Solid rocket engine expansion section and forming method thereof

Abstract

The invention relates to the field of solid rocket engines, in particular to a solid rocket engine expansion section and a forming method thereof.The expansion section comprises a carbon layer, and the carbon layer comprises a carbon cloth tape / phenolic resin material layer; the high silica layer comprises a high silica cloth tape / phenolic resin material layer; the high silica layer is wound on the outer side of the carbon layer, and the connection interface of the carbon layer and the high silica layer is a conical surface; the high silica layer and the carbon layer are integrally cured and formed; the expansion section product does not need to be machined for multiple times, the interface bonding strength of the carbon layer and the high-silica layer of the expansion section product is high, waste of the carbon cloth belt / phenolic resin material layer and the high-silica cloth belt / phenolic resin material layer is reduced, and meanwhile the thickness requirements of the carbon layer and the high-silica layer are met; and the performance requirements of the expansion section when bearing high temperature, ablation and mechanical load are met.

Description

Technical Field

[0001] The invention relates to the field of solid rocket engines, and in particular to an expansion section of a solid rocket engine and a molding method thereof. Background Art

[0002] The expansion section is a key component in the rocket engine nozzle to improve the energy conversion efficiency. During the operation of the solid engine, the nozzle diffusion section needs to provide a stable aerodynamic interface under the scouring effect of the high-temperature and high-condensed phase component airflow to ensure the thrust conversion efficiency of the solid engine; the expansion section needs to withstand the combined effects of high temperature, ablation and mechanical loads;

[0003] With the development of solid rocket engine technology, diversified technical requirements have been put forward for nozzle expansion section technology. Since the insulation layer of the diffusion section is generally composed of a carbon layer and a high silicon oxide layer, or a single carbon layer, the main function of the carbon layer is to resist ablation, and the main function of the high silicon oxide layer is to insulate, the resin-based expansion section has the advantages of high reliability, short production cycle and low cost. Therefore, it is widely used in high-performance solid rocket engines at home and abroad.

[0004] However, the traditional winding method involves first winding the carbon layer, then winding the high-silicon oxide layer after one machining process, or first winding the carbon layer, then winding the high-silicon oxide layer after one machining process after pre-curing. This results in the problem of waste of carbon cloth tape / phenolic resin material layers and weak interface bonding between the carbon layer and the high-silicon oxide layer. The interlayer shear strength is less than 10 MPa, resulting in delamination problems. The performance requirements of the expansion section when subjected to high temperature, ablation and mechanical loads cannot be met.

[0005] Therefore, it is necessary to design an expansion section forming method that improves the above problems. Summary of the invention

[0006] In order to solve the problems of the prior art, the present invention provides a solid rocket engine expansion section, the expansion section comprising:

[0007] A carbon layer, the carbon layer comprising a carbon cloth tape / phenolic resin material layer;

[0008] A high-silicon oxide layer, the high-silicon oxide layer comprises a high-silicon oxide cloth tape / phenolic resin material layer; the high-silicon oxide layer is wrapped around the outside of the carbon layer, the connection interface between the carbon layer and the high-silicon oxide layer is a conical surface; and the high-silicon oxide layer and the carbon layer are integrally solidified.

[0009] Furthermore, the thicknesses of the carbon layer and the high silicon oxide layer are confirmed according to the actual working conditions of the expansion section, and according to the heat transfer path, the thickness of the carbon layer at the outlet part of the solid rocket nozzle is set to be gradually smaller than the thickness of the carbon layer at the inlet part of the solid rocket nozzle.

[0010] Furthermore, the thickness of the carbon layer at the outlet portion of the solid rocket nozzle is smaller than the thickness of the carbon layer at the inlet portion of the solid rocket nozzle.

[0011] A solid rocket engine expansion section and a forming method thereof, comprising the following steps:

[0012] S1, carbon layer winding, the carbon layer includes a carbon cloth tape / phenolic resin material layer, according to the carbon layer winding procedure, the carbon cloth tape / phenolic resin material layer is wound on the outer side of the core mold in a variable thickness manner;

[0013] S2, high silica layer winding, the high silica tape / phenolic resin material layer is wound on the conical section of the expansion section with the carbon tape / phenolic resin material layer in the trapezoidal area II of the straight section of the core mold in equal thickness, so that the carbon layer and the high silica layer are wound on the outside of the core mold as a whole;

[0014] S3, after the winding is completed, a core mold coated with the carbon layer and the high silicon oxide layer is obtained, and then the core mold is placed in an autoclave for temperature rise and curing, and after curing is completed, the mold is demolded to obtain an expansion section blank, and the expansion section blank is machined to obtain an expansion section product, and the autoclave molding pressure is not greater than 3.0MPa;

[0015] S4: Conduct demoulding inspection on the expanded section products and keep records;

[0016] Further, the carbon cloth tape / phenolic resin material layer is wound in a variable thickness manner, specifically including: firstly overlapping one side of the carbon cloth tape / phenolic resin material layer to the intersection of the straight section and the conical section of the core mold, executing the carbon layer winding procedure until the carbon cloth tape / phenolic resin material layer reaches the end of the conical section of the core mold, the procedure ends, and the carbon layer winding of area I is completed; then, the carbon cloth tape / phenolic resin material layer is continued to be overlapped, and the trapezoidal area II of the straight section of the core mold is leveled in a semi-overlapping manner;

[0017] Further, the high-silica tape / phenolic resin material layer is wound in an equal-thickness manner, specifically including: the high-silica tape / phenolic resin material layer includes a first high-silica tape / phenolic resin material layer and a second high-silica tape / phenolic resin material layer, firstly, one side of the first high-silica tape / phenolic resin material layer is overlapped to the intersection of the carbon tape / phenolic resin material layer in the trapezoidal area II of the straight section of the core mold and the core mold cone section, and the high-silica layer winding procedure is performed until the end of the core mold cone section The procedure is completed to complete the high-silica layer winding in the core mold cone section area III; then the second high-silica tape / phenolic resin material layer is reciprocatedly wound at the end of the core mold cone section in a semi-overlapping manner to complete the high-silica layer winding in the core mold cone section area IV;

[0018] Further, the width of the carbon tape / phenolic resin material layer is determined by the width of the intersection of the carbon layer cone section and the core mold straight section, and the width of the high silica tape / phenolic resin material layer climbing section is determined by the width of the intersection of the high silica tape and the core mold straight section minus the width of the carbon tape / phenolic resin material layer;

[0019] Further, in step S3, before curing and molding in the autoclave, the coated core mold is vacuum-packed with a breathable film, a rubber-absorbing felt and a vacuum bag, and the vacuum is evacuated to a vacuum degree of less than -0.098 MPa;

[0020] Further, in step S3, the core mold is placed in an autoclave for temperature curing, and demoulding is performed after curing to obtain an expansion section blank, and the expansion section blank is machined to obtain an expansion section product, which specifically includes:

[0021] Raise the temperature from room temperature to 60-80°C at a rate of 1°C / min and 0.03MPa / min, increase the pressure by 0.8-1MPa, and keep warm for 1-2h;

[0022] Raise the temperature from 80°C to 100°C at a rate of 0.5°C / min and 0.03MPa / min, maintain the pressure at 2MPa, and keep warm for 1.5-2h;

[0023] Raise the temperature from 100°C to 130°C at a rate of 0.5°C / min and 0.03MPa / min, maintain the pressure at 2MPa, and keep warm for 2-3h;

[0024] The temperature is raised from 130°C to 160°C at a rate of 0.5°C / min and 0.03MPa / min, and the pressure is maintained at 2MPa for 2-3 hours; after the curing is completed, when the temperature in the autoclave drops to below 50°C, the core mold to be cured is taken out, and the core mold to be cured is cooled to below 30°C at room temperature, and the expansion section blank formed by the carbon layer and the high silicon oxide layer is removed from the mold, and the expansion section blank is machined to obtain an expansion section product;

[0025] Furthermore, a carbon layer climbing program is provided in the carbon layer winding program. The feed F of each small section of the carbon layer in the carbon layer climbing program is: the axial length of the core mold cone section is evenly divided, F = axial feed / cosα;

[0026] Wherein, axial feed = carbon layer cloth tape / phenolic resin material layer width / number of layers; α is the angle between the straight section and the tapered section of the carbon layer in region I;

[0027] The high-silicon layer winding program is provided with a high-silicon layer climbing program. The feed F of each small section of the high-silicon layer program is: the axial length of the core mold cone section is evenly divided, F = high-silicon cloth tape / phenolic resin material layer / sinα;

[0028] Beneficial effects of the present invention:

[0029] The solid rocket engine expansion section molding method of the present invention comprises the following steps: a carbon layer and a high silica layer are integrally wound on the outer side of a core mold, a carbon cloth tape / phenolic resin material layer is wound on the outer side of the core mold in a variable thickness manner; after the carbon layer is wound, the high silica layer is directly wound, and the high silica cloth tape / phenolic resin material layer is compositely wound on the conical section of the expansion section with the carbon cloth tape / phenolic resin material layer in a straight section trapezoidal region II of the core mold in a constant thickness manner; after the winding is completed, the core mold coated with the carbon layer and the high silica layer is placed in an autoclave for temperature-raising and curing, and after the curing is completed, the mold is demoulded to obtain an expansion section blank in which the carbon layer and the high silica layer are integrally fixed and molded, and the expansion section blank is mechanically processed to obtain an expansion section product, without the need for multiple machining, thereby reducing the waste of the carbon cloth tape / phenolic resin material layer and the high silica cloth tape / phenolic resin material layer, while ensuring the required thickness requirements of the carbon layer and the high silica layer, so that the carbon layer and the high silica layer of the expansion section product have high interface bonding strength. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 Schematic diagram of carbon layer winding and high silicon oxide layer winding in an embodiment of the present invention;

[0031] Figure 2 Schematic diagram of the carbon layer winding process in an embodiment of the present invention;

[0032] Figure 3 A schematic structural diagram of the expansion section product of the present invention. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] The present invention provides a solid rocket engine expansion section, the expansion section comprising:

[0035] A carbon layer, the carbon layer comprising a carbon cloth tape / phenolic resin material layer;

[0036] A high-silicon oxide layer, the high-silicon oxide layer comprises a high-silicon oxide cloth tape / phenolic resin material layer; the high-silicon oxide layer is wrapped around the outside of the carbon layer, the connection interface between the carbon layer and the high-silicon oxide layer is a conical surface; and the high-silicon oxide layer and the carbon layer are integrally solidified.

[0037] Furthermore, the thicknesses of the carbon layer and the high silicon oxide layer are confirmed according to the actual working conditions of the expansion section, and according to the heat transfer path, the thickness of the carbon layer at the outlet part of the solid rocket nozzle is set to be gradually smaller than the thickness of the carbon layer at the inlet part of the solid rocket nozzle.

[0038] Furthermore, the thickness of the carbon layer at the outlet portion of the solid rocket nozzle is smaller than the thickness of the carbon layer at the inlet portion of the solid rocket nozzle.

[0039] See also Figure 1-2 , a solid rocket engine expansion section and a forming method thereof, comprising the following steps:

[0040] S1, carbon layer winding, the carbon layer includes a carbon cloth tape / phenolic resin material layer, according to the carbon layer winding procedure, the carbon cloth tape / phenolic resin material layer is wound on the outer side of the core mold in a variable thickness manner;

[0041] S2, high silica layer winding, the high silica tape / phenolic resin material layer is wound on the conical section of the expansion section with the carbon tape / phenolic resin material layer in the trapezoidal area II of the straight section of the core mold in equal thickness, so that the carbon layer and the high silica layer are wound on the outside of the core mold as a whole;

[0042] S3, after the winding is completed, a core mold coated with the carbon layer and the high silicon oxide layer is obtained, and then the core mold is placed in an autoclave for temperature rise and curing, and after curing is completed, the mold is demolded to obtain an expansion section blank, and the expansion section blank is machined to obtain an expansion section product, and the autoclave molding pressure is not greater than 3.0MPa;

[0043] S4: Conduct demoulding inspection on the expanded section products and keep records;

[0044] Further, the carbon cloth tape / phenolic resin material layer is wound in a variable thickness manner, specifically including: firstly overlapping one side of the carbon cloth tape / phenolic resin material layer to the intersection of the straight section and the conical section of the core mold, executing the carbon layer winding procedure until the carbon cloth tape / phenolic resin material layer reaches the end of the conical section of the core mold, the procedure ends, and the carbon layer winding of area I is completed; then, the carbon cloth tape / phenolic resin material layer is continued to be overlapped, and the trapezoidal area II of the straight section of the core mold is leveled in a semi-overlapping manner;

[0045] Furthermore, the high-silica tape / phenolic resin material layer is wound in an equal thickness manner, specifically including: the high-silica tape / phenolic resin material layer includes a first high-silica tape / phenolic resin material layer and a second high-silica tape / phenolic resin material layer, firstly, one side of the first high-silica tape / phenolic resin material layer is overlapped to the intersection of the carbon tape / phenolic resin material layer and the core mold conical section in the trapezoidal area II of the straight section of the core mold, such as Figure 1 As shown, that is, at point G; the high-silicon oxide layer winding procedure is performed until the procedure ends at the end of the core mold cone section, and the high-silicon oxide layer winding in the core mold cone section area III is completed; then the second high-silicon oxide cloth tape / phenolic resin material layer is reciprocatedly wound at the end of the core mold cone section in a semi-overlapping manner to complete the high-silicon oxide layer winding in the core mold cone section area IV;

[0046] Further, the width of the carbon tape / phenolic resin material layer is determined by the width of the intersection of the carbon layer cone section and the core mold straight section, and the width of the high silica tape / phenolic resin material layer climbing section is determined by the width of the intersection of the high silica tape and the core mold straight section minus the width of the carbon tape / phenolic resin material layer;

[0047] Further, in step S3, before curing and molding in the autoclave, the coated core mold is vacuum-packed with a breathable film, a rubber-absorbing felt and a vacuum bag, and the vacuum is evacuated to a vacuum degree of less than -0.098 MPa;

[0048] Vacuum packaging and vacuuming are performed before curing to remove air from the product, reduce the generation of bubbles during the curing process, and improve the quality of the composite material;

[0049] Further, in step S3, the core mold is placed in an autoclave for temperature curing, and demoulding is performed after curing to obtain an expansion section blank, and the expansion section blank is machined to obtain an expansion section product, which specifically includes:

[0050] Raise the temperature from room temperature to 60-80°C at a rate of 1°C / min and 0.03MPa / min, increase the pressure by 0.8-1MPa, and keep warm for 1-2h;

[0051] Raise the temperature from 80°C to 100°C at a rate of 0.5°C / min and 0.03MPa / min, maintain the pressure at 2MPa, and keep warm for 1.5-2h;

[0052] Raise the temperature from 100°C to 130°C at a rate of 0.5°C / min and 0.03MPa / min, maintain the pressure at 2MPa, and keep warm for 2-3h;

[0053] The temperature is raised from 130°C to 160°C at a rate of 0.5°C / min and 0.03MPa / min, and the pressure is maintained at 2MPa for 2-3 hours; after the curing is completed, when the temperature in the autoclave drops to below 50°C, the core mold to be cured is taken out, and the core mold to be cured is cooled to below 30°C at room temperature, and the expansion section blank formed by the carbon layer and the high silicon oxide layer is removed from the mold, and the expansion section blank is machined to obtain an expansion section product;

[0054] Furthermore, a carbon layer climbing program is provided in the carbon layer winding program, and the feeding F of each small section of the carbon layer in the carbon layer climbing program is:

[0055] Divide the axial length of the core mold cone section equally, F = axial feed / cosα;

[0056] Wherein, axial feed = carbon layer cloth tape / phenolic resin material layer width / number of layers; α is the angle between the straight section and the tapered section of the carbon layer in region I;

[0057] The high silicon oxide layer winding program is provided with a high silicon oxide layer ramping program. The feed F of each small section of the high silicon oxide layer program is:

[0058] Divide the axial length of the core mold cone section equally, F = high silica tape / phenolic resin material layer thickness

[0059] / sinα;

[0060] Example 1, the autoclave molding pressure is 2.0 MPa, and the interface bonding strength between the carbon layer and the high silicon oxide layer is required to be high. The specific steps are:

[0061] S1, carbon layer winding, the carbon layer includes a carbon cloth tape / phenolic resin material layer, according to the carbon layer winding procedure, the carbon cloth tape / phenolic resin material layer is wound on the outer side of the core mold in a variable thickness manner;

[0062] like Figure 1 As shown, the right side of the carbon cloth tape / phenolic resin material layer with a width of 43 mm is overlapped to the intersection point A of the straight section and the conical section of the core mold, and the carbon layer winding procedure is started until the cloth tape reaches point B and the procedure ends, completing the carbon layer winding of area I; then it returns to the small end of the core mold, continues to overlap the carbon cloth tape / phenolic resin material layer, and uses a semi-overlapping method to level the trapezoidal area II of the straight section of the core mold;

[0063] The carbon layer winding program is provided with a carbon layer climbing program. The feed F of each small section of the carbon layer in the carbon layer climbing program is: the axial length of the core mold cone section is evenly divided, F = axial feed / cos α; wherein, axial feed = carbon layer cloth tape / phenolic resin material layer width / number of layers; α is the angle between the straight section and the cone section of the carbon layer in area I;

[0064] Specifically, the feed F refers to the distance that the carbon cloth tape / phenolic resin material layer or high silica cloth tape / phenolic resin material layer moves along the core mold cone section for each rotation of the winding machine spindle; the carbon layer winding procedure of the climbing section, such as Figure 2 As shown, it specifically includes: dividing the axial length of the core mold AB segment equally, the number of equal divisions is determined according to the axial length of AB, ensuring that the length of each segment is 10-40mm, and the number of equal divisions is controlled within 10-30 segments, so that the program control is accurate, and according to the actual required carbon layer size, appropriate volume is released to prevent the carbon layer from shrinking after solidification, resulting in insufficient size, and the actual designed carbon layer size CE is obtained; Figure 2 The radial length of sections 1-10 is measured, that is, the radial design thickness is L, L / 0.2 (carbon cloth tape / phenolic resin material layer thickness) = number of layers;

[0065] Calculate the axial feed = 43 (carbon cloth tape / phenolic resin material layer width) / number of layers;

[0066] Depend on Figure 2 As shown, measure the angle α between the CE segment and the AE segment, which is α = 15.86°;

[0067] Calculate the feed F of each small program segment = axial feed / cosα; based on the feed F of each small program segment of the carbon layer, obtain the axial length and radial length of each segment of the carbon layer AB segment after being evenly divided; at this point, the carbon layer climbing program is set;

[0068] S2, high silica layer winding, the high silica tape / phenolic resin material layer is wound on the conical section of the expansion section with the carbon tape / phenolic resin material layer in the trapezoidal area II of the straight section of the core mold in equal thickness, so that the carbon layer and the high silica layer are wound on the outside of the core mold as a whole;

[0069] Among them, high silica layer winding: the carbon cloth tape / phenolic resin material layer is replaced with a first high silica cloth tape / phenolic resin material layer with a width of 80 mm, one side of the first high silica cloth tape / phenolic resin material layer is overlapped to point G, and the high silica layer winding program is executed until the program at point C ends, and the high silica layer winding of area III of the core mold cone section is completed; then it is replaced with a second high silica cloth tape / phenolic resin material layer with a width of 40 mm, and reciprocatingly wound from point D to point B in a semi-overlapping manner to form area IV; wherein the width of the carbon cloth tape / phenolic resin material layer is determined by the width of the intersection line of the carbon layer cone section and the core mold straight section, and the width of the climbing section of the high silica cloth tape / phenolic resin material layer is determined by the width of the intersection line of the high silica layer cone section and the core mold straight section minus the width of the carbon cloth tape / phenolic resin material layer, and 10% to 20% shrinkage margin is reserved for both the carbon layer and the high silica layer;

[0070] During the high-silica layer winding process, high-silica tapes / phenolic resin material layers of different widths are set in different areas of the winding method and path to ensure the coverage and structural strength of the high-silica layer at different parts of the expansion section, so that it and the carbon layer together form a complete insulation layer shape to meet the requirements of thermal insulation and anti-ablation performance;

[0071] Among them, the nozzle expansion section has an insulating layer formed by integrally winding and curing a carbon layer and a high-silicon oxide layer, wherein the interface bonding strength between the carbon layer and the high-silicon oxide layer is high, and the thickness of the carbon layer is guaranteed by the winding program, and no pre-curing or carbon layer machining is required; the composite winding of the carbon layer and the high-silicon oxide layer is realized on the straight cone section of the core mold, the carbon layer is wound in a variable thickness manner, and the high-silicon oxide layer is wound in a constant thickness manner in cooperation with the carbon layer, so as to jointly meet the performance requirements of the expansion section when subjected to high temperature, ablation and mechanical loads; wherein, during the carbon layer winding process, the winding path of the carbon cloth tape / phenolic resin material layer is precisely controlled by the carbon layer winding program during the entire process to ensure that the initial forming of the carbon layer meets expectations, and when leveling the trapezoidal area II of the straight section of the core mold, the semi-overlapping method makes the carbon cloth tape / phenolic resin material layer fit closely to the surface of the core mold to reduce gaps and unevenness.

[0072] Among them, a high-silicon layer climbing program is set in the high-silicon layer winding program, and the program feed F of each small section of the high-silicon layer is: the axial length of the core mold cone section is evenly divided, F = high-silicon cloth tape / phenolic resin material layer thickness / sinα; specifically, in the high-silicon layer winding step, the high-silicon winding program of the climbing section is set as: program feed F = high-silicon cloth tape / phenolic resin material layer thickness / sinα; based on the program feed F of each small section of the high-silicon layer, the axial and radial coordinate changes of the GC section are obtained;

[0073] S3, after the winding is completed, a core mold coated with the high-silica cloth tape / phenolic resin material layer / carbon cloth tape / phenolic resin material layer is obtained, and then cured and molded in an autoclave, and the autoclave molding pressure is 2.0 MPa;

[0074] Before curing and molding in the autoclave, the coated core mold is vacuum-packed with a breathable film, adhesive felt and vacuum bag, and the vacuum is evacuated to a vacuum degree of less than -0.098MPa;

[0075] Vacuum packaging and vacuuming are performed before curing to remove air from the product, reduce the generation of bubbles during the curing process, and improve the quality of the composite material;

[0076] The core mold is placed in an autoclave for heating and curing, and demoulding is performed after curing to obtain an expansion section blank, and the expansion section blank is machined to obtain an expansion section product, specifically including:

[0077] Raise the temperature from room temperature to 60-80°C at a rate of 1°C / min and 0.03MPa / min, increase the pressure to 0.8-1MPa, and keep warm for 1-2h; raise the temperature from 80°C to 100°C at a rate of 0.5°C / min and 0.03MPa / min, keep the pressure at 2MPa, and keep warm for 1.5-2h; raise the temperature from 100°C to 130°C at a rate of 0.5°C / min and 0.03MPa / min, keep the pressure at 2MPa, and keep warm for 2-3h; .5℃ / min, 0.03MPa / min, the temperature is raised from 130℃ to 160℃, the pressure is maintained at 2MPa, and the temperature is maintained for 2-3h; after the curing is completed, when the temperature in the autoclave drops to below 50℃, the core mold to be cured is taken out, the core mold to be cured is cooled to below 30℃ at room temperature, the expansion section blank formed by the carbon layer and the high silicon oxide layer is removed from the mold, the expansion section blank is machined to obtain the expansion section product; and then it is machined to the required size of the nozzle expansion section;

[0078] It should be noted that the parameters such as the heating rate, pressure increase rate, holding time and temperature in the curing step are set to ensure that the resin in the prepreg tape flows evenly and is fully cured during the curing process, avoiding the generation of bubbles, excessive internal stress, material cracking or deformation, and improving the density, mechanical properties, heat resistance and dimensional stability of the composite material. Among them, the machining step is carried out after curing, cooling and demolding, and is used to accurately adjust the size of the expansion section to achieve the final size required by the product, ensuring that the dimensional accuracy and performance of the product meet the design requirements;

[0079] S4: After curing, demoulding test was carried out. After demoulding test, it was found that the interface bonding strength between the carbon layer and the high silica layer was high, which met the performance requirements of the expansion section under high temperature, ablation and mechanical load. The interlayer shear strength of the carbon cloth tape / phenolic resin material layer was 16MPa, and the interlayer shear strength of the high silica cloth tape / phenolic resin material layer was 19MPa, which met the requirements of GB1450.1-2005 standard.

[0080] Example 2: The other conditions in the solid rocket engine expansion section and the molding method thereof are the same as those in the example. The solid rocket engine expansion section is cured and molded in an autoclave. The molding pressure of the autoclave is 2.0 MPa. After the curing is completed, a demolding test is performed. After the demolding test, it is found that the interface bonding strength between the carbon layer and the high silica layer is high, the interlaminar shear strength of the carbon cloth tape / phenolic resin material layer is 15 MPa, and the interlaminar shear strength of the high silica cloth tape / phenolic resin material layer is 17 MPa. The requirements of GB 1450.1-2005 standard are met, and the performance requirements of the expansion section when subjected to high temperature, ablation and mechanical load are met.

[0081] It is worth noting that the solid rocket engine expansion section molding method of the present invention adopts a carbon layer and a high silica layer to be integrally wound on the outside of the core mold, and a carbon cloth tape / phenolic resin material layer is wound on the outside of the core mold in a variable thickness manner; after the carbon layer is wound, the high silica layer is directly wound, and the high silica cloth tape / phenolic resin material layer is compositely wound on the conical section of the expansion section with the carbon cloth tape / phenolic resin material layer in the trapezoidal region II of the straight section of the core mold in a constant thickness manner, and after the winding is completed, the core mold coated with the carbon layer and the high silica layer is placed in an autoclave for temperature curing, and after the curing is completed, the mold is demolded to obtain an expansion section blank in which the carbon layer and the high silica layer are integrally fixed and molded; and the expansion section blank is mechanically processed to obtain an expansion section product, without the need for multiple machining, thereby reducing the waste of the carbon cloth tape / phenolic resin material layer and the high silica cloth tape / phenolic resin material layer, while ensuring the required thickness requirements of the carbon layer and the high silica layer, so that the interface bonding strength of the carbon layer and the high silica layer of the expansion section product is high. Among them, the carbon layer winding procedure ensures the thickness of the carbon layer, and the thickness of the high silicon oxide layer is ensured by machining after curing; the problem that the existing expansion section insulation layer composite winding process requires multiple machining-winding is solved.

[0082] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A solid rocket engine expansion section, characterized in that: The expansion section comprises: A carbon layer, the carbon layer comprising a carbon cloth tape / phenolic resin material layer; A high-silicon oxide layer, the high-silicon oxide layer comprises a high-silicon oxide cloth tape / phenolic resin material layer; the high-silicon oxide layer is wrapped around the outside of the carbon layer, the connection interface between the carbon layer and the high-silicon oxide layer is a conical surface; and the high-silicon oxide layer and the carbon layer are integrally solidified.

2. The solid rocket motor expansion section according to claim 1, characterized in that: The thicknesses of the carbon layer and the high silicon oxide layer are confirmed according to the actual working conditions of the expansion section, and according to the heat transfer path, the thickness of the carbon layer at the outlet of the solid rocket nozzle is set to be gradually smaller than the thickness of the carbon layer at the inlet of the solid rocket nozzle.

3. The solid rocket motor expansion section according to claim 1, characterized in that: The thickness of the carbon layer at the outlet portion of the solid rocket nozzle is smaller than the thickness of the carbon layer at the inlet portion of the solid rocket nozzle.

4. A solid rocket engine expansion section and a forming method thereof, characterized in that: The steps include: S1, carbon layer winding, the carbon layer includes a carbon cloth tape / phenolic resin material layer, according to the carbon layer winding procedure, the carbon cloth tape / phenolic resin material layer is wound on the outer side of the core mold in a variable thickness manner; S2, high silica layer winding, the high silica tape / phenolic resin material layer is wound on the conical section of the expansion section with the carbon tape / phenolic resin material layer in the trapezoidal area II of the straight section of the core mold in equal thickness, so that the carbon layer and the high silica layer are wound on the outside of the core mold as a whole; S3, after the winding is completed, a core mold coated with the carbon layer and the high silicon oxide layer is obtained, and then the core mold is placed in an autoclave for temperature rise and curing, and after curing is completed, the mold is demolded to obtain an expansion section blank, and the expansion section blank is machined to obtain an expansion section product, and the autoclave molding pressure is not greater than 3.0MPa; S4: Carry out demoulding inspection on the expansion section products and keep records.

5. The solid rocket engine expansion section and the forming method thereof according to claim 1, characterized in that: The carbon cloth tape / phenolic resin material layer is wound in a variable thickness manner, specifically including: first overlapping one side of the carbon cloth tape / phenolic resin material layer to the intersection of the straight section and the conical section of the core mold, executing the carbon layer winding procedure until the carbon cloth tape / phenolic resin material layer reaches the end of the conical section of the core mold, the procedure ends, and the carbon layer winding of area I is completed; then continue to overlap the carbon cloth tape / phenolic resin material layer, and use a semi-overlapping method to flatten the trapezoidal area II of the straight section of the core mold.

6. The solid rocket engine expansion section and the molding method thereof according to claim 5, characterized in that: The high-silica tape / phenolic resin material layer is wound in an equal-thickness manner, specifically including: the high-silica tape / phenolic resin material layer includes a first high-silica tape / phenolic resin material layer and a second high-silica tape / phenolic resin material layer. First, one side of the first high-silica tape / phenolic resin material layer is overlapped to the intersection of the carbon tape / phenolic resin material layer in the trapezoidal area II of the core mold straight section and the core mold cone section, and the high-silica layer winding procedure is executed until the procedure ends at the end of the core mold cone section, completing the high-silica layer winding in the core mold cone section area III; then the second high-silica tape / phenolic resin material layer is reciprocatedly wound at the end of the core mold cone section in a semi-overlapping manner to complete the high-silica layer winding in the core mold cone section area IV.

7. The solid rocket motor expansion section and the molding method thereof according to claim 1, characterized in that: The width of the carbon cloth tape / phenolic resin material layer is determined by the width of the intersection line of the carbon layer cone section and the core mold straight section, and the width of the climbing section of the high silica cloth tape / phenolic resin material layer is determined by subtracting the width of the carbon cloth tape / phenolic resin material layer from the width of the intersection line of the high silica layer cone section and the core mold straight section.

8. The solid rocket motor expansion section and the molding method thereof according to claim 1, characterized in that: In step S3, before curing and molding in the autoclave, the coated core mold is vacuum-packed with a breathable film, adhesive-absorbing felt and a vacuum bag, and the vacuum is evacuated to a vacuum degree of less than -0.098 MPa.

9. The solid rocket motor expansion section and the forming method thereof according to claim 1, characterized in that: In step S3, the core mold is placed in an autoclave for temperature rise and curing, and demoulding is performed after curing to obtain an expansion section blank, and the expansion section blank is machined to obtain an expansion section product, which specifically includes: Raise the temperature from room temperature to 60-80°C at a rate of 1°C / min and 0.03MPa / min, increase the pressure by 0.8-1MPa, and keep warm for 1-2h; Raise the temperature from 80°C to 100°C at a rate of 0.5°C / min and 0.03MPa / min, maintain the pressure at 2MPa, and keep warm for 1.5-2h; Raise the temperature from 100°C to 130°C at a rate of 0.5°C / min and 0.03MPa / min, maintain the pressure at 2MPa, and keep warm for 2-3h; Raise the temperature from 130°C to 160°C at a rate of 0.5°C / min and 0.03MPa / min, maintain the pressure at 2MPa, and keep the temperature for 2-3h; After the curing is completed, when the temperature in the autoclave drops to below 50°C, the core mold to be cured is taken out, and the core mold to be cured is cooled to below 30°C at room temperature. The expansion section blank formed integrally with the carbon layer and the high silicon oxide layer is demoulded and taken out, and the expansion section blank is machined to obtain an expansion section product.

10. The solid rocket engine expansion section and the forming method thereof according to claim 5, characterized in that: The carbon layer winding program is provided with a carbon layer climbing program. The feed F of each small section of the carbon layer in the carbon layer climbing program is: the axial length of the core mold cone section is evenly divided, F = axial feed / cosα; Wherein, axial feed = carbon layer cloth tape / phenolic resin material layer width / number of layers; α is the angle between the straight section and the tapered section of the carbon layer in region I; A high silica layer climbing program is provided in the high silica layer winding program. The feed F of each small section of the high silica layer program is: the axial length of the core mold cone section is evenly divided, F = high silica cloth tape / phenolic resin material layer / sinα.

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