WO2014115251A1

WO2014115251A1 - Metal covered resin structure body and method for manufacturing same

Info

Publication number: WO2014115251A1
Application number: PCT/JP2013/051231
Authority: WO
Inventors: 茂菊池; 澤田　貴彦; 正藤枝; 利昭石井; 俊雄宮武; 正也小境
Original assignee: 株式会社日立製作所
Priority date: 2013-01-23
Filing date: 2013-01-23
Publication date: 2014-07-31
Also published as: JPWO2014115251A1

Abstract

A metal coating having a sturdy structure is formed at high speed and with high efficiency on a large-sized/large-surface-area structure having an organic material as a main component. The present invention has a resin base material, an intermediate layer covering the resin base material, and a metal layer covering the intermediate layer, the intermediate layer containing at least either resin or glass and metal particles, the metal particles contained in the intermediate layer being metallurgically bonded with the metal layer, the resin or glass contained in the intermediate layer being chemically bonded with the resin base material.

Description

Metal-coated resin structure and method for producing the same

The present invention relates to a metal-coated resin structure and a method for producing the same.

The blade surface of a wind turbine in a wind turbine is generally made of light-weight and high-strength Glass-Fiber Reinforced Plastics (hereinafter GFRP). GFRP is a glass fiber impregnated with resin and has electrical insulation. Almost one-third of the failure factors of wind turbine blades are due to lightning strikes, and this blade failure is caused by rapid high voltage-large current being applied to insulating blades, which cause burnout and breakage, rupture due to internal water expansion. , Caused by shockwave-induced bursting. If the blade is broken, power generation can not be performed during that time, and not only the cost of replacing and repairing the blade, but also significant economic damage such as compensation for interruption of the power supply will occur.

In order to prevent lightning strikes, it has been proposed to embed a metallic lightning striker called a receptor at the tip of the blade and install a metal conductor from the receptor to the ground (earth potential) inside the blade. However, the effect is thin, and lightning strikes randomly throughout the blade as well as the receptor, and blade breakage as described above occurs frequently. Therefore, it is desirable to provide a conductive metal coating on the entire surface of the blade to ground the lightning current. In addition, if the surface of the structure containing an organic material as a main component is coated with a metal, it can be an effective measure against ultraviolet ray deterioration, which is one of the major causes of organic material deterioration.

Unexamined-Japanese-Patent No. 2010-100802 Unexamined-Japanese-Patent No. 2006-137143 Unexamined-Japanese-Patent No. 2006-150595

As a general method of coating an organic material such as a resin with GFRP, such as resin, there is a plating method (chemical plating). In the plating method, the film forming rate is slow and a metal film of several mm order is formed Takes a lot of time. In addition, it is necessary to immerse an object in a plating solution, and it is practically and industrially difficult to coat a wind turbine blade having a length of about 100 m by a plating method.

Another method is thermal spraying. The thermal spraying method is capable of forming a thick film in a relatively short time, but since it is sprayed on the substrate (resin) in a molten state of the metal powder of the raw material, the resin substrate is also melted and a sound film is formed. Can not be obtained. Therefore, it is necessary to provide an intermediate layer (or an adhesive layer) in advance on the resin base material, and thermally spray on the intermediate layer. Since this intermediate layer is required to have heat resistance enough to withstand the subsequent thermal spray coating, it is necessary to include relatively expensive ceramic particles and the like, and formation of the intermediate layer can be performed separately from thermal spraying such as slurry spraying. This leads to an increase in manufacturing costs.

Therefore, an object of the present invention is to form a metal film of a healthy structure at high speed with high efficiency on a large-sized, large-area structure mainly composed of an organic material.

In order to achieve the above object, the present invention comprises a resin substrate, an intermediate layer covering the resin substrate, and a metal layer covering the intermediate layer, wherein the intermediate layer is at least resin or glass. The metal particles contained in the intermediate layer and the metal layer are metallurgically bonded, and any resin or glass contained in the intermediate layer is chemically bonded to the resin base material. There is.

Further, the step of accelerating each powder of at least one of resin and glass and metal particles with a gas flow, and colliding at least one of the resin or the glass and the metal particles with the resin base material Depositing and forming an intermediate layer covering the resin substrate, and depositing the metal particles in collision with the intermediate layer to deposit on the intermediate layer and forming a metal layer covering the intermediate layer And.

According to the present invention, it is possible to form a metal film of a healthy structure at high speed and with high efficiency on a large-sized and large-area structure mainly composed of an organic material.

Cross-sectional structure of metal-coated resin structure. Another cross-sectional structure of the metal-coated resin structure.

The metal-coated resin structure imparts conductivity by covering the surface of a resin base mainly composed of an organic material with a metal layer, and when it is used for a windmill blade or the like, grounds from the metal layer. Can prevent damage caused by lightning strikes. Although it is difficult to directly coat metal on the surface of an organic material-based substrate because metallurgical or chemical bonding does not occur between the organic material and metal, it is difficult to By providing an intermediate layer in which metal and resin are mixed, or an intermediate layer in which metal and low melting glass are mixed, metal coating is possible. That is, the main attachment mechanism is chemical bonding between the intermediate layer and the substrate, and metallurgical bonding between the intermediate layer and the metal layer, and metalization to the organic material substrate is possible via the intermediate layer. Become. Further, the intermediate layer may be a mixture of three types of metal, resin and low melting point glass.

The intermediate layer containing metal and resin, or the intermediate layer containing metal and low melting glass may have a uniform single composition ratio between the substrate and the metal layer, but the composition is continuous or stepwise It is desirable that the composition of the resin or the low melting point glass is large on the side in contact with the substrate, and the composition of the metal is large on the side in contact with the metal layer. As a result, the chemical bond between the intermediate layer on the substrate side and the substrate and the metallurgical bond between the intermediate layer on the metal layer side and the metal layer become stronger, and the intermediate layer has high adhesion strength. And the formation of metal layers.

The substrate is a glass fiber reinforced plastic, a carbon fiber reinforced plastic, a thermoplastic resin, or a thermosetting resin widely used as a general organic material-based structural material. The metal layer is a typical metal having a atomic number of 12 or more and a melting point of 420 ° C. or more, a transition metal, or an alloy mainly comprising them. The resin contained in the intermediate layer is a thermoplastic resin or thermosetting resin containing a curing agent and a catalyst, and the low melting point glass is a glass having a glass transition point of 600 ° C. or less. The combination of the substrate composed of these materials, the intermediate layer and the metal layer causes the above-mentioned bonding mechanism between the respective layers, and a metal-coated resin structure to which the metal layer is attached with high adhesion strength is obtained.

The metal particles constituting the metal layer have a ratio of the maximum diameter to the minimum thickness of 2 or more, and the metal particles are metallurgically bonded to each other. This is realized by the method described later. That is, the metal particles forming the metal layer are accelerated by a high-speed gas flow (carrier gas) and collided on the intermediate layer to adhere and deposit, so the metal particles are plastically deformed by the collision and perpendicular to the gas flow (intermediate Flatten parallel to the plane of the layer). Also, they collide metallurgically with each other by colliding with and contacting adjacent particles. As a result, a dense and strong metal layer is formed to impart conductivity to the surface. Furthermore, when corrosion occurs on the surface of the metal layer, the grain interface distance in the film thickness direction, which is a path in which corrosion proceeds, is longer than in the case where spherical particles are deposited, as compared with the case where spherical particles are deposited. Corrosion also improves. The metallurgical bond between these metal particles and the effect of prolonging the corrosion path appear when the ratio of the maximum width to the minimum thickness of the particles is approximately 2 or more. Here, the thickness in the particle deposition direction and the width in the plane of the intermediate layer are represented.

The resin or low melting glass contained in the intermediate layer chemically integrates with the substrate. This is because when the resin or low melting glass particles collide with the substrate by the high velocity gas flow, the kinetic energy is converted to heat, and the surface of the resin or low melting glass particles and the surface of the substrate melt. It is for solidification and integration. When the constituent component of the intermediate layer is a resin, integration is similarly caused by a method of applying, drying and solidifying using a liquid resin as described later. As a result, an intermediate layer having high adhesion strength is formed on the substrate, and the substrate is covered with the metal layer firmly adhered through the intermediate layer.

The manufacturing method of the metal-coated resin structure is to accelerate the powder such as metal with a high-speed gas flow, to cause it to collide with the substrate and to deposit it, and is a method called cold spray or kinetic spray. This is to cause particles to be plastically deformed to adhere and deposit on the substrate by causing the powder to collide with the substrate at high speed, but deposition is possible even if the metal powder is sprayed directly onto the substrate made of an organic material. No metal film can be obtained. The reason is that when metal particles harder than organic materials collide with the substrate, the substrate is scraped off and worn away. Therefore, by mixing a resin softer than metal or low-melting glass with metal particles, it is possible to form a layer (intermediate layer) in which the metal particles are also contained on the base of the organic material. Since the intermediate layer contains metal particles, even if the metal particles are injected onto the intermediate layer, they are metallurgically bonded to the metal particles in the intermediate layer, which enables the deposition of the metal particles, and the metal film becomes can get.

The intermediate layer desirably has a composition of metal-resin or metal-low melting point glass continuously or stepwise changed from the side in contact with the substrate to the side of the metal layer. That is, there is a large amount of resin or low melting point glass on the side in contact with the base material, and the gradient composition in which the amount of metal increases toward the metal layer. As described above, the chemical bond between the intermediate layer and the base material and the metallurgical bond between the intermediate layer and the metal layer become strong, and the formation of the intermediate layer as well as the metal layer with high adhesion strength is possible. In order to This intermediate layer having a graded composition is obtained by continuously or stepwise changing the gas flow rate and the powder feed rate from the side in contact with the substrate to the side of the metal layer.

If the collision speed of the resin or the low melting point glass is too high to the base material mainly composed of the organic material, the amount of heat converted from the kinetic energy is increased, and the resin or the low melting point glass is excessively melted. It collides with the substrate and is removed along the gas flow without adhering. Therefore, on the side in contact with the substrate, the raw material powder of metal-resin or metal-low-melting glass containing a large amount of resin or low melting glass collides with the substrate in a state where the gas flow speed is suppressed by lowering the gas temperature and pressure. You need to

On the other hand, since metal particles forming the metal layer are harder than resin and low melting glass, relatively high kinetic energy (ie, relatively high collision velocity) is required to plastically deform the particles for deposition. It is necessary to make it collide. Therefore, the intermediate layer to be the base must have a hardness not to be worn away by high-speed collision of hard metal particles, and must have a composition having a high metal content. Therefore, on the side closer to the metal layer, it is necessary to cause the raw material powder of metal-rich resin or metal-low melting point glass to collide with the substrate using a high gas flow rate by raising the gas temperature and pressure. Therefore, it is desirable that the gas flow rate set by the gas temperature or pressure be gradually or stepwise changed from the side in contact with the substrate to the side of the metal layer.

In addition, changes in the composition of metal-resin or metal-low melting glass are used to fill metal powder and powder of resin or low melting glass in separate powder feeders, and to nozzles for injecting high-speed gas flow and raw material powder. On the other hand, the composition of the intermediate layer can be changed in the thickness direction by changing the feed amounts of the metal powder and the resin powder, or the metal powder and the low melting point glass powder.

When the above intermediate layer is made of metal and resin, a mixture of metal particles forming the intermediate layer and liquid resin is applied to the surface of the substrate, dried and cured to form an intermediate layer, and then the metal powder is added. The metal layer can also be formed by accelerating with a high velocity gas flow and causing the substrate to collide and deposit. In this case, although the composition of the intermediate layer is generally a single composition, if a mixture in which the content of the metal particles is changed is applied in layers, the intermediate layer whose composition changes stepwise in the thickness direction should be produced. Can. By providing these intermediate layers, deposition of metal particles becomes possible in the same manner as described above, and a structure having a metal film formed on the outermost surface can be obtained.

The film structure improvement and densification of the metal layer and the intermediate layer can also be achieved by forming the intermediate layer and the metal layer on the substrate and then heating to a temperature lower than the heat resistance temperature of the organic material forming the substrate. That is, by heat treatment after film formation, metallurgical bonding increases with sintering between metal particles, resin particles produced by high-speed collision, repair of micro cracks in low melting glass particles, disappearance of pores between particles, etc. Progress, and film quality improvement and densification can be achieved.

The above-mentioned metal-coated resin structure is a light-weight and electrically conductive structure such as a wind turbine blade for wind power generation, aircraft fuselage, car body, etc., and a member requiring light weight and corrosion resistance such as automobile fuel tank Effectively use those functions.

Hereinafter, embodiments for carrying out the invention will be described in detail by way of examples, but the present invention is not limited to these examples.

Under the conditions shown in Table 1, a structure in which the surface of the epoxy resin was coated with Al was made on a trial basis. In Table 1, formation of the metal layer which consists of Al is all by cold spray.

No. 1 is a comparative example in which an attempt was made to coat Al directly on the surface of a substrate made of epoxy resin. A spherical powder with a particle size of 20 to 45 μm was used as the raw material powder of Al. When Al raw material powder was injected to the resin base material with compressed air of 100 ° C, 0.6MPa as carrier gas and injection distance (distance from tip of cold spray nozzle to base material) of 20 mm, the base material was Al particles It was scraped off, the substrate thickness decreased, and an Al film was not formed. From this, it is understood that direct metal film formation on a resin substrate is difficult.

No. 2 was formed by cold spray forming an intermediate layer of a single composition consisting of 60% by volume Al-40% by volume epoxy resin on a resin substrate and then coating Al thereon. FIG. 1 is a part of this cross-sectional structure. 1 is a metal layer, 2 is an intermediate layer, 3 is a substrate, 4 is Al particles, and 5 is an epoxy. The raw material powder of Al is a spherical powder similar to the above No. 1, the raw material powder of an epoxy resin is a crushed powder of 30 to 60 μm containing a curing agent, and the carrier gas for cold spray is compressed air. The intermediate layer is formed by feeding each of the Al raw material powder and the epoxy resin raw material powder from separate powder feeders to the nozzle so as to have the above composition, and using a carrier gas temperature of 100 ° C., a pressure of 0.6 MPa and a jet distance of 20 mm It injected it. The thickness of the formed intermediate layer was 250 to 500 μm, and when the porosity was determined by image processing at several locations of its cross-sectional structure, it was about 0.5% or less. Furthermore, Al raw material powder was cold-sprayed thereon under the same conditions to form a metal layer having a thickness of less than 50 μm. The porosity of the metal layer was measured by image processing in the cross-sectional structure and was about 40%.

No. 3 is a composition in which the composition of the intermediate layer is continuously changed from the substrate side to the metal layer side from 60Al-40 epoxy to 80Al-20 epoxy, and No. 4 is from 60Al-40 epoxy to 100Al-0 epoxy And continuously changed. Under these conditions, the amounts of each of the Al raw material powder and the epoxy resin raw material powder were continuously adjusted so as to obtain the above-mentioned composition under the same conditions as in the above No. 2. The porosity of these intermediate layers is 0.7% or less and 1% or less, respectively, and the porosity tends to increase when the amount of the epoxy resin decreases, but it is a range in which there is no problem in practical use. An Al metal layer was formed on these intermediate layers under the same conditions as No. 2, and the porosity was measured. As a result, No. 3 was about 10% and No. 4 was 1% or less, The metal layer becomes denser as the amount of metal (amount of Al) increases. Therefore, although the intermediate layer may have a single composition such as No. 2, the composition is inclined in the thickness direction, and the composition having a large amount of metal on the metal layer side (that is, having a large hardness) It is confirmed that it is desirable to densify the

In No. 5, when forming the intermediate | middle layer similar to No. 4, and a metal layer by a cold spray, it forms while the injection location was locally heated with a laser. As a result, the porosity of the intermediate layer and the metal layer was both reduced as compared with No. 4. Therefore, it was confirmed that the local heating at the cold spray site is effective for the formation of a dense metal layer.

No. 6 was heated at 250 ° C. for 1 hour in the atmosphere after forming No. 4. As a result, the porosity of the intermediate layer and the metal layer was both reduced as compared with No. 4. Therefore, it was confirmed that heating below the heat-resistant temperature of a base material after formation of an intermediate | middle layer and a metal layer is effective in densification of a metal layer.

In No. 7, a mixture of liquid epoxy resin containing Al powder and a curing agent (composition 30Al-70 epoxy) is applied to the surface of a substrate, dried and cured to form an intermediate layer, and then Al metal is formed on the surface. The layer was formed by cold spray. FIG. 2 is a part of this cross-sectional structure. No. 8 is a mixture of the composition 70Al-30 epoxy, and the intermediate layer and the metal layer are formed by the same method as No. 7. Thus, it has been confirmed that the intermediate layer can be formed also by a method in which a mixture of metal powder and liquid resin is applied to a substrate and solidified.

The ratio of the maximum diameter to the minimum thickness of the Al particles was measured from the cross-sectional structure of the metal layers of No. 2 to No. 8. As a result, almost all the particles in all cases were 2 or more. Moreover, as a result of observing the cross-sectional structure in any case, it was confirmed that the resin of the intermediate layer had a structure chemically integrated with the base material, and metallurgical bonding was made between the Al particles of the metal layer. . Accordingly, it was confirmed that a structure in which a base material containing an organic material as a main component was coated with metal was obtained.

The intermediate layer and the metal layer can be formed by the same method even when the base material is a thermoplastic resin, GFRP whose outermost surface is covered with a resin, carbon fiber reinforced plastics, etc. It is. In addition, when the metal forming the intermediate layer and the metal layer is another transition metal, or when the component constituting the intermediate layer is low-melting glass, the respective layers can be similarly formed.

1: Metal layer
2: Middle layer
3: Base material
4: Al particles
5: Epoxy

Claims

It has a resin base material, an intermediate layer which covers the resin base material, and a metal layer which covers the intermediate layer,
The intermediate layer contains at least one of resin or glass and metal particles,
Metallurgically bonding the metal particles contained in the intermediate layer and the metal layer,
A metal-coated resin structure, wherein a resin or glass contained in the intermediate layer and the resin base are chemically bonded.
In the intermediate layer, the composition of the resin or the glass is more than the composition of the metal particles on the resin base side, and the composition of the resin or the glass is more than the composition of the metal particles on the metal layer side The metal-coated resin structure according to claim 1, wherein the amount is smaller.
The resin base material is at least one of glass fiber reinforced plastic, carbon fiber reinforced plastic, thermoplastic resin, and thermosetting resin,
The metal layer contains at least one of a group metal having an atomic number of 12 or more and a melting point of 420 ° C. or more, a transition metal, or an alloy mainly containing them.
The resin includes at least one of a thermoplastic resin containing a curing agent and a catalyst, and a thermosetting resin,
The metal-coated resin structure according to claim 1, wherein the glass has a glass transition point of 600 ° C. or less.
The metal-coated resin structure according to any one of claims 1 to 3, wherein 90% or more of the metal particles contained in the metal layer have a ratio of the maximum width to the minimum thickness of 2 or more. .
Accelerating the powder of each of at least one of resin and glass and metal particles with a gas flow;
Forming an intermediate layer covering the resin base material by causing the resin base material to collide with at least any one of the resin or the glass and the metal particles and depositing them on the resin base material;
And D. colliding the metal particles with the intermediate layer to deposit them on the intermediate layer to form a metal layer covering the intermediate layer.
The velocity of the gas flow in the step of forming the intermediate layer is larger on the metal layer side than on the resin base side, and the powder supply amount of the metal particles in the step of forming the intermediate layer is The method for producing a metal-coated resin structure according to claim 5, wherein the metal layer side is more than the resin base side.
The method for producing a metal-coated resin structure according to claim 5 or 6, further comprising the step of heating to a temperature equal to or lower than the heat resistant temperature of the resin base after the step of forming the metal layer.
The metal-coated resin structure according to any one of claims 1 to 4, which is used for any of wind turbine blades for wind power generation, aircraft, and automobiles.