A lithium-in-polymer alloy fuel, its preparation method and application

Abstract

The application provides a lithium cohesive alloy fuel, a preparation method and application thereof, and belongs to the field of metal fuels, and comprises aluminum, silicon and lithium, wherein the aluminum is used as a base body, the mass of the silicon accounts for 0.5-20% of the total mass of the metal fuel, the mass of the lithium accounts for 0.5-10% of the total mass of the metal fuel, and the silicon and the lithium are combined with the aluminum and exist in the form of AlSiLi intermetallic compounds in the elemental Al base body. Preferably, the mass of the silicon accounts for 10% of the total mass of the metal fuel, and the mass of the lithium accounts for 5% of the total mass of the metal fuel. The metal fuel is used for combustion energy release in the field of aerospace. The aluminum, the silicon and the lithium are smelted into an alloy base material by using an ultrahigh-temperature vacuum suspension smelting method, and then the alloy base material is prepared into spherical particles by using a high-temperature gas atomization powder preparation method. The application solves the problems that the aluminum-lithium alloy powder in the existing alloy fuel is easy to oxidize and difficult to store for a long time.

Description

Technical Field

[0001] This invention belongs to the field of metal fuels, and more specifically, relates to a lithium-in-polymer gold fuel, its preparation method and application. Background Technology

[0002] Solid propellant is the core component of missile weapon engines, and its performance has a significant impact on the combat effectiveness of missiles. Since the main energy source of solid propellant is metallic fuel, it is necessary to improve the performance of metallic fuel in order to increase the energy density of solid propellant.

[0003] Elemental aluminum powder is widely used as a metallic fuel in the fields of solid propellants and explosives due to its high energy density and low price. However, it still has some defects in the combustion process: the dense alumina film on the surface of aluminum powder leads to a longer combustion time and a slower combustion rate. In addition, aluminum powder is prone to agglomeration during combustion, resulting in incomplete combustion and insufficient energy release.

[0004] The theoretical mass enthalpy of combustion of lithium is 1.39 times that of aluminum. Lithium can be added as an additive to elemental aluminum fuel to effectively improve its energy performance. However, due to the low melting point of lithium, aluminum-lithium intermetallic compounds exist on the particle surface during solidification. In addition, lithium is highly reactive and easily oxidized, resulting in aluminum-lithium alloy powder exhibiting problems of easy oxidation and difficulty in long-term storage.

[0005] Therefore, there is a need to develop a new type of metallic fuel with lithium cohesion, good antioxidant properties, and excellent energy performance to overcome the above-mentioned problems of existing technologies. Summary of the Invention

[0006] In view of the shortcomings of the prior art, the purpose of this invention is to provide a lithium-in-polymer gold fuel, its preparation method and application, aiming to solve the problems of easy oxidation and difficulty in long-term storage of aluminum-lithium alloy powder in existing alloy fuels.

[0007] To achieve the above objectives, the present invention provides a lithium-in-polymer gold fuel comprising aluminum, silicon and lithium, wherein aluminum is used as the matrix of the alloy fuel, and silicon accounts for 0.5% to 20% of the total mass of the alloy fuel. The silicon element is used to fix the lithium element and inhibit the oxidation of the lithium element.

[0008] Furthermore, lithium accounts for 0.5% to 10% of the total mass of the alloy fuel.

[0009] Furthermore, silicon and lithium exist in the alloy fuel in the form of AlSiLi intermetallic compounds.

[0010] Furthermore, it includes at least elemental Al phase and AlSiLi intermetallic compound phase.

[0011] Furthermore, it is a regularly shaped spherical granular powder with an average particle size D. 50 Not exceeding 50μm.

[0012] Furthermore, its mass combustion enthalpy is not less than 31 kJ / g.

[0013] Furthermore, silicon accounts for 10% of the total mass of the alloy fuel, and lithium accounts for 5% of the total mass of the alloy fuel.

[0014] According to a second aspect of the present invention, a method for preparing the lithium-in-polymer gold fuel as described above is also provided, wherein firstly, aluminum, silicon and lithium are melted by vacuum arc melting to prepare an alloy master material, and then the alloy master material is prepared into spherical particulate powder.

[0015] Furthermore, a high-temperature gas atomization powder preparation method is adopted to melt and atomize the alloy base material, and then condense it to prepare spherical particle powder. In the high-temperature gas atomization powder preparation method, the moving atomizing gas impacts the molten metal or alloy liquid to form fine droplets. The fine droplets are condensed to form solid powder to maintain sphericity.

[0016] According to a third aspect of the invention, the application of the lithium-in-polymer gold fuel described above is also provided, which is used as a solid propellant.

[0017] In summary, compared with the prior art, the above-described technical solutions conceived by this invention have the following advantages:

[0018] Beneficial effects:

[0019] This invention employs a unique formulation design to provide a novel metallic fuel with lithium cohesion, excellent oxidation resistance, and superior energy performance. The silicon additive effectively cohedes the lithium additive, reducing the lithium content on the surface of the metallic fuel powder, hindering lithium contact with air, reducing its oxidation rate, and significantly improving the storage stability of the metallic fuel. This solves the problems of low combustion efficiency, insufficient energy release, and difficulty in long-term storage of existing fuels. Specifically, in the alloy fuel formulation of this invention, silicon and lithium are added to metallic aluminum, and both silicon and lithium are combined with aluminum, existing in the metallic fuel as AlSiLi intermetallic compounds. The addition of lithium can improve the overall energy level of the metallic fuel. Specifically, the lithium additive has high energy content; the theoretical enthalpy of combustion of elemental lithium is as high as 43100 J / g, far exceeding that of other metals, which can greatly improve the energy level of the metallic fuel. Lithium has a low melting point and is easily oxidized. During solidification, the aluminum-lithium intermetallic compound phase exists on the particle surface, causing the aluminum-lithium alloy powder to be easily oxidized, making long-term storage difficult. The silicon element in the metal fuel provided by this invention can effectively fix the lithium element inside the alloy powder particles, thereby improving the oxidation resistance and storage stability of the metal fuel.

[0020] Furthermore, the preferred mass percentage of lithium additive is 0.5–10% of the total mass of the metal fuel; the preferred mass percentage of silicon additive is 0.5–20% of the total mass of the metal fuel. Within this composition range, the metal fuel can ensure the large-scale preparation of alloy fuel powder while fully utilizing its antioxidant properties, exhibiting excellent energy performance. In engineering practice, the preferred mass percentage of lithium is 5% of the total mass of the metal fuel, and the preferred mass percentage of silicon is 10% of the total mass of the metal fuel. The measured mass enthalpy of combustion of the metal fuel under this composition ratio is not lower than the theoretical mass enthalpy of combustion of elemental aluminum fuel (31 kJ / g), and it can meet the requirements of large-scale pulverization. Attached Figure Description

[0021] Figure 1 This is a SEM image of the Al-Si-Li metal fuel powder provided in an embodiment of the present invention.

[0022] Figure 2 This is a magnified SEM image of a single particle of Al-Si-Li metal fuel powder provided in an embodiment of the present invention.

[0023] Figure 3 This is the XRD pattern of Al-Si-Li metal fuel powder provided in an embodiment of the present invention.

[0024] Figure 4 This is an XRD pattern of the combustion products of Al-Si-Li metal fuel provided in an embodiment of the present invention.

[0025] Figure 5 This is a comparison chart of the theoretical and measured enthalpy of combustion of Al-Si-Li metal fuel powder provided in the embodiments of the present invention.

[0026] Figure 6 These are SEM images of Al-Si-Li metal fuel powder and Al-Li metal fuel powder with the same Li content, aged in air for the same amount of time, provided in the embodiments of the present invention.

[0027] Figure 7 This is a line graph comparing the measured mass enthalpy of combustion and combustion efficiency of Al-Si-Li metal fuel powder and Al-Li metal fuel powder with the same Li content, aged in air for the same time, according to embodiments of the present invention.

[0028] Figure 8 These are SIMS images of the surface elemental distribution of Al-Si-Li metal fuel powder and Al-Li metal fuel powder with the same Li content, provided in the embodiments of the present invention. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0030] This invention relates to a metallic fuel with lithium cohesion, good antioxidant properties, and excellent energy performance, its preparation method, and its applications. In terms of composition, it includes aluminum, silicon, and lithium, wherein aluminum serves as the matrix, silicon accounts for 0.5% to 20% of the total mass of the metallic fuel, and lithium accounts for 0.5% to 10% of the total mass of the metallic fuel. Preferably, silicon accounts for 10% of the total mass of the metallic fuel, and lithium accounts for 5% of the total mass of the metallic fuel. In terms of phase composition, both silicon and lithium are combined with aluminum, existing in the metallic fuel as AlSiLi intermetallic compounds. During combustion, silicon fixes lithium, reducing the Li content on the surface of the powder particles and hindering its oxidation. The measured mass enthalpy of combustion of the metallic fuel is not less than 31 kJ / g. In terms of appearance, it consists of regular spherical particles with an average particle size D. 50 With a particle size not exceeding 50 μm, this size offers the advantage of a high specific surface area, ensuring sufficient contact area between the metal fuel powder particles and the oxidizer for complete combustion and improved energy release efficiency. This metal fuel is intended for the aerospace and military fields for combustion energy release, such as as a rocket propellant.

[0031] In terms of composition design, this invention proposes adding silicon and lithium to metallic aluminum, with both silicon and lithium bonded to aluminum, existing in the metal fuel as AlSiLi intermetallic compounds. Silicon effectively fixes lithium within the powder, promoting lithium co-existence, reducing the lithium content on the surface of the metal powder particles, hindering lithium contact with air, thereby slowing its oxidation rate and improving the storage stability of the metal fuel. However, on the other hand, excessive silicon content will increase the melting point of the metal fuel, making it difficult to successfully prepare spherical powder (because when the Si content is too high, on the one hand, it leads to an increase in the melting point of the metal fuel, and on the other hand, it reduces the content of the Al matrix. During the powder preparation process, the Al matrix will not be able to completely occupy the outer surface of the particles, thus leaving pores on the surface of the metal fuel powder). Furthermore, silicon, which plays a catalytic role in energy release, is itself difficult to completely burn; adding too much will affect the energy level of the metal fuel itself. The amount of silicon is crucial in the composition design.

[0032] Specifically, extensive research has shown that the preferred mass percentage of silicon additive is 0.5% to 20% of the total mass of the metal fuel. The preferred mass percentage of lithium additive is 0.5% to 10% of the total mass of the metal fuel. Further, the preferred mass percentage of silicon is 10% of the total mass of the metal fuel, and the preferred mass percentage of lithium is 5% of the total mass of the metal fuel. The measured mass enthalpy of combustion of the metal fuel under this composition ratio is not less than 31 kJ / g, and it can meet the requirements of large-scale pulverization.

[0033] This invention also provides a method for preparing the aforementioned metallic fuel with lithium cohesion, good oxidation resistance, and excellent energy performance. The method involves using vacuum arc melting to melt aluminum, silicon, and lithium to prepare an alloy base material, followed by high-temperature gas atomization powdering technology to melt, atomize, and condense the alloy base material into spherical particles. Specifically, the vacuum arc melting method refers to using arc heat in a vacuum environment to prepare a low-segregation, high-purity alloy base material. The high-temperature gas atomization powdering technology involves using rapidly moving atomizing gas to impact molten metal or alloy liquid to form atomized, broken fine droplets. These droplets then condense to form solid powder, achieving the requirement of preparing alloy powder with high sphericity.

[0034] Specifically, firstly, an Al-Si-Li alloy base material with uniform composition distribution is prepared by melting appropriate amounts of lithium particles (preferably 99.99 wt.% purity, preferably less than 1 mm particle size), silicon wafers (preferably 99.99 wt.% purity, preferably less than 0.5 mm thickness), and aluminum ingots (preferably 99.95 wt.% purity) in a fixed ratio using an ultra-high temperature vacuum suspension melting method. Then, a high-temperature gas atomization powder preparation method is used to appropriately adjust parameters such as spray gas pressure and heating temperature to prepare the alloy base material into Al-Si-Li metal fuel powder with uniform composition and high sphericity. Specifically, when preparing spherical powder using the high-temperature gas atomization powder preparation method, for example, the spray gas pressure is 5 MPa and the heating temperature is 1600℃.

[0035] The following detailed description is provided in conjunction with specific embodiments.

[0036] Example 1

[0037] In this embodiment, the lithium-in-metal alloy fuel is composed of aluminum, silicon, and lithium. The mass of silicon accounts for 0.5% of the total mass of the metal fuel, and the mass of lithium accounts for 0.5% of the total mass of the metal fuel. In terms of phase composition, the alloy fuel includes a single Al phase and an AlSiLi intermetallic compound phase. Both silicon and lithium are bonded to aluminum and exist in the metal fuel in the form of AlSiLi intermetallic compounds.

[0038] The preparation method of this embodiment is as follows: An Al-Si-Li alloy base material with uniform composition distribution is prepared by melting appropriate amounts of lithium particles (preferably with a purity of 99.99 wt.%, and a particle size preferably less than 1 mm), silicon wafers (preferably with a purity of 99.99 wt.%, and a thickness preferably less than 0.5 mm), and aluminum ingots (preferably with a purity of 99.95 wt.%) using an ultra-high temperature vacuum suspension melting method. In this embodiment, the masses of lithium particles, silicon wafers, and aluminum ingots are matched so that the composition of the base material contains 0.5 wt.% Si and 0.5 wt.% Li.

[0039] By appropriately adjusting parameters such as spray gas pressure and heating temperature using a high-temperature gas atomization powder preparation method, the alloy base material is prepared into Al-Si-Li metallic fuel powder with uniform composition and high sphericity. Specifically, when preparing spherical powder using the high-temperature gas atomization powder preparation method, the spray gas pressure is 8 MPa, the heating temperature is 1600℃, and it is cooled in the furnace to obtain Al-Si-Li metallic fuel powder with high sphericity, a particle size of 22-48 μm, and an average particle size D. 50 The value is 31 μm, and it does not exceed 50 μm.

[0040] During the combustion process, the measured mass enthalpy of combustion of metallic fuel is 28.9 kJ / g.

[0041] Example 2

[0042] In this embodiment, the lithium-in-metal alloy fuel is composed of aluminum, silicon, and lithium. Silicon accounts for 2% of the total mass of the metal fuel, and lithium accounts for 1% of the total mass of the metal fuel. In terms of phase composition, the alloy fuel includes elemental Al phase and AlSiLi intermetallic compound phase. Both silicon and lithium are combined with aluminum and exist in the metal fuel in the form of AlSiLi intermetallic compound.

[0043] The preparation method of this embodiment is as follows: An Al-Si-Li alloy masterbatch with uniform composition distribution is prepared by melting appropriate amounts of lithium particles (preferably with a purity of 99.99 wt.%, and a particle size preferably less than 1 mm), silicon wafers (preferably with a purity of 99.99 wt.%, and a thickness preferably less than 0.5 mm), and aluminum ingots (preferably with a purity of 99.95 wt.%) using an ultra-high temperature vacuum suspension melting method. In this embodiment, the masses of lithium particles, silicon wafers, and aluminum ingots are matched so that Si accounts for 2 wt.% and Li accounts for 1 wt.% of the wood composition.

[0044] By appropriately adjusting parameters such as spray gas pressure and heating temperature using a high-temperature gas atomization powder preparation method, the alloy base material is prepared into Al-Si-Li metallic fuel powder with uniform composition and high sphericity. Specifically, when preparing spherical powder using the high-temperature gas atomization powder preparation method, the spray gas pressure is 8 MPa, the heating temperature is 1600℃, and it is cooled in the furnace to obtain Al-Si-Li metallic fuel powder with high sphericity, a particle size of 22-48 μm, and an average particle size D. 50 It is 31 μm. It should not exceed 50 μm.

[0045] During the combustion process, the measured mass enthalpy of combustion of metallic fuel is 29.8 kJ / g.

[0046] Example 3

[0047] In this embodiment, the lithium-in-metal alloy fuel is composed of aluminum, silicon, and lithium. Silicon accounts for 5% of the total mass of the metal fuel, and lithium accounts for 3% of the total mass of the metal fuel. In terms of phase composition, the alloy fuel includes elemental Al phase and AlSiLi intermetallic compound phase. Both silicon and lithium are combined with aluminum and exist in the metal fuel in the form of AlSiLi intermetallic compound.

[0048] The preparation method of this embodiment is as follows: An Al-Si-Li alloy masterbatch with uniform composition distribution is prepared by melting appropriate amounts of lithium particles (preferably with a purity of 99.99 wt.%, and a particle size preferably less than 1 mm), silicon wafers (preferably with a purity of 99.99 wt.%, and a thickness preferably less than 0.5 mm), and aluminum ingots (preferably with a purity of 99.95 wt.%) using an ultra-high temperature vacuum suspension melting method. In this embodiment, the masses of lithium particles, silicon wafers, and aluminum ingots are matched so that Si accounts for 5 wt.% and Li accounts for 3 wt.% of the wood composition.

[0049] By appropriately adjusting parameters such as spray gas pressure and heating temperature using a high-temperature gas atomization powder preparation method, the alloy base material is prepared into Al-Si-Li metallic fuel powder with uniform composition and high sphericity. Specifically, when preparing spherical powder using the high-temperature gas atomization powder preparation method, the spray gas pressure is 9 MPa, the heating temperature is 1600℃, and it is cooled in the furnace to obtain Al-Si-Li metallic fuel powder with high sphericity, a particle size of 22-48 μm, and an average particle size D. 50 The value is 31 μm, and it does not exceed 50 μm.

[0050] During the combustion process, the measured mass enthalpy of combustion of metallic fuel is 30.7 kJ / g.

[0051] Example 4

[0052] In this embodiment, the lithium-in-metal alloy fuel is composed of aluminum, silicon, and lithium. Silicon accounts for 10% of the total mass of the metal fuel, and lithium accounts for 5% of the total mass of the metal fuel. In terms of phase composition, the alloy fuel includes elemental Al phase and AlSiLi intermetallic compound phase. Both silicon and lithium are combined with aluminum and exist in the metal fuel in the form of AlSiLi intermetallic compound.

[0053] The preparation method of this embodiment is as follows: An Al-Si-Li alloy masterbatch with uniform composition distribution is prepared by melting appropriate amounts of lithium particles (preferably with a purity of 99.99 wt.%, and a particle size preferably less than 1 mm), silicon wafers (preferably with a purity of 99.99 wt.%, and a thickness preferably less than 0.5 mm), and aluminum ingots (preferably with a purity of 99.95 wt.%) using an ultra-high temperature vacuum suspension melting method. In this embodiment, the masses of lithium particles, silicon wafers, and aluminum ingots are matched so that Si accounts for 10 wt.% and Li accounts for 5 wt.% of the wood composition.

[0054] By appropriately adjusting parameters such as spray gas pressure and heating temperature using a high-temperature gas atomization powder preparation method, the alloy base material is prepared into Al-Si-Li metallic fuel powder with uniform composition and high sphericity. Specifically, when preparing spherical powder using the high-temperature gas atomization powder preparation method, the spray gas pressure is 8 MPa, the heating temperature is 1600℃, and it is cooled in the furnace to obtain Al-Si-Li metallic fuel powder with high sphericity, a particle size of 22-48 μm, and an average particle size D. 50 The value is 31 μm, and it does not exceed 50 μm.

[0055] During the combustion process, the measured mass enthalpy of combustion of metallic fuel is 31.7 kJ / g.

[0056] Example 5

[0057] In this embodiment, the lithium-in-metal alloy fuel is composed of aluminum, silicon, and lithium. In this embodiment, silicon accounts for 20% of the total mass of the metal fuel, and lithium accounts for 10% of the total mass of the metal fuel. In terms of phase composition, the alloy fuel includes elemental Al phase and AlSiLi intermetallic compound phase. Both silicon and lithium are combined with aluminum and exist in the metal fuel in the form of AlSiLi intermetallic compound.

[0058] The preparation method of this embodiment is as follows: An Al-Si-Li alloy masterbatch with uniform composition distribution is prepared by melting appropriate amounts of lithium particles (preferably with a purity of 99.99 wt.%, and a particle size preferably less than 1 mm), silicon wafers (preferably with a purity of 99.99 wt.%, and a thickness preferably less than 0.5 mm), and aluminum ingots (preferably with a purity of 99.95 wt.%) using an ultra-high temperature vacuum suspension melting method. In this embodiment, the masses of lithium particles, silicon wafers, and aluminum ingots are matched so that Si accounts for 20 wt.% and Li accounts for 10 wt.% of the wood composition.

[0059] By appropriately adjusting parameters such as spray gas pressure and heating temperature using a high-temperature gas atomization powder preparation method, the alloy base material is prepared into Al-Si-Li metallic fuel powder with uniform composition and high sphericity. Specifically, when preparing spherical powder using the high-temperature gas atomization powder preparation method, the spray gas pressure is 8 MPa, the heating temperature is 1600℃, and it is cooled in the furnace to obtain Al-Si-Li metallic fuel powder with high sphericity, a particle size of 22-48 μm, and an average particle size D. 50 The value is 31 μm, and it does not exceed 50 μm.

[0060] During the combustion process, the measured mass enthalpy of combustion of metallic fuel is 29.1 kJ / g.

[0061] Figure 1 The image shows an SEM image of Al-Si-Li metal fuel powder particles provided in this embodiment of the invention. As can be seen from the image, the alloy powder particles prepared by the combination of ultra-high temperature suspension melting and high temperature gas atomization have high sphericity and no obvious agglomeration phenomenon.

[0062] Figure 2 This is a magnified SEM image of a single Al-Si-Li metal fuel powder particle provided in an embodiment of the present invention. As can be seen from the image, the particle surface is not smooth, forming a large number of uniformly distributed network gap structures, which plays a role in refining the grains.

[0063] Figure 3 The image shows the XRD pattern of Al-Si-Li metal fuel powder provided in this embodiment of the invention. As can be seen from the image, Al-Si-Li metal fuel is composed of elemental Al and AlSiLi intermetallic compounds.

[0064] Figure 4 The XRD pattern of the combustion products of Al-Si-Li metal fuel powder provided in this embodiment of the invention shows that the combustion products are mainly composed of Al2O3, SiO2, LiAlO2, and LiAlSiO4.

[0065] Figure 5 This is a comparison chart of the theoretical and measured enthalpy of combustion of Al-Si-Li metallic fuel powder provided in the embodiments of the present invention. Figure 5 (a) in the content is a line graph comparing the theoretical and measured enthalpy of combustion of Al-Si-Li metal fuel powders with different mass proportions of AlSiLi intermetallic compound phases. Figure 5 (b) in the content is a line graph showing the combustion efficiency of Al-Si-Li metallic fuel powder, combined with... Figure 5 In the content (a) and Figure 5As shown in (b) of the content, the measured enthalpy of combustion of Al-Si-Li metal fuel powder shows a trend of first increasing and then decreasing. The maximum measured mass enthalpy of combustion, which is 31.739 kJ / g, is found when the Al-Si-Li intermetallic compound phase reaches 20 wt.%.

[0066] Figure 6 These are SEM images of Al-Si-Li metal fuel powder and Al-5Li metal fuel powder with the same Li content, aged in air for the same amount of time, provided in the embodiments of the present invention. Figure 6 In the content, (a), (b), (c), (d), and (e) are SEM images of Al-5Li metallic fuel powder after aging in air for 0, 10, 20, 30, and 40 days, respectively. Figure 6 In the content, (f), (g), (h), (i), and (j) are SEM images of Al-Si-Li metallic fuel powder after aging in air for 0, 10, 20, 30, and 40 days, respectively. Figure 6 As can be seen from (a), (b), (c), (d), (e), (f), (g), (h), (i), and (j) in the content, the oxidation degree of Al-Si-Li metal fuel powder is significantly lower than that of Al-5Li metal fuel powder with the same Li content, indicating that the addition of Si element does indeed slow down the oxidation of the powder.

[0067] Figure 7 This is a line graph comparing the measured mass enthalpy of combustion and combustion efficiency of Al-Si-Li metal fuel powder and Al-5Li metal fuel powder with the same Li content after aging in air for the same time, according to embodiments of the present invention. Figure 7 In the content (a), the measured mass enthalpy change of Al-Si-Li metallic fuel powder and Al-5Li metallic fuel powder after aging in air for 0, 10, 20, 30 and 40 days are shown in the graph. Figure 7 (b) in the text refers to the line graphs showing the changes in combustion efficiency of Al-Si-Li and Al-5Li metal fuel powders after aging in air for 0, 10, 20, 30, and 40 days, respectively. As shown in the graphs, the rate of decrease in the measured mass enthalpy of combustion of Al-Si-Li metal fuel powder is significantly lower than that of Al-5Li metal fuel powder. The rate of decrease in combustion efficiency of Al-Si-Li metal fuel powder is also significantly lower than that of Al-5Li metal fuel powder.

[0068] Figure 8 These are SIMS images of the surface elemental distribution of Al-Si-Li metal fuel powder and Al-5Li metal fuel powder with the same Li content, provided in the embodiments of the present invention. Figure 8In the content, (a), (b), and (c) refer to SIMS photographs of the Al, Li, and Si content on the surface of Al-5Li metallic fuel powder, respectively. Figure 8 In the content, (d), (e), and (f) refer to SIMS photographs of the Al, Li, and Si content on the surface of Al-Si-Li metallic fuel powder, respectively. As shown in the figures, the Li content on the surface of the Al-Si-Li metallic fuel powder is significantly reduced.

[0069] Table 1 shows the theoretical and measured mass enthalpy of combustion and combustion efficiency of Al-Si-Li metallic fuels with different component ratios, illustrating the relationship between the measured mass enthalpy of combustion of Al-Si-Li metallic fuels and the content of AlSiLi intermetallic compound phase. It can be seen that the addition of a small amount of AlSiLi intermetallic compound phase can effectively improve the energy release level of the metallic fuel. Furthermore, the measured mass enthalpy of combustion of Al-4.35Li metallic fuel is 30325 J / g. After adding 0.5–3 wt.% Si, the measured mass enthalpy of combustion of the alloy fuels all increased to over 31000 J / g, exceeding the theoretical mass enthalpy of combustion of elemental aluminum, further proving that the AlSiLi intermetallic compound phase can indeed improve the overall energy release level of the alloy fuel. Among them, the Al-Si-Li metallic fuel with an AlSiLi intermetallic compound phase content of 20 wt.% has the highest measured mass enthalpy of combustion, reaching 31739 J / g. Si is inherently difficult to combust; therefore, when the Si content exceeds 5 wt.% (or the AlSiLi intermetallic compound phase content exceeds 20 wt.%), the measured mass enthalpy of combustion of Al-Si-Li metal fuel decreases. Considering both the fixation effect of Si on Li and the influence of Li content on the overall energy performance of the alloy, the Al-Si-Li metal fuel with an AlSiLi intermetallic compound phase content of 20 wt.% exhibits the best energy performance. This corresponds to an addition of 10 wt.% Si and 5 wt.% Li by weight of the total alloy powder.

[0070] Table 1. Theoretical and measured mass enthalpy of combustion and combustion efficiency of AlSiLi metallic fuels with different composition ratios.

[0071]

[0072] Table 2 shows the measured mass enthalpy of combustion and combustion efficiency of Al-Si-Li and Al-Li metallic fuels at different aging times. In the table, Al-5Li refers to metallic fuels containing only Al and Li, with Li accounting for 5 wt.% and Al for 95 wt.%; Al-5Li-20Si refers to metallic fuels containing Al, Si, and Li, with Si accounting for 10 wt.%, Li for 5 wt.%, and Al for 85 wt.%. As can be seen from the table, with the same Li content, adding Si can significantly improve the oxidation resistance of metallic fuels and enhance their storage stability.

[0073] Table 2. Measured mass enthalpy of combustion and combustion efficiency of Al-Si-Li and Al-Li metal fuels at different aging times.

[0074]

[0075] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A lithium-in-polymer gold fuel, characterized in that, It includes aluminum, silicon and lithium, with aluminum used as the matrix of the alloy fuel. Silicon accounts for 0.5% to 20% of the total mass of the alloy fuel. Silicon and lithium exist in the alloy fuel in the form of AlSiLi intermetallic compounds. Silicon is used to fix lithium and prevent lithium oxidation.

2. The lithium-in-polymer gold fuel as described in claim 1, characterized in that, Lithium accounts for 0.5% to 10% of the total mass of the alloy fuel.

3. The lithium-in-polymer gold fuel as described in claim 1, characterized in that, It includes the elemental Al phase.

4. The lithium-in-polymer gold fuel as described in claim 1, characterized in that, It is a regular spherical granular powder with an average particle size D 50 Not exceeding 50μm.

5. The lithium-in-polymer gold fuel as described in claim 1, characterized in that, Its mass combustion enthalpy is not less than 31 kJ / g.

6. A lithium-in-polymer gold fuel as described in any one of claims 1-5, characterized in that, Silicon accounts for 10% of the total mass of the alloy fuel, and lithium accounts for 5%.

7. A method for preparing lithium-in-polymer gold fuel as described in any one of claims 1-6, characterized in that, First, aluminum, silicon, and lithium are melted using a vacuum arc melting method to prepare an alloy base material. Then, the alloy base material is prepared into spherical granular powder.

8. The method as described in claim 7, characterized in that, The alloy base material is melted, atomized, and then condensed to prepare spherical powder particles using a high-temperature gas atomization powder preparation method. In high-temperature gas atomization powder production, moving atomizing gas impacts molten metal or alloy liquid to form fine droplets, which are then condensed to form solid powder to maintain sphericity.

9. The application of lithium-polymerized gold fuel as described in any one of claims 1-6, characterized in that, It is used as a solid propellant.

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