Ceramic head cover rapid densification method based on flow channel

Abstract

The present application relates to ceramic head cover braided body composite forming technical field, disclose a kind of based on flow channel type's ceramic head cover rapid densification method, comprising the following steps: according to head cover size, design flow channel mould, and set in glue mouth and out glue mouth;Braided body is molded into flow channel mould;Flow channel mould is glued by in glue mouth and out glue mouth, so that sol flows in from in glue mouth, then flows out from out glue mouth, the flow of each glue injection is 30-50 liters, after glue injection is completed, sol fills flow channel mould, braided body is soaked in flow channel mould 10-18h, then braided body is taken out and air-dried 10-14h at room temperature, 5-65 DEG C drying 12-18h;Glue injection is repeated 2-4 times, i.e. the densification of head cover is completed.The present application based on flow channel type's ceramic head cover rapid densification method, three-dimensional braided body is loaded into composite mould, so that braided body is always immersed in flowing sol, increase the contact of sol and braided body fiber bundle, greatly improve sol impregnation method composite efficiency.

Description

Technical Field

[0001] This invention relates to the field of ceramic headgear fabric composite molding technology, specifically to a rapid densification method for ceramic headgear based on a flow channel. Background Technology

[0002] Wave-transparent ceramic materials are key candidate materials for components such as hypersonic vehicle radomes and antenna windows. Depending on the environmental conditions of the radome, when high resistance to ablation and load-bearing capacity are required, quartz fiber-reinforced silica, nitride fiber-reinforced silica, or nitride composite ceramic materials are generally selected. The sol-gel method is the main molding method for preparing high-temperature resistant wave-transparent ceramic materials. It typically involves repeatedly impregnating a woven three-dimensional fabric in a sol to increase the overall density of the blank. However, this composite method is time-consuming, has unsatisfactory impregnation effects, and low utilization of raw materials such as the sol. Summary of the Invention

[0003] The purpose of this invention is to address the shortcomings of the above-mentioned technologies by providing a rapid densification method for ceramic headgear based on a flow channel. This method involves loading a three-dimensional braided body into a composite mold, ensuring that the braided body is always immersed in a flowing sol, thereby increasing the contact between the sol and the fiber bundles of the braided body and significantly improving the composite efficiency of the sol-impregnation method.

[0004] To achieve the above objectives, the present invention provides a rapid densification method for ceramic headgear based on a flow channel, comprising the following steps:

[0005] A) Runner mold design: Design the runner mold according to the size of the headgear, and set the inlet and outlet;

[0006] B) Installation: The braided body is fitted into the flow channel mold;

[0007] C) Glue injection: Glue is injected into the flow channel mold through the glue inlet and glue outlet, so that the molten glue flows in from the glue inlet and flows out from the glue outlet. The flow rate of each injection is 30 to 50 liters. After the glue injection is completed, the molten glue fills the flow channel mold. The knitted body is soaked in the flow channel mold for 10 to 18 hours. Then the knitted body is taken out and air-dried at room temperature for 10 to 14 hours, and then dried at 55 to 65°C for 12 to 18 hours.

[0008] D) Repeat step C) 2 to 4 times to complete the densification of the headgear.

[0009] Preferably, the glue inlet is located at the contact point between the tail of the braid and the flow channel mold, and the glue outlet is located at the contact point between the head of the braid and the flow channel mold.

[0010] Preferably, the inner surface of the flow channel mold is coated with epoxy resin.

[0011] Preferably, the surface of the woven body is covered with a fiber mesh.

[0012] Preferably, in step C), during glue injection, the glue inlet of the flow channel mold is connected in sequence to a glue injection tank and a pneumatic pump, and the glue outlet of the flow channel mold is connected in sequence to a glue storage tank and a vacuum pump, so that the molten glue flows from the glue injection tank to the glue storage tank.

[0013] Preferably, the storage tank has a water level line function for observing the level line of the sol. After the sol in the storage tank is compounded as required, the density and viscosity of the sol in the storage tank are measured. If the difference between the density and viscosity of the sol measured in the dispensing tank and the storage tank is ≤10%, the storage tank can be reused.

[0014] Preferably, the pressure of the pneumatic pump is ≥ 5 atmospheres, and the vacuum pump has a vacuum capacity of one atmosphere.

[0015] Preferably, during the injection process, the injection tank is first filled with molten adhesive, and then the valves of the air pressure pump, injection tank, runner mold, storage tank, and vacuum pump are opened, allowing the molten adhesive to flow sequentially from the injection tank into the runner mold and the storage tank.

[0016] Preferably, when the volume of the dispensing tank is less than the flow rate of each dispensing, the sol collected in the storage tank is introduced into the dispensing tank to continue dispensing, so that the sol can be reused repeatedly.

[0017] Compared with the prior art, the present invention has the following advantages:

[0018] 1. The traditional static soaking and bonding method of the braided fabric is changed to a flow channel bonding method. Under the pressure of the flow channel, the sol flows in the braided fabric, increasing the contact between the sol and the fiber bundles of the braided fabric, and quickly flowing to all parts of the braided fabric, reducing the time required for traditional soaking.

[0019] 2. The runner mold plays a shaping role, allowing the sol to flow in and out of the entire runner, resulting in good uniformity;

[0020] 3. The flow channel composite method allows the sol to circulate through the braid, maximizing the contact probability between the sol and the braid fibers, thus greatly reducing the amount of sol used.

[0021] 4. The solvent in the storage tank can be reused repeatedly, reducing the amount of solvent used by more than 20% compared to traditional static impregnation lamination;

[0022] 5. It has a good impregnation effect, a short compounding cycle, and a low density gradient. Detailed Implementation

[0023] The present invention will be further described in detail below with reference to specific embodiments.

[0024] Example 1

[0025] A rapid densification method for ceramic headgear based on a flow channel includes the following steps:

[0026] A) Runner mold design: The runner mold is designed according to the size of the hood. The inner and outer surface dimensions of the runner mold are consistent with the surface dimensions of the hood's woven body, and an inlet and outlet are provided.

[0027] B) Installation: Fit the braided body into the runner mold;

[0028] C) Glue injection: Glue is injected into the flow channel mold through the glue inlet and glue outlet, so that the molten glue flows in from the glue inlet and flows out from the glue outlet. The flow rate of each injection is 30 liters. After the glue injection is completed, the molten glue fills the flow channel mold. The braid is soaked in the flow channel mold for 10 hours, and then the braid is taken out and aired at room temperature for 10 hours, and then dried at 55℃ for 12 hours.

[0029] D) Repeat step C) twice to complete the densification of the headgear.

[0030] Example 2

[0031] A rapid densification method for ceramic headgear based on a flow channel includes the following steps:

[0032] A) Runner mold design: Design the runner mold according to the size of the headgear, and set the inlet and outlet;

[0033] B) Installation: Fit the braided body into the runner mold;

[0034] C) Glue injection: Glue is injected into the flow channel mold through the glue inlet and glue outlet, so that the molten glue flows in from the glue inlet and flows out from the glue outlet. The flow rate of each injection is 50 liters. After the glue injection is completed, the molten glue fills the flow channel mold. The braid is soaked in the flow channel mold for 18 hours. Then the braid is taken out and aired at room temperature for 14 hours and dried at 65℃ for 18 hours.

[0035] D) Repeat step C) 4 times to complete the densification of the headgear.

[0036] Example 2

[0037] A rapid densification method for ceramic headgear based on a flow channel includes the following steps:

[0038] A) Runner mold design: Design the runner mold according to the size of the headgear, and set the inlet and outlet;

[0039] B) Installation: Fit the braided body into the runner mold;

[0040] C) Glue injection: Glue is injected into the flow channel mold through the glue inlet and glue outlet, so that the molten glue flows in from the glue inlet and flows out from the glue outlet. The flow rate of each injection is 40 liters. After the glue injection is completed, the molten glue fills the flow channel mold. The braid is soaked in the flow channel mold for 14 hours, and then the braid is taken out and aired at room temperature for 12 hours and dried at 60℃ for 15 hours.

[0041] D) Repeat step C) 3 times to complete the densification of the headgear.

[0042] The density of the headgear prepared in the above embodiments can reach 1.6 ± 0.05 g / cm³. 3 .

[0043] In addition, to ensure that the hood knitted body can be placed in the flow channel, the glue inlet is located at the contact point between the tail of the knitted body and the flow channel mold, and the glue outlet is located at the contact point between the head of the knitted body and the flow channel mold.

[0044] To allow the sol to flow better through the woven body, epoxy resin can be sprayed onto the inner surface of the flow channel mold, or a fiber mesh can be wrapped around the surface of the woven body.

[0045] In step C) of the above embodiment, during glue injection, the glue inlet of the runner mold is connected in sequence to a glue injection tank and an air pressure pump, and the glue outlet of the runner mold is connected in sequence to a glue storage tank and a vacuum pump, so that the molten glue flows from the glue injection tank to the glue storage tank. The pressure of the air pressure pump is ≥ 5 atmospheres, and the vacuum pump has a vacuum capacity of 1 atmosphere.

[0046] The storage tank has a water level line function, which is used to observe the level line of the sol. After the sol in the storage tank is compounded as required, the density and viscosity of the sol in the storage tank are measured. If the difference between the density and viscosity of the sol measured in the injection tank is ≤10%, it can be reused.

[0047] Specifically, during the glue injection process, first fill the glue injection tank with molten glue, then open the valves of the air pressure pump, glue injection tank, runner mold, glue storage tank, and vacuum pump, so that the molten glue flows from the glue injection tank into the runner mold and the glue storage tank in sequence.

[0048] When the volume of the dispensing tank is less than the flow rate of each dispensing, the sol collected in the storage tank is transferred into the dispensing tank to continue dispensing. For example, when the capacity of the dispensing tank is 10L, the sol collected in the storage tank can be transferred into the dispensing tank to keep dispensing.

[0049] In the above embodiments, the inner and outer molds of the runner mold are made of materials such as stainless steel and aluminum alloy, which do not react with silica sol and have high strength. The inlet and outlet are equipped with DN15 to DN25 ball valves to control the flow of the sol. The injection tank and storage tank are also made of stainless steel or aluminum alloy to ensure airtightness. Before use, an airtightness test is performed. The inlet valve of the runner mold is closed, the outlet valve of the runner mold and the inlet and outlet valves of the storage tank are opened, and the vacuum pump is turned on to conduct a system airtightness test. The pressure drop must be ≤0.005 MPa for more than 30 minutes.

[0050] This invention is based on a rapid densification method for ceramic headgear using a flow channel system. It replaces the traditional static immersion lamination method with a flow channel lamination method. Under the pressure of the flow channel, the sol flows within the woven fabric, increasing the contact between the sol and the fiber bundles, and allowing it to quickly reach all parts of the fabric, reducing the time required for traditional immersion. The flow channel mold acts as a shaping element, ensuring the sol flows in and out of the entire channel with good uniformity. The flow channel lamination method allows the sol to circulate through the woven fabric, maximizing the contact probability between the sol and the fibers, significantly reducing the amount of sol used. The sol in the storage tank can be reused repeatedly, reducing sol usage by more than 20% compared to traditional static immersion lamination. It also results in better immersion effects, a shorter lamination cycle, and a lower density gradient.

Claims

1. A method for rapid densification of ceramic headgear based on a flow channel, characterized in that: Includes the following steps: A) Flow channel mold design: The flow channel mold is designed according to the size of the headgear, and an inlet and an outlet are set. The inlet is located at the contact point between the tail of the knitted body and the flow channel mold, and the outlet is located at the contact point between the head of the knitted body and the flow channel mold. B) Installation: The braided body is fitted into the flow channel mold; C) Glue Injection: Glue is injected into the flow channel mold through the glue inlet and glue outlet, allowing the molten glue to flow in from the glue inlet and out from the glue outlet. The flow rate for each injection is 30-50 liters. After injection, the molten glue fills the flow channel mold. The knitted fabric is then immersed in the flow channel mold for 10-18 hours, followed by removal and air-drying at room temperature for 10-14 hours, and then drying at 55-65°C for 12-18 hours. During glue injection, the glue inlet of the flow channel mold is connected in sequence to a glue injection tank and a pneumatic pump, and the glue outlet of the flow channel mold is connected in sequence to a glue storage tank and a vacuum pump. The sol is allowed to flow from the dispensing tank to the storage tank. The pressure of the pneumatic pump is ≥5 atmospheres, and the vacuum pump has a vacuum capacity of 1 atmosphere. The storage tank has a water level line function for observing the sol level. After the sol in the storage tank is compounded as required, the density and viscosity of the sol in the storage tank are measured. If the difference between the density and viscosity of the sol measured in the dispensing tank and those in the dispensing tank is ≤10%, the sol can be reused. When the volume of the dispensing tank is less than the flow rate of each dispensing, the sol collected in the storage tank is introduced into the dispensing tank, and dispensing continues. D) Repeat step C) 2 to 4 times to complete the densification of the headgear.

2. The rapid densification method for ceramic headgear based on flow channel as described in claim 1, characterized in that: The inner surface of the flow channel mold is coated with epoxy resin.

3. The rapid densification method for ceramic headgear based on flow channel as described in claim 1, characterized in that: The surface of the woven body is covered with a fiber mesh.

4. The rapid densification method for ceramic headgear based on flow channel as described in claim 1, characterized in that: During the injection process, first fill the injection tank with molten adhesive, then open the valves of the air pressure pump, injection tank, runner mold, storage tank, and vacuum pump to allow the molten adhesive to flow sequentially from the injection tank into the runner mold and storage tank.