阅读说明：本技术 一种复合材料蜂窝夹层结构零件的成型方法 (Forming method of composite material honeycomb sandwich structure part ) 是由 马秀菊 黎玉钦 郭渊 倪敏轩 仲睿 盛毅 任慧敏 于 2019-11-28 设计创作，主要内容包括：本发明公开了一种复合材料蜂窝夹层结构零件的成型方法,包括工装制备、铺贴脱模布、铺贴零件构层、压板封装、固化成型等步骤。使用一种表面带柔性功能橡胶层蜂窝夹层零件成型工装,将热压罐的压力均匀、精确地传递给蜂窝夹层零件的内蒙皮,而不使蜂窝芯受压过大产生滑移甚至坍塌的状况；此外,在成型工装余量区的柔性橡胶层可以起到防滑带的作用,防止内蒙皮预浸料在固化过程中产生滑移,进而影响蜂窝夹层零件成型质量。因此,本发明成型方法工艺简单,易与控制,可大大提高复合材料蜂窝夹层结构零件的成型质量及合格率。(The invention discloses a forming method of a composite material honeycomb sandwich structure part, which comprises the steps of tool preparation, paving and pasting of demolding cloth, paving and pasting of a part layer, pressing plate packaging, curing and forming and the like. The forming tool for the honeycomb sandwich part with the rubber layer with the flexible function on the surface is used for uniformly and accurately transmitting the pressure of the autoclave to the inner skin of the honeycomb sandwich part, so that the condition that a honeycomb core is pressed too much to cause slippage and even collapse is avoided; in addition, the flexible rubber layer in the forming tool allowance area can play a role of an anti-slip belt, so that the inner skin prepreg is prevented from sliding in the curing process, and the forming quality of the honeycomb sandwich part is further influenced. Therefore, the forming method has simple process and easy control, and can greatly improve the forming quality and the qualification rate of the composite material honeycomb sandwich structure parts.)

1. A forming method of a composite material honeycomb sandwich structure part is characterized by comprising the following steps: the method comprises the following steps:

1) preparing a tool: the forming tool for the honeycomb sandwich structure part is formed by compositely connecting a rigid structure and a flexible structure of the forming tool for the honeycomb sandwich structure part into a whole;

2) paving and sticking demolding cloth: paving demolding cloth in a part molding area of the molding tool in the step 1), and cleaning the surface of the part molding area by using acetone;

3) paving and pasting a part layer: laying a layer material of the composite material honeycomb sandwich structure part on the demoulding cloth cleaned in the step 2), and vacuumizing to pre-compact and form the part;

4) and (3) packaging by a pressing plate: selecting a pressure equalizing plate with proper thickness, cleaning the surface of the pressure equalizing plate by using acetone, and covering the pressure equalizing plate on the part layer material pre-compacted and molded in the step 3); then packaging the pressure equalizing plate and the honeycomb sandwich part material together on a forming tool;

5) curing and forming: and (4) sending the parts and the tools packaged in the step 4) into an autoclave for curing and forming, and demoulding after the parts are taken out of the autoclave to obtain the honeycomb sandwich parts with good quality.

2. The method of forming a composite honeycomb sandwich structural part of claim 1, wherein: in the step 1), the rigid structure is made of a metal material or a metal and carbon fiber composite material; the flexible structure is rubber with a flexible function and is attached to the surface of the rigid structure in a vulcanization connection mode, a glue film connection mode or a co-curing connection mode.

3. A method of forming a composite honeycomb sandwich structural part according to claim 2, wherein: the rigid structure is made of a metal material, the surface of the rigid structure is required to be cleaned and modified before use, a sealing rubber strip is used for manufacturing a vacuum bag on the surface of the rigid structure after the rigid structure is attached to rubber, and then negative pressure is formed between the metal material and the rubber through vacuumizing, so that the rubber is uniformly pressed on the surface of the rigid structure; and then, packaging the rigid structure and the rubber together, and placing the rigid structure and the rubber in a vulcanizing tank for vulcanization connection to form the honeycomb sandwich part molding tool.

4. A method of forming a composite honeycomb sandwich structural part according to claim 3, wherein: the reagent used for the modification treatment is a silane coupling agent; the conditions of the vulcanized connection are as follows: the vulcanization temperature is 180 ℃, and the vulcanization time is 2 h.

5. A method of forming a composite honeycomb sandwich structural part according to claim 2, wherein: the rigid structure is made of metal and carbon fiber composite materials, and is attached to rubber, a vacuum bag is made on the surface of the rigid structure by using a sealing rubber strip, and the vacuum bag is compacted in a vacuum mode; then laying and pasting carbon fiber prepreg, packaging, and sending into a hot-pressing tank for co-curing connection to form the honeycomb interlayer part forming tool.

6. The method of forming a composite honeycomb sandwich structural part of claim 5, wherein: the number of the carbon fiber prepreg paving layers is 5; the conditions of the co-curing connection are as follows: the co-curing pressure is 0.6MPa, the co-curing temperature is 180 ℃, and the co-curing time is 2 h.

7. A method of forming a composite honeycomb sandwich structural part according to claim 2, wherein: the rubber with the flexible function is silicon rubber, and the thickness of the rubber is 1-2 mm.

8. The method of forming a composite honeycomb sandwich structural part of claim 1, wherein: in the step 2), when the demolding cloth is paved, 10-20 mm allowance areas are reserved at the edges of the part forming areas and used as anti-skid belts for paving and paving the honeycomb interlayer parts.

9. The method of forming a composite honeycomb sandwich structural part of claim 1, wherein: in the step 3), the component layer materials are laid sequentially, namely an inner skin prepreg layer, an inner adhesive film layer, a honeycomb core, an outer adhesive film layer and an outer skin prepreg layer.

10. The method of forming a composite honeycomb sandwich structural part of claim 1, wherein: in the step 4), the pressure equalizing plate is a thin aluminum plate or a carbon fiber laminated plate, and the thickness of the pressure equalizing plate is 0.5 mm.

Technical Field

The invention relates to a method for forming a composite material honeycomb sandwich structure part.

Background

The composite material honeycomb sandwich structure generally comprises a middle light honeycomb core and skins on the upper surface and the lower surface, the skins have higher elastic modulus and strength and bear tension, compression and shear loads in a plane, and the middle light core layer has low density and only bears the transverse shear load, so that the rigidity of the structure is improved. The composite material sandwich structure has the advantages of small density, high bending rigidity, strong instability resistance and stability, heat insulation and sound insulation and the like, so that the composite material sandwich structure is widely applied to aerospace non-main bearing structures.

The existing preparation method of the composite material honeycomb sandwich structure mainly adopts the molding processes of co-curing, secondary bonding and co-bonding on a molding tool at present. The traditional forming die is high in rigidity and uneven in pressure transmission, the honeycomb core is of a thin-wall and elastic structure, when the honeycomb core is pressed, the honeycomb core is extruded with the forming die with high rigidity due to overlarge local pressure, the honeycomb core is prone to slipping even to tearing, crumpling, collapsing and other adverse conditions due to overlarge interaction force, in order to guarantee that the honeycomb core does not slip when formed, the pressure cannot be overlarge when a tank is filled for solidification, but the pressure is lower and uneven in pressure distribution when the skin is formed, and the internal quality of the skin is difficult to control.

Disclosure of Invention

Aiming at the problems of the existing preparation method of the composite material honeycomb sandwich structure, the invention provides a forming method of a composite material honeycomb sandwich structure part, aiming at solving the problems that in the curing process, a honeycomb with overlarge pressure slides or even collapses, and the inner skin and the outer skin with undersized pressure are unqualified, so that the forming quality and the product percent of pass of the composite material honeycomb sandwich structure part are improved. The specific technical scheme is as follows:

a forming method of a composite material honeycomb sandwich structure part comprises the following steps:

1) preparing a tool: the forming tool for the honeycomb sandwich structure part is formed by compositely connecting a rigid structure and a flexible structure of the forming tool for the honeycomb sandwich structure part into a whole;

2) paving and sticking demolding cloth: paving demolding cloth in a part molding area of the molding tool in the step 1), and cleaning the surface of the part molding area by using acetone;

3) paving and pasting a part layer: paving a preparation material of the composite material honeycomb sandwich structure part on the demolding cloth cleaned in the step 2), and vacuumizing to pre-compact and form the composite material honeycomb sandwich structure part;

4) and (3) packaging by a pressing plate: selecting a pressure equalizing plate with proper thickness, cleaning the surface of the pressure equalizing plate by using acetone, and covering the pressure equalizing plate on the part material pre-compacted and molded in the step 3); then packaging the pressure equalizing plate and the honeycomb sandwich part material together on a forming tool;

5) curing and forming: and (4) sending the parts and the tools packaged in the step 4) into an autoclave for curing and forming, and demoulding after the parts are taken out of the autoclave to obtain the honeycomb sandwich parts with good quality.

As a preferable technical solution, in the step 1), the rigid structure is made of a metal material or a metal and carbon fiber composite material; the flexible structure is rubber with a flexible function and is attached to the surface of the rigid structure in a vulcanization connection mode, a glue film connection mode or a co-curing connection mode.

When the rigid structure is made of a metal material, the surface of the rigid structure needs to be cleaned and modified before use, a sealing rubber strip is used for manufacturing a vacuum bag on the surface of the rigid structure after the rigid structure is attached to rubber, and then negative pressure is formed between the metal material and the rubber through vacuumizing, so that the rubber is uniformly pressed on the surface of the rigid structure; and then, packaging the rigid structure and the rubber together, and placing the rigid structure and the rubber in a vulcanizing tank for vulcanization connection to form the honeycomb sandwich part molding tool. Further, a reagent used for the modification treatment is a silane coupling agent; the conditions of the vulcanized connection are as follows: the vulcanization temperature is 180 ℃, and the vulcanization time is 2 h.

When the rigid structure is made of metal and carbon fiber composite materials, after the rigid structure is attached to rubber, a vacuum bag is made on the surface of the rigid structure by using a sealing rubber strip, the rigid structure is compacted through vacuum hot pressing, then carbon fiber prepreg is laid and packaged, and then the rigid structure is sent into a hot pressing tank to be connected through co-curing, so that the honeycomb interlayer part forming tool is formed. Further, the number of the carbon fiber prepreg paving layers is 5; the conditions of the co-curing connection are as follows: the co-curing pressure is 0.6MPa, the co-curing temperature is 180 ℃, and the co-curing time is 2 h.

According to a further preferable technical scheme, the rubber with the flexible function is silicon rubber, and the thickness of the rubber is 1-2 mm.

In addition, as a preferable technical scheme, in the step 2), when the demolding cloth is paved, margin areas of 10-20 mm are reserved at the edges of the part forming area to serve as anti-skid belts for paving the honeycomb sandwich part.

As a preferable technical scheme, in the step 3), the part preparation materials are sequentially laid as an inner skin prepreg layer, an inner adhesive film layer, a honeycomb core, an outer adhesive film layer and an outer skin prepreg layer.

In a preferable technical solution, in the step 4), the pressure equalizing plate is a thin aluminum plate or a carbon fiber laminated plate, and the thickness of the pressure equalizing plate is 0.5 mm.

The invention has the beneficial effects that:

the rubber layer is laid on the forming die, the elasticity of the rubber is fully utilized, the covering surface of the rubber layer can uniformly and accurately transmit the pressure applied by the autoclave without causing the honeycomb core to slide or even collapse due to overlarge pressure, and the problems that the honeycomb with overlarge pressure slides or even collapses in the traditional curing process, and the forming quality of the inner skin and the outer skin is unqualified due to undersize pressure are effectively solved.

In addition, the margin area is reserved on the periphery of the part forming area when the demolding cloth is paved, and the rubber layer in the margin area effectively serves as an anti-skid strip for paving and adhering the prepreg of the honeycomb sandwich part, so that the slippage of the inner skin is reduced.

In addition, the laminated plate ensures that the outer surface quality of the outer skin of the composite material honeycomb sandwich structure part is smooth and has no scratch. Therefore, the forming method can realize the integrated forming preparation of the composite material honeycomb sandwich structure part with high quality and high qualification rate, not only ensures that the honeycomb is formed without slippage, but also improves the forming quality of the inner skin and the outer skin.

Drawings

FIG. 1 is a schematic view of the assembly of a composite material honeycomb sandwich structure part and a forming tool (wherein the rigid structure of the forming tool is made of a metal material) according to the present invention;

FIG. 2 is a schematic structural view of a composite honeycomb sandwich structure part of the present invention;

fig. 3 is another schematic diagram of the composite material honeycomb sandwich structure part forming tool of the present invention (wherein the rigid structure of the forming tool is made of metal and carbon fiber composite material).

In the figure: 1. forming a tool; 2. a rigid structure; 3. a flexible structure; 4. demolding the cloth; 5. an anti-slip band; 6. composite honeycomb sandwich structure parts; 7. a pressure equalizing plate; 8. a prepreg layer; 9. a glue film; 10. a honeycomb core; 11. a carbon fiber prepreg layer; 12. carrying out vacuum packaging; 13. and (4) an insulating rubber strip.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the following embodiments of the present invention and the accompanying drawings, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.