Aluminum and aluminum alloy grain refiner and preparation and use method thereof

Abstract

The invention discloses an aluminum and aluminum alloy grain refiner and a preparation and use method thereof, and belongs to the technical field of aluminum and aluminum alloy production. The grain refiner is composed of titanium powder, KBF4 and aluminum powder, during preparation, all the raw materials are evenly mixed according to the formula proportion, the evenly-mixed materials are pressed and formed through a granulator under the forming pressure of 15 MPa to 25 MPa, and then particles of 0.5 mm to 3.0 mm are prepared through a crusher. When in use, the grain refiner is added into molten aluminum, so that the grain refiner is uniformly dispersed, the temperature of the molten aluminum reaches 730-780 DEG C, the refinement time is 10-20 minutes within the addition temperature range, stirring is performed once every 4-6 minutes, and pouring is performed at the temperature range of 670-710 DEG C. The titanium element content of the prepared grain refiner can reach 15%-65%, the grain refinement effect is good, the preparation method is simple and efficient, the technological process is short, high-temperature reaction or melting is not needed, energy consumption is low, fluorine-containing gas emission is not generated, the environmental protection risk is extremely low, the use method is convenient, and the application and popularization value is extremely high.

Description

Technical Field

[0001] The invention belongs to the technical field of aluminum and aluminum alloy production, and specifically relates to an aluminum and aluminum alloy grain refiner and a preparation and use method thereof. Background Art

[0002] Aluminum and aluminum alloys have a wide range of uses. In the production of aluminum and aluminum alloys, adding grain refiners is an important way to improve their organizational properties. At present, there are many types of grain refiners used in aluminum alloy production, and the most widely used are Al-5Ti-1B and Al-5Ti-0.2B, both of which have relatively high production technology thresholds. Compared with well-known foreign brand products, domestic products still have obvious gaps in the control of TiAl3 and TiB2 particle size, shape, dispersibility and inclusions. Therefore, when producing high-quality alloy products, most of them use products from companies such as KBM in the Netherlands and AMG in the United States.

[0003] The existing Al-Ti-B grain refiner preparation process is to add potassium fluorotitanate and potassium fluoroborate to aluminum liquid at 800℃~850℃, and the aluminum liquid reacts with potassium fluorotitanate and potassium fluoroborate at a high temperature of 900℃~1000℃ to generate TiAl3 and TiB2, and remove impurities in the alloy melt through special smelting and purification processes, and form under strict casting process conditions, so as to achieve precise control of the shape, size and distribution of TiAl3 and TiB2 particles. The present invention aims at the problems of large aluminum liquid burnout, large amount of fluorine-containing smoke, complex production process and low titanium content in the preparation of the existing Al-Ti-B grain refiner, and provides a new grain refiner formula and its preparation and use method. Summary of the invention

[0004] The first object of the present invention is to provide a grain refiner for aluminum and aluminum alloys; the second object of the present invention is to provide a method for preparing the grain refiner; and the third object of the present invention is to provide a method for using the grain refiner.

[0005] The first object of the present invention is achieved in that the grain refiner consists of titanium powder, KBF4 and aluminum powder, the mass percentage of titanium powder is 15% to 65%, the mass percentage of KBF4 is 25% to 75%, the mass percentage of aluminum powder is 2% to 15%, and the sum of titanium powder, KBF4 and aluminum powder is 100%.

[0006] The second object of the present invention is achieved as follows: the preparation method of the grain refiner comprises the following steps: mixing the raw materials according to the formula ratio evenly, passing the mixed material through a granulator, pressing and molding at a molding pressure of 15MPa~25MPa, and then using a crusher to obtain particles of 0.5mm~3.0mm.

[0007] The third object of the present invention is achieved as follows: the method for using the grain refiner is as follows: when using, the grain refiner is added into aluminum or aluminum alloy melt (hereinafter referred to as aluminum liquid), the aluminum liquid temperature needs to reach 730°C~780°C, so that it is evenly dispersed, the refinement time within the addition temperature range is 10min~20min, stirring is performed every 4min~6min, and pouring is performed at a temperature range of 670°C~710°C.

[0008] Compared with the prior art, the technical solution of the present invention has the following outstanding features and beneficial effects: the titanium content in the prepared grain refiner can reach 15%~65%, which is 3 times~13 times higher than the existing Al-5Ti-1B grain refiner. The preparation method is simple and efficient, with a short process flow, no high-temperature reaction or melting required, which greatly reduces energy consumption, and the preparation process does not produce fluorine-containing gas emissions, with extremely low environmental risks. The prepared grain refiner is easy to use and requires a small amount, which is beneficial for enterprises to reduce costs and increase efficiency. During the production of aluminum alloys, after adding according to the method of use, the grain refining effect is good, and the comparative effect is shown in the attached figure. Figures 1 to 5 As shown in the figure, the refining effect of Al-5Ti-1B wire with titanium content in the range of 0.02% to 0.03% is significantly better than that of TiB refining agent. Figure 1 , Attachment Figure 4 , Attachment Figure 5 When the titanium content is greater than 0.03%, the refining effect of Al-5Ti-1B wire is not obvious, while the refining effect of TiB refiner is more obvious. When the titanium content reaches more than 0.05%, the refining effect of TiB refiner can achieve the same effect as Al-5Ti-1B wire. Figure 2 , Attachment Figure 3 From the perspective of refinement mechanism, the effect of Al-Ti-B grain refiner depends on the shape, size and dispersion of TiAl3 and TiB2 particles, while the effect of TiB grain refiner mainly depends on the Ti content and the uniformity of the distribution of Ti and B elements in the aluminum liquid. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 This is a diagram showing the refinement effect of the aluminum alloy after adding the grain refiner prepared in Example 1; Figure 2 This is a diagram showing the refinement effect of the aluminum alloy after adding the grain refiner prepared in Example 2; Figure 3 This is a diagram showing the refinement effect of the aluminum alloy after adding the grain refiner prepared in Example 3; Figure 4 This is the refinement effect of aluminum alloy after adding imported Al-5Ti-1B refiner; Figure 5This is the refinement effect of aluminum alloy after adding the purchased domestic Al-5Ti-1B refiner. DETAILED DESCRIPTION

[0010] The present invention is further described below, but the present invention is not limited in any way. Any changes or substitutions made based on the teachings of the present invention belong to the protection scope of the present invention.

[0011] The grain refiner consists of titanium powder, KBF4 and aluminum powder, the mass percentage of titanium powder is 15% to 65%, the mass percentage of KBF4 is 25% to 75%, the mass percentage of aluminum powder is 2% to 15%, and the sum of titanium powder, KBF4 and aluminum powder is 100%.

[0012] The titanium powder is hydrogenated dehydrogenated titanium powder with a particle size of 0.05 mm to 0.15 mm.

[0013] The particle size of the aluminum powder is 0.020 mm to 0.045 mm.

[0014] The grain refiner does not contain sodium element, and the titanium element content is 15% to 65%.

[0015] The grain refiner is prepared by the following steps: The raw materials according to the formula ratio are mixed evenly, the mixed materials are passed through a granulator, pressed into shape at a molding pressure of 15-25 MPa, and then a crusher is used to obtain particles of 0.5 mm-3.0 mm.

[0016] The preparation method of the grain refiner comprises the following steps: uniformly mixing the raw materials according to the formula ratio, passing the uniformly mixed materials through a granulator, pressing and molding at a molding pressure of 15MPa-25MPa, and then using a crusher to obtain particles of 0.5mm-3.0mm.

[0017] The method for using the grain refiner is as follows: when using, the grain refiner is added into aluminum liquid, the temperature of the aluminum liquid needs to reach 730°C to 780°C, so that it is evenly dispersed, the refinement time within the addition temperature range is 10min to 20min, stirring is performed every 4min to 6min, and pouring is performed at a temperature range of 670°C to 710°C.

[0018] The addition ratio of the grain refiner is 0.020% to 0.080% of the material mass.

[0019] Example 1 The grain refiner is composed of hydrogenated dehydrogenated titanium powder with a particle size of 0.05mm-0.10mm, KBF4 and ultrafine aluminum powder with a particle size of 0.020mm-0.035mm, the mass percentage of titanium powder is 40%, the mass percentage of KBF4 is 50%, and the mass percentage of aluminum powder is 10%.

[0020] During preparation, the raw materials are mixed evenly according to the formula ratio, and the mixed materials are passed through a granulator, pressed under a molding pressure of 20MPa, and then crushed to obtain particles of 0.5mm~3.0mm. The titanium content in the prepared grain refiner is 40%.

[0021] When in use, add the grain refiner into the aluminum liquid at a mass ratio of 0.035%. The aluminum liquid temperature is 780℃, and the temperature is controlled at 730~760℃ for 15 minutes. Stir every 5 minutes and pour at 710℃.

[0022] Example 2 The grain refiner is composed of hydrogenated dehydrogenated titanium powder with a particle size of 0.10mm-0.15mm, KBF4 and ultrafine aluminum powder with a particle size of 0.025mm-0.040mm, the mass percentage of titanium powder is 60%, the mass percentage of KBF4 is 25%, and the mass percentage of aluminum powder is 15%.

[0023] During preparation, the raw materials are mixed evenly according to the formula ratio, and the mixed materials are passed through a granulator, pressed under a molding pressure of 25MPa, and then crushed to obtain particles of 0.5mm~3.0mm. The titanium content in the prepared grain refiner is 60%.

[0024] When in use, add the grain refiner into the aluminum liquid at a mass ratio of 0.05%. The temperature of the aluminum liquid is 760℃, and the temperature is controlled at 745~760℃ for 20 minutes. Stir every 4 minutes and pour at 695℃.

[0025] Example 3 The grain refiner is composed of hydrogenated dehydrogenated titanium powder with a particle size of 0.05mm-0.15mm, KBF4 and ultrafine aluminum powder with a particle size of 0.030mm-0.045mm, the mass percentage of titanium powder is 20%, the mass percentage of KBF4 is 75%, and the mass percentage of aluminum powder is 5%.

[0026] During preparation, the raw materials are mixed evenly according to the formula ratio, the mixed materials are passed through a granulator, pressed under a molding pressure of 15MPa, and then crushed to obtain particles of 0.5mm~3.0mm. The titanium content in the prepared grain refiner is 20%.

[0027] When in use, add the grain refiner into the aluminum liquid at a mass ratio of 0.08%. The aluminum liquid temperature is 760℃, and the temperature is controlled at 730~750℃, maintained for 10 minutes, stirred every 6 minutes, and poured at 690℃.

[0028] Example 4 The grain refiners prepared in Examples 1 to 3, imported Al-5Ti-1B refiners, and domestically purchased Al-5Ti-1B refiners were used in aluminum alloy production at the same addition amounts and addition conditions. The results are shown in the following table and the accompanying drawings.

[0029] Table 1 .

Claims

1. A grain refiner for aluminum and aluminum alloys, characterized in that The grain refiner consists of titanium powder, KBF4 and aluminum powder, the mass percentage of titanium powder is 15% to 65%, the mass percentage of KBF4 is 25% to 75%, the mass percentage of aluminum powder is 2% to 15%, and the sum of titanium powder, KBF4 and aluminum powder is 100%.

2. The grain refiner according to claim 1, characterized in that The titanium powder is hydrogenated dehydrogenated titanium powder with a particle size of 0.05 mm to 0.15 mm.

3. The grain refiner according to claim 1, characterized in that The particle size of the aluminum powder is 0.020 mm to 0.045 mm.

4. The grain refiner according to claim 1, characterized in that The grain refiner does not contain sodium element.

5. The grain refiner according to claim 1, characterized in that The titanium content in the grain refiner is 15% to 65%.

6. The grain refiner according to claim 1, characterized in that The grain refiner is prepared by the following steps: The raw materials according to the formula ratio are mixed evenly, the mixed materials are passed through a granulator, pressed into shape at a molding pressure of 15MPa~25MPa, and then a crusher is used to obtain particles of 0.5mm~3.0mm.

7. A method for preparing the grain refiner according to any one of claims 1 to 5, characterized in that Including the following processes: The raw materials according to the formula ratio are mixed evenly, the mixed materials are passed through a granulator, pressed into shape at a molding pressure of 15MPa~25MPa, and then a crusher is used to obtain particles of 0.5mm~3.0mm.

8. A method for using the grain refiner according to any one of claims 1 to 6, characterized in that When using, add the grain refiner to the aluminum liquid. The temperature of the aluminum liquid needs to reach 730℃~780℃ to make it evenly dispersed. The refinement time within this addition temperature range is 10min~20min, stir every 4min~6min, and pour at a temperature range of 670℃~710℃.

9. The method for using the grain refiner according to claim 8, characterized in that The addition ratio of the grain refiner is 0.020% to 0.080% of the material mass.

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