RU2185965C1 - Process of manufacture of articles from composite materials - Google Patents

Abstract

FIELD: aerospace technology, radio engineering. SUBSTANCE: process can also be employed for manufacture of articles of complex shape, for instance, antennas. Process of manufacture of articles from composite materials includes assembly of package by laying layers of reinforcing material impregnated with thermally reactive binder, formation and metallization. Metallization is conducted by electric arc spraying in air with deposition of coat on metallized cloth pressed into working surface. EFFECT: raised adhesive strength of coat, potential for repair and correction of parameters of working surface of article. 1 dwg

Description

 The present invention relates to the field of aerospace engineering, the radio industry, in particular to the production of layered products from composite materials and can be used in the development and manufacture of products of complex geometric shapes, such as antenna devices.

 A known method of manufacturing an element for antenna devices, including assembling a carrier package by laying layers of a carbon-fiber filler impregnated with a binder, curing the binder, applying a combined titanium-nickel-aluminum combined thin-film coating directly to the outer surfaces of the carbon-fiber package. The coating is applied by the ion-plasma vacuum method in an installation with a planar magnetron system / 1 /.

 However, this method is technologically unacceptable for mass production of products, as well as the manufacture of products of large dimensions. In addition, the high cost of technology, its unprofitability significantly increases the cost of products.

 Closest to the claimed method in technical essence is a method of manufacturing carbon fiber products, comprising assembling a package by laying layers of a reinforcing material impregnated with a thermosetting binder predominantly epoxy, forming into the outer reinforcing layers of metal foil sheets and molding, and the perforated foil sheets are molded flush from the outside outer layers. This technology increases the stability of the geometric dimensions of the product and allows the manufacture of products of large dimensions / 2 /.

 The disadvantage of this method is the low adhesive strength of the coating, which is higher than that of the similar method, due to the use of perforated foil. However, in places where there is no perforation, the release of volatile substances from the composite package in surface micro-voids creates excessive pressure and stress in the coating inside the structure. And the technology of applying finished smooth foil to the surface of the bag with microroughnesses, micropores does not allow for reliable adhesion of metal to all parts of the surface. Adhesion strength is reduced.

 In addition, the use of the known method is impossible with mass serial production of products of complex geometric shapes.

 The objective of the invention is to increase the adhesive strength of the coating, the possibility of manufacturing products of complex geometric shapes, large and small dimensions, simplifying the process, as well as obtaining the possibility of repairing the coating and adjusting the geometric parameters of the working surface of the product.

 This goal is achieved by the fact that in the method of manufacturing products from composite materials, including assembling a package by laying layers of reinforcing material impregnated with a thermosetting binder, molding and metallization - metallization is performed by spraying in air with an electric arc method on a layer of metallized fabric molded into the outer layer of the product .

 Description of the manufacturing technology of the sample, the meaning of the individual parameters will be given below. Here we only note that the manufacture of the claimed method of samples in comparison with the prototype is distinguished by technological simplicity and allows you to get samples of any size and with any complexity of the geometric shape of the product.

 Example.

 The manufacture of carbon fiber products of the type "Plate with a surface of complex geometric shape with a metal coating" of the claimed method.

 The assembly of the package is carried out by laying layers of a binder-impregnated reinforcing material.

 The material used was carbon tape LU-P-0.2 GOST 28006-88, metallized fabric APT 56041 TU 17 RSFSR 62-4504-77, filter cloth N3 GOST 15978-93 (technological layer).

 The binder used is FFE-70 OST 92-0957-74, the volume fraction of which in carbon fiber is 44%.

The manufacture of the product is carried out in the following sequence (product assembly diagram is shown in the drawing):
On the working surface of the mold (1) with the heat-treated grease K-21 TU 6-02-909-79 coated on it and a package consisting of a layer of filter cloth (2), a layer of metallized cloth (3), twelve layers of carbon tape (4) are collected impregnated with a binder and assembled according to the reinforcement scheme 0 ^o , 90 ^o , 0 ^o , 90 ^o , 0 ^o , 90 ^o , 90 ^o , 0 ^o , 90 ^o , 0 ^o , 90 ^o , 0 ^o ; a layer of fiberglass E2-62 (5), impregnated with a binder.

The tsulag is laid on the assembled bag, and the drainage layer is laid (four layers of E3-400 fiberglass and a layer of metal mesh) and a vacuum bag is installed. Next, the vacuum molding of the carbon fiber plate is carried out in the polymerization furnace / oven / in the following mode:
- create a pressure under a vacuum bag of 0.8 ÷ 0.95 kgf / cm ² ;
- raise the temperature in the furnace to 150 ± 5 ^o C for 4 hours;
- maintain the product at a temperature of 150 ± 5 ^o C for 1 h;
- raise the temperature in the furnace to 160 ± 5 ^o With a speed of not more than 0.3 ^o With in min;
- maintain the product at a temperature of 160 ± 5 ^o C for 2 hours;
- cool the product in the furnace at a speed of not more than 2 ^o C per min.

 After molding, a layer of filter cloth (technological layer) is removed from the working side of the plate, thereby preparing the plate for coating.

 Then a metallized fabric molded into the working surface of the plate is sprayed with a 90 μm thick zinc layer using an ARC SPREY 8830 electric arc spraying machine. The sprayed coating is processed (grinding, polishing) in accordance with the requirements for roughness of the working surface.

Made by the claimed method, the product is characterized by the following indicators of adhesive strength, coating density:
- adhesive strength of the coating to the substrate material is not less than 90 MPa;
the density of the zinc coating is 2.87 g / cm ² (zinc density is 7.13 g / cm ² ), therefore, the coating is porous.

 In the method proposed in the application, an increase in the adhesion strength of the coating is achieved by adhesion of the particles of the sprayed coating to the metallized fabric molded into the outer layer of the product.

 In products made using smooth metal foil, there is no reliable adhesion of the coating to all surface irregularities of the layers of the reinforcing material, in addition, the release of volatile substances from the material of the package creates excessive pressure from the inside of the structure, which impairs the adhesive strength of the coating, which does not occur when applying the coating by the claimed method because the coating is quite porous.

 The product manufactured by the claimed method, maintainable, because there is the possibility of repairing a damaged coating by electric arc spraying.

 In the manufacture of products with high accuracy requirements for the geometric parameters of the working surface (for example, a mirror of a space radio telescope), it becomes possible to adjust the geometric parameters of the working surface of the products by dusting in certain places the additional coating thickness with subsequent polishing.

 The claimed method allows to manufacture metallized products of complex geometric shapes.

 The method is economical in comparison with the known ones, since one of the most complicated operations — metallization of the product’s surface — is extremely simplified / the coating is applied by the electric arc method in air using the well-known high-performance installation /. The cost of products manufactured in this way, below known. The dimensions of the product are determined only by the size of the polymerization furnace - a heating cabinet, but at the same time, in comparison with known methods, the manufacturing technology of such products is simpler. It is possible to use cold curing binders (in air without a heating cabinet). In this case, the dimensions of the manufactured product are practically unlimited.

SOURCES OF INFORMATION
1. Tailor K.I. et al. Structure and properties of composite materials. M.: Mechanical Engineering, 1979, p.168-176 - analogue.

 2. Copyright certificate of the USSR, 1775316 A1, cl. B 32 B 15/14, 7/14, 1992 - prototype.

 3. Determination of compliance of technical solutions with the criterion of "significant differences". - Issues of invention, 1984, 4, p. 62.

 4. Patent Law of the Russian Federation, 1992, 3517-1.

Claims (1)

 A method of manufacturing products from composite materials, including assembling a package by laying layers of a reinforcing material impregnated with a thermosetting binder, molding and metallization, characterized in that the metallization is carried out by spraying a metal coating by an electric arc method in air onto a metallized fabric molded into a work surface.