High-calorific-value aluminum boron alloy fuel and preparation method and application thereof

Abstract

The present application relates to the field of aluminum-based alloy materials, in particular to a high-calorific-value aluminum boron alloy fuel and a preparation method and application thereof.The present application controls the content of boron and uses a combination of smelting and gas flow atomization to accurately control the micro-morphology of the aluminum boron alloy fuel to be prepared, thereby preparing a high-calorific-value aluminum boron alloy fuel with uniform spherical micro-morphology.The high-calorific-value aluminum boron alloy fuel provided by the present application has spherical particles, a high sphericity rate, uniform particle size, and is not prone to agglomeration, and has good process safety when applied to energetic materials.The high-calorific-value aluminum boron alloy fuel provided by the present application has a combustion heat of not less than 29.2kJ / g and a density of not less than 2.72g / cm3, and has the advantages of high density, high calorific value, low ignition temperature, and fast combustion rate.

Description

Technical Field

[0001] This invention relates to the field of aluminum-based alloy materials, and more specifically, to a high-calorific-value aluminum-boron alloy fuel, its preparation method, and its application. Background Technology

[0002] Metallic fuels are a unique form of energy, characterized by their high calorific value and metallic composition. Their high energy density, ease of storage and handling make them promising for applications in the aerospace field. The addition of high-calorific-value metallic fuels has a significant impact on the energy release of energetic materials.

[0003] Aluminum powder, as the most widely used metallic fuel among energetic materials, has a faster reaction rate and lower ignition temperature compared to boron powder, but its calorific value and density are also lower. In contrast, boron, being an atomic crystal, has a higher melting and boiling point than aluminum and other metallic fuels. During the detonation and afterburning reactions of mixed explosives, boron is not easily melted or vaporized, and its combustion reaction is mainly layer-by-layer combustion, resulting in a slower rate. The oxidation products of boron, such as B₂O₃, have low melting points and high boiling points, and are generally liquid in the combustion reaction environment, hindering further contact between oxidizing gases and the pure boron powder inside the boron particles, leading to a lower boron combustion reaction rate. Therefore, combining the advantages of both, developing aluminum-boron alloy fuels is of great significance for the energy release of energetic materials.

[0004] Currently, a series of studies on the preparation, performance testing, and application of aluminum-boron alloy fuels have been conducted both domestically and internationally. Existing preparation methods for aluminum-boron alloy fuels include high-energy ball milling mechanical alloying and sintering ball milling. High-energy ball milling mechanical alloying involves adding powder to a ball mill and using microspheres of different sizes to achieve alloying of the powder under high-speed ball milling. The aluminum-boron alloy powder prepared by this process can achieve a boron content of 10-50%; however, the aluminum-boron alloy powder is granular or flake-shaped, uneven in size, and prone to agglomeration, with a large number of flakes of different sizes appearing on its surface, surrounded by many small fragment aggregates; there are problems such as inaccurate control of boron content, inconsistent morphology, uneven particle size, and easy agglomeration. Sintering ball milling involves sintering the powder into alloy ingots in a melting furnace, and then crushing the alloy ingots and adding them to a ball mill to form spherical alloy fuel. This process can achieve precise control of boron content, but the prepared aluminum-boron alloy fuel has a poor morphology with many angular particles, which poses a problem of poor process safety in the application of energetic materials. Summary of the Invention

[0005] The technical problem solved by this invention is that existing methods for preparing aluminum-boron alloy fuels are difficult to control precisely in terms of microstructure, resulting in inconsistent morphology of the prepared aluminum-boron alloy fuels.

[0006] This invention precisely controls the microstructure of the aluminum-boron alloy fuel to be prepared by adjusting the boron content and using a combination of melting and airflow atomization, thus producing a high-calorific-value aluminum-boron alloy fuel with a uniform spherical microstructure.

[0007] One of the objectives of this invention is to provide a high-calorific-value aluminum-boron alloy fuel.

[0008] The aluminum-boron alloy fuel is in powder form; it contains aluminum-boron alloy microparticles, which are spherical.

[0009] Based on the total amount of aluminum and boron in the aluminum-boron alloy fuel being 100%, the mass content of boron is greater than 0-15%; preferably 3-12%.

[0010] The particle size of the aluminum-boron alloy microparticles is 2–500 μm, preferably 2–150 μm, and more preferably 5–45 μm. Specifically, the particle size of the aluminum-boron alloy microparticles can be any value or a value between any two values ​​from 2, 2.5, 5, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, and 150 μm.

[0011] The sphericity of the aluminum-boron alloy microparticles is greater than or equal to 85%; specifically, the sphericity of the high-calorific-value spherical aluminum-boron alloy fuel can be greater than 85%, greater than 86%, greater than 87%, greater than 88%, greater than 89%, greater than 90%, greater than 91%, greater than 92%, or greater than 93%; preferably, the sphericity of the aluminum-boron alloy microparticles is greater than or equal to 90%.

[0012] The aluminum-boron alloy microparticles have an oxide layer covering their surface; the oxide layer is a composite aluminum oxide, and the thickness of the oxide layer is 0.5–10 nm, preferably 0.5–6 nm.

[0013] The density of the aluminum-boron alloy fuel with an oxide layer is 2.70–2.867 g / cm³. 3 The preferred value is 2.72–2.83 g / cm³. 3 ;

[0014] The calorific value of the aluminum-boron alloy fuel with oxide layer is 28.0–32.3 kJ / g, preferably 29.2–31.6 kJ / g.

[0015] A second objective of this invention is to provide a method for preparing the high-calorific-value aluminum-boron alloy fuel described in one of the objectives of this invention.

[0016] The preparation method of the aluminum-boron alloy fuel includes steps such as premixing, pre-pressing, melting, and gas atomization.

[0017] Specifically, the preparation method of the aluminum-boron alloy fuel includes the following steps:

[0018] (1) Under a protective gas atmosphere, aluminum powder and boron powder are premixed to obtain premixed powder;

[0019] (2) Press the premixed powder into shape to obtain aluminum boron blocks;

[0020] (3) The aluminum-boron blocks are vacuum melted to obtain aluminum-boron alloy ingots;

[0021] (4) Melt the aluminum-boron alloy ingot to obtain a molten liquid; atomize the molten liquid under protective gas backflushing to obtain high-calorific-value aluminum-boron alloy fuel.

[0022] Experiments revealed that directly melting aluminum blocks and boron powder resulted in boron powder floating on the surface of the molten aluminum, leading to boron-aluminum stratification. Gas backflushing failed to yield aluminum-boron alloy particles. Melting aluminum and boron powder separately and then mixing them also resulted in stratification between the molten boron and aluminum, again failing to yield aluminum-boron alloy particles after gas backflushing. This invention, by "premixing aluminum and boron powder," ensures uniform mixing of aluminum and boron. "Pre-melting into aluminum-boron blocks" prevents boron-aluminum stratification during the melting process and eliminates unalloyed boron powder, thus ensuring full alloying of aluminum and boron and obtaining a fully alloyed aluminum-boron alloy ingot. In other words, this invention obtains a fully alloyed aluminum-boron alloy ingot through steps (1), (2), and (3). In step (3), during the melting process of the aluminum-boron blocks, aluminum and boron react fully to form the alloy compound AlB2. After melting the fully alloyed aluminum-boron alloy ingot, gas backflushing produces aluminum-boron alloy particles with uniform internal composition and particle size. In this invention, step (4) uses a tightly coupled gas atomization method to prepare powder, which can effectively achieve precise control over the microstructure, particle size, and uniformity of aluminum-boron alloy fuel.

[0023] In step (1):

[0024] Specifically, a ball mill can be used to premix aluminum powder and boron powder under vacuum conditions.

[0025] The aluminum powder and boron powder can be any existing aluminum powder and boron powder of any particle size, and those skilled in the art can select according to the actual situation.

[0026] In step (2):

[0027] Compression molding can be carried out using a compression molding machine, specifically any existing compression molding machine capable of pressing metal powder into metal blocks;

[0028] The molding pressure should be such that the premixed aluminum powder and boron powder can be pressed into a block, and can be selected within a wide range. Those skilled in the art can select according to the actual situation. As a preferred option, the molding pressure is 5 to 15 MPa, and more preferably 7 to 12 MPa.

[0029] In step (3):

[0030] Vacuum melting can be carried out in a melting furnace, specifically any existing melting furnace capable of melting aluminum and boron.

[0031] The melting temperature should be such that aluminum and boron can be melted, and can be selected within a wide range. Those skilled in the art can choose according to the actual situation; as a preferred option, the melting temperature is 660℃~1300℃.

[0032] The vacuum level can be selected within a wide range, and those skilled in the art can choose according to the actual situation; as a preferred option, the vacuum level is 0.3 to 1.0 Pa.

[0033] In step (4):

[0034] The protective gas can be a commonly used protective gas in the gas flow atomization process. Technical personnel in the field can choose according to the actual situation. Specifically, one of the inert gases can be selected, such as argon.

[0035] The temperature of the protective gas can be the conventional temperature used in the airflow atomization process, and those skilled in the art can choose according to the actual situation; as a preferred option, the temperature of the protective gas is 10-40℃, and more preferably 20-30℃.

[0036] The flow rate of the protective gas can be the conventional flow rate used in airflow atomization processes, and those skilled in the art can select it according to the actual situation; as a preferred option, the flow rate of the protective gas is 0.5–20 m³ / h. 3 / min, more preferably 1 to 10m 3 / min.

[0037] The backflush pressure of the protective gas can be the conventional backflush pressure in the airflow atomization process, and those skilled in the art can choose according to the actual situation; as a preferred option, the backflush pressure of the protective gas is 3 to 5 MPa, and more preferably 3 to 4 MPa.

[0038] The aluminum-boron alloy ingot obtained in step (3) is prone to forming an oxide layer on its surface. The presence of the oxide layer will cause the calorific value of the high-calorific-value aluminum-boron alloy fuel to decrease. Therefore, as a preferred option, in step (4), before melting the aluminum-boron alloy ingot, impurities on the surface of the aluminum-boron alloy ingot are removed under a protective gas atmosphere. More preferably, sandpaper is used to remove impurities on the surface of the aluminum-boron alloy ingot.

[0039] The above method may further include step (5) oxidizing the high-calorific-value aluminum-boron alloy fuel and sieving it. The purpose of the oxidation is to form an oxide layer on the surface of the aluminum-boron alloy fuel particles to passivate the high-calorific-value aluminum-boron alloy fuel. The oxidation atmosphere is a mixture of air and a protective gas. The protective gas is selected from at least one inert gas. As a preferred embodiment, the oxidation includes cold blowing the aluminum-boron alloy fuel with the mixed gas.

[0040] In step (5), the oxide layer of the high-calorific-value aluminum-boron alloy fuel particles can be thinned and the oxide layer content can be lower by controlling the oxidation conditions, reducing the content of oxidizing gas, and increasing the oxidation time.

[0041] Preferably, the volume percentage of air in the mixed gas is 1-20%.

[0042] Preferably, the flow rate of the mixed gas is 2 to 50 L / min, and more preferably 5 to 30 L / min.

[0043] Preferably, the oxidation temperature is 20–40°C.

[0044] Preferably, the oxidation time is 1 to 2 days.

[0045] The third objective of this invention is to provide an application of the high-calorific-value aluminum-boron alloy fuel described in the first objective of the invention, or the high-calorific-value aluminum-boron alloy fuel obtained by the preparation method described in the second objective of the invention, in the field of explosives.

[0046] This invention provides a high-calorific-value spherical Al-B alloy fuel and its preparation method. Compared with aluminum powder, the aluminum-boron alloy fuel provided by this invention has higher density and calorific value, and compared with boron powder, it has higher sphericity, lower ignition temperature, and faster combustion rate.

[0047] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0048] This invention provides a high-calorific-value aluminum-boron alloy fuel, comprising aluminum and boron metal elements. Boron metal has high density and calorific value, enabling it to release more energy into energetic materials. Adding it to aluminum powder to form an aluminum-boron alloy fuel can improve its calorific value and density.

[0049] The high-calorific-value aluminum-boron alloy fuel provided by this invention has spherical particles with high sphericity, uniform particle size, and is not prone to agglomeration, resulting in good process safety when applied to energetic materials. This is of great significance for the energy release and process safety of energetic materials.

[0050] The high-calorific-value aluminum-boron alloy fuel provided by this invention has an oxide layer coated on the surface of its particles. The oxide layer is thin and has a low oxide content. The high-calorific-value aluminum-boron alloy fuel provided by this invention has a heat of combustion of not less than 29.2 kJ / g and a density of not less than 2.72 g / cm3, and has the advantages of high density, high calorific value, low ignition temperature, and fast combustion rate.

[0051] This invention ensures the uniformity of aluminum and boron powders and prevents boron powder stratification during melting by preparing premixed / pre-pressed aluminum-boron powders. Vacuum melting of aluminum-boron blocks achieves full alloying of aluminum and boron powders. Controlling the time and temperature in the atomizing furnace and employing a tightly coupled gas atomization method effectively achieves precise control over the microstructure, particle size, and uniformity of the aluminum-boron alloy fuel. Furthermore, a slow oxidation passivation control technology is used. After adding boron, the composition changes. By controlling the slow oxidation conditions, using an inert gas atmosphere, reducing the content of oxidizing gases, and increasing the passivation time, the resulting aluminum-boron alloy powder material has a thinner shell (oxide layer) and a lower oxide layer content. This invention provides a high-calorific-value spherical aluminum-boron alloy fuel. Attached Figure Description

[0052] Figure 1 The image shows a scanning electron microscope (SEM) image of the high-calorific-value spherical aluminum-boron alloy fuel prepared in Example 1.

[0053] Figure 2 The image shows a scanning electron microscope (SEM) image of the high-calorific-value spherical aluminum-boron alloy fuel prepared in Example 2.

[0054] Figure 3 This is a scanning electron microscope image of the high-calorific-value spherical aluminum-boron alloy fuel prepared in Example 3. Detailed Implementation

[0055] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be noted that the following embodiments are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the content of the present invention are still within the scope of protection of the present invention.

[0056] Unless otherwise specified, the raw materials used in the examples and comparative examples are all disclosed in the prior art, such as those that can be directly purchased or prepared according to the preparation methods disclosed in the prior art.

[0057] Example 1

[0058] The preparation of high-calorific-value spherical aluminum-boron alloy fuel includes the following steps.

[0059] (1) Under argon protection, 1.94 kg of aluminum powder and 60 g of boron powder were placed in a ball mill for premixing to obtain premixed powder; then the premixed powder was placed in In the mold, it is pressed into shape under a pressure of 8 MPa to obtain an aluminum boron block.

[0060] (2) Place the aluminum boron block into the crucible and place it inside the induction coil of the induction melting furnace. Evacuate to 1 Pa, preheat at 600°C, then raise the temperature to 1100°C. Stir at a stirring rate of 27000 rpm for 10 minutes. After the crucible has completely cooled, open the furnace lid and take out the aluminum boron alloy ingot.

[0061] (3) Under argon protection and a pressure of 200 Pa, aluminum-boron alloy ingots were added to a vacuum melting furnace. The furnace body was heated to 1100℃ using a medium-frequency heating coil, and the alloy ingots were melted for 40 minutes to obtain molten liquid. Argon gas at 25 kPa was introduced into the atomization chamber and the melting furnace. Under argon protection, the melting furnace valve was opened, and the molten liquid flowed out from the 3.5 mm guide pipe at the bottom of the melting furnace under gravity, flowing into the atomization chamber through a tightly coupled gas atomizing nozzle. After flowing out of the guide pipe, the molten liquid was accelerated by the nozzle. The accelerated molten liquid was impacted by the supersonic gas jet, and the molten liquid was broken into small droplets. Some droplets underwent secondary breakage, and the droplets cooled and solidified during the descent, forming aluminum-boron alloy particles. The gas jet flow rate was 2 m³ / s. 3 / min, gas jet pressure is 4MPa.

[0062] (4) A mixture of high-speed argon and air (air volume percentage 1%) is used to accelerate the cold blowing of aluminum-boron alloy particles. The flow rate of the mixed gas is 20 L / min. The particles undergo slow surface oxidation passivation treatment at room temperature (25℃) for 1 day. After separation by a hydrocyclone separator, the powder enters a dust collection tank. The gas undergoes secondary dust removal by a bag filter and is then filtered before being discharged. The powder in the dust collection tank consists of aluminum-boron alloy particles with an oxide layer protection.

[0063] The prepared aluminum-boron alloy microparticles with oxide layer protection were tested and found to contain 96.9% Al and 3.1% B by mass, with a particle size of 2–500 μm, a sphericity of 0.90, and a density of 2.72 g / cm³. 3 Its calorific value is 29.4 kJ / g.

[0064] Method for testing the thickness of the oxide layer on the surface of aluminum-boron alloy microparticles: Aluminum-boron alloy microparticles were sliced ​​using a focused ion fabrication (FIB) instrument. Using an ion beam, the aluminum-boron alloy microparticles loaded on conductive adhesive were initially sliced ​​under platinum (Pt) protection to obtain thin slices approximately a few micrometers thick. These slices were then extracted and fixed onto a copper grid, and further thinned to ultrathin slices less than 100 nm thick. The thickness and composition of the oxide layer were then analyzed using transmission electron microscopy (TEM). The internal microstructure of the aluminum-magnesium alloy powder material was analyzed using a combination of metallurgical microscopy and scanning electron microscopy (SEM). Testing showed that the oxide layer on the surface of the aluminum-boron alloy microparticles prepared in this embodiment consisted of composite alumina with a thickness of 5.9 nm.

[0065] The surface morphology SEM images of the aluminum-boron alloy microparticles with a particle size of 10–20 μm and protected by an oxide layer prepared in this embodiment are shown below. Figure 1 As shown.

[0066] Example 2

[0067] The preparation of high-calorific-value spherical aluminum-boron alloy fuel includes the following steps.

[0068] (1) 1.8 kg of aluminum powder and 200 g of boron powder were placed in a ball mill for premixing to obtain a premixed powder; then the premixed powder was placed in a ball mill. In the mold, it is pressed into shape under a pressure of 8 MPa to obtain an aluminum boron block.

[0069] (2) Place the aluminum boron block into the crucible and place it inside the induction coil of the induction melting furnace. Evacuate to 1 Pa, preheat at 600°C, then raise the temperature to 1400°C. Stir at a stirring rate of 27000 rpm for 10 minutes. After the crucible has completely cooled, open the furnace lid and take out the aluminum boron alloy ingot.

[0070] (3) Under argon protection and a pressure of 200 Pa, aluminum-boron alloy ingots were added to a vacuum melting furnace. The furnace body was heated to 1400℃ using a medium-frequency heating coil to melt the alloy ingots for 40 minutes, resulting in molten liquid. Argon gas at 45 kPa was introduced into the atomization chamber and the melting furnace. Under argon protection, the melting furnace valve was opened, and the molten liquid flowed out from the 7 mm guide pipe at the bottom of the melting furnace under gravity, flowing into the atomization chamber through a tightly coupled gas atomizing nozzle. After flowing out of the guide pipe, the molten liquid was accelerated by the nozzle. The accelerated molten liquid was impacted by the supersonic gas jet, breaking the molten liquid into small droplets. Some droplets underwent secondary breakage, and the droplets cooled and solidified during their descent, forming aluminum-boron alloy particles. The gas jet flow rate was 2 m³ / min, and the gas jet pressure was 4 MPa.

[0071] (4) A mixture of high-speed argon and air (air volume percentage 1%) is used to accelerate the cold blowing of aluminum-boron alloy particles. The flow rate of the mixed gas is 20 L / min. The particles undergo slow surface oxidation passivation treatment at room temperature (25℃) for 1 day. After separation by a hydrocyclone separator, the powder enters a dust collection tank. The gas undergoes secondary dust removal by a bag filter and is then filtered before being discharged. The powder in the dust collection tank consists of aluminum-boron alloy particles with an oxide layer protection.

[0072] The prepared aluminum-boron alloy microparticles with oxide layer protection were tested and found to contain 90.1% Al and 9.9% B by mass, with a particle size of 2–500 μm, a sphericity of 0.90, and a density of 2.8 g / cm³. 3 Its calorific value is 31.1 kJ / g.

[0073] Method for testing the thickness of the oxide layer on the surface of aluminum-boron alloy microparticles: Aluminum-boron alloy microparticles were sliced ​​using a focused ion fabrication (FIB) instrument. Using an ion beam, the aluminum-boron alloy microparticles loaded on conductive adhesive were initially sliced ​​under platinum (Pt) protection to obtain thin slices approximately a few micrometers thick. These slices were then extracted and fixed onto a copper grid, and further thinned to ultrathin slices less than 100 nm thick. The thickness and composition of the oxide layer were then analyzed using transmission electron microscopy (TEM). The internal microstructure of the aluminum-magnesium alloy powder material was analyzed using a combination of metallographic microscopy and scanning electron microscopy (SEM). Testing showed that the oxide layer on the surface of the aluminum-boron alloy microparticles prepared in this embodiment consisted of composite alumina with a thickness of 3.9 nm.

[0074] The surface morphology SEM images of the aluminum-boron alloy microparticles with a particle size of 10–20 μm and protected by an oxide layer prepared in this embodiment are shown below. Figure 2 As shown.

[0075] Example 3

[0076] The preparation of high-calorific-value spherical aluminum-boron alloy fuel includes the following steps.

[0077] (1) 1.88 kg of aluminum powder and 120 g of boron powder were placed in a ball mill for premixing to obtain a premixed powder; then the premixed powder was placed in a ball mill. In the mold, it is pressed into shape under a pressure of 8 MPa to obtain an aluminum boron block.

[0078] (2) Place the aluminum boron block into the crucible and place it inside the induction coil of the induction melting furnace. Evacuate to 1 Pa, preheat at 600°C, then raise the temperature to 1200°C. Stir at a stirring rate of 27000 rpm for 10 minutes. After the crucible has completely cooled, open the furnace lid and take out the aluminum boron alloy ingot.

[0079] (3) Under argon protection and a pressure of 200 Pa, aluminum-boron alloy ingots are added to a vacuum melting furnace. The furnace body is heated to 1200℃ using a medium-frequency heating coil, and the alloy ingots are melted for 40 minutes to obtain molten liquid. Argon gas at 35 kPa is introduced into the atomization chamber and the melting furnace. Under argon protection, the melting furnace valve is opened, and the molten liquid flows out from the 5 mm guide pipe at the bottom of the melting furnace under gravity, flowing into the atomization chamber through a tightly coupled gas atomizing nozzle. After flowing out of the guide pipe, the molten liquid is accelerated by the nozzle. The accelerated molten liquid is impacted by the supersonic gas jet, and the molten liquid is broken into small droplets. Some droplets undergo secondary breakage, and the droplets cool and solidify during the descent, forming aluminum-boron alloy particles. The gas jet flow rate is 2 m³ / s. 3 / min, gas jet pressure is 4MPa.

[0080] (4) A mixture of high-speed argon and air (air volume percentage 1%) is used to accelerate the cold blowing of aluminum-boron alloy particles. The flow rate of the mixed gas is 20 L / min. The particles undergo slow surface oxidation passivation treatment at room temperature (25℃) for 1 day. After separation by a hydrocyclone separator, the powder enters a dust collection tank. The gas undergoes secondary dust removal by a bag filter and is then filtered before being discharged. The powder in the dust collection tank consists of aluminum-boron alloy particles with an oxide layer protection.

[0081] The prepared aluminum-boron alloy microparticles with oxide layer protection were tested and found to contain 93.8% Al and 6.2% B by mass, with a particle size of 2–500 μm, a sphericity of 0.90, and a density of 2.75 g / cm³. 3 Its calorific value is 30.1 kJ / g.

[0082] Method for testing the thickness of the oxide layer on the surface of aluminum-boron alloy microparticles: Aluminum-boron alloy microparticles were sliced ​​using a focused ion fabrication (FIB) instrument. Using an ion beam, the aluminum-boron alloy microparticles loaded on conductive adhesive were initially sliced ​​under platinum (Pt) protection to obtain thin slices approximately a few micrometers thick. These slices were then extracted and fixed onto a copper grid, and further thinned to ultrathin slices less than 100 nm thick. The thickness and composition of the oxide layer were then analyzed using transmission electron microscopy (TEM). The internal microstructure of the aluminum-magnesium alloy powder material was analyzed using a combination of metallographic microscopy and scanning electron microscopy (SEM). Testing showed that the oxide layer on the surface of the aluminum-boron alloy microparticles prepared in this embodiment consisted of composite alumina with a thickness of 4.5 nm.

[0083] The surface morphology SEM images of the aluminum-boron alloy microparticles with a particle size of 10–20 μm and protected by an oxide layer prepared in this embodiment are shown below. Figure 3 As shown.

Claims

1. A high-calorific-value aluminum-boron alloy fuel, characterized in that, The aluminum-boron alloy fuel is in powder form and contains aluminum-boron alloy microparticles; the aluminum-boron alloy microparticles are spherical. Based on the total amount of aluminum and boron in the aluminum-boron alloy fuel being 100%, the mass content of boron is greater than 0-15%; preferably 3-12%.

2. The aluminum-boron alloy fuel as described in claim 1, characterized in that, The particle size of the aluminum-boron alloy microparticles is 2–500 μm, preferably 5–45 μm; or / and, The sphericity of the aluminum-boron alloy microparticles is greater than or equal to 85%, preferably greater than or equal to 90%.

3. The aluminum-boron alloy fuel as described in claim 1, characterized in that, The aluminum-boron alloy microparticles have an oxide layer covering their surface; the oxide layer is a composite aluminum oxide, and the thickness of the oxide layer is 0.5–10 nm, preferably 0.5–6 nm.

4. The aluminum-boron alloy fuel as described in claim 3, characterized in that, The density of the aluminum-boron alloy fuel is 2.70–2.867 g / cm³. 3 The preferred value is 2.72–2.83 g / cm³. 3 ; or / and, The calorific value of the aluminum-boron alloy fuel is 28.0–32.3 kJ / g, preferably 29.2–31.6 kJ / g.

5. A method for preparing an aluminum-boron alloy fuel as described in any one of claims 1 to 4, characterized in that, The preparation method includes the following steps: (1) Under a protective gas atmosphere, aluminum powder and boron powder are premixed to obtain premixed powder; (2) Press the premixed powder into shape to obtain aluminum boron blocks; (3) The aluminum-boron blocks are vacuum melted to obtain aluminum-boron alloy ingots; (4) Melt the aluminum-boron alloy ingot to obtain a molten liquid; atomize the molten liquid under protective gas backflushing to obtain high-calorific-value aluminum-boron alloy fuel.

6. The preparation method according to claim 5, characterized in that, In step (1), a ball mill is used to premix aluminum powder and boron powder; or / and, In step (2), the pressing pressure is 5–15 MPa, preferably 7–12 MPa; or / and, In step (3), the vacuum degree is 0.3–1.0 Pa; the melting temperature is 660℃–1300℃; or / and, In step (4): The protective gas is selected from inert gases; and / or, The temperature of the protective gas is 10–40°C, preferably 20–30°C; and / or, The flow rate of the protective gas is 0.5–20 m³. 3 / min, preferably 1-10m 3 / min The backflush pressure of the protective gas is 3-5 MPa, preferably 3-4 MPa.

7. The preparation method according to claim 5, characterized in that, It also includes the following steps: Before melting the aluminum-boron alloy ingot, impurities on the surface of the aluminum-boron alloy ingot are removed under a protective gas atmosphere; preferably, sandpaper is used to remove impurities from the surface of the aluminum-boron alloy ingot.

8. The preparation method according to claim 5, characterized in that, It also includes the following steps: (5) Oxidize the high-calorific-value aluminum-magnesium alloy fuel and sieve it; preferably, the oxidation includes cold blowing the high-calorific-value aluminum-magnesium alloy fuel with a mixed gas, the mixed gas being composed of air and a protective gas.

9. The preparation method according to claim 8, characterized in that, In step (5), The volume percentage of air in the gas mixture is 1-20%; or / and, The protective gas is selected from at least one of inert gases; and / or, The flow rate of the mixed gas is 2–50 L / min, preferably 5–30 L / min; and / or, The oxidation temperature is 20–40°C; and / or, The oxidation time is 1 to 2 days.

10. The application of a high-calorific-value aluminum-boron alloy fuel according to any one of claims 1 to 4, or a high-calorific-value aluminum-boron alloy fuel obtained by the preparation method according to any one of claims 5 to 9, in the field of explosives.

Images