TiB-Re aluminum and aluminum alloy grain refiner and preparation and use method thereof

Abstract

The invention discloses a TiB-Re aluminum and aluminum alloy grain refiner and a preparation and use method thereof, and belongs to the technical field of aluminum alloy production. The grain refiner is composed of titanium powder, KBF4 and Re powder, and 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 15-25 MPa, and then particles of 0.5-3.0 mm are prepared through a crusher. When in use, the grain refiner is added into an aluminum or aluminum alloy melt (molten aluminum for short), so that the grain refiner is uniformly dispersed, the temperature of the molten aluminum needs to reach 730-760 DEG C, the refinement time in the temperature range is 10-20 minutes, stirring is performed once every 4-6 minutes, and the pouring temperature is 670-710 DEG C. The titanium element content of the prepared grain refiner can reach 15%-65%, and the grain refiner is small in adding and using amount, good in grain refinement effect, simple in production process, free of high-temperature reaction or melting, low in energy consumption, free of fluorine-containing gas emission, extremely low in environmental protection risk and convenient to use.

Description

Technical Field

[0001] The invention belongs to the technical field of aluminum alloy production, and specifically relates to a TiB-Re 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 800℃~850℃ 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 accurate 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 TiB-Re master alloy 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 TiB-Re aluminum and aluminum alloy grain refiner; the second object is to provide a preparation method of the grain refiner; and the third object 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 Re powder, the mass percentage of titanium powder is 15% to 65%, the mass percentage of KBF4 is 25% to 75%, the mass percentage of Re powder is 0.1% to 5.0%, and the sum of titanium powder, KBF4 and Re 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 characterized in that the grain refiner is added into aluminum or aluminum alloy melt (hereinafter referred to as aluminum liquid) to make it evenly dispersed, the aluminum liquid temperature needs to reach 730°C~760°C, the refinement time within this temperature range is 10min~20min, stirring is performed every 4min~6min, and the pouring temperature is 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 0.020% to 0.030% is significantly better than that of TiB and TiB-Re. When the titanium content is greater than 0.03%, the refining effect of Al-5Ti-1B wire is not significantly increased, while the refining effect of TiB and TiB-Re can achieve the same effect as Al-5Ti-1B wire. Figure 2 , Attachment Figure 3 , Attachment Figure 4 As shown in the figure, the addition of rare earth elements such as La, Ce, and Pr is beneficial to improving the refinement effect of TiB. Figure 1 and attached Figure 5 When the titanium element is added in an amount of 0.025%, the grain size of pure aluminum refined by TiB-Re is significantly smaller and the refining effect is better. At the same time, adding trace amounts of rare earth elements is also beneficial to purifying the aluminum melt and reducing the gas content and oxide inclusions. 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 the refinement effect of aluminum alloy after adding imported Al-5Ti-1B refiner; Figure 4 This is the refinement effect of aluminum alloy after adding the purchased domestic Al-5Ti-1B refiner; Figure 5This is the refinement effect of aluminum alloy after adding TiB. 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 Re powder, the mass percentage of titanium powder is 15% to 65%, the mass percentage of KBF4 is 25% to 75%, the mass percentage of Re powder is 0.1% to 5.0%, and the sum of titanium powder, KBF4 and Re powder is 100%.

[0012] The titanium powder is hydrogenated dehydrogenated titanium powder with a particle size of 0.020 mm to 0.080 mm.

[0013] The Re powder is a mixture of one or more salts of La, Ce and Pr. Preferably, the mass percentage of the mixed salt of La and Ce is 2.5% to 5.0%, and the mass percentage of the mixed salt of La, Ce and Pr is 0.1% to 3.0%.

[0014] The titanium content in the grain refiner 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 and molded at a molding pressure of 15% to 25 MPa, and then a crusher is used to obtain particles of 0.5 mm to 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 or aluminum alloy melt (hereinafter referred to as aluminum liquid) to make it evenly dispersed. The temperature of the aluminum liquid needs to reach 730°C to 760°C. The refinement time within this temperature range is 10min to 20min, and the grain refiner is stirred every 4min to 6min. The pouring temperature is 670°C to 710°C.

[0018] The titanium content of the grain refiner is 0.02% to 0.08% of the total material mass.

[0019] Example 1

[0020] The grain refiner is composed of hydrogenated dehydrogenated titanium powder with a particle size of 0.020 mm to 0.080 mm, KBF4 and dry rare earth Pr salt, the mass percentage of the titanium powder is 40%, the mass percentage of KBF4 is 59%, and the mass percentage of the Pr salt is 1%.

[0021] During preparation, the raw materials are mixed evenly according to the formula ratio, and the mixed materials are passed through a granulator, pressed and molded at a molding pressure of 15MPa~25MPa, and then crushed to obtain particles of 0.5mm~3.0mm. The titanium content in the prepared grain refiner is 15%~65%.

[0022] When in use, add the grain refiner into the aluminum liquid at a titanium content of 0.025% of the total material volume. The aluminum liquid temperature is 745°C, and the temperature is controlled at 740°C~750°C, maintained for 10 minutes, stirred every 4 minutes, and poured at 700°C.

[0023] Example 2

[0024] The grain refiner is composed of hydrogenated dehydrogenated titanium powder with a particle size of 0.020mm-0.080mm, KBF4 and Re powder, and the Re powder is composed of 40%-60% La salt and 40%-60% Ce salt. The mass percentage of titanium powder is 60%, the mass percentage of KBF4 is 35%, and the mass percentage of Re powder is 5%.

[0025] During preparation, the raw materials are mixed evenly according to the formula ratio, and the mixed materials are passed through a granulator, pressed and molded at a molding pressure of 15MPa~25MPa, and then crushed to obtain 0.5~3.0mm particles. The titanium content in the prepared grain refiner is 15%~65%.

[0026] When in use, add the grain refiner into the aluminum liquid at a titanium content of 0.035% of the total material volume. The aluminum liquid temperature is 755°C, and the temperature is controlled at 730°C~755°C, maintained for 20 minutes, stirred every 6 minutes, and poured at 710°C.

[0027] Example 3

[0028] The grain refiner is composed of hydrogenated dehydrogenated titanium powder with a particle size of 0.020mm~0.080mm, KBF4 and Re powder, and the Re powder is composed of 35%~45% La salt, 35%~45% Ce salt and 10%~15% Pr. The mass percentage of titanium powder is 43%, the mass percentage of KBF4 is 55%, and the mass percentage of Re powder is 2%.

[0029] 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 of the prepared grain refiner is 43%.

[0030] When in use, 0.055% of the titanium content of the total material is added to the aluminum liquid. The temperature of the aluminum liquid is 735℃, and the temperature is controlled at 735℃~745℃, maintained for 15 minutes, stirred every 5 minutes, and poured at 690℃.

[0031] Example 4

[0032] The grain refiner prepared in Examples 1-2, imported Al-5Ti-1B refiner, domestically purchased Al-5Ti-1B refiner, and TiB were used in aluminum alloy production with the same addition amount and addition conditions. The results are shown in the following table and the accompanying drawings.

[0033] Table 1 .

Claims

1. A TiB-Re aluminum and aluminum alloy grain refiner, characterized in that The grain refiner consists of titanium powder, KBF4 and Re powder, the mass percentage of titanium powder is 15% to 65%, the mass percentage of KBF4 is 25% to 75%, the mass percentage of Re powder is 0.1% to 5%, and the sum of titanium powder, KBF4 and Re 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 0.020 mm to 0.080 mm.

3. The grain refiner according to claim 1, characterized in that The Re powder is a mixture of one or more salts of La, Ce and Pr.

4. The grain refiner according to claim 1, characterized in that The Re powder is a mixture of one or more salts of La, Ce, and Pr, and the preferred formula is: the mass percentage of the mixed salt of La and Ce is 2.5%~5.0%, and the mass percentage of the mixed salt of La, Ce, and Pr is 0.1%~3.0%.

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, and the mixed materials are passed through a granulator, pressed and molded 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, and the mixed materials are passed through a granulator, pressed and molded 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 into the aluminum liquid to make it evenly dispersed. The aluminum liquid temperature needs to reach 730℃~760℃. The refinement time within this temperature range is 10min~20min, stirring every 4~6min, and the pouring temperature is 670℃~710℃.

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

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