Large-thickness special-shaped quartz member and preparation method thereof

Abstract

The invention discloses a large-thickness special-shaped quartz member and a preparation method thereof, and belongs to the technical field of fiber reinforced composite materials. By utilizing the rigidity and machinability of the quartz fiber reinforced silicon dioxide ceramic matrix composite material, the manufacturing process is optimized, and the manufacturing of the large-thickness special-shaped quartz component is realized.

Description

Technical Field

[0001] The present invention relates to a large-thickness special-shaped quartz component and a preparation method thereof, belonging to the technical field of fiber-reinforced composite materials. Background Art

[0002] With the continuous increase in the flight Mach number and flight time of hypersonic aircraft, the thermal protection problem of the aircraft has become increasingly severe. In order to keep the internal temperature of the metal cabin at a relatively low level, a large number of rigid heat insulation components are required on the surface of the metal cabin or the contact surface between the metal cabin and high-temperature heat sources such as engines. In recent years, quartz components have been widely used in the fields of hypersonic aircraft structure and thermal protection due to their good high-temperature resistance and mechanical properties.

[0003] When the quartz component is used for heat insulation on the surface of the metal cabin, etc., the quartz component is often special-shaped, and in many working conditions, the size in the thickness direction is relatively large (greater than 50 mm). The quartz component is machined from a regular blank of quartz fiber-reinforced silica composite material. The large-thickness blank often has a hollow phenomenon due to the drawing forming process. After the machined sample is detected by industrial CT, continuous hole defects will appear, and the hole size is basically greater than 1.8 mm 2 , which affects the bearing capacity of the component.

[0004] In summary, it is very necessary to provide a large-thickness special-shaped quartz component and a preparation method thereof. Summary of the Invention

[0005] The present invention provides a large-thickness special-shaped quartz component and a preparation method thereof to solve the above-mentioned existing technical problems.

[0006] A large-thickness special-shaped quartz component and a preparation method thereof, the method comprising the following steps:

[0007] (1) Pretreat the orthogonal three-directional structure quartz fiber flat fabric with a cleaning agent;

[0008] (2) Immerse the fabric with a high-concentration silica sol for several hours, and then perform air drying and high-temperature treatment;

[0009] (3) Repeat step (2) twice to obtain a quartz component blank;

[0010] (4) Rough-machine the blank of the above quartz component. The inner and outer cavities of the flat plate are machined according to the component profiling and a margin of 1-4 mm is left; in addition, a circle with a diameter of 5-10 mm is opened at a position 5 mm away from the edge around the flat plate;

[0011] (5) Dry the rough-machined blank of the above material and repeat step (3) once;

[0012] (6) Finish machining the blanks of the above materials, and perform drying treatment after finish machining;

[0013] (7) Immerse the above materials in low-concentration silica sol for several hours, and perform air-blowing drying and high-temperature treatment;

[0014] (8) Repeat step (7) 1 to 3 times to obtain a large-thickness special-shaped quartz component;

[0015] Preferably, the cleaning agent is acetone or ethanol;

[0016] Preferably, the number of plies of the XYZ-direction yarns of the orthogonal triaxial flat fabric is 442 or 224;

[0017] Preferably, the solid content of the silica sol is 20-25%, the density of the high-concentration silica sol is 1.24-1.37 g / cm 3 , and high-concentration impregnation can be carried out in a gradient impregnation manner; the density of the low-concentration silica sol is 1.12-1.18 g / cm 3 ; the time for the silica sol to impregnate the quartz fabric is 24-72 h;

[0018] Preferably, the temperature of the air-blowing drying is 200-250 °C, and the time of the air-blowing drying is 8-12 h;

[0019] Preferably, the temperature of the high-temperature treatment is 500-600 °C, and the time of the high-temperature treatment is 2-3 h;

[0020] Advantages of the present invention compared with the prior art:

[0021] (1) Compared with the method of improving the impregnation effect by designing a density gradient fabric, the fabric structure of the present invention is simple, no additional design is required, the process is reduced, and the manufacturing cost is lowered;

[0022] (2) The present invention makes full use of the rigidity and good processing performance of the quartz fiber-reinforced silica composite material, and can be flexibly applied according to the shape and thickness of the quartz component;

[0023] (3) The operation process of the present invention is simple and the manufacturing cost is low, which broadens the application scenarios of large-thickness special-shaped quartz components. Specific embodiments

[0024] The present invention will be described in detail below with reference to specific examples.

[0025] Example 1:

[0026] (1) Clean the 442-structure orthogonal triaxial flat fabric with acetone. The fabric size is 300*300*60 mm. After cleaning, place it in a fume hood and dry it for 3 days;

[0027] (2) Impregnate the above-mentioned flat fabric successively with silica sols having concentrations of 1.35 g / cm 3 and 1.32 g / cm 3 for 48 h, and then conduct air drying at 200 °C for 8 h;

[0028] (3) Heat-treat the blank of the above material at 600 °C for 2 h to obtain a rough blank of a quartz component;

[0029] (4) Rough-machine the blank of the above quartz component. Machine the inner and outer cavities of the flat plate according to the profile of the component and leave a margin of 2 mm. In addition, open a circle with a diameter of 10 mm at a position 5 mm away from the edge around the flat plate; After rough machining, conduct air drying on the blank at 250 °C for 8 h;

[0030] (5) Impregnate the blank of the above quartz component successively with silica sols having concentrations of 1.28 g / cm 3 and 1.25 g / cm 3 for 48 h, and then conduct air drying at 200 °C for 8 h;

[0031] (6) Heat-treat the blank of the above material at 600 °C for 2 h to obtain a precision blank of a quartz component;

[0032] (7) Finish-machine the blank of the above quartz component; After finish machining, conduct air drying on the quartz component at 250 °C for 8 h;

[0033] (8) Impregnate the above quartz component twice with a silica sol having a concentration of 1.14 g / cm 3 for 48 h, and then conduct air drying at 200 °C for 8 h;

[0034] (9) Heat-treat the above quartz component at 600 °C for 2 h to obtain a large-thickness special-shaped quartz component;

[0035] Example 2:

[0036] (1) Clean the 442-structure orthogonal three-way flat fabric with acetone. The fabric size is 300*300*65 mm. After cleaning, place it in a fume hood and let it dry for 3 days;

[0037] (2) Impregnate the above-mentioned flat fabric successively with silica sols having concentrations of 1.36 g / cm 3 and 1.33 g / cm 3 for 48 h, and then conduct air drying at 200 °C for 8 h;

[0038] (3) Heat the blank of the above material at 600 °C for 2 h to obtain a rough blank of the quartz component;

[0039] (4) Rough machine the blank of the above quartz component. The inner and outer cavities of the flat plate are machined according to the shape of the component with a 2 mm allowance left; in addition, a circle with a diameter of 10 mm is opened at a distance of 5 mm from the edge around the flat plate; after rough machining, dry the blank part by blowing air at 250 °C for 8 h;

[0040] (5) Immerse the blank of the above quartz component successively in silica sol with concentrations of 1.29 g / cm 3 and 1.26 g / cm 3 for 48 h, then dry it by blowing air at 200 °C for 8 h;

[0041] (6) Heat the blank of the above material at 600 °C for 2 h to obtain a fine blank of the quartz component;

[0042] (7) Finish machine the blank of the above quartz component; after finish machining, dry the quartz component by blowing air at 250 °C for 8 h;

[0043] (8) Immerse the above quartz component twice in silica sol with a concentration of 1.14 g / cm 3 for 48 h, then dry it by blowing air at 200 °C for 8 h;

[0044] (9) Heat the above quartz component at 600 °C for 2 h to obtain a large-thickness special-shaped quartz component;

[0045] Example 3:

[0046] (1) Clean the 442 structure orthogonal three-way flat fabric with acetone. The fabric size is 300 * 300 * 70 mm. After cleaning, place it in a fume hood to dry for 3 days;

[0047] (2) Immerse the above flat fabric successively in silica sol with concentrations of 1.37 g / cm 3 and 1.34 g / cm 3 for 48 h, then dry it by blowing air at 200 °C for 8 h;

[0048] (3) Heat the blank of the above material at 600 °C for 2 h to obtain a rough blank of the quartz component;

[0049] (4) Rough machine the blank of the above-mentioned quartz component. The inner and outer cavities of the flat plate are machined according to the profile of the component with a 2-mm allowance left. Additionally, drill a 10-mm diameter circle at a position 5 mm away from the edge around the flat plate. After rough machining, air-dry the blank at 250 °C for 8 h.

[0050] (5) Immerse the blank of the above-mentioned quartz component successively in silica sol with concentrations of 1.30 g / cm 3 and 1.27 g / cm 3 for 48 h each, then air-dry at 200 °C for 8 h.

[0051] (6) Heat-treat the blank of the above-mentioned material at 600 °C for 2 h to obtain a precision blank of the quartz component.

[0052] (7) Finish machine the blank of the above-mentioned quartz component. After finish machining, air-dry the quartz component at 250 °C for 8 h.

[0053] (8) Immerse the above-mentioned quartz component twice in silica sol with a concentration of 1.14 g / cm 3 for 48 h each, then air-dry at 200 °C for 8 h.

[0054] (9) Heat-treat the above-mentioned quartz component at 600 °C for 2 h to obtain a large-thickness special-shaped quartz component.

[0055] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A large-thickness special-shaped quartz component and a preparation method thereof, characterized in that, The method comprises the following steps: Step 1, pretreating the orthogonal three-directional structural quartz fiber flat fabric with a cleaning agent; Step 2, impregnating the fabric with a high-concentration silica sol for several hours, and then performing air-blowing drying and high-temperature treatment; Step 3, repeating Step 2 twice to obtain a blank of a quartz component; Step 4, rough-machining the blank of the quartz component, machining the inner and outer cavities of the flat according to the profile of the component and leaving a margin of 1-4 mm; in addition, a circle with a diameter of 5-10 mm is opened at a distance of 5 mm from the edge around the flat; Step 5, drying the rough-machined blank of the above material, and repeating Step 3 once; Step 6, performing finish machining on the blank of the above material, and performing drying treatment after finish machining; Step 7, impregnating the above material with a low-concentration silica sol for several hours, and performing air-blowing drying and high-temperature treatment; Step 8, repeating Step 7 one to three times to obtain a large-thickness special-shaped quartz component.

2. A large-thickness special-shaped quartz component and a preparation method according to claim 1, characterized in that, The cleaning agent is acetone or ethanol.

3. A large-thickness special-shaped quartz component and a preparation method according to claim 1, characterized in that, The number of ply yarns in the X, Y, and Z directions of the orthogonal three-directional flat fabric is 442 or 224.

4. A large-thickness special-shaped quartz component and a preparation method according to claim 1, characterized in that, The solid content of the silica sol is 20-25%, and the density of the high-concentration silica sol is 1.24-1.37 g / cm 3 , and gradient impregnation can be adopted for high-concentration impregnation; the density of the low-concentration silica sol is 1.12-1.18 g / cm 3 ; the time for the silica sol to impregnate the quartz fabric is 24-72 h.

5. A large-thickness special-shaped quartz component and a preparation method according to claim 1, characterized in that The temperature of the air-blowing drying is 200-250 °C, and the time of the air-blowing drying is 8-; 6. A large-thickness special-shaped quartz component and a preparation method according to claim 1, characterized in that The temperature of the high-temperature treatment is 500-600 °C, and the time of the high-temperature treatment is 2-3 h.