An aluminum-titanium-boron composite additive and its preparation method

Abstract

This invention relates to the field of alloy smelting and discloses an aluminum-titanium-boron composite additive and its preparation method. The aluminum-titanium-boron additive comprises the following raw materials by mass percentage: 10-30% boron salt, 30-60% TiO2 powder, 0.5-2.5% surfactant, 0.1-2.8% flux, and the balance being aluminum powder. The boron salt and TiO2 powder are gradient-mixed, with the following particle size gradient range and proportions: 80-150 mesh 15-25%, 150-300 mesh 10-15%, 300-350 mesh 25-30%, 350-500 mesh 15-30%, and the balance being particles ≥500 mesh. The aluminum-titanium-boron additive prepared by this invention has a low metal melting temperature, short melting time, and high additive recovery rate. Applying the aluminum-titanium-boron additive prepared by this technical solution to the preparation of aluminum alloys can ensure the corrosion resistance, wear resistance, hardness, and fatigue strength of the aluminum alloys, and can also improve the grain refinement of the alloy.

Description

Technical Field

[0001] This invention relates to the field of alloy smelting, and specifically to an aluminum-titanium-boron composite additive and its preparation method. Background Technology

[0002] Aluminum alloys are among the most widely used non-ferrous metal structural materials in industry, with extensive applications in aerospace, automotive, machinery manufacturing, shipbuilding, and chemical industries. With the continuous development of aluminum processing and the aluminum alloy industry, the research and development of aluminum alloys has been listed as a key technology for development. Commonly used alloying elements in aluminum alloys include silicon, iron, copper, magnesium, nickel, zinc, and vanadium. Alloying is a crucial step in the aluminum alloy production process. In recent years, research has found that the addition of titanium and boron has become a refining element for aluminum alloys. There are two traditional methods for adding titanium and boron: one is through the use of intermediate alloys; the other is through the use of metallic additives.

[0003] The inventors discovered the following problems during practical application: When adding titanium and boron as metal additives, the furnace temperature needs to reach above 1668℃ to ensure complete melting and uniform dispersion of the elements within the molten aluminum. However, aluminum's melting point is only 660℃. High temperatures cause the molten aluminum to vaporize, leading to burn-off. Furthermore, during this process, unvaporized molten aluminum readily reacts with surrounding oxygen, hydrogen, and water at high temperatures, forming impurities that are difficult to remove. This results in low purity aluminum alloys with mechanical properties that do not meet application requirements. Summary of the Invention

[0004] The present invention aims to provide an aluminum-titanium-boron composite additive and its preparation method, so as to solve the problem that in the prior art, the addition of titanium and boron during the preparation of aluminum alloys requires melting at high temperature, resulting in low purity and unsatisfactory mechanical properties of the aluminum alloys.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: an aluminum-titanium-boron composite additive, comprising the following raw materials by mass percentage: 10-30% boron salt, 30-60% TiO2 powder, 0.5-2.5% surfactant, 0.1-2.8% flux, and the balance being aluminum powder; the boron salt and TiO2 powder are mixed in a gradient, and the particle size gradient range and the proportion of each particle size are as follows: 80-150 mesh 15-25%, 150-300 mesh 10-15%, 300-350 mesh 25-30%, 350-500 mesh 15-30%, and the balance being particles ≥500 mesh.

[0006] Preferably, as an improvement, the aluminum powder biological particle size is also gradient mixed, and the particle size gradient range and the proportion of each particle size are: 30-35% for 200-250 mesh, 35-45% for 250-400 mesh, and the remainder is particle size ≥500 mesh.

[0007] Preferably, as an improvement, the boron salt is boron fluoride.

[0008] Preferably, as an improvement, the surfactant is at least one of sodium dodecyl sulfonate and sodium dodecylbenzene sulfonate.

[0009] Preferably, as an improvement, the flux is at least one of potassium fluoroborate, potassium fluorotitanate, potassium fluorosilicate, and potassium fluoroaluminate.

[0010] Preferably, as an improvement, the surfactant is a mixture of sodium dodecyl sulfonate and sodium dodecylbenzene sulfonate in a mass ratio of (1-3.5):(3-5).

[0011] Preferably, as an improvement, the flux is potassium fluoroborate, potassium fluorotitanate and potassium fluoroaluminate in a mass ratio of (1-3):(2-5):(3.5-6).

[0012] Preferably, as an improvement, a method for preparing an aluminum-titanium-boron composite additive includes the following steps:

[0013] Step 1: Raw material crushing and sieving: Boron salt, TiO2 powder and aluminum powder are crushed and sieved. After sieving, the particle sizes of boron salt, TiO2 powder and aluminum powder are all gradient mixtures.

[0014] Step 2, Ingredients and Mixing: The sieved boron salt, TiO2 powder, and aluminum powder are mixed with surfactants and fluxes to obtain a mixture;

[0015] Step 3: Pressing: Press the mixture into shape to obtain a blank;

[0016] Step 4: Dry the billet;

[0017] Step 5: Sieving.

[0018] Preferably, as an improvement, in step two, the mixing time is 45-60 min and the mixing speed is 15-20 rpm.

[0019] Preferably, as an improvement, in step three, the pressing pressure is 23-26 MPa; in step four, the drying temperature is 100℃.

[0020] The principle and advantages of this solution are as follows: In practical applications, this technical solution addresses the problem in existing technologies where the addition of titanium and boron during aluminum alloy preparation requires high-temperature melting, resulting in low purity and unsatisfactory mechanical properties in the aluminum alloy. A reverse analysis is conducted to address this issue: For metal additives to achieve maximum effectiveness, they need to melt rapidly and completely within the melt system and disperse uniformly. The inventors discovered a strong correlation between melting speed, dispersion degree, and the particle size of the metal powder. Larger metal powder particle sizes result in lower compactness of the pressed billet, making it easy for the powdered material to detach from the aluminum alloy system. Furthermore, large-particle detachments melt more slowly. Conversely, smaller metal powder particle sizes, while resulting in denser pressing, do not significantly lower the melting temperature. Excessive pressing density can also cause the billet to sink rapidly to the bottom of the furnace, preventing the additive from fully melting and further hindering melting and dispersion. Moreover, existing metal additives generally use metal powders of a single particle size for pressing, making it difficult to simultaneously address the issues of detachment and sedimentation through particle size control.

[0021] In this technical solution, the inventors' team, after years of dedicated research, has broken through existing technological barriers and creatively employed a gradient particle size ratio of metal element powders, along with the addition of flux and surfactants. This not only balances the issues of powder material shedding and melting temperature but also reduces the settling rate under the action of surfactants and increases the melting rate under the action of flux, ensuring complete melting and efficient function of the additives. Applying the aluminum-titanium-boron additive prepared by this technical solution to the preparation of aluminum alloys ensures the corrosion resistance, wear resistance, hardness, and fatigue strength of the aluminum alloys, while also improving the grain refinement of the alloy. Detailed Implementation

[0022] The following detailed description provides further details on specific embodiments, but the embodiments of the present invention are not limited thereto. Unless otherwise specified, the technical means used in the following embodiments are conventional means well known to those skilled in the art; the experimental methods used are all conventional methods; and the materials and reagents used are all commercially available.

[0023] An aluminum-titanium-boron composite additive comprises the following raw materials by mass percentage: 10-30% boron salt, 30-60% TiO2 powder, 0.5-2.5% surfactant, 0.1-2.8% flux, and the balance being aluminum powder.

[0024] Among them, the boron salt is boron fluoride.

[0025] The surfactant is at least one of sodium dodecyl sulfonate and sodium dodecylbenzene sulfonate.

[0026] The flux is at least one of potassium fluoroborate, potassium fluorotitanate, potassium fluorosilicate, and potassium fluoroaluminate.

[0027] Furthermore, the particle sizes of boron salt, TiO2 powder, and aluminum powder are all gradient mixtures. The particle size gradient range and the proportion of each particle size for boron salt and TiO2 powder are as follows: 80-150 mesh 15-25%, 150-300 mesh 10-15%, 300-350 mesh 25-30%, 350-500 mesh 15-30%, and the remainder is particles with a particle size ≥500 mesh.

[0028] The particle size gradient range and the proportion of each particle size of aluminum powder are as follows: 30-35% for 200-250 mesh, 35-45% for 250-400 mesh, and the remainder is particles with a particle size ≥500 mesh.

[0029] A method for preparing an aluminum-titanium-boron composite additive includes the following steps:

[0030] Step 1: Raw material crushing and sieving: Boron salt, TiO2 powder and aluminum powder are crushed and sieved. After sieving, the particle sizes of boron salt, TiO2 powder and aluminum powder are all gradient mixtures. The particle size gradient range and the proportion of each particle size of boron salt and TiO2 powder are as follows: 80-150 mesh 15-25%, 150-300 mesh 10-15%, 300-350 mesh 25-30%, 350-500 mesh 15-30%, and the remainder is particles with a particle size ≥500 mesh.

[0031] The particle size gradient range and the proportion of each particle size of aluminum powder are as follows: 30-35% for 200-250 mesh, 35-45% for 250-400 mesh, and the remainder is particles with a particle size ≥500 mesh.

[0032] Step 2, Ingredients and Mixing: Mix the sieved boron salt, TiO2 powder, aluminum powder with surfactant and flux. The mixing time is 45-60 min and the mixing speed is 15-20 rpm to obtain the mixture.

[0033] Step 3, pressing: Press the mixture into shape at a pressure of 23-26 MPa to obtain a billet;

[0034] Step 4: Drying: Dry the billet at a temperature of 100℃;

[0035] Step 5, sieving: sieve through a 10-15mm sieve.

[0036] Example 1

[0037] An aluminum-titanium-boron composite additive comprises the following raw materials by mass percentage: 10% boron fluoride, 30% TiO2 powder, 0.5% surfactant, 0.1% flux, and the balance being aluminum powder.

[0038] The surfactant is a mixture of sodium dodecyl sulfonate and sodium dodecylbenzene sulfonate in a mass ratio of 1:3.

[0039] The flux is a mixture of potassium fluoroborate, potassium fluorotitanate and potassium fluoroaluminate in a mass ratio of 1:2:3.5.

[0040] Furthermore, the particle sizes of boron salt, TiO2 powder, and aluminum powder are all gradient mixtures. The particle size gradient range and the proportion of each particle size for boron salt and TiO2 powder are as follows: 15% for 80-150 mesh, 10% for 150-300 mesh, 25% for 300-350 mesh, 15% for 350-500 mesh, and the remainder is particles with a particle size ≥500 mesh.

[0041] The particle size gradient range and the proportion of each particle size in aluminum powder are as follows: 30% for 200-250 mesh, 35% for 250-400 mesh, and the remainder is ≥500 mesh.

[0042] A method for preparing an aluminum-titanium-boron composite additive includes the following steps:

[0043] Step 1: Raw material crushing and sieving: Boron salt, TiO2 powder and aluminum powder are crushed and sieved. After sieving, the particle sizes of boron salt, TiO2 powder and aluminum powder are all gradient mixtures. The particle size gradient range and the proportion of each particle size of boron salt and TiO2 powder are as follows: 80-150 mesh 15%, 150-300 mesh 10%, 300-350 mesh 25%, 350-500 mesh 15%, and the remainder is particles with a particle size ≥500 mesh.

[0044] The particle size gradient range and the proportion of each particle size in aluminum powder are as follows: 30% for 200-250 mesh, 35% for 250-400 mesh, and the remainder is particles with a particle size ≥500 mesh.

[0045] Step 2, Ingredients and Mixing: Mix the sieved boron salt, TiO2 powder, aluminum powder with surfactant and flux. The mixing time is 45 min and the mixing speed is 20 rpm to obtain the mixture.

[0046] Step 3: Pressing: Press the mixture into shape at a pressure of 25 MPa to obtain a billet;

[0047] Step 4: Drying: Dry the billet at a temperature of 100℃;

[0048] Step 5, sieving: sieve through a 12mm sieve.

[0049] Example 2

[0050] The difference between this embodiment and Embodiment 1 is that in this embodiment, the particle size gradient range and the proportion of each particle size of boron salt and TiO2 powder are as follows: 25% for 80-150 mesh, 15% for 150-300 mesh, 30% for 300-350 mesh, and 30% for 350-500 mesh.

[0051] The particle size gradient range and the percentage of each particle size in aluminum powder are as follows: 35% for 200-250 mesh, 45% for 250-400 mesh, and the remainder is 20% for particles with a size ≥500 mesh.

[0052] Example 3

[0053] The difference between this embodiment and Embodiment 1 is that in this embodiment, the surfactant is sodium dodecyl thiosulfate.

[0054] Example 4

[0055] The difference between this embodiment and Embodiment 1 is that in this embodiment, the flux is a mixture of potassium fluoroborate, potassium fluorotitanate, and potassium fluoroaluminate in a mass ratio of 3:5:6.

[0056] Comparative Example 1

[0057] The difference between this comparative example and Example 1 is that the particle size of both the boron salt and TiO2 powder in this comparative example is 300 mesh.

[0058] Comparative Example 2

[0059] The difference between this comparative example and Example 1 is that the particle size of boron salt, TiO2 powder and aluminum powder in this comparative example is 300 mesh.

[0060] Comparative Example 3

[0061] The difference between this comparative example and Example 1 is that no surfactant was added in this comparative example.

[0062] Comparative Example 4

[0063] The difference between this comparative example and Example 1 is that the flux in this comparative example is potassium chloride.

[0064] Comparative Example 5

[0065] The difference between this comparative example and Example 1 is that no flux was added in this comparative example.

[0066] Experimental Example 1: Performance Verification of Aluminum-Titanium-Boron Additives

[0067] The additives prepared in the above embodiments and comparative examples were subjected to performance tests. The test indicators included: additive melting temperature, additive melting time, and additive recovery rate. The additive melting temperature and additive melting time were recorded by traditional observation. The additive recovery rate was calculated as (recovery amount / addition amount) × 100%. The test results are shown in the table below. When using the aluminum-titanium-boron additives prepared in Examples 1-4 of this technical solution for aluminum alloy smelting, the melting temperature can be significantly reduced, the melting time can be shortened, and the recovery rate can reach over 99%. However, using metal powder with a single particle size cannot achieve the same effect. Furthermore, the selection and addition of flux and surfactant have a significant impact on the additive melting temperature, time, and recovery rate.

[0068] Table 1

[0069] Additive melting temperature (°C) Additive melting time (min) Additive recovery rate % Example 1 705 8 99.53 Example 2 696 12 99.2 Example 3 703 10 99.3 Example 4 690 12 99.5 Comparative Example 1 896 15 72.5 Comparative Example 2 893 17 70.4 Comparative Example 3 733 25 65.3 Comparative Example 4 762 24 70.2 Comparative Example 5 834 31 68.5

[0070] Application examples

[0071] Aluminum-titanium-boron additives prepared using the above embodiments and comparative examples were used for aluminum alloy smelting. The properties of the aluminum alloys were tested, including corrosion resistance, wear resistance, hardness, and fatigue strength. The results showed that the additives prepared using this technical solution can significantly improve the corrosion resistance, wear resistance, hardness, and fatigue strength of aluminum alloys.

[0072] The above descriptions are merely embodiments of the present invention, and common knowledge such as specific technical solutions and / or characteristics are not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the technical solutions of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. An aluminum-titanium-boron composite additive, characterized in that: The raw materials include the following by mass percentage: 10-30% boron salt, 30-60% TiO2 powder, 0.5-2.5% surfactant, 0.1-2.8% flux, and the balance being aluminum powder; the particle sizes of boron salt and TiO2 powder are gradient mixtures, and the particle size gradient range and the proportion of each particle size are as follows: 15-25% for 80-150 mesh, 10-15% for 150-300 mesh, 25-30% for 300-350 mesh, 15-30% for 350-500 mesh, and the balance being particles ≥500 mesh; the surfactant is a mixture of sodium dodecyl sulfonate and sodium dodecylbenzene sulfonate in a mass ratio of (1-3.5):(3-5).

2. The aluminum-titanium-boron composite additive according to claim 1, characterized in that: The aluminum powder is also a gradient mixture with a particle size range of 30-35% for 200-250 mesh, 35-45% for 250-400 mesh, and the remainder being particles ≥500 mesh.

3. The aluminum-titanium-boron composite additive according to claim 2, characterized in that: The boron salt is boron fluoride.

4. The aluminum-titanium-boron composite additive according to claim 3, characterized in that: The flux is at least one of potassium fluoroborate, potassium fluorotitanate, potassium fluorosilicate, and potassium fluoroaluminate.

5. The aluminum-titanium-boron composite additive according to claim 4, characterized in that: The flux is potassium fluoroborate, potassium fluorotitanate and potassium fluoroaluminate in a mass ratio of (1-3):(2-5):(3.5-6).

6. A method for preparing an aluminum-titanium-boron composite additive according to any one of claims 1-5, characterized in that, Includes the following steps: Step 1: Raw material crushing and sieving: Boron salt, TiO2 powder and aluminum powder are crushed and sieved. After sieving, the particle sizes of boron salt, TiO2 powder and aluminum powder are all gradient mixtures. Step 2, Ingredients and Mixing: The sieved boron salt, TiO2 powder, and aluminum powder are mixed with surfactants and fluxes to obtain a mixture; Step 3: Pressing: Press the mixture into shape to obtain a blank; Step 4: Dry the billet; Step 5: Sieving.

7. The method for preparing an aluminum-titanium-boron composite additive according to claim 6, characterized in that: In step two, the mixing time is 45-60 minutes and the mixing speed is 15-20 rpm.

8. The method for preparing an aluminum-titanium-boron composite additive according to claim 7, characterized in that: In step three, the pressing pressure is 23-26 MPa; in step four, the drying temperature is 100℃.