Propellant containing active metal fuel and preparation method thereof

Abstract

The invention belongs to the technical field of solid propellants, and particularly relates to a propellant containing active metal fuel and a preparation method of the propellant. 3.0-4.0% of a plasticizer; 0.3-0.4% of a curing agent; 0.1%-2.0% of a combustion rate regulator; 0.01%-0.5% of a bonding agent; 15-19% of an active metal fuel; 10-18% of a nitramine explosive; the metal fuel is an aluminum-gallium metal alloy, and the aluminum-gallium metal alloy is an aluminum-gallium metal alloy of which the outer layer is coated with an aluminum film. The propellant provided by the invention has the advantage of high combustion efficiency, and can meet the requirement of a solid rocket engine on the high energy performance of the propellant.

Description

Technical Field

[0001] This invention belongs to the field of solid propellant technology, specifically relating to a propellant containing active metal fuel and its preparation method. Background Technology

[0002] Solid propulsion is the prerequisite and foundation for the combat effectiveness of missile weapons and equipment, the key to supporting the generation of combat power of missile weapons and equipment, and the core of promoting the upgrading and replacement of missile weapons and equipment.

[0003] Hydroxybutadiene propellant (HPP) is widely used in strategic and tactical engines due to its stable and reliable comprehensive performance and relatively low price. It is currently the mainstream solid propellant and has made important contributions to the energy output of advanced strategic and tactical solid rocket engines.

[0004] Metal fuels, as the main component of hydroxyl butadiene propellant binders, have a significant impact on the energy performance of propellants. The use of active metal fuels is of great practical significance for improving the energy performance of hydroxyl butadiene propellants and enhancing the strike capability of missile weapons.

[0005] Micron-sized aluminum powder remains one of the most important metallic fuels for solid propellants due to its high energy density and low cost. However, during combustion, micron-sized aluminum powder melts and agglomerates on the propellant combustion surface, forming large agglomerates. On the one hand, this causes unburned Al to be encased within these large Al agglomerates, resulting in incomplete Al combustion and energy loss. On the other hand, the larger the Al agglomerates, the larger the Al₂O₃ particles generated during combustion. Since the Al₂O₃ particles move at a much lower velocity than the airflow during ejection from the nozzle, and larger Al₂O₃ particles have lower thermal conductivity, they cannot fully transfer energy to the airflow for expansion and work, resulting in severe two-phase flow losses and a decrease in engine specific impulse. Summary of the Invention

[0006] The purpose of this invention is to overcome the above-mentioned defects and provide a propellant containing active metal fuel, which solves the problems of low energy and low combustion efficiency of existing propellants.

[0007] The technical solution of the present invention is that, on one hand, the present invention provides a propellant containing active metal fuel, including a binder, plasticizer, curing agent, burning rate regulator, bonding agent, active metal fuel, nitramine explosive and oxidizer.

[0008] Furthermore, the mass percentage of each component of the propellant is as follows: binder 6.5~8.5%; plasticizer 3.0~4.0%; curing agent 0.3~0.4%; burn rate modifier 0.1~2.0%; bonding agent 0.01~0.5%; active metal fuel 15~19%; nitramine explosive 10~18%; oxidizer 52~65%.

[0009] Furthermore, the binder in the propellant of the present invention is hydroxyl-terminated polybutadiene (HTPB); the plasticizer is tributyl citrate (TBC); the curing agent is isophorone diisocyanate (IPDI); the burning rate modifier is ferric oxide; the bonding agent is a complex of triethanolamine and boron trifluoride (T313); the nitramine explosive is octogen (HMX); and the oxidizer is ammonium perchlorate (AP).

[0010] Furthermore, the active metal fuel is an aluminum-gallium metal alloy with an outer layer coated with an aluminum thin film.

[0011] Furthermore, in the active metal fuel, the mass percentage of gallium is 5%, and the thickness of the aluminum thin film is 1.0-2.0 nm; the active metal fuel is a solid powder of 200-500 mesh.

[0012] Furthermore, the preparation steps of the active metal fuel include: S1. Prepare a molten mixture comprising AlF3, Al2O3, and Ga2O3; S2. Electrolyze the molten mixture to obtain an aluminum-gallium alloy; S3. The aluminum-gallium alloy is ball-milled to obtain the active metal fuel. The ball-milling process conditions are as follows: trimethylaluminum vapor is introduced into the system at a rate of 1-2 L / min under an inert gas environment, and the system temperature is maintained at 400°C for 1 hour.

[0013] Furthermore, in step S1, the mass content of Ga2O3 in the molten mixture is 5%, and the mass contents of AlF3 and Al2O3 are 45% and 50%, respectively.

[0014] Furthermore, in step S2, during electrolysis, the molten mixture is used as the electrolyte, graphite is used as the anode and cathode, and electrolysis is carried out under argon protection. During electrolysis, the temperature of the electrolyte is 880~1000℃, the voltage of the electrolytic cell is 2.5~25.0V, and the electrolysis time is 3~12h.

[0015] This invention also provides a method for preparing the above-mentioned propellant containing active metal fuel, comprising the following steps: 1. Use a mixer to mix the various components of the propellant. The water bath temperature of the mixer is 30-70℃, the mixing time is 70-110 min, and the speed of the mixer is 50-150 r / min to obtain the propellant slurry. 2. Use a vacuum casting system to pour the propellant slurry into the engine casing or mold; 3. Place the cast engine or mold into an oven for curing. The oven temperature is 30-70℃ and the curing time is 120-192 hours.

[0016] Furthermore, in step one, before the propellant components are mixed in the mixer, a premixing step and a feeding step are also included: the binder, plasticizer and burn rate regulator are premixed to obtain a premixed material, and then the premixed material is added to the mixing pot, followed by the addition of active metal fuel, nitramine explosive, oxidizer and curing agent.

[0017] Compared with the prior art, the present invention has the following advantages: The active metallic fuel used in this invention is an aluminum-gallium alloy coated with an aluminum film. This alloy has a thin aluminum film, is insensitive to environmental temperature and humidity, and is easy to store. During propellant combustion, this alloy exhibits a micro-explosion effect, which improves propellant combustion efficiency and increases specific impulse. The measured specific impulse of this propellant in the engine is ≥2499 N·s / kg. This propellant possesses the advantage of high combustion efficiency, meeting the high-energy performance requirements of solid rocket engines.

[0018] The second objective of this invention is to provide an active metallic fuel that improves propellant energy performance and provides stable performance. This active metal comprises aluminum and gallium elements and is coated with an aluminum thin film, forming an aluminum-gallium alloy material. This invention significantly enhances propellant energy performance. Gallium elements can break down the alumina film on the surface of the metallic fuel during combustion, thereby increasing the combustion efficiency of aluminum. Furthermore, the aluminum-gallium metal surface obtained through organometallic chemical vapor deposition has a uniform aluminum thin film, making the metal powder insensitive to moisture in the air, which is beneficial for engineering applications. Detailed Implementation

[0019] The embodiments of this application will be described in further detail below. Obviously, the described embodiments are only a part of the embodiments of this application, and not an exhaustive list of all embodiments. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other.

[0020] The terms “first,” “second,” etc. (if applicable) in the specification and claims are used to distinguish similar objects and are not necessarily used to describe a particular order or sequence. It should be understood that such data used can be interchanged where appropriate so that the embodiments described herein can be implemented in orders other than those described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover a non-exclusive inclusion, such as a process, method, system, product, or apparatus that comprises a series of steps or units, not necessarily limited to those explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0021] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0022] Example 1 A propellant with a solid content of 89.5% by mass (of which the active metal fuel is both undersize (400-mesh) and oversize (500-mesh) to meet the requirements of high-solids-content propellants for fine-particle solid components) has the following formulation composition as shown in Table 1, and the performance data of the resulting propellant are shown in Table 2. Table 1 Propellant formulation composition of Example 1 Table 2 Propellant performance obtained in Example 1 Example 2 A propellant with a solid content of 89.0% by mass (of which the active metal fuel is the undersize of a 400-mesh sieve and the oversize of a 500-mesh sieve) has the following formulation composition as shown in Table 3, and the performance data of the resulting propellant are shown in Table 4: Table 3 Propellant formulation in Example 2 Table 4. Propellant performance obtained in Example 2 Example 3 A propellant with a solid content of 85.0% by mass (of which the active metal fuel is the undersize of a 200-mesh sieve and the oversize of a 325-mesh sieve) has the following formulation composition as shown in Table 5, and the performance data of the resulting propellant are shown in Table 6: Table 5. Propellant formulation in Example 3 Table 6. Propellant properties obtained in Example 3: Example 4 A propellant with a solid content of 85.0% by mass (of which the active metal fuel is the undersize of a 400-mesh sieve and the oversize of a 500-mesh sieve) has the following formulation composition as shown in Table 7, and the performance data of the resulting propellant are shown in Table 8: Table 7 Propellant formulation in Example 4 Table 8. Propellant properties obtained in Example 4: As can be seen from Examples 3 and 4, when the particles of the active metal fuel are changed from 200-mesh sieve under 400-mesh sieve, the propellant's heat of explosion increases, the dynamic burning rate increases, and the active aluminum content of the combustion residue decreases under the same solid content.

[0023] Example 5 A propellant with a solid content of 85.0% by mass (wherein the active metal fuel and aluminum powder are both undersize (400 mesh) and oversize (500 mesh) is shown in Table 9 below, and the performance data of the resulting propellant are shown in Table 10. Table 9. Propellant formulation in Example 5 Table 10 Propellant properties obtained in Example 5: As can be seen from Examples 4 and 5, when 7% of ordinary aluminum powder is used to replace the same amount of active metal fuel, the propellant's heat of explosion is significantly reduced, the dynamic burning rate is reduced, and the active aluminum content of the combustion residue is sharply increased under the same solid content.

[0024] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. For those skilled in the art, other variations or modifications can be made based on the above description. It is impossible to exhaustively list all the implementation methods here. All obvious variations or modifications derived from the technical solutions of the present invention are still within the protection scope of the present invention.

Claims

1. A propellant containing active metal fuel, characterized in that, include: The ingredients include adhesives, plasticizers, curing agents, burn rate modifiers, bonding agents, active metal fuels, nitramine explosives, and oxidants; the active metal fuel is an aluminum-gallium metal alloy with an outer layer coated with an aluminum film.

2. The propellant containing active metal fuel according to claim 1, characterized in that: The mass percentage of each component is as follows: Adhesive: 6.5~8.5%; Plasticizer: 3.0~4.0%; Hardener: 0.3~0.4%; Burn rate regulator: 0.1~2.0%; Bonding agent: 0.01~0.5%; Active metal fuels: 15~19%; Nitroamine explosive: 10~18%; Oxidizing agent: 52~65%.

3. The propellant containing active metal fuel according to claim 1, characterized in that, The adhesive is hydroxyl-terminated polybutadiene; The plasticizer is tributyl citrate; The curing agent is isophorone diisocyanate; The combustion rate regulator is ferric oxide; The bonding agent is a complex of triethanolamine and boron trifluoride; The nitramine explosive is octogen; The oxidant is ammonium perchlorate.

4. The propellant containing active metal fuel according to claim 1, characterized in that, In the active metal fuel, the mass percentage of gallium is 5%, and the thickness of the aluminum thin film is 1.0-2.0 nm; the active metal fuel is a solid powder of 200-500 mesh.

5. The propellant containing active metal fuel according to claim 1, characterized in that, The preparation steps of the active metal fuel include: S1. Prepare a molten mixture comprising AlF3, Al2O3, and Ga2O3; S2. Electrolyze the molten mixture to obtain an aluminum-gallium alloy; S3. The aluminum-gallium alloy is ball-milled to obtain the active metal fuel.

6. The propellant containing active metal fuel according to claim 5, characterized in that, In step S1, the mass content of Ga2O3 in the molten mixture is 5%, and the mass contents of AlF3 and Al2O3 are 45% and 50%, respectively.

7. The propellant containing active metal fuel according to claim 5, characterized in that, In step S2, during electrolysis, the molten mixture is used as the electrolyte, and graphite is used as the anode and cathode. Electrolysis is carried out under argon protection. During electrolysis, the temperature of the electrolyte is 880~1000℃, the voltage of the electrolytic cell is 2.5~25.0V, and the electrolysis time is 3~12h.

8. The propellant containing active metal fuel according to claim 5, characterized in that, In step S3, the ball milling process conditions are as follows: under an inert gas environment, trimethylaluminum vapor is introduced into the system at a rate of 1~2 L / min, and the system temperature is maintained at 400℃ for 1 hour.

9. A method for preparing a propellant containing active metal fuel according to claim 1, characterized in that, Includes the following steps:

1. Use a mixer to mix the various components of the propellant. The water bath temperature of the mixer is 30-70℃, the mixing time is 70-110 min, and the speed of the mixer is 50-150 r / min to obtain the propellant slurry.

2. Use a vacuum casting system to cast the propellant slurry into the engine casing or mold; 3. Place the cast engine housing or mold into an oven for curing. The oven temperature is 30-70℃ and the curing time is 120-192 hours.

10. The method for preparing a propellant containing active metal fuel according to claim 9, characterized in that, In step one, before the propellant components are mixed in the mixer, there are also a premixing step and a feeding step: the binder, plasticizer and burning rate regulator are premixed to obtain a premixed material, and then the premixed material is added to the mixing pot, followed by the addition of active metal fuel, nitramine explosive, oxidizer and curing agent.

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