Stage spacer material for multi-pulse solid rocket engine and preparation method thereof

Abstract

A stage spacer material suitable for multi-pulse solid rocket engines belongs to the field of energetic materials and contains the following components in percentage by mass: adhesive: 10% to 28%; oxidant: 70% to 85%; curing agent: 1% to 5%; other functional additives: 0% to 3.5%. The novel stage spacer material prepared by the present invention has a linear ablation rate lower than 0.8 mm / s, a mass ablation rate lower than 0.55 g / s, and a thermal conductivity of only about 0.05 W / (m·K). It has good flame insensitivity, high-temperature ablation resistance, and electrical combustion resistance, and has two major advantages: compared with existing inert spacers, this material has higher energy characteristics and can serve as a working fluid; in addition, the electrical combustion characteristic can avoid carrying an igniter, improving the safety performance of the engine system. This technology has broad application prospects in the spacer device of multi-pulse solid rocket engines.

Description

Technical Field

[0001] The invention belongs to the field of solid propellants and relates to a stage spacer material for a multi-pulse solid rocket engine and a preparation method thereof. Background Art

[0002] As a recent development in solid rocket engine technology, the multi-pulse solid rocket engine boasts advantages such as simple structure, easy processing, and simplified assembly. It also effectively offsets the shortcomings of traditional solid rocket engines. This engine utilizes an interstage separator to separate the solid rocket engine combustion chamber into two or more independent combustion chambers, which share a common nozzle. Each combustion chamber ignites and starts sequentially, achieving controllable thrust. This significantly expands the solid rocket engine's operational range across various speed, air, and geographical regions, thereby comprehensively improving the range, accuracy, stealth, and maneuverability of various missile weapon systems. Certain technologies within the engine enable rapid flameout and ignition, allowing for multiple engine starts and multi-pulse thrust.

[0003] The interstage spacer used in a multi-pulse solid rocket engine structurally separates the individual pulse grains. The selection and design of the spacer material is crucial, considering whether it can withstand the prolonged erosion of the high-temperature combustion gases during the operation of the first-stage propellant and maintain structural integrity. The second-stage propellant is covered by the spacer, which acts as a thermal barrier during the operation of the first-stage propellant, ensuring thermal insulation and ablation resistance, preventing ignition of the second-stage propellant, and ensuring reliable operation. Therefore, breakthroughs in interstage spacer technology and its materials are key to the engineering application of multi-pulse engines.

[0004] At present, commonly used interstage isolation devices are mainly divided into two types: hard partitions and soft partitions; the materials used for hard partitions are mainly metals or ceramics, and the materials used for soft partitions are generally polymer materials, such as silicone rubber, EPDM rubber and other rubbers and epoxy resin, polyurethane and other resins.

[0005] However, the above-mentioned spacer materials are all energy-free inert materials. If an energetic material that can withstand high-temperature ablation can be found as a new spacer material, it will be helpful to further improve the overall energy performance and energy control capabilities of solid rocket engines. Summary of the Invention

[0006] The purpose of the present invention is to overcome the shortcomings of the existing technology and provide a multi-pulse solid rocket engine stage spacer material and a preparation method thereof. The stage spacer material provided by the present invention has a linear ablation rate of less than 0.8 mm / s, a mass ablation rate of less than 0.55 g / s, and a low thermal conductivity of only about 0.05 W / (m·K); the preparation method of the present invention is simple and stable, and the synthetic raw materials have a wide source and low price. In addition, it has low toxicity, high safety, and is easy to scale up and control quality. It can significantly improve the problems of complex structure and high proportion of negative mass in existing spacers.

[0007] The technical solution employed in this invention is that the interlayer material is an electrically controlled energetic material using barium perchlorate (PP) as an oxidant. Ablation tests have shown a low ablation rate and a dull flame. Furthermore, its components possess unique electrochemical properties, initiating combustion when a certain current is applied, and the greater the power applied, the faster the burning rate.

[0008] The technical solution of the present invention is to first provide a stage spacer material for a multi-pulse solid rocket engine, including the following components in percentage by mass: adhesive: 10% to 28%; oxidizer: 70% to 85%; curing agent: 1% to 5%; other functional additives: 0% to 3.5%.

[0009] Furthermore, the adhesive is a water-soluble adhesive.

[0010] Furthermore, the water-soluble adhesive is one of polyvinyl alcohol (PVA), polyacrylic acid, polyacrylamide, or a combination of two of the above.

[0011] Furthermore, when the adhesive includes polyvinyl alcohol, the number average molecular weight of the polyvinyl alcohol is 70,000 to 80,000, and the alcoholysis degree is 99%.

[0012] Furthermore, the above-mentioned oxidant is barium perchlorate (PP).

[0013] Furthermore, the curing agent is boric acid or borax (NB).

[0014] Furthermore, the functional additives include one or more of process additives and defoaming agents.

[0015] Furthermore, the process aid is hydroxy silicone oil or methyl silicone oil, and the defoaming agent is lauric acid or fluorinated alkyl phosphate.

[0016] The present invention also provides a method for preparing the stage spacer material for the multi-pulse solid rocket engine. Under room temperature, a curing agent is added to an oxidizer concentrate and stirred until the curing agent is completely dissolved; then an adhesive is added to the mixed solution and the adhesive is completely dissolved; other functional additives are added and stirred to disperse evenly, and then the slurry is placed in a vacuum oven to remove air bubbles and placed in an oven at 50°C for 7 days for curing and forming, thereby obtaining the stage spacer material for the multi-pulse solid rocket engine.

[0017] Furthermore, the method for judging whether the above-mentioned adhesive is completely dissolved is that the viscosity of the slurry increases, the system is uniform, and it is in a stringy state.

[0018] The present invention is more advanced than the prior art in that:

[0019] 1. The interlayer material with barium perchlorate as the main component is a non-metallic composite material with a density far lower than that of metals and ceramics. It has the advantages of light weight and low negative mass ratio when used in engines.

[0020] 2. Compared with existing inert interlayer materials, the interlayer material of the present invention has higher energy characteristics and can serve as a working medium.

[0021] 3. In addition, the energized combustion feature can avoid carrying an igniter and improve the safety performance of the engine system.

[0022] The interlayer material of the present invention can be applied to the field of multi-pulse solid rocket engines. As a new type of interlayer material, it can greatly improve the comprehensive performance of multi-pulse solid rocket engines and will have good application prospects therein. DETAILED DESCRIPTION

[0023] The present invention is described in detail below with reference to specific embodiments, but the protection scope of the present invention is not limited to the following embodiments.

[0024] Example 1

[0025] A stage spacer material for a multi-pulse solid rocket engine, the composition of which is shown in Table 1, and its density is measured to be 1.763 g / cm 3 Example 1 was subjected to ablation resistance test and thermal conductivity test. The test results showed that its linear ablation rate was 0.722 mm / s, the mass ablation rate was 0.508 g / s, and the thermal conductivity was 0.049 W / (m·K) (Table 2).

[0026] Table 1 Composition of barrier materials of Example 1

[0027]

[0028] Table 2 Performance parameters of Example 1

[0029]

[0030] Example 2

[0031] A multi-pulse solid rocket engine stage spacer material, the composition of which is shown in Table 3, and its density is measured to be 1.725 g / cm 3 Example 2 was subjected to ablation resistance test and thermal conductivity test. The test results showed that its linear ablation rate was 0.794 mm / s, the mass ablation rate was 0.553 g / s, and the thermal conductivity was 0.063 W / (m·K) (Table 4).

[0032] Table 3 Composition of interlayer materials of Example 2

[0033]

[0034] Table 4 Performance parameters of Example 2

[0035]

[0036] Example 3

[0037] A multi-pulse solid rocket engine stage spacer material, the composition of which is shown in Table 5, and its density is measured to be 1.755 g / cm 3 Example 3 was subjected to ablation resistance test and thermal conductivity test. The test results showed that its linear ablation rate was 0.766 mm / s, the mass ablation rate was 0.534 g / s, and the thermal conductivity was 0.058 W / (m·K) (Table 6).

[0038] Table 5 Interlayer material composition of Example 3

[0039]

[0040] Table 6 Performance parameters of Example 3

[0041]

[0042] Example 4

[0043] A multi-pulse solid rocket engine stage spacer material, the composition of which is shown in Table 7, and its density is measured to be 1.751 g / cm 3 Interlayer material 4 was subjected to ablation resistance test and thermal conductivity test. The test results showed that its linear ablation rate was 0.770 mm / s, mass ablation rate was 0.537 g / s, and thermal conductivity was 0.058 W / (m·K) (Table 8).

[0044] Table 7 Composition of interlayer materials of Example 4

[0045]

[0046] Table 8 Performance parameters of Example 4

[0047]

[0048] Example 5

[0049] A multi-pulse solid rocket engine stage spacer material, the composition of which is shown in Table 9, and its density is measured to be 1.756 g / cm 3 Interlayer material 5 was subjected to ablation resistance test and thermal conductivity test. The test results showed that its linear ablation rate was 0.765 mm / s, mass ablation rate was 0.531 g / s, and thermal conductivity was 0.056 W / (m·K) (Table 10).

[0050] Table 9 Composition of interlayer materials of Example 5

[0051]

[0052] Table 10 Performance parameters of Example 5

[0053]

[0054] Example 6

[0055] A multi-pulse solid rocket engine stage spacer material, the composition of which is shown in Table 11, and its density is measured to be 1.732 g / cm 3 Interlayer material 6 was subjected to ablation resistance test and thermal conductivity test. The test results showed that its linear ablation rate was 0.792 mm / s, mass ablation rate was 0.552 g / s, and thermal conductivity was 0.062 W / (m·K) (Table 12).

[0056] Table 11 Interlayer material composition of Example 6

[0057]

[0058] Table 12 Performance parameters of Example 6

[0059]

[0060] Example 7

[0061] A multi-pulse solid rocket engine stage spacer material, the composition of which is shown in Table 13, and its density is measured to be 1.758 g / cm 3 Interlayer material 7 was subjected to ablation resistance test and thermal conductivity test. The test results showed that its linear ablation rate was 0.758 mm / s, mass ablation rate was 0.526 g / s, and thermal conductivity was 0.055 W / (m·K) (Table 14).

[0062] Table 13 Interlayer material composition of Example 7

[0063]

[0064] Table 14 Performance parameters of Example 7

[0065]

[0066] Example 8

[0067] A multi-pulse solid rocket engine stage spacer material, the composition of which is shown in Table 15, and its density is measured to be 1.761 g / cm 3 Interlayer material 8 was subjected to ablation resistance test and thermal conductivity test. The test results showed that its linear ablation rate was 0.744 mm / s, mass ablation rate was 0.519 g / s, and thermal conductivity was 0.052 W / (m·K) (Table 16).

[0068] Table 15 Interlayer material composition of Example 8

[0069]

[0070] Table 16 Performance parameters of Example 8

[0071]

[0072] Example 9

[0073] A multi-pulse solid rocket engine stage spacer material, the composition of which is shown in Table 17, and its density is measured to be 1.762 g / cm 3 Interlayer material 9 was subjected to ablation resistance test and thermal conductivity test. The test results showed that its linear ablation rate was 0.739 mm / s, mass ablation rate was 0.516 g / s, and thermal conductivity was 0.051 W / (m·K) (Table 18).

[0074] Table 17 Composition of barrier materials of Example 9

[0075]

[0076] Table 18 Performance parameters of Example 9

[0077]

[0078] While various embodiments of the present invention have been described above, the foregoing description is intended to be illustrative, non-exhaustive, and not limiting of the disclosed embodiments. Numerous modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. Therefore, the scope of the present invention shall be determined by the scope of the claims.

Claims

1. A stage spacer material for a multi-pulse solid rocket engine, characterized in that: It includes the following components in percentage by mass: Adhesive: 10%~28%; Oxidant: 70%~85%; Curing agent: 1%~5%; Other functional additives: 0%~3.5%; The adhesive is a water-soluble adhesive; The water-soluble adhesive is one of polyvinyl alcohol, polyacrylic acid, polyacrylamide, or a combination of two thereof; when the adhesive includes polyvinyl alcohol, the number average molecular weight of the polyvinyl alcohol is 70,000 to 80,000, and the alcoholysis degree is 99%; The oxidant is barium perchlorate; The curing agent is boric acid or borax; The other functional additives include one or more of process additives and defoaming agents.

2. The stage spacer material for a multi-pulse solid rocket engine according to claim 1, characterized in that: The process aid is hydroxy silicone oil or methyl silicone oil, and the defoaming agent is lauric acid or fluorinated alkyl phosphate.

3. A method for preparing a stage spacer material for a multi-pulse solid rocket engine according to any one of claims 1 to 2, characterized in that: At room temperature, a curing agent is added to the oxidizer concentrate and stirred until the curing agent is completely dissolved; then an adhesive is added to the mixed solution and the adhesive is completely dissolved; other functional additives are added, stirred and dispersed evenly, and the slurry is placed in a vacuum oven to remove air bubbles and solidify into shape, thereby obtaining the stage spacer material for the multi-pulse solid rocket engine.

4. The method for preparing a stage spacer material for a multi-pulse solid rocket engine according to claim 3, characterized in that: The method for judging whether the adhesive is completely dissolved is that the viscosity of the slurry increases, the system is uniform, and it is in a stringy state.

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