 2.5min, and 3min, preferably 10s~2min, more preferably 10s.

[0036] In this invention, when adding fluoroborate and fluorotitanate, they are added while stirring, and the total addition time is 5 to 30 minutes. For example, it can be any point value or any range between two points from 5 minutes, 10 minutes, 15 minutes, 20 minutes, 25 minutes, to 30 minutes, preferably 10 to 20 minutes, and more preferably 10 minutes. The addition method of fluoroborate and fluorotitanate is one-step addition or step-by-step addition. When adding fluoroborate and fluorotitanate in a step-by-step manner, the step-by-step addition can be two additions, three additions, or four additions, preferably two additions.

[0037] In this invention, aluminum ingots are melted to obtain molten aluminum. The molten aluminum is heated to 700-800°C and subjected to degassing and slag removal treatment before fluoroborate and fluorotitanate are added. The temperature of the molten aluminum is raised to 700-800°C, for example, any point value or range between any two points from 700°C, 710°C, 720°C, 730°C, 740°C, 750°C, 760°C, 770°C, 780°C, 790°C, and 800°C, preferably 750-780°C.

[0038] In this invention, argon gas is introduced during the degassing of molten aluminum. The argon gas tube is an aluminum corrosion resistant graphite tube with a diameter of 20 mm. The argon gas pressure is 0.1~0.5 MPa, for example, any value or range between any two values ​​from 0.1 MPa, 0.2 MPa, 0.3 MPa, 0.4 MPa, and 0.5 MPa. The argon gas introduction time is 5~15 min, for example, any value or range between any two values ​​from 5 min, 6 min, 7 min, 8 min, 9 min, 10 min, 11 min, 12 min, 13 min, 14 min, and 15 min, preferably 8~10 min.

[0039] In this invention, argon gas is introduced during the degassing of the aluminum melt. The argon gas tube is an aluminum corrosion resistant graphite tube with a diameter of 20 mm. The argon gas pressure is 0.1~0.5 MPa, for example, any value or range between any two values ​​from 0.1 MPa, 0.2 MPa, 0.3 MPa, 0.4 MPa, and 0.5 MPa. The argon gas introduction time is 5~15 min, for example, any value or range between any two values ​​from 5 min, 6 min, 7 min, 8 min, 9 min, 10 min, 11 min, 12 min, 13 min, 14 min, and 15 min, preferably 8~10 min.

[0040] In this invention, during alloying treatment, the temperature is 700~900℃, for example, any point value or the range between any two points from 700℃, 710℃, 720℃, 730℃, 740℃, 750℃, 760℃, 770℃, 780℃, 790℃, 800℃, 810℃, 820℃, 830℃, 840℃, 850℃, 860℃, 870℃, 880℃, 890℃, and 900℃, preferably 850~900℃, more preferably 900℃; the time is 10~60min, for example, any point value or the range between any two points from 10min, 15min, 20min, 25min, 30min, 35min, 40min, 45min, 50min, 55min, and 60min, preferably 10~40min, more preferably 10~20min.

[0041] In this invention, in step S1, light calcium carbonate is sprinkled on the surface of the alloyed melt for 5-10 mm to remove slag. The light calcium carbonate can adsorb the water slag containing impurities in the melt to form a slag layer that is easy to remove, thereby improving the purity of the aluminum melt.

[0042] In this invention, in step S2, after adjusting the temperature of the molten aluminum to 700-780°C, it is transferred to the casting furnace through a flow channel. Then, argon gas is used to refine and degas the molten aluminum in the casting furnace. After degassing, the molten aluminum undergoes a second mechanical vibration. After vibration, it is allowed to stand for 5-30 minutes, and surface slag is removed to obtain an alloy liquid. The alloy liquid is then continuously cast to obtain an Al-Ti-B grain refiner. The molten aluminum temperature is adjusted to 700-780°C, for example, 700°C. The settling time is 5 to 30 minutes, for example, any point value from 710℃, 720℃, 730℃, 740℃, 750℃, 760℃, 770℃, and 780℃, and the range between any two point values, preferably 700~750℃, more preferably 750℃; the settling time is 5~30 minutes, for example, any point value from 5 minutes, 10 minutes, 15 minutes, 20 minutes, 25 minutes, and 30 minutes, and the range between any two point values, preferably 5~15 minutes.

[0043] To further illustrate the present invention, the following embodiments will provide a detailed description. The raw materials used in the following embodiments and comparative examples of the present invention are all commercially available products, wherein: Aluminum ingots, with a purity of 99.7 wt%; KBF4, purity 98 wt%; K2TiF6, purity 98wt%; Light calcium carbonate with an average particle size of 10 μm; The argon tube is an aluminum corrosion resistant graphite tube with a diameter of 20mm; The wire diameter for the Al-Ti-B grain refiner is 9.6 mm.

[0044] Example 1 A method for an Al-Ti-B grain refiner includes the following steps: S1. Add 90kg of aluminum ingot to a medium-frequency induction furnace for melting, heat to 750℃, and degas the aluminum liquid by passing argon through an argon gas pipe (argon pressure is 0.4MPa, argon passage time is 10min). After slag removal, weigh and mix 13kg of KBF4 and 26kg of K2TiF6 and add them to the aluminum liquid in a one-step feeding method, stirring the melt continuously during the feeding process. The feeding time is 10min. Then raise the temperature of the aluminum liquid to 900℃ and alloy it at 900℃ for 10min. Perform X-direction mechanical vibration on the aluminum liquid at a vibration frequency of 50Hz and an amplitude of 1.0mm for 10s. Then evenly sprinkle light calcium carbonate on the surface of the melt for 5mm, remove residual water slag, and obtain aluminum melt. S2. Adjust the temperature of the aluminum melt to 750℃. Transfer the aluminum melt into the casting furnace through a flow channel. First, use argon gas to refine and degas the aluminum melt in the casting furnace for 10 minutes (argon gas pressure is 0.4MPa). After degassing, mechanically vibrate the aluminum melt in the X direction for 10 seconds at a vibration frequency of 50Hz and an amplitude of 1.0mm. After vibration, let it stand for 5 minutes to remove surface slag and obtain alloy liquid. Adjust the temperature of the alloy liquid to 750℃ and transfer it into a continuous casting and rolling mill through a flow channel for continuous casting to obtain Al-Ti-B grain refiner. After rolling, Al-Ti5-B1 ​​alloy wire with a diameter of 9.6mm is obtained. The optical microstructure of the Al-Ti-B grain refiner prepared in Example 1 is shown in the figure below. Figure 1 As shown; The image of TiAl3-coated TiB2 prepared by the Al-Ti-B grain refiner in Example 1 under transmission electron microscopy is shown below. Figure 5 As shown.

[0045] Example 2 A method for an Al-Ti-B grain refiner includes the following steps: S1. Add 90kg of aluminum ingot to a medium-frequency induction furnace for melting and heat to 700℃. After degassing the aluminum liquid by passing argon through an argon gas pipe (argon pressure is 0.1MPa, and argon passage time is 15min) and removing slag, weigh and mix 8.1kg of KBF4 and 18.9kg of K2TiF6 and add them to the aluminum liquid in a one-step feeding method. Stir the melt continuously during the feeding process for 5min. Then maintain the temperature of the aluminum liquid at 700℃ and alloy it at 700℃ for 60min. Perform mechanical vibration in the X direction on the aluminum liquid for 2min at a vibration frequency of 40Hz and an amplitude of 0.8mm. Then evenly sprinkle light calcium carbonate on the surface of the melt for 8mm and remove residual water slag to obtain aluminum melt. S2. Adjust the temperature of the aluminum melt to 700℃. Transfer the aluminum melt to the casting furnace through a flow channel. First, use argon gas to refine and degas the aluminum melt in the casting furnace for 15 minutes (argon gas pressure is 0.1MPa). After degassing, mechanically vibrate the aluminum melt in the X direction for 2 minutes at a vibration frequency of 40Hz and an amplitude of 0.8mm. After vibration, let it stand for 30 minutes to remove surface slag and obtain alloy liquid. Adjust the temperature of the alloy liquid to 700℃ and transfer it to a continuous casting and rolling mill through a flow channel for continuous casting to obtain Al-Ti-B grain refiner. After rolling, Al-Ti5-B1 ​​alloy wire with a diameter of 9.6mm is obtained.

[0046] Example 3 A method for an Al-Ti-B grain refiner includes the following steps: S1. Add 90kg of aluminum ingot to a medium-frequency induction furnace for melting and heat to 800℃. After degassing the aluminum liquid by passing argon through an argon gas pipe (argon pressure is 0.5MPa, and argon passage time is 5min) and removing slag, weigh and mix 27kg of KBF4 and 27kg of K2TiF6 and add them to the aluminum liquid in a one-step feeding method. Stir the melt continuously during the feeding process for 30min. Then adjust the temperature of the aluminum liquid to 900℃ and alloy it at 900℃ for 10min. Perform X-direction mechanical vibration on the aluminum liquid at a vibration frequency of 60Hz and an amplitude of 1.2mm for 3min. Then evenly sprinkle light calcium carbonate on the surface of the melt for 8mm and remove residual water slag to obtain aluminum melt. S2. Adjust the temperature of the aluminum melt to 780℃. Transfer the aluminum melt into the casting furnace through a flow channel. First, use argon gas to refine and degas the aluminum melt in the casting furnace for 5 minutes (argon gas pressure is 0.5MPa). After degassing, mechanically vibrate the aluminum melt in the X direction for 3 minutes at a vibration frequency of 60Hz and an amplitude of 1.2mm. After vibration, let it stand for 15 minutes to remove surface slag and obtain alloy liquid. Adjust the temperature of the alloy liquid to 780℃ and transfer it into a continuous casting and rolling mill through a flow channel for continuous casting to obtain Al-Ti-B grain refiner. After rolling, Al-Ti5-B1 ​​alloy wire with a diameter of 9.6mm is obtained.

[0047] Example 4 A method for an Al-Ti-B grain refiner includes the following steps: S1. Add 90kg of aluminum ingot to a medium-frequency induction furnace for melting and heat to 750℃. After degassing the aluminum liquid by passing argon through an argon gas pipe (argon pressure is 0.4MPa, and argon passage time is 10min) and removing slag, weigh and mix 13kg of KBF4 and 26kg of K2TiF6 and add them to the aluminum liquid in a one-step feeding method. Stir the melt continuously during the feeding process for 10min. Then raise the temperature of the aluminum liquid to 900℃ and alloy it at 900℃ for 10min. Perform mechanical vibration in the Y direction on the aluminum liquid for 10s at a vibration frequency of 50Hz and an amplitude of 1.0mm. Then evenly sprinkle light calcium carbonate on the surface of the melt for 5mm and remove residual water slag to obtain aluminum melt. S2. Adjust the temperature of the aluminum melt to 750℃. Transfer the aluminum melt into the casting furnace through a flow channel. First, use argon gas to refine and degas the aluminum melt in the casting furnace for 10 minutes (argon gas pressure is 0.4MPa). After degassing, mechanically vibrate the aluminum melt in the Y direction for 10 seconds at a vibration frequency of 50Hz and an amplitude of 1.0mm. After vibration, let it stand for 5 minutes to remove surface slag and obtain alloy liquid. Adjust the temperature of the alloy liquid to 750℃ and transfer it into a continuous casting and rolling mill through a flow channel for continuous casting to obtain Al-Ti-B grain refiner. After rolling, Al-Ti5-B1 ​​alloy wire with a diameter of 9.6mm is obtained.

[0048] Example 5 A method for an Al-Ti-B grain refiner includes the following steps: S1. Add 90kg of aluminum ingot to a medium-frequency induction furnace for melting, heat to 750℃, and degas the aluminum liquid by passing argon through an argon gas pipe (argon pressure is 0.4MPa, argon passage time is 10min). After slag removal, weigh and mix 13kg of KBF4 and 26kg of K2TiF6 and add them to the aluminum liquid in a one-step feeding method, stirring the melt continuously during the feeding process. The feeding time is 10min. Then raise the temperature of the aluminum liquid to 900℃ and alloy it at 900℃ for 10min. Perform X-direction mechanical vibration on the aluminum liquid at a vibration frequency of 50Hz and an amplitude of 1.0mm for 10s. Then evenly sprinkle light calcium carbonate on the surface of the melt for 5mm, remove residual water slag, and obtain aluminum melt. S2. Adjust the temperature of the aluminum melt to 750℃. Transfer the aluminum melt into the casting furnace through a flow channel. First, use argon gas to refine and degas the aluminum melt in the casting furnace for 10 minutes (argon gas pressure is 0.4MPa). After degassing, mechanically vibrate the aluminum melt in the Y direction for 10 seconds at a vibration frequency of 50Hz and an amplitude of 1.0mm. After vibration, let it stand for 5 minutes to remove surface slag and obtain alloy liquid. Adjust the temperature of the alloy liquid to 750℃ and transfer it into a continuous casting and rolling mill through a flow channel for continuous casting to obtain Al-Ti-B grain refiner. After rolling, Al-Ti5-B1 ​​alloy wire with a diameter of 9.6mm is obtained.

[0049] Example 6 A method for an Al-Ti-B grain refiner includes the following steps: S1. Add 90kg of aluminum ingot to a medium-frequency induction furnace for melting, heat to 750℃, and degas the aluminum liquid by passing argon through an argon gas pipe (argon pressure is 0.4MPa, argon passage time is 10min). After slag removal, weigh and mix 13kg of KBF4 and 26kg of K2TiF6 and add them to the aluminum liquid in a one-step feeding method, stirring the melt continuously during the feeding process. The feeding time is 10min. Then, raise the temperature of the aluminum liquid to 900℃ and alloy it at 900℃ for 10min. Then, mechanically vibrate the aluminum liquid in the Z direction for 10s at a vibration frequency of 50Hz and an amplitude of 1.0mm. Afterward, evenly sprinkle light calcium carbonate on the surface of the melt for 5mm, remove residual water slag, and obtain aluminum melt. S2. Adjust the temperature of the aluminum melt to 750℃. Transfer the aluminum melt into the casting furnace through a flow channel. First, use argon gas to refine and degas the aluminum melt in the casting furnace for 10 minutes (argon gas pressure is 0.4MPa). After degassing, mechanically vibrate the aluminum melt in the X direction for 10 seconds at a vibration frequency of 50Hz and an amplitude of 1.0mm. After vibration, let it stand for 5 minutes to remove surface slag and obtain alloy liquid. Adjust the temperature of the alloy liquid to 750℃ and transfer it into a continuous casting and rolling mill through a flow channel for continuous casting to obtain Al-Ti-B grain refiner. After rolling, Al-Ti5-B1 ​​alloy wire with a diameter of 9.6mm is obtained. The optical microstructure of the Al-Ti-B grain refiner prepared in Example 6 is shown in the figure below. Figure 2 As shown.

[0050] Example 7 A method for developing an Al-Ti-B grain refiner includes the following steps: S1. Add 90kg of aluminum ingot to a medium-frequency induction furnace for melting, heat to 750℃, and degas the aluminum liquid by passing argon through an argon gas pipe (argon pressure is 0.4MPa, argon passage time is 10min). After slag removal, weigh and mix 13kg of KBF4 and 26kg of K2TiF6 and add them to the aluminum liquid in a one-step feeding method, stirring the melt continuously during the feeding process. The feeding time is 10min. Then raise the temperature of the aluminum liquid to 900℃ and alloy it at 900℃ for 10min. Perform X-direction mechanical vibration on the aluminum liquid at a vibration frequency of 50Hz and an amplitude of 1.0mm for 10s. Then evenly sprinkle light calcium carbonate on the surface of the melt for 5mm, remove residual water slag, and obtain aluminum melt. S2. Adjust the temperature of the aluminum melt to 750℃. Transfer the aluminum melt into the casting furnace through a flow channel. First, use argon gas to refine and degas the aluminum melt in the casting furnace for 10 minutes (argon gas pressure is 0.4MPa). After degassing, mechanically vibrate the aluminum melt in the Z direction for 10 seconds at a vibration frequency of 50Hz and an amplitude of 1.0mm. After vibration, let it stand for 5 minutes to remove surface slag and obtain alloy liquid. Adjust the temperature of the alloy liquid to 750℃ and transfer it into a continuous casting and rolling mill through a flow channel for continuous casting to obtain Al-Ti-B grain refiner. After rolling, Al-Ti5-B1 ​​alloy wire with a diameter of 9.6mm is obtained. The optical microstructure of the Al-Ti-B grain refiner prepared in Example 7 is shown in the figure below. Figure 3 As shown.

[0051] Example 8 A method for developing an Al-Ti-B grain refiner includes the following steps: S1. Add 90kg of aluminum ingot to a medium-frequency induction furnace for melting, heat to 750℃, and degas the aluminum liquid by passing argon through an argon gas pipe (argon pressure is 0.4MPa, argon passage time is 10min). After slag removal, weigh and mix 13kg of KBF4 and 26kg of K2TiF6 and add them to the aluminum liquid in a one-step feeding method, stirring the melt continuously during the feeding process. The feeding time is 10min. Then, raise the temperature of the aluminum liquid to 900℃ and alloy it at 900℃ for 10min. Then, mechanically vibrate the aluminum liquid in the Z direction for 10s at a vibration frequency of 50Hz and an amplitude of 1.0mm. Afterward, evenly sprinkle light calcium carbonate on the surface of the melt for 5mm, remove residual water slag, and obtain aluminum melt. S2. Adjust the temperature of the aluminum melt to 750℃. Transfer the aluminum melt into the casting furnace through a flow channel. First, use argon gas to refine and degas the aluminum melt in the casting furnace for 10 minutes (argon gas pressure is 0.4MPa). After degassing, mechanically vibrate the aluminum melt in the Z direction for 10 seconds at a vibration frequency of 50Hz and an amplitude of 1.0mm. After vibration, let it stand for 5 minutes to remove surface slag and obtain alloy liquid. Adjust the temperature of the alloy liquid to 750℃ and transfer it into a continuous casting and rolling mill through a flow channel for continuous casting to obtain Al-Ti-B grain refiner. After rolling, Al-Ti5-B1 ​​alloy wire with a diameter of 9.6mm is obtained. The optical microstructure of the Al-Ti-B grain refiner prepared in Example 8 is shown in the figure below. Figure 4 As shown.

[0052] Example 9 A method for an Al-Ti-B grain refiner includes the following steps: S1. Add 90kg of aluminum ingot to a medium-frequency induction furnace for melting, heat to 750℃, and degas the aluminum liquid by passing argon through an argon gas pipe (argon pressure is 0.4MPa, argon passage time is 10min). After slag removal, weigh and mix 13kg of KBF4 and 26kg of K2TiF6 and add them to the aluminum liquid in a one-step feeding method, stirring the melt continuously during the feeding process. The feeding time is 10min. Then raise the temperature of the aluminum liquid to 900℃ and alloy it at 900℃ for 10min. Perform X-direction mechanical vibration on the aluminum liquid at a vibration frequency of 50Hz and an amplitude of 1.0mm for 10s. Then evenly sprinkle light calcium carbonate on the surface of the melt for 5mm, remove residual water slag, and obtain aluminum melt. S2. Adjust the temperature of the aluminum melt to 750℃. Transfer the aluminum melt into the casting furnace through a flow channel. First, use argon gas to refine and degas the aluminum melt in the casting furnace for 10 minutes (argon gas pressure is 0.4MPa). After degassing, ultrasonically treat the aluminum melt at a frequency of 20kHz for 10 minutes. After ultrasonic treatment, let it stand for 5 minutes to remove surface slag and obtain alloy liquid. Adjust the temperature of the alloy liquid to 750℃ and transfer it into a continuous casting and rolling mill through a flow channel for continuous casting to obtain Al-Ti-B grain refiner. After rolling, Al-Ti5-B1 ​​alloy wire with a diameter of 9.6mm is obtained.

[0053] Example 10 A method for an Al-Ti-B grain refiner includes the following steps: S1. Add 90kg of aluminum ingot to a medium-frequency induction furnace for melting, heat to 750℃, and degas the aluminum liquid by passing argon through an argon gas pipe (argon pressure is 0.4MPa, argon passage time is 10min). After slag removal, weigh and mix 13kg of KBF4 and 26kg of K2TiF6 and add them to the aluminum liquid in a one-step feeding method, stirring the melt continuously during the feeding process for 10min. Then raise the temperature of the aluminum liquid to 900℃ and alloy it at 900℃ for 10min. Ultrasonically treat the aluminum liquid at a frequency of 20kHz for 10min. Then evenly sprinkle light calcium carbonate on the surface of the melt for 5mm, remove residual water slag, and obtain aluminum melt. S2. Adjust the temperature of the aluminum melt to 750℃. Transfer the aluminum melt to the casting furnace through a flow channel. First, use argon gas to refine and degas the aluminum melt in the casting furnace for 10 minutes (argon gas pressure is 0.4MPa). After degassing, mechanically vibrate the aluminum melt in the X direction for 10 seconds at a vibration frequency of 50Hz and an amplitude of 1.0mm. After vibration, let it stand for 5 minutes to remove surface slag and obtain alloy liquid. Adjust the temperature of the alloy liquid to 750℃ and transfer it to a continuous casting and rolling mill through a flow channel for continuous casting to obtain Al-Ti-B grain refiner. After rolling, Al-Ti5-B1 ​​alloy wire with a diameter of 9.6mm is obtained.

[0054] Comparative Example 1 A method for an Al-Ti-B grain refiner includes the following steps: S1. Add 90kg of aluminum ingot to a medium-frequency induction furnace for melting, heat to 750℃, and degas the aluminum liquid through an argon gas pipe (argon pressure is 0.4MPa, argon time is 10min). After slag removal, weigh and mix 13kg of KBF4 and 26kg of K2TiF6 and add them to the aluminum liquid in a one-step feeding method, stirring the melt continuously during the feeding process. The feeding time is 10min. Then raise the temperature of the aluminum liquid to 900℃ and alloy at 900℃ for 10min. Then evenly sprinkle light calcium carbonate on the surface of the melt for 5mm, remove residual water slag, and obtain aluminum melt. S2. Adjust the temperature of the aluminum melt to 750℃. Transfer the aluminum melt to the casting furnace through a flow channel. First, use argon gas to refine and degas the aluminum melt in the casting furnace for 10 minutes (argon gas pressure is 0.4MPa). After degassing, mechanically vibrate the aluminum melt in the X direction for 10 seconds at a vibration frequency of 50Hz and an amplitude of 1.0mm. After vibration, let it stand for 5 minutes to remove surface slag and obtain alloy liquid. Adjust the temperature of the alloy liquid to 750℃ and transfer it to a continuous casting and rolling mill through a flow channel for continuous casting to obtain Al-Ti-B grain refiner. After rolling, Al-Ti5-B1 ​​alloy wire with a diameter of 9.6mm is obtained.

[0055] Comparative Example 2 A method for an Al-Ti-B grain refiner includes the following steps: S1. Add 90kg of aluminum ingot to a medium-frequency induction furnace for melting, heat to 750℃, and degas the aluminum liquid by passing argon through an argon gas pipe (argon pressure is 0.4MPa, argon passage time is 10min). After slag removal, weigh and mix 13kg of KBF4 and 26kg of K2TiF6 and add them to the aluminum liquid in a one-step feeding method, stirring the melt continuously during the feeding process. The feeding time is 10min. Then raise the temperature of the aluminum liquid to 900℃ and alloy it at 900℃ for 10min. Perform X-direction mechanical vibration on the aluminum liquid at a vibration frequency of 50Hz and an amplitude of 1.0mm for 10s. Then evenly sprinkle light calcium carbonate on the surface of the melt for 5mm, remove residual water slag, and obtain aluminum melt. S2. Adjust the temperature of the aluminum melt to 750℃. Transfer the aluminum melt into the casting furnace through the ladle. First, use argon gas to refine and degas the aluminum melt in the casting furnace for 10 minutes (argon gas pressure is 0.4MPa). After degassing, let it stand for 5 minutes to remove surface slag and obtain alloy liquid. Adjust the temperature of the alloy liquid to 750℃ and transfer it into the continuous casting and rolling mill through the ladle for continuous casting to obtain Al-Ti-B grain refiner. After rolling, Al-Ti5-B1 ​​alloy wire with a diameter of 9.6mm is obtained.

[0056] Comparative Example 3 A method for an Al-Ti-B grain refiner includes the following steps: S1. Add 90kg of aluminum ingot to a medium-frequency induction furnace for melting, heat to 750℃, and degas the aluminum liquid through an argon gas pipe (argon pressure is 0.4MPa, argon time is 10min). After slag removal, weigh and mix 13kg of KBF4 and 26kg of K2TiF6 and add them to the aluminum liquid in a one-step feeding method, stirring the melt continuously during the feeding process. The feeding time is 10min. Then raise the temperature of the aluminum liquid to 900℃ and alloy at 900℃ for 10min. Then evenly sprinkle light calcium carbonate on the surface of the melt for 5mm, remove residual water slag, and obtain aluminum melt. S2. Adjust the temperature of the aluminum melt to 750℃. Transfer the aluminum melt into the casting furnace through the ladle. First, use argon gas to refine and degas the aluminum melt in the casting furnace for 10 minutes (argon gas pressure is 0.4MPa). After degassing, let it stand for 5 minutes to remove surface slag and obtain alloy liquid. Adjust the temperature of the alloy liquid to 750℃ and transfer it into the continuous casting and rolling mill through the ladle for continuous casting to obtain Al-Ti-B grain refiner. After rolling, Al-Ti5-B1 ​​alloy wire with a diameter of 9.6mm is obtained.

[0057] Experimental Example 1 The Al-Ti-B grain refiners prepared in Examples 1-10 and Comparative Examples 1-3 were added to pure aluminum (the mass fraction of Al-Ti-B grain refiner was 0.2%), cast into standard conical specimens, and the specimen molds were cooled by circulating water cooling. The average grain size of the specimens was detected by the line intercept method to evaluate the refining ability of the Al-Ti-B grain refiner. The test results are shown in Table 1.

[0058] Table 1. Average grain size of aluminum alloy samples with Al-Ti-B grain refiner added.

[0059] Compared with Comparative Examples 1-3, when the Al-Ti-B grain refiner prepared in Examples 1-5 was added to pure aluminum, the average grain size of the resulting aluminum alloy sample was significantly reduced. This indicates that in the preparation of the Al-Ti-B grain refiner, using both a first and a second mechanical vibration, and ensuring that the vibration directions of the two mechanical vibrations are in the X or Y direction, can improve the grain refiner's refining ability.

[0060] In addition, in Example 9, the second mechanical vibration in the X direction was changed to ultrasonic treatment during the Al-Ti-B grain refiner process, and in Example 10, the first mechanical vibration in the X direction was changed to ultrasonic treatment. Ultrasonic treatment has a small range of effect on the internal structure of the refiner, and can only disperse in the local area of ​​the ultrasonic probe, which is not conducive to the formation of a uniform and effective grain refiner phase. Compared with Examples 9-10, the average grain size of the aluminum alloy samples in Examples 1-5 was reduced. This shows that in the preparation of Al-Ti-B grain refiner, using the first and second mechanical vibrations together, and making the vibration directions of the two mechanical vibrations in the X or Y direction, can improve the refining ability of Al-Ti-B grain refiner.

[0061] Experimental Example 2 The Al-Ti-B grain refiners prepared in Examples 1-10 and Comparative Examples 1-3 were added to Al-4.5Cu-1.5Mg alloy (the mass fraction of Al-Ti-B grain refiner was 0.3%), and cast into standard conical specimens. The friction coefficient was tested according to the method in GB / T 12444-2006 "Metallic Materials Wear Test Methods - Test Ring-Block Sliding Wear Test". The test results are shown in Table 2.

[0062] Table 2. Test results of friction coefficient of aluminum alloy samples with added Al-Ti-B grain refiner.

[0063] Compared with Comparative Examples 1-3, when the Al-Ti-B grain refiner prepared in Examples 1-5 was added to the aluminum alloy sample, the average friction coefficient decreased. This indicates that in the preparation of the Al-Ti-B grain refiner, using both the first and second mechanical vibrations and making the vibration directions of the two mechanical vibrations in the X or Y direction can not only improve the refining ability of the Al-Ti-B grain refiner, but also improve the wear resistance of the final alloy.

[0064] Experimental Example 3 The Al-Ti-B grain refiners prepared in Examples 1 and 6-8 were added to pure aluminum (the mass fraction of the Al-Ti-B grain refiner was 0.2%). Cooling curve analysis was used to plot the phase transformation process of the aluminum alloy materials with the added Al-Ti-B grain refiner. Figure 6 As shown.

[0065] Figure 6 In the examples, Example 1 is the cooling curve of Example 1, Example 2 is the cooling curve of Example 8, Example 3 is the cooling curve of Example 7, and Example 4 is the cooling curve of Example 6. Figure 6In this context, ΔT represents the degree of supercooling, which is the difference between the theoretical crystallization temperature and the actual nucleation temperature. Figure 6 As can be seen from the data, compared with Examples 6 to 8, Example 1 has the smallest undercooling ΔT and the strongest grain refinement ability. This indicates that using a first mechanical vibration and a second mechanical vibration, and making the vibration directions of the two mechanical vibrations in the X or Y direction, can improve the grain refinement ability of the Al-Ti-B grain refiner.

[0066] Experiment Example 4 The optical microstructure of the Al-Ti-B grain refiner prepared in Example 1 is shown in the figure below. Figure 1 As shown, the optical microstructure of the Al-Ti-B grain refiner prepared in Example 6 is illustrated in the figure below. Figure 2 As shown, the optical microstructure of the Al-Ti-B grain refiner prepared in Example 7 is illustrated in the figure below. Figure 3 As shown, the optical microstructure of the Al-Ti-B grain refiner prepared in Example 8 is illustrated in the figure below. Figure 4 As shown. In the Al-Ti-B grain refiners prepared in Examples 6 and 7, the TiAl3 and TiB2 particles were unevenly distributed in the core area, with blank strips present. In the Al-Ti-B grain refiner prepared in Example 8, oxide and salt inclusions were present. The Al-Ti-B grain refiner prepared in Example 1 had the most uniform microstructure and the fewest oxide and salt inclusions. This indicates that using a first and second mechanical vibration during the preparation of the Al-Ti-B grain refiner, with the vibration directions of the two mechanical vibrations in the X or Y direction, can improve the grain refiner's refining ability.

[0067] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing an Al-Ti-B grain refiner, characterized in that, Includes the following steps: S1. Fluoroborate and fluorotitanate are added to the aluminum melt, alloyed, and slag is removed to obtain the aluminum melt. During the alloying process, TiB2 and TiAl3 are generated. A first mechanical vibration treatment is then applied to refine and disperse the TiB2 and TiAl3. S2. After refining and degassing the aluminum melt, it undergoes a second mechanical vibration treatment to remove slag and is then continuously cast to obtain the Al-Ti-B grain refiner. The second mechanical vibration treatment is used to refine and disperse the TiB2 and TiAl3 after the first mechanical vibration treatment to form a TiAl3-coated TiB2 structure. The vibration directions of the first mechanical vibration and the second mechanical vibration are each independently one of the X direction and the Y direction; Wherein, the X direction is the horizontal left-right direction and the Y direction is the horizontal front-back direction.

2. The method for preparing an Al-Ti-B grain refiner according to claim 1, characterized in that, The vibration frequency of the first mechanical vibration treatment is 40~60Hz, the amplitude is 0.8~1.2mm, and the vibration time is 5~180s; The vibration frequency of the second mechanical vibration treatment is 40~60Hz, the amplitude is 0.8~1.2mm, and the vibration time is 5~180s.

3. The method for preparing an Al-Ti-B grain refiner according to claim 1, characterized in that, The amount of fluoroborate added is 30% to 50% of the total mass of the fluoroborate and the fluorotitanate.

4. The method for preparing an Al-Ti-B grain refiner according to claim 1, characterized in that, The mass ratio of the fluoroborate and the fluorotitanate to the molten aluminum is 3~6:

10.

5. The method for preparing an Al-Ti-B grain refiner according to claim 1, characterized in that, The fluoroborate and fluorotitanate are added either in one step or in stages. When adding fluoroborate and fluorotitanate, add them while stirring, and the total addition time is 5~30 minutes.

6. The method for preparing an Al-Ti-B grain refiner according to claim 1, characterized in that, In step S1, the alloying treatment is carried out at a temperature of 700~900℃ for 10~60 minutes.

7. The method for preparing an Al-Ti-B grain refiner according to claim 1, characterized in that, In step S1, before adding fluoroborate and fluorotitanate to the molten aluminum, the molten aluminum is heated to 700~800℃ to degas and remove slag.

8. The method for preparing an Al-Ti-B grain refiner according to claim 1, characterized in that, In step S1, during slag removal, light calcium carbonate is sprinkled 5-10 mm onto the surface of the alloyed melt.

9. The method for preparing an Al-Ti-B grain refiner according to claim 1, characterized in that, In step S2, during the refining and degassing process, argon gas is introduced at a pressure of 0.1~0.5MPa for a duration of 5~15min.

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