Laminar material from metal sheets and polymer

FIELD: process engineering.

SUBSTANCE: invention relates to laminar material made from metal sheets and polymer layer reinforced by fibers and bonded therewith, to be used in aircraft or aerospace engineering. Laminar material comprises at least one first metal layer of invariable thickness of at least 1.5 mm and at least one second of invariable thickness of at least 1.5 mm. Said first and second layers are bonded together by polymer layer reinforced by fibers, volume content of fibers not exceeding 45%. Aforesaid polymer layer comprises reinforcing fibers laid in polymer matrix and selected from the group including fiber glass, carbon fibers, drawn thermoplastic fibers, natural fibers and combinations thereof. Said fibers are impregnated by polymer matrix in partially hardened state.

EFFECT: hardened, high fatigue strength material.

17 cl, 6 dwg

 

The invention relates to a layered material made of sheet metal and connected with them reinforced fiber polymer layers. The invention also includes the use of such laminated material as a reinforcing sheet for components of aircraft or spacecraft.

Molded parts made of a layered material containing at least one metal sheet and one connected with him, fiber reinforced polymer layer (hereinafter referred to as metal-laminate, fiber-metal laminate material or for short layered material), are increasingly used in industry, for example, in the transport industry, for example, in automobiles, trains, airplanes, and spacecraft. Such laminates can be used, for example, for the wings, fuselage and tail panels and/or other panels for the hull of an airplane, and usually provide superior fatigue strength of components of the aircraft.

Known fiber-metal laminates have been developed in the period between 1978 and 1990 and sold on the market under the trademarks Arall® and Glare®. Known fiber-metal laminate formed from a large number of relatively thin (typically with a thickness of 0.2 to 0.4 mm) aluminum sheets separated by a polymer adhesive is layers, reinforced with aramid fibers (Arall®) or high-strength glass fiber (Glare®). This means that the volume content of fibers in the adhesive layer is relatively high, with typical values of about 50 vol.% for Arall® and 60% vol. for Glare®. Fiber-metal laminates usually have good resistance to crack growth. Thus, the fatigue cracks that appear in metal sheet subjected to variable load, will not continue rapid growth, and Vice versa, crack growth will be impeded. According to current knowledge this is due reinforced fibers, polymer layers, in particular, their fibers overlapping the crack and at least partially absorbing the forces responsible for the growth of cracks.

Although known layered filled with fiber material exhibits good fatigue properties for the skin of the fuselage and wings, for example, in aircraft, it was found that the cost of production is relatively high. This is due to several factors. Typical molded parts, in particular the wing of the aircraft, can have a total thickness up to several centimeters. This means that in order to make moulded laminates filled with fiber material, typically require tens or even hundreds of different layers. In addition, thin metallicheskie leaves, used in layered filled with fiber material should be milled to a very high degree, to obtain the thickness required for good fatigue properties. Metal sheets and reinforced fiber polymer layers must also meet the narrow tolerances in respect of their composition and thickness. In addition, in the known layered filled with fiber material, all plates should be handled so that they effectively communicated with reinforced fiber polymer layers. Thus, each sheet metal should be, for example, anodized and primed. Finally, to obtain a molded part from the well-known layered filled with fiber material, all layers are placed in a molding matrix. The more layers requires structure, the more time is required and, therefore, more expensive to produce molded item.

A number of the aforementioned problems can be solved by using thicker metal sheets in known fiber-metal laminate material. However, if such metal sheets there is a crack, a higher load will inevitably be transferred to the reinforced fiber polymer layers, the crack bridging. Although known reinforced fiber polymer layers effectively carry out their options is Yu overlap cracks in the well-known layered filled with fiber material, but if the metal sheets are much thicker, they will create too large of a zone of separation between the cracked metal sheet and the adjacent reinforced fiber polymer layer.

The aim of the invention is to develop a layered material specified in the introduction of a type that can be used to more effectively meet the highest requirements of the aerospace industry, and which also can be produced at lower cost. For this purpose, the layered material according to the invention is distinguished by the features indicated in paragraph 1 of the claims. Unexpectedly it was found that the resistance to delamination is greatly improved if the layered material comprises at least one thick metal sheet with a thickness of at least 1 mm, and if this thick metal sheet is connected with the rest of layered material through at least one fiber-reinforced polymeric layer, the volumetric fiber content which does not exceed 45%. Thus, the layered material is given more than sufficient fatigue strength and, moreover, it can be produced easier and cheaper than the well-known layered material. Thanks to the measures described in the independent claim of the invention, in fiber-metal laminates mate what materials you can use thicker metal sheets, than it was possible up to the present time. When using thicker metal sheets in the laminated material according to the invention there is an increased likelihood of heterogeneity in the impregnation of fibres. This is due to the high Flexural rigidity of such leaves, causing the leaves to create a pressure drop in the reinforced fiber polymer layers of the laminate when the laminate is cured, for example, in an autoclave, which in turn complicates the impregnation of the contained fibers. A further advantage of using at least one fiber-reinforced polymer layer having a low volumetric fiber content, is that it reduces the risk of insufficient impregnation of the fibers in the reinforced fiber polymer layers. Despite the fact that the layered material according to the invention contains one or more reinforced fiber polymer layers having a low volume content of fibers, layered material has good mechanical properties.

One embodiment of the laminate according to the invention is characterized by the fact that the volume content of fibers of a particular fiber-reinforced polymeric layer is at most 39%, at most 34%, at most 30 vol.%. Such volumetric fiber content lower than that maintained the I, commonly used in reinforced fiber polymer. When this application is mentioned fiber reinforced polymer layer with low volumetric fiber content, it is understood that a layer having a volume content of fibers is not more than 45 vol.%, not more than 39%, no more than 34%, not more than 30 vol.%. Fiber reinforced polymer layer with low volume content of fibers can be obtained, for example, using the semi-finished product in which the fibers in a given three-dimensional content is impregnated with a suitable resin in a partially cured state (referred to as a prepreg). You can also combine the prepreg having, for example, volumetric fiber content of 60 vol.%, with one or more polymeric adhesive layers in order to obtain the average low volume content of fibers. In this case, use an adhesive layer provided with a carrier, for example, in the form of a network of polymeric fibers, for example, polyamide fibers. The media ensures that the adhesive will retain specific, predetermined thickness even after adhesion and hardening. It is also beneficial for resistance to delamination. According to the invention can also be combined dry, i.e. not impregnated fibers with a polymeric adhesive layer in a suitable volumetric relationships.

In the next version of the implementation of the layered material is about the invention includes at least one thick metal sheet with a thickness of at least 1.5 mm It turns out that a particularly good fatigue characteristics are achieved if the thickness of the thick sheet metal ranges from 1.5 to 2.5 mm. According to the invention, it is also possible to use more than a single thick sheet metal. For example, in layered fibrous material according to the invention can connect more than one sheet metal thickness of at least 1 mm with the formation of compound (thicker) sheet metal. In one embodiment, the implementation of the layered material according to the invention contains at least two thick sheet metal, which are connected to each other using fiber-reinforced polymer layer having a low volumetric fiber content.

The remainder of the layered material can in principle be made of any material known to the person skilled in the art. So, you can have the rest of layered material contained metal sheet or more than one metal sheet, glued to each other with adhesive layers, which may be reinforced with fibers. In this regard, the thickness of the metal sheets in the rest of the layered material can be selected in a wide range. The remainder of the layered material may also contain fiber reinforced polymer. In one embodiment, the realization of the remaining net assets shall be layered material contains metal sheets and United with them reinforced fiber polymer layers, volumetric fiber content which is at least 50 vol.%. In this embodiment, the remainder of the layered material essentially corresponds to the layered material are already known in the prior art. The use of such laminated material further improves the mechanical properties, particularly fatigue strength.

Another embodiment of the laminate according to the invention is characterized in that when the laminate is in the unloaded state, the metal leaves the rest of the laminate on the average prevailing compressive stress, and the reinforced fiber polymer layers on average tensile stress. It should be noted that the presence of tensile stresses in reinforced fiber polymer layers does not mean that these layers show only tensile stresses. On the contrary, tensile stress prevails on average in a certain direction. Reinforced fiber polymer layers may be subjected to tensile stress by stretching the laminate in a certain direction, in accordance with which metal sheets are plastically deformed. In this direction in the polymer layers is dominated by the average tensile stress, resulting in average compressive stresses in t the m direction in the metal sheets of the layered material. Fatigue characteristics further improved pre-stress the rest of the laminate and then bond it with at least one thick metal sheet by means of fiber-reinforced polymer layer having a low volumetric fiber content.

The layered material according to the invention has the advantage that the metal sheets and/or reinforced fiber polymer layers in the rest of the laminate contain material that is different from the thick metal sheets and/or reinforced fiber polymer layers having a low volumetric fiber content. This way you can set the properties of the metal layers and/or reinforced fiber polymer layers so that they are optimal for functions required in layered material for this layer. Thus, it appears, for example, that the fatigue strength is enhanced, if the layered material according to the invention is characterized in that the metal sheets in the rest of the layered material has a higher yield strength than thicker metal sheets. Also is advantageous if the fiber reinforced polymer layer in the rest of the laminate closest to thick sheet metal, has a p is lower volumetric fiber content.

In another embodiment, the implementation of the layered material according to the invention has a thickness of metal sheets in the rest of the laminate is less than 0.8 mm, is from 0.2 to 0.8 mm inclusive, from 0.3 to 0.6 mm, While the use of thinner metal sheets in itself leads to higher costs and therefore is not obvious in advance, it appears that their use in the rest of the layered material leads to a significant improvement of the properties of the whole laminate. The layered material according to the invention is additionally advantageous that to achieve these improved properties over thin metal sheets is sufficient to use only part of the layered material. These same advantages are achieved if the thickness of the reinforced fiber polymer layers in the rest of the laminate is less than 0.8 mm, and preferably from 0.2 to 0.6 mm inclusive.

Reinforced fibers of the polymers used in fiber-metal laminate material, are light and durable and contain reinforcing fibers embedded in the polymer. The polymer also acts as a bonding agent between the different layers. Reinforcing fibers suitable for use in the reinforced fibers of the polymer include, for example, fiberglass, carbon fiber and metal fiber, and when necessary is Timoti may also include drawn thermoplastic polymer fibers, such as aramid fiber, PBO fiber (Zylon®), fiber M5® fiber ultracytochemical polyethylene or polypropylene, as well as natural fibers such as linen, wood and hemp fibers and/or combinations of the above fibers. You can also use mixed and/or twisted rovings. Such rovings contain reinforcing fiber and thermoplastic polymer in the form of fibers. Examples of suitable matrix materials for the reinforcing fibers are thermoplastic polymers such as polyamides, polyimides, polyethersulfones, polyetheretherketones, polyurethane, polyethylene, polypropylene, polyphenylensulfide (PPS), polyamidimide, copolymers of Acrylonitrile/butadiene/styrene (ABS), styrene/maleic anhydride (SMA), polycarbonate, polyphenyleneoxides mixture (PPO), a complex thermoplastic polyesters such as polyethylene terephthalate, polybutylene terephthalate, and mixtures and copolymers of one or more of the above polymers. In addition, the preferred thermoplastic polymers contain almost amorphous thermoplastic polymer having a glass transition temperature Tgabove 140°C, preferably above 160°C, such as polyarylate (PAR), polysulfone (PSO), polyethersulfone (PES), polyetherimide (PEI) or Polyphenylene ether (PPE), in particular, poly-2,6-dimethylaniline ether. According to the invention can also IP alsowhat semi-crystalline or paracrystalline thermoplastic polymer, having a melting point of crystals Tmabove 170°C, preferably above 270°C, such as polyster (PPS), polyetherketone, in particular, polyetheretherketone (PEEK), polyetherketone (PEK) and polyetherketoneketone (PEKK), "liquid crystal polymers", such as XYDAR from Dartco, derived from Monomeric biphenol, terephthalic acid and hydrobenzoic acid. Suitable matrix materials also contain thermosetting polymers such as epoxy, unsaturated polyester resins, melamineformaldehyde resin, phenol resin, polyurethane, etc.

In the layered material according to the invention fiber reinforced polymer of one or more layers may contain essentially continuous fibers, which are mainly in one direction (so-called UD-material). It is advantageous to use fiber reinforced polymer in the form of pre-impregnated semi-finished product. Such prepreg usually finds good mechanical properties after curing, among other things because the fibers were soaked in advance polymer matrix. In one embodiment, the implementation of the layered material according to the invention at least part of the reinforced fiber polymer layer contains mainly two groups of continuous fibers running parallel, with each group is the same Hugo the intermediate direction. Such stacking prepregs specialist in this field is also referred to as "stacking layers at an angle". In particular, best layered material having a reinforced fiber polymer layers in the rest of the layered material, which contain mainly two groups of continuous fibers running parallel and forming the same angle with the intermediate direction, especially if layered material used in the casing, for example, for an airplane wing.

Fiber-metal laminate according to the invention can be obtained by connection of a number of metal sheets and an intermediate reinforced fiber polymer layers to each other by heating them under pressure and then cooling. If desired, the fiber-metal laminate obtained in this way, you can pull to get favorable stress state. Then, this laminate glued with at least one thick metal sheet through the medium of the at least one fiber-reinforced polymer layer having a low volumetric fiber content. According to the invention the layers are combined in a known manner, putting them on a suitable adhesive and then at least partially otorita the adhesive when the temperature is suitable. This glue can be applied separately. Od the ako is also possible, to the matrix material of the fiber-reinforced polymer acted as the glue between the layers. Fiber-metal laminates according to the invention have good specific mechanical properties (properties per unit density), in particular, with regard to metals, such as aluminum.

In the implementation of the layered material according to the invention is a laminated material according to the invention is obtained by bonding at least one of the first thick metal sheet with at least one second thick metal sheet medium from at least one fiber-reinforced polymer layer having a low volumetric fiber content. According to the prior art is not customary to glue a thick metal sheets to each other, for example, in cases where one of the metal sheets for the connection is not solid. In the case of thick metal sheets, detecting a discontinuity, a large load will inevitably be transferred from the non-continuous metal sheet to the adjacent sheet metal. Cuts sheet metal of relatively large thickness transmits significant stress concentration in the adjacent sheet metal at a relatively wide area. In a situation of static load when, for example, requires a high strength, it may, if it is the input to delamination at the interface between the two metal plates and/or plastic deformation, leading, in turn, to a loss of strength in a solid metal sheet. If the thickness of the bonded non-continuous metal sheets exceeds a certain value, the adjacent metal sheets can also easily arise crack, that will greatly affect the strength of the structure as a whole. The above problem can also occur, although to a lesser extent, with metal sheets, which extend around the size of the structure, such as a wing. The layered material according to the invention solves the above problem at least partially. This is achieved by using fiber-reinforced polymer according to the invention as a boundary between two thick metal plates reduces the stress concentration in the adjacent metal sheet, and between the metal sheets will also be gradually increasing stratification, which further reduces the stress concentration in the adjacent layers. Advantageously prevents abrupt changes in thickness in the structure of the bonded metal sheets, and the specified thickness change caused by an unexpected loss in the continuity of one of the metal sheets on the large width. On the edge of the sheet metal thickness of the considered layer is preferably reduced to a relatively small value. This can easily be achieved,for example, the milling of the material.

Especially suitable for use metals include light metals, in particular aluminum alloys, such as alloys of aluminum with copper and/or aluminum with zinc or titanium alloys. Metal sheets, preferably consisting of aluminum alloy, according to the invention can be selected from the following group of aluminum alloys, such as alloys of the AA(USA) N 2024, AA(USA) 7075 N, AA(USA) N 7085, AA(USA) N 7475 and/or AA(USA) N 6013. In other respects the invention is not limited to layered materials using these metals, so that, if desired, can be applied to other aluminum alloys and/or, for example, steel or other suitable structural metals.

In one embodiment, the layered material according to the invention contains metal sheets, at least part of which contains socialiniai alloy. Such alloys increase the shear stiffness of the layered material and are used, in particular, in thick metal sheets. Another preferred embodiment includes a laminate with metal sheets, at least part of which contains an alloy of aluminum/magnesium/scandium. Such alloys further enhance the corrosion resistance and are used, in particular, in thick metal sheets.

Depending on the intended application and sovokupnostei, the person skilled in the art can easily determine the optimal number of metal sheets. Because the invention in the layered material can be used thick metal sheets, the total number of metal sheets to be molded normal thickness, as a rule, will not exceed thirty, although the invention is not limited to layered materials with the same maximum number of metal sheets. According to the invention, the number of metal sheets is from 2 to 20, for example, from 2 to 10. As in the layered material according to the invention can be used thicker metal sheets than is known at present, the number of layers in the moulded parts is much less than is known to the prior art, and to produce such moulded easier, quicker and therefore cheaper than the molded detail on the basis of known layered material.

In one embodiment, the layered material according to the invention is a laminate made from the outside to the inside of at least one thick metal sheet, at least one fiber-reinforced polymer layer having a reduced volume content of fibers, and the rest of the laminate. The remainder of the layered material preferably contains metal sheets and United with n the mi reinforced fiber polymer layers, volumetric fiber content which is at least 50 vol.%. In one embodiment, given a layered material, which is made symmetrical from the outside in. Such a symmetric variant implementation contains at least two thick sheet metal on the outside, between which is placed the Central layered material in the form of a series of sheet metal and connected with them reinforced by fibers of polymeric layers, the volumetric fiber content which is at least 50 vol.%. Two thick metal sheet connected to the Central layered material through at least one fiber-reinforced polymer layer having a low volumetric fiber content. Due to the implementation structure of the layered material according to the invention is symmetrical about a plane passing through the center of the thickness of the layered material, preventing at least partial deformation of the layered material as a result of internal stresses. This option is the implementation of the layered material according to the invention is also advantageous because this material can also be used in essentially the same most of the infrastructure is used at present in the aircraft industry for fastening panels of the aircraft. In addition, the thickness profile in this material mo is but easy to implement way which is currently the case for massive aluminum casings, namely, removing the milling thick outer metal (aluminum) layer. In addition, fatigue properties in this implementation meet the requirements imposed by the aviation industry to "requiring no worries" materials, while reducing the number of reinforced fiber layers and the number of metal sheets for processing and transportation. When in this application speaks of material that "requiring no worries", this refers to the material in which fatigue cracks subjected to fatigue loading, remain so small that the strength of the structure remains greater than the strength required for the application. However, in the material which is not sensitive to fatigue cracks remain so small that they cannot be detected using conventional methods for the examination of the aircraft structure. Although this is not a limitation to the invention, a crack in the material, do not require the hassle, during the life of the aircraft (from 20000 to 60000 flights) will usually grow no more than about 100 mm, from the initial (made artificially) cracks. However, the maximum crack length can vary and, among other things, associated with the residual strength of the damaged structure.

<> Laminates according to the invention are particularly suitable for the formation of the cladding sheet for the fuselage and/or wings of an aircraft or spacecraft. The invention relates also to the aircraft or spacecraft, the fuselage and/or wing which is wholly or partially made of cladding sheets of laminated materials according to the invention. In one embodiment of the invention the covering, for example, an airplane wing, formed of a layered material, which is made symmetrically from the outside to the inside, at least one thick metal sheet, then at least one fiber-reinforced polymer layer having a reduced volume content of fibers, and the rest of the layered material containing in this illustrative embodiment, from 5 to 10 metal sheets and from 4 to 9 United with them reinforced by fibers of polymeric layers, the volumetric fiber content which is at least 50 vol.%. However, it is also possible that the remainder of the layered material contained fewer layers, for example, only two sheet metal with intermediate reinforced fiber polymer layer. In addition, it is possible that the remainder of the layered material contained only one thick metal sheet. If desired, such a laminate may contain tools the haunted metal sheets are different and, if desired, gradually tapering thickness, for example, to be able to handle it the thickness profile. Wing aircraft according to the invention is preferably provided with such cladding sheets so that the fiber reinforced polymeric fibers of the layers in the rest of the layered material contains mainly two groups of continuous fibers running parallel, with each group makes the same angle with the intermediate direction, which corresponds to the longitudinal direction of the wing. Thus, preferably, for example, to allow at least some of these reinforcing fibers go in the direction that forms an angle of about 45 degrees with the longitudinal direction of the wing. When this application is referred to the longitudinal direction of the wing, it is assumed that the direction from the fuselage to the top of the wing. The longitudinal direction is the direction of the bow at an angle, which may vary depending on the position of the wings, and the specified direction of the bow corresponds to the direction of air flow from the front edge to the rear edge of the wing. In critical towards the fatigue zones of the wing, such as the root of the wing, the wing can optionally be reinforced according to the invention one or more known layered materials (in this case called typically the "doubles"), such as Glare®, and/or the layered material according to the invention. The reduction in the average voltage is achieved using the local structure thickness.

Cladding sheet according to the invention, which is particularly suitable, in addition, strengthened locally by at least one longitudinal element stiffness connected with him, adhesive layer, a specialist in this field also called the "stringer". The longitudinal element of rigidity may include metal-laminate, possibly reinforced with fibers, and more preferably a laminated material according to the invention. In one embodiment, the longitudinal element stiffness contains layered material according to the invention, which contains essentially only thick metal sheets made from flat sheet material or obtained by separate extrusion of thin-walled profiles, which are glued to each other reinforced fiber polymer layers having a low volumetric fiber content. Typical suitable implementation includes, for example, thick aluminum sheet of a thickness of approximately 1.5 mm

In the following implementation of the cladding sheet according to the invention the longitudinal element stiffness connected with cladding sheet through an adhesive layer containing a fiber reinforced polymer. Cladding sheet, which is also the person is but appropriate, made of layered material containing, outside, inside, at least one thick metal sheet, at least one fiber reinforced polymer layer having a reduced volume content of fibers, and the rest of the layered material, and the outer thick metal sheet contains a worksheet that all stiffeners. Such cladding sheet usually is not symmetric. Sheet, stiffeners may include extruded aluminum sheet called experts in this field "molded". Such compaction contain flat sheet portion, provided on a substantial part of the stiffening elements, with the specified sheet part obtained by the extrusion of tubular form and then its cut, straighten and milling and, optionally, pre-treatment for bonding.

According to the invention receive layered material shows, in particular, high tolerances, and which can be produced simply and at low cost.

Further features of the invention will emerge from the following schematic figures, but are not limited to.

Figure 1 shows a portion of the layered material (referred to in the present application is "the rest of the layered material") according to the invention with nine layers,

Figo is and 2 shows the layered material according to the invention, including the rest of the laminate to figures 1,

figure 3 shows the cross-section of another variant implementation of the layered material according to the invention,

figure 4 shows the propagation of cracks by applying a variable load to the aluminum sheet 2024-T3 4 mm thick and three options for the implementation of the layered material according to the invention,

figure 5 shows the structure of the cladding sheet for the wing, which uses a laminated material according to the invention, and finally,

figure 6 shows the number of structural options for the implementation of the cladding sheet to the wing, using a laminated material according to the invention.

Figure 2 shows the layered material 1 according to the invention, containing a total of 11 layers. It should be noted that the thickness of the layers shown in the figures do not necessarily correspond to the actual thickness ratio. Layered material 1 on both outer sides contains two thick metal layers 2 and 3, made of a suitable aluminum alloy. The middle of the layered material 1 formed the rest of laminated material 10, which is connected on both sides with thick metal plates 2 and 3 by using one fiber-reinforced polymeric layer (4, 5) on each side, with low volume content of fibers. Although it is on the figure 2 is not shown, when VC is Sri you can install more than one thick metal sheet (2, 3) to each other, as shown in figure 3 for two pairs of thick metal sheets (2A, 2b) and (3A, 3b)to obtain the desired thickness. You can also order the thick metal sheets (2, 3) go across each other, and the overlapping sheets are beveled on the edges of the sides and are arranged so that they at least partially overlap along the bevel edge (a method called "splices"). More than one thick metal sheet (2A, 2b) and (3A, 3b) are connected preferably by means of reinforced fiber polymer layers (4A, 5A), with reduced volume content of fibers, as shown in figure 3. The connection between the thick metal plates (2b, 3b) and the rest 10 of the layered material formed of reinforced fiber polymer layers (4b, 5b)having a low volumetric fiber content. It is possible that the layers (4A, 5A) and (4b, 5b) were formed in different ways.

Figure 1 shows a variant implementation of the remaining part 10 of the layered material according to the invention in the form of a flat rectangular sheet. In the shown illustrative embodiment, the rest of laminated material 10 contains a portion of the layered material 1 that does not include thick metal sheets (2, 3) and the connecting layers (4, 5). The rest of laminated material 10 is made of five metal plates 12, having a thickness of, for example, the R, 0.2 mm, containing aluminum alloy such as 2024-T3. The metal sheets 12 are firmly bonded to four reinforced fiber polymer layers 11 on the basis of epoxy resin, which is also a good glue for metal. Fiber reinforced connecting layer 11 contains and is formed from glass fibers, impregnated with a specific polymer, and has a volumetric fiber content of approximately 60%. These pre-impregnated prepregs 11 with the thickness of about 0.25 mm is formed of unidirectional fibers running parallel to each other in the direction 13. The rest of laminated material 10 obtained by stacking, for example, in flat form, the set of layers 11 and 12 to each other in the sequence shown in figure 1. After layering the whole structure utverjdayut at a temperature suitable for epoxy resin. For most applications, the most appropriate epoxy resin with a high glass transition temperature. Such epoxy resins are usually otverzhdajutsja at a temperature of approximately 175°C. Although it is not essential to the invention, preferably after curing the structure shown in figure 1, to carry out the stretching in the longitudinal direction of the structure, which is more elastic elongation of the metal sheets 12 and less relative elongation at rupture of reinforced fiber into the us polymeric layers 11. This pre-tension the rest of the laminate 10 can be achieved, for example, creating the elongation ε from 0.1 to 2 percent of the rest of the laminate 10 in its longitudinal direction. Depending on the fibers used in reinforced fiber polymer layers, the range of this elongation may be different. The rest of laminated material 10 may be pre-strained by conducting it through a rolling mill under pressure. Thus, it provides a method that can be applied on an industrial scale. Setting the applied compressive efforts at a high enough level, get deformation in the plane of the rest of the laminate 10 of this magnitude that is created in the longitudinal direction elongation ε exceeds the limit of plasticity in metal sheets 12, which will cause the metal sheets 12 continuously deformed without causing defects reinforced fiber polymer layers 11. Pulling the rest of the laminate 10 in the longitudinal direction is created especially favorable state of stress in which each metal sheet 12 in the unloaded state average has a compressive stress, and each of the reinforced fiber polymer layer 11 has, on average tensile stress. Thus, the prob is tenderly, to the layered substructure and/or the obtained laminated material was demonstrated, for example, increased yield strength. It is also beneficial for the fatigue characteristics. The increased yield strength additionally advantageous if in layered material uses aluminum types, which are intrinsic to the increased yield in comparison with the known aluminum alloys based on copper and zinc, such as alloys of the 2000 series.

Figures 5(a), 5(b) and 5(C) show three options for the implementation of the cladding sheet 30 to the wing. Cladding sheet 30 is formed of a layered material 1 according to the invention, containing added into the center of the rest of laminated material 10 made of metal sheets, which are firmly bonded reinforced fiber polymer layers on the basis of epoxy resin having a volume content of fibers of at least 50 vol.%. Three shows sheathing sheet 30 are on the upper side (according to the figure), thick sheet metal in the form of sheet 32, which are fully equipped with ribs 35, preferably extruded, containing aluminium sheet. In the embodiment shown in figure 5(a), the bottom side is formed from a thick metal sheet 33. Both thick sheet 32 and 33 are connected with located at the center of the rest of laminated material 10 by means of two reinforced fiber polymer layers 36, with reduced volume content of fibers. In the embodiment shown in figure 5(b), the lower side cladding sheet 30 (which corresponds to the side of the wing, facing outwards) formed from a series of thick metal layers 34 are connected to each other and with the Central rest of laminated material 10 through the reinforced fiber polymer layer 36 having a reduced volume content of fibers. In the embodiment shown in figure 5(C), the lower side cladding sheet 30 is formed of several thick metal layers 34, which are interrupted and are connected across each other (partially overlapping each other) through the reinforced fiber polymer layer 36 having a reduced volume content of fibers. However, it is preferable to arrange the edges of thick metal sheets essentially opposite each other ("stacked edge"), so that you can establish less stringent accuracy requirements of the location.

Figures 6(a) through 6(i), inclusive, show nine embodiments of the cladding sheet 30 to the wing. In these figures the positions of the links listed only once. In these embodiments, the implementation of the cladding sheet 30 reinforced several longitudinal stiffeners 40, United with him adhesive layer 41. rodolia the stiffening elements 40 may contain aluminum profiles, but preferably they contain a laminated material according to the invention, in accordance with the adhesive layer 41 preferably contains a fiber reinforced polymer. In this illustrative embodiment, the longitudinal element stiffness 40, the specified element stiffness contains, therefore, at least one thick metal sheet, preferably aluminum sheet, and at least one fiber reinforced polymer layer having a reduced volume content of fibers and used for bonding of thick sheet metal with the rest of the longitudinal element stiffness 40. In this case, the remainder of the specified element stiffness can be made of more than one thick metal sheet, glued to each other via a fiber-reinforced polymer layer, optionally having a low volume content of fibres; or from the known laminates such as Glare®; or from a combination of thick metal sheets and the well-known layered material, for example, Glare®. You can also do a longitudinal element stiffness mainly of thick metal sheets formed from flat sheet material, or received by pressing a separate thin-walled profiles, which are glued to each other reinforced polymer fibers SL is s, with reduced volume content of fibers. Further, the cladding sheet 30 is formed of a layered material 1 according to the invention, containing placed in the middle of the rest of laminated material 10 made of metal sheets, which are firmly bonded by means of reinforced fiber polymer layers on the basis of epoxy resin having a volume content of fibers of at least 50 vol.%. Cladding sheet 30, is shown in figure 6(a), contains a thick metal sheet (42, 43) on both sides and placed in the middle of the rest of the laminate 10. Both thick sheet (42, 43) connected with located in the center of the rest of laminated material 10 by means of two reinforced fiber polymer layer 46 having a reduced volumetric fiber content.

In variants of the implementation shown in figures 6(b), 6(C) and 6(d), the lower and/or upper side of the cladding sheet 30 are formed by several thick metal layers 44, which are connected with each other and with the Central rest of laminated material 10 through the reinforced fiber polymer layer 46 having a reduced volume content of fibers. In variants of the implementation shown in figures 6(e) 6(i), inclusive, of the lower and/or upper side of the cladding sheet 30 is formed of several thick metal layers 44, which is s interrupted and connected across each other (possibly partially overlapping each other) through the reinforced fiber polymer layer 46 having a reduced volume content of fibers. Sheeting the wings usually have a thickness varying from 3 mm at the end of the wing and up to a maximum of about 30 mm from the wing root. With the well-known layered material of such thickness can be achieved only by obtaining a structure of about 50 aluminum sheets and 49 layers reinforced by fibres of polymer, assuming a thickness of 3 mm in the design 5/4 (5 layers of aluminum sheets and 4 layers of fiber-reinforced polymer between them). It should be noted that the laying of such number of sheets, in particular metal sheets, is almost impracticable the production process, from the point of view of manipulation with many thin sheets and their pre-processing. This problem is solved layered material according to the invention.

A number of layered material 1 according to the invention were tested in fatigue under load applied in the direction 13. The figure 4 shows the fatigue properties of the layered material 1 according to the invention, which are compared with the fatigue characteristics of aluminum sheet type 2024-T3 4 mm For this test samples of layered materials by size 200x500 mm was subjected to a tensile stress with a sinusoidally-varying medium load 100 is PA and a frequency of 10 Hz. Samples for testing pre-made thin initial crack across the direction of stretch, having a length of 2A=10 mm figure 4, half crack length "a" pending on the vertical axis. The horizontal axis represents the total number of flights 50 in modeled the wing loading.

Line I corresponds to the crack growth of aluminum sheet type 2024-TK 4 mm

Line II corresponds to the crack growth of the layered material, containing in the center of the rest of the layered material made of fiber-metal laminate Glare®, taped in the second autoclave cycle between two aluminum sheets of 2024-T3 4 mm thick, using an adhesive film FM 94 (without fibers). The adhesive film is provided with a carrier which retains the thickness of the adhesive layer during the autoclave cycle. Central to the rest of layered material includes a laminate Glare® 1-5/4-0 .4 (on the basis of five aluminum layer with a thickness of 0.4 mm), which was pre-stretched prior to elongation of 0.5%. This fiber-metal laminate material Glare® was used a standard glass prepreg S2 based glue FM 94. Volume content of fibers in the prepreg was 60%vol.

Line III corresponds to the crack growth of the layered material 1 made as a laminate corresponding to the line II, provided that CE is Central to the rest of the layered material was pasted on the most extreme aluminum layers 2024-T3 4 mm thick, using the same glass prepreg S2, which was used in the Central layered material.

Finally, line IV corresponds to the layered material according to the invention. This laminated material is formed as a laminate corresponding to the line III, provided that the prepreg fiberglass S2 and epoxy FM 94 connected with adhesive tape FM 94 used in the second autoclave cycle for bonding aluminum sheets 4 mm thick with a Central fiber-metal laminate material. Thus, in the end, this adhesive layer has a reduced amount of fibers.

As can be seen in figure 4, the layered material 1 according to the invention (line IV) clearly shows a reduced crack growth in a given load compared to the aluminum layered material (line I) or other layered materials (lines II and III) according to the preceding level.

In all cases, when in the description and the formula says about the module of elasticity, tensile strength and relative elongation at break of the fibers, it is understood that they refer to values under tensile load in the longitudinal direction of the fibers and determined by measurements on the finished layered material.

In the framework of the invention can be introduced various changes. Although in layered materials according to the invention use is used metal sheets are mainly the same thickness, in principle it is also possible to use metal sheets having two or more different thicknesses in the same laminated material as possible symmetric stacking. Generally speaking, the thickness of the polymer layer between two successive metal sheets in the rest of the layered material is approximately the same size as the thickness of each of the metal sheets. If desired, the layered materials may also be decreasing thickness, and decreasing depth.

1. Layered material containing at least one first metal layer having a constant thickness of at least 1.5 mm, and at least one second metal layer having a constant thickness of at least 1.5 mm, and the first metal layer and second metal layer are connected to each other by reinforced fiber polymer layer, the volumetric fiber content which does not exceed 45%, and fiber reinforced polymer layer contains reinforcing fibers are laid in a polymer matrix and reinforcing fibers selected from the group consisting of glass fibers, carbon fibers, drawn thermoplastic fibers, natural fibers, and combinations thereof, and the reinforcing fibers are impregnated with a polymer matrix in a partially cured state.

2. The layered material according to claim 1, in which polymer the I matrix is a thermoplastic polymer matrix or termotorgmash polymer matrix.

3. The layered material according to claim 1, in which the thickness of the first metal layer and second metal layer is 2.5 mm

4. The layered material according to claim 1, in which the reinforcing fibers are continuous and are in the same direction.

5. The layered material according to claim 1 for use in the wing of the plane in which the reinforcing fibers are present in the two groups, which are continuous and stacked in parallel, and each group makes the same angle with the longitudinal direction of the wing.

6. The layered material according to claim 1, in which the first metal layer and second metal layer containing aluminum alloy.

7. The layered material according to claim 1, in which the first metal layer and second metal layer contain socialiniai alloy.

8. The layered material according to claim 1, in which the first metal layer and second metal layer composed of aluminum alloy with magnesium and scandium.

9. Layered material containing a layered substructure, containing at least one first metal layer, having a thickness of not more than 0.8 mm, at least one second metal layer, having a thickness of not more than 0.8 mm, and a fiber reinforced polymer layer between them with volumetric fiber content of at least 50%, at least one upper metal layer connected with the top of the layered substructure and having the second constant thickness of at least 1.0 mm, and at least one lower metal layer, connected with the bottom of the layered substructure and having a constant thickness of at least 1.0 mm, and the at least one first metal layer and the at least one second metal layer is connected with the layered substructure reinforced fiber polymer layer, the volumetric fiber content which does not exceed 45%.

10. The layered material according to claim 9, in which the fiber reinforced polymeric layer, the volumetric fiber content which does not exceed 45%, it contains the reinforcing fibers are laid in a polymeric matrix.

11. The layered material of claim 10 in which the reinforcing fibers are selected from the group consisting of glass fibers, carbon fibers, drawn thermoplastic fibers, natural fibers and combinations thereof.

12. The layered material of claim 10 in which the polymer matrix is a thermoplastic polymer matrix or termotorgmash polymer matrix.

13. The layered material according to claim 9, in which at least one upper metal layer and at least one lower metal layer composed of aluminum alloy.

14. The layered material according to claim 9, in which when layered material is in an unstressed state, the layered substructure is pre-strained fiber-metal laminates is the material, at least one upper metal layer and at least one lower metal layer have an average compressive stress, and fiber reinforced polymer layer has an average tensile stress.

15. The layered material according to claim 9, in which at least the first metal layer and at least a second metal layer of the layered substructure have a higher yield strength than the at least one upper metal layer and at least one lower metal layer.

16. The layered material of claim 10 in which the reinforcing fibers are impregnated with a polymer matrix in a partially cured state.

17. The layered material according to claim 9, forming a wing of the aircraft.



 

Same patents:

FIELD: machine-building industry.

SUBSTANCE: invention is referred to a complicated profile (1), consisting of a metal profile (2) coated with metal foil (3), and a method of coating application on production line by means of the metal foil (4). The method includes subsequent transportation of preliminary cut-out sections of shaped profiles (2) made from plastic or metal. The coating of each shaped profile (2) section with metal foil (3) is ensured to couple the said foil (3) with the said profile (2) in any point of surfaces of metal foil. This coating also ensures detection of the first, the lower by downstream, end (6) and/or the second, the upper by downstream, end (7) of each shaped profile (2) section and their cutting at the level of each end of each shaped profile section. The above metal foil (3) is selected so that its surface hardness could be higher than the hardness of the above shaped profile (2).

EFFECT: shaped profile coated with metal foil and provided with excellent adhesion with foil.

21 cl, 2 dwg

FIELD: machine-building industry.

SUBSTANCE: substrate material is coated with a layer containing, at least, one metal for producing the applied layer on the substrate material. In order to produce metal protective layer, the applied layer is then treated thermally in recovering environment at pressure below atmospheric level.

EFFECT: improved protection properties of part with metal layer.

42 cl, 2 dwg, 1 tbl, 13 ex

FIELD: metallurgy.

SUBSTANCE: composition of bath has following ratio of components, wt %: water 38.0-40.0, caustic soda 40.0-43.0, sulphide soda 1.5-2.5, hypo-sulphurous soda 2.0-3.0, sulphurous titanium 7.0-8.0, copper sulphide 2.5-3.5, potassium 3.0-4.0.

EFFECT: raised anti-friction properties and hardness of processed items.

1 tbl

FIELD: metallurgy.

SUBSTANCE: heat resistant component contains main part of TiAl of inter-metallic compound having friction surface rubbing against another component and resistant to abrasion coating. Coating is applied on friction surface and is formed by sedimentation in discharge of material of a consumable electrode of metal resistant to abrasion.

EFFECT: raised resistance.

14 cl, 11 dwg, 3 tbl

FIELD: metallurgy.

SUBSTANCE: strips of alloyed metals are built-up in direction of lengthwise generatrix of blade body ensuring gaps between built-up strips at least on part of blade body and forming layer. As built-up metal there are used alloys on base of nickel with Co, Cr, Al, Mo, W, Ti, Y or their combination. Further, a blade body is mechanically processed ensuring its specified geometry. Successive thermal treatment corresponds to thermo-cycling.

EFFECT: manufacture of coating possessing high operational properties.

20 cl, 1 dwg

FIELD: machine building.

SUBSTANCE: slurry is applied by pouring into stator inner cavity through inlet branch pipe in amount sufficient for complete immersion of guide naves in slurry. Inlet branch pipe is sealed to turn turbine stator about its axis through angle at which inlet branch pipe stays at its bottom position. Then, turbine stator is turned clockwise about axis perpendicular to its axis through angle of inclination to horizon at which slurry does not flows out of turbine stator with inlet branch pipe and guide vanes unsealed. Thereafter, turbine stator is turned about said axis counter clockwise to drain slurry. Now with slurry drained, turbine stator is rotated about its axis with turbine in horizontal position, unless slurry layer water glare disappears.

EFFECT: regular application, no surface defects.

3 cl, 1 dwg, 1 ex

FIELD: electricity.

SUBSTANCE: pulse discharge is created between an end surface of an electrode (37) and an end part of a metal plate (11), in order to cause the electrode (37) wear and form a groove (41) in its end surface, shape of which complies with the shape of the end part of the metal plate (11). The relative displacement of the electrode (37) is done in direction perpendicular to the side of the metal plate (11). A pulse discharge is created between the inner side surface of the groove (41) of the electrode (37) and the side surface (11b, 11c) of the end part of the metal plate (11), in order to create an auxiliary coating (43) or (45) at the side (11b, 11c) of the end part of the metal plate (11), and a pulse discharge is created between the lower surface of the groove (41) of the electrode (37) and the upper surface of the end part of the metal plate (11), in order to form a plating layer (47) on the end part of the metal plate (11).

EFFECT: improved strength characteristics of a surface layer.

2 cl, 6 dwg

FIELD: chemistry.

SUBSTANCE: invention relates to treatment of the surface of a titanium article for orthodontic application, used in form of a prosthetic device or component thereof. The method involves immersing the article to be treated in a suspension containing titanium dioxide nanoparticles while ensuring complete wetting of the article, heating the article in order to remove the solvent and performing a thermal cycle in order to fix the nanoparticles on the treated surface of the article.

EFFECT: obtaining titanium articles with bactericidal properties.

11 cl, 6 ex

FIELD: metallurgy.

SUBSTANCE: tool is positioned in chamber which is vacuumised and is supplied with process gas to working pressure (P). At this pressure there is possible gas break down at minimal strength of electro-magnetic field. Further, positive voltage of bias (U) is supplied on the tool forming electrostatic field around the tool sufficient for maintaining stable generation of plasma and there is generated micro-wave energy to a level of super-high frequency - SHF of power (W) 10-90 Wt. Cutting edges of the tool are subjected to plasma during 1.5-17 minutes (tpr), further, the tool is cooled. Also, during treatment process there is performed control over bias current (I) occurring in a measuring circuit at plasma generation chosen from the range 2÷17 mcA and final lag temperature (T) chosen from the range 10÷230°C. At deviation from the allowed value of bias current (I) the mode of treatment is normalised by changing anode current of a magnetron (Ian). At exceeding the allowed value of final lag temperature (T) treatment of the tool is terminated earlier.

EFFECT: raised wear resistance of cutting tool.

4 cl, 10 dwg, 3 tbl

FIELD: metallurgy.

SUBSTANCE: layer of nano composite structure containing silicon oxide dissolved in litol is applied on parts of metals or alloys. Further, the layer is radiated with electro-magnetic field of high frequency f=3÷5 MHz during specified interval of time t=5-15 seconds chosen depending on geometric dimension of parts. Owing "to skin-effect" the surface layer of treated part is heated to temperature within the range from 700° to 900°C. Dislocations of the surface layer are blocked with positive ions of heavy metals by the method of electro-mechanic implantation when direct electric current is transmitted through the contact a part-implanted strengthening metal.

EFFECT: obtaining nano structured wear resistant surfaces designed for strengthening surface layer of machine parts of cylinder form and threaded surfaces.

3 cl, 3 ex, 4 dwg

FIELD: process engineering.

SUBSTANCE: set of inventions relates to plain bearing and method of its production. Proposed plain bearing comprises metal base, intermediate layer applied thereon and antifriction layer applied on said intermediate layer. Said intermediate layer comprises at least one thermoplastic polymer containing functional groups of the formula

.

Note here that R stands for cyclic or linear organic radicals with 1-20 carbon atoms. Note also that functional groups are implanted into thermoplastic polymer by adding at least one modifying agent, namely, toxilic acid and its derivatives, in particular its anhydride and or itaconic acid and its derivatives, particularly, its anhydride, and/or citraconic acid and its derivatives, particularly, its anhydride.

EFFECT: bearing that requires no servicing.

24 cl, 2 dwg

FIELD: chemistry.

SUBSTANCE: coating composition contains a polyvinyl chloride polymer, an acrylic resin which is preferably a polymer obtained from monomer acrylates or methacrylates, such as acrylic acid, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, pentyl acrylate, hexyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, pentyl methacrylate, hexyl methacrylate resins, copolymer resins of said components or mixtures thereof, a cross-linking agent which is obtained from phenol, para-tert-butylphenol, xylenol or mixture thereof, and formaldehyde, an additive, a dye and a solvent component, and the composition essentially does not contain bisphenol A diglycidyl ether (BADGE) and bisphenol A resin. The coatings are suitable for containers made from three parts, as well as for metal cans made through deep-drawing. The coatings are particularly useful for covers which are torn in order to open due to their unusual flexibility and resistance to sterilisation.

EFFECT: composition provides coatings for metal cans which have suitable flexibility, resistance to scratching, adhesion and sterilisation during processing while in contact with food.

18 cl

FIELD: process engineering.

SUBSTANCE: invention relates to sensor foil and sensor switch made thereof. Sensor foil is made up of multiple superimposed layers. Note that carrier second conducting layer 2 is arranged above first carrier layer 1, while second carrier layer 3 coated by paint 4 is arranged on conducting later 2. First carrier layer 1 provided with conducting layer 2 and second carrier layer 3 with pint coat 4 are glued together by adhesive layer 5. Device assembled of said layers 1 - 5 is glued to carrier layer 7 by adhesive 6 made, for example, from glass.

EFFECT: possibility to use in household electrical appliances, eg furnaces.

7 cl, 2 dwg

FIELD: process engineering.

SUBSTANCE: invention relates to coat and method of coating outer surfaces. Proposed method of coating pipeline outer surfaces by polymer capable of forming cross-links under action of water comprises the following stages: a) pipeline outer surface is coated by, at least, one polymer that forms cross-links under action of water. Note here that said polymer represents HDPE grafted by alkoxy silane. b) Polymer is cross linked on subjecting it to water at increased temperature to produce cross-linked polymer layer unless cross linking degree makes ≥30% to ≤80%. c) Polymer is cross linked that can form cross links under action of water at ≥50°C to ≤350°C, preferably at ≥150°C to ≤300°C, more preferably at ≥200°C to ≤260°C. Note here that during these stages, pipeline is heated to ≥170°C to ≤230°C, preferably to ≥180°C to ≤220°C, more preferably to ≥190°C to ≤210°C. Powder ionic spraying method is used epoxy resin layer is applied with thickness of ≥0.08 to ≤0.16 mm, preferably of ≥0.10 to ≤0.13 mm, more preferably, 0.125 mm. Method of envelopment extrusion is used to apply a layer of glue with thickness of ≥0.15 mm to ≤0.30 mm, preferable of ≥0.22 mm to ≤0.27 mm, more preferably of 0.25 mm. By method of extrusion, applied is upper layer of HDPE with thickness of ≥2.8 mm to ≤3.2 mm, preferably of ≥2.9 mm to ≤3.1 mm, more preferably of 3 mm. Extrusion is used to apply layer of HDPE cross linked by silane with thickness of ≥0.8 mm to ≤1.2 mm, preferably of ≥0.9 mm to ≤1.1 mm, more preferably of 1 mm. Now, pipeline is treated by water with temperature of ≥10°C to ≤40°C, preferably of ≥20°C to ≤30°C, more preferably of 25°C. Coat is made as described above. Invention covers also coated pipeline.

EFFECT: improved operating performances and expanded applications.

11 cl, 2 tbl, 3 dwg, 2 ex

FIELD: process engineering.

SUBSTANCE: invention relates to multilayer metallised biaxially-oriented polypropylene films used for food packing and to method of their production. Said film comprises main layer A made from crystalline home- or copolymers of propylene comprising bonds C2-C10 of alpha-olefine, one top layer B made from propylene copolymer containing 3 to 6 wt % of the bonds of linear C4-C10-1-alkene, and metal layer M applied on the surface of top layer B. Propylene copolymer of layer B has fraction soluble in xylene at 23°C, less than 4.0 wt %, Vick softening point above 135°C indenter depth in Vick test smaller than or equal to 0.05 mm at 120°C. Method of film production comprises co-extrusion of layers A and B, biaxial orienting of co-extruded layer A and B, treatment of top layer B surface and metal deposition on said layer.

EFFECT: multilayer metallised biaxially-oriented polypropylene films with high oxygen and steam barrier properties.

FIELD: process engineering.

SUBSTANCE: invention relates to multilayer metallised biaxially-oriented polypropylene films used for food packing and to method of their production. Said film comprises main layer A made from crystalline home- or copolymers of propylene comprising bonds C2-C10 of alpha-olefine, one top layer B made from propylene copolymer containing 3 to 6 wt % of the bonds of linear C4-C10-1-alkene, and metal layer M applied on the surface of top layer B. Propylene copolymer of layer B has fraction soluble in xylene at 23°C, less than 4.0 wt %, Vick softening point above 135°C indenter depth in Vick test smaller than or equal to 0.05 mm at 120°C. Method of film production comprises co-extrusion of layers A and B, biaxial orienting of co-extruded layer A and B, treatment of top layer B surface and metal deposition on said layer.

EFFECT: multilayer metallised biaxially-oriented polypropylene films with high oxygen and steam barrier properties.

FIELD: personal use articles.

SUBSTANCE: unit of external panels comprises front panel made of transparent polyethylene terephthalate, which forms front surface of refrigerator, back surface of which has printed area with specified colour and/or print, and back surface made of polyvinyl chloride, which is installed on back surface of front panel. Unit of external panels is installed outside refrigerator. Refrigerator door comprises door unit, which comprises external door that forms front surface of refrigerator door, and inner lining of door, which is connected to back surface of outer door, unit of panels, which comprises front panel made of transparent polyethylene terephthalate, forming front surface of refrigerator that has back surface with printed area, which has specified colour and/or print, and back panel made of polyvinyl chloride installed in back surface of front panel. Unit of panels is installed on front surface of refrigerator.

EFFECT: simplified manufacturing of refrigerator.

6 cl, 4 dwg

FIELD: metallurgy.

SUBSTANCE: metal tube has polymer coat with low surface energy. At least a part of said polymer coat is activated. A part of said polymer coat of the mainline constructed by area adjoining each uncoated section has activated surface. Fixation-prone coat with high surface energy is applied on said part with activated surface.

EFFECT: possibility to decontaminate surfaces in-situ prior to erection welding.

25 cl, 8 dwg, 3 tbl, 1 ex

FIELD: metallurgy.

SUBSTANCE: sheet has insulating coating containing composite resin consisting of polysiloxane and polymer containing carbon element. Method involves application of composite resin and burning at temperature of 150 to 350°C till the coating with weight of 0.05 g/m2 to 10 g/m2 is formed.

EFFECT: obtaining the sheet with insulating coating providing high corrosion resistance and formability, which are equivalent to or higher than those properties of chrome-containing insulating coating.

16 cl, 6 tbl, 1 ex

FIELD: metallurgy.

SUBSTANCE: invention refers to sheet of electro-technical steel with insulating coating and can be used in engines and transformers. The sheet out of electro-technical steel containing poly-siloxane polymer is produced by applying coating liquid on surface of sheet and in successive baking. Coating liquid contains 100 weight shares of poly-siloxane polymer preliminary prepared with co-polymerisation of poly-siloxane with one or more organic resins and from 1 to 50 weight shares in sum of one or more coupling agents. Organic resins are chosen from a group consisting of acrylic resin, sterol resin, vinyl-acetate resin, poly-ether resin, urethane resin, poly-ethylene resin, poly-propylene resin, phenol resin, alkyd resin and epoxy resin. The coupling agent is chosen from a group consisting of melamine, isocyanate, silane agent of combination and oxazoline.

EFFECT: production of sheet of electro-technical steel possessing upgraded corrosion resistance and ability to perforating.

4 cl, 4 tbl, 1 ex

FIELD: shaping or joining of plastics.

SUBSTANCE: method comprises applying adhesive polymeric composition on the metallic surface, molding a plastic covering on the metallic surface, and heating and pressing the metallic surface. The surface is pressed during five seconds or less, the pressure ranging from 0.01 MPa to 5 MPa.

EFFECT: enhanced adhesion between the polymeric and metallic surfaces.

4cl, 2 ex

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