JP4635015B2 - Method for manufacturing metal honeycomb - Google Patents

Description

  The present invention relates to a method for manufacturing a metal honeycomb. That is, the present invention relates to a method for manufacturing a metal honeycomb, which is composed of a planar aggregate of hollow columnar cells using stainless steel or aluminum alloy as a base material.

《Technical background》
First, the technical background will be described in detail. Honeycomb cores consisting of planar aggregates of hollow columnar cells partitioned by cell walls have various excellent properties including excellent weight specific strength and are widely used as various structural materials. Yes.
As the base material of the cell wall of the honeycomb core, metal, plastic, paper, or the like is used depending on the application, and stainless steel or aluminum alloy is typical as the metal. As is well known, stainless steel has the basic performance of being excellent in heat resistance, high temperature strength, oxidation resistance, corrosion resistance, workability, and the like. Also, aluminum alloys containing magnesium Mg have obtained basic performances such as heat resistance, high temperature strength, corrosion resistance, workability, etc., for example, heat treatment type 6000 series alloys represented by A6951 and non heat treatment type The 5000 series alloy is particularly excellent in strength.
Therefore, the honeycomb core made of a foil-like stainless steel or aluminum alloy as a base material has a characteristic as a honeycomb core and, in view of such excellent basic performance of the base material, for example, structural materials and structures for aircraft and railway vehicles. In addition to being used as parts, it is used in a wide variety of applications in many other fields.
Next, as a method for manufacturing a honeycomb core, a stretching method and a corrugated method are generally used. First, in the spreading method, after applying adhesive or brazing material to the foil-shaped base material in the form of stripes, multiple sheets are stacked in a positional relationship shifted by half a pitch, then pressurized and heated, A honeycomb core was manufactured by bonding and brazing between base materials in a line shape and then applying a tensile force in the stacking direction and stretching.
On the other hand, in the corrugated system, after corrugating the foil-shaped base material into the corrugated sheet, the formed corrugated sheet is shifted by half a pitch, and stacked in a positional relationship that aligns the valley and the top, Honeycomb cores were manufactured by bonding or brazing between each other in the form of a line with an adhesive or brazing material (including spot welding).

In the honeycomb core manufacturing method, as described above, in both the expansion method and the corrugation method, an adhesive or brazing material is generally used for joining the line-shaped joining target parts (node parts), and adhesion and brazing are performed. It was done.
However, the following difficulties have been pointed out in the case of adhesion. That is, the adhesive has a low heat-resistant temperature (generally 300 ° C. or less) and a low bonding strength. Therefore, when manufacturing a honeycomb core using the above-mentioned stainless steel or aluminum alloy as a base material, bonding with an adhesive prevents the excellent basic performance of the base material from being utilized for the manufactured honeycomb core, resulting in heat resistance. However, there are difficulties in high-temperature strength, etc., and the applications are greatly limited.
On the other hand, the following difficulties were pointed out also by brazing. That is, a brazing material such as a nickel-based brazing material is used for brazing stainless steel, and a brazing material such as an aluminum-based brazing material is used for brazing an aluminum alloy. When manufacturing a honeycomb core using stainless steel or an aluminum alloy as a base material, brazing is performed using a brazing material such as a nickel-based brazing material or an aluminum-based brazing material. For example, in the case of a nickel-based brazing material, about 1000 ° C. Since brazing is performed at a predetermined temperature, a certain degree of heat resistance and high-temperature strength can be expected, but melting occurs at such a predetermined temperature or higher.
Therefore, the manufactured honeycomb core often fails to make use of the excellent basic performance of the base material (for example, the brazing material melts at 1000 ° C. or higher), and the heat resistance and high-temperature strength are limited. Was limited.
In addition, honeycomb cores manufactured by brazing have oxidation resistance, corrosion resistance, etc. due to interposition of different types of metal brazing materials having different compositions between stainless steel and aluminum alloy as base materials. From this aspect, the excellent basic performance of the base material was not utilized, and the application was limited.
Furthermore, the brazing material used for the manufacture of the honeycomb core using the aluminum alloy as a base material is often used in the form of a brazing sheet that is preliminarily formed in a plate shape, not in the form of powder or paste, but less than 100 μm. It is difficult to obtain a brazing sheet having a thickness (foil thickness) by rolling, and a thickness of 100 μm or more has been used in practice. However, when a thick brazing sheet is used in this way, the weight increases by the thickness, and the honeycomb core manufactured in this way does not take advantage of its excellent weight ratio strength. Limited.

When a honeycomb core is manufactured by using stainless steel or an aluminum alloy as a base material, and using an adhesive or a brazing material, the characteristics of the honeycomb core and the basic performance of the base material are not utilized as described above, and the use is limited. There were many things.
In conclusion, the conventional method for manufacturing a metal honeycomb by the stretch method or the corrugated method has such limitations due to bonding and brazing.
The technical background is as above.

<Conventional technology>
Now, based on such a technical background, a method for manufacturing a metal honeycomb using diffusion bonding instead of bonding or brazing is being developed. That is, for the base material using stainless steel or aluminum alloy, when joining the line-shaped joining target part (node part), without using any adhesive or brazing material, it is joined directly by diffusion joining, Thus, a metal honeycomb manufacturing method for manufacturing a honeycomb core has been recently developed.
According to the metal honeycomb manufacturing method by diffusion bonding, the base materials are directly bonded with the same composition, and no adhesive or brazing material is interposed. Therefore, the manufactured honeycomb core makes use of the basic properties of stainless steel and aluminum alloy as the base material as it is, and has excellent heat resistance, high temperature strength, oxidation resistance, corrosion resistance, etc. Will come to life.
By the way, this recently developed method of manufacturing a metal honeycomb by diffusion bonding is applied to the stretching method and not to the corrugated method.
That is, in order to perform diffusion bonding, it is essential to heat and pressurize between the base materials at high pressure. In the stretching method, the stacked flat plates, that is, foil-shaped base materials are pressed from above and below, so that the base materials can easily withstand the applied pressure. On the other hand, in the corrugated method, the foil-shaped base material is corrugated and formed on the corrugated plate and stacked, and such corrugated plates are pressed from above and below for diffusion bonding. The base material that can be used cannot withstand this pressure. In general, it is known that the stretch method is easy to manufacture a honeycomb core having a large overall size as compared with the corrugated method, and is excellent in manufacturing cost.

Now, when a honeycomb core is manufactured by a stretch method using stainless steel or an aluminum alloy as a base material by the recently developed manufacturing method using diffusion bonding, a release agent is indispensably used.
That is, in this method for manufacturing a metal honeycomb, first, a release agent is applied to a foil-like base material while leaving the background in a line shape. That is, prior to direct diffusion bonding of stainless steel or aluminum alloy, which is a foil-shaped base material, between the grounds, a release agent in advance for non-bonded portions other than such diffusion bonding target portions It is necessary to coat and cover so as not to be diffusion bonded. The release agent is applied by a printing method or a coating method, and the applied release agent is immediately dried.
After that, the base material to which the release agent is applied in this manner is stacked while being shifted by half a pitch, and then exposed and contacted by the surface to be diffusion bonded by pressing and heating in a vacuum furnace. In the meantime, diffusion bonding is performed in a line shape. Then, a honeycomb core having a base material as a cell wall is manufactured by applying a tensile force in the stacking direction and expanding the non-joined portion covered with the release agent. In addition, the honeycomb core manufactured in this way is washed after the fact to remove the release powder of the release agent remaining.

In the manufacturing method of the metal honeycomb by the spreading method using diffusion bonding, the mold release agent is indispensable as described above.
And this type of conventional release agent is usually a release powder that exhibits a release effect, a resin binder that can be applied to the release powder and fixed to the base material, and the binder is dissolved, diluted, And a solvent for adjusting the viscosity. That is, in this type of conventional release agent, a solvent-based solvent used by dissolving in a resin solvent is generally used as a binder.
(Release agent = release powder + binder + solvent)
Ceramic powder is used as the release powder of the release agent, organic binders, paints, inks, etc. that are generally used widely are used as the binder, and fat such as acetone is used as the solvent. Aromatics, ketones such as isophorone, aromatics such as xylene, and alcohols such as ethanol were used.
The solvent contained in the mold release agent has been volatilized, evaporated, and disappeared by a drying process performed after the application process to the base material. In addition, the binder contained in the release agent was thermally decomposed, evaporated, disappeared, or ashed during the joining process in which the stacked base materials were diffusion joined. The release powder contained in the release agent was removed together with the residual binder ash in the subsequent cleaning step.

By the way, in this recently developed method for manufacturing a metal honeycomb, the following problems have been pointed out with regard to the release agent used conventionally.
First, the organic solvent contained in the mold release agent is dried and volatilized when the mold release agent is applied to the base material in the coating process, that is, during the coating or coating process. , The problem that it evaporates and workability is bad was pointed out. In other words, many organic solvents used in this type of release agent have a low boiling point of less than 100 ° C., and often dry, volatilize and evaporate simultaneously with use. There was a problem that it was difficult to use the entire mold release agent.
In addition, if a high boiling point solvent having a boiling point of 100 ° C. or more and 300 ° C. or less is used, such a problem is considerably solved, but a subsequent drying step is essential, and workability is poor from this aspect. The problem was pointed out. That is, not only in the case of using a high boiling point solvent, in this kind of conventional example, a drying step is performed after the coating step, and the base material coated with the release agent is carried into a drying furnace, The organic solvent contained in the applied release agent was volatilized, evaporated and disappeared by hot air drying or the like. Such a drying step needs to be carried out for a long time, and also from this aspect, there is a problem in workability. Thus, firstly, problems have been pointed out in workability.

Secondly, as described above, in the drying process, the solvent in the release agent is volatilized and evaporated, but the solvent thus volatilized and evaporated is often harmful to the human body. That is, when an organic solvent volatilizes and evaporates and is sucked into the human body, there is a danger of adversely affecting the human body, and a problem has been pointed out in terms of safety.
Thus, in this type of conventional example, a local exhaust device is often attached to the drying furnace in the drying process, but this causes a problem in cost. Secondly, problems have been pointed out in terms of safety and cost.

Third, there has been an attempt to use an ultraviolet (UV) curable resin as a binder. That is, instead of this type of conventional example described above, a binder using a prepolymer of an ultraviolet curable resin, a diluent using a monomer of an ultraviolet curable resin, a photoinitiator and the like are mixed in a release powder. In the past, attempts have been made to use the above as a release agent.
Thus, the release agent using the ultraviolet curable resin as the binder of the release powder is the above-mentioned conventional release agent (release powder + general organic binder + aliphatic, ketone type). , Aromatic and alcohol solvents), it is excellent in workability and safety. That is, UV curable resins are basically hard to volatilize and evaporate. First, they do not dry, volatilize or evaporate during the application process, and the time for UV irradiation is short. Second, there is little danger to the human body. .
However, with regard to the release agent using the ultraviolet curable resin as a binder as described above, a problem that the coating thickness is first increased has been pointed out. That is, in this metal honeycomb manufacturing method, the release agent needs to be applied with a coating thickness as thin as possible in the coating step. As described above, since the strip-shaped ground surface to which the base material release agent has not been applied becomes the diffusion bonding target part in the bonding process, and is exposed, contacted, and diffusion bonded, The agent must be applied as thinly as possible (see also FIG. 3 below).
If the coating thickness of the release agent during diffusion bonding is too thick, the degree of contact and adhesion between the base materials will be insufficient, and the base materials will not be diffusely bonded in a straight line, resulting in insufficient bonding strength. Or unjoined parts occur. When a tensile force is applied between the base materials to expand the honeycomb core manufactured, so-called stray spots are generated in which the cells are not reliably partitioned by cell walls. Serious defects will occur.
And in the manufacturing method of the metal honeycomb using this kind of conventional ultraviolet curable resin, such skipping has been pointed out.
In other words, this release agent contains a release powder having a large particle size so as to exert a release effect, and the UV curable resin used as a binder is less likely to volatilize and evaporate after application, and further to a solvent. In the past, it was difficult to apply with a thin coating thickness of less than 30 μm. Therefore, in the case of a honeycomb core having a large cell size, the occurrence of skipping is relatively small, but in the case of a small honeycomb core having a cell size of, for example, 10 mm or less, the occurrence of skipping is remarkable. Thirdly, the occurrence of skipping has been a problem.

Fourthly, in this type of conventional method for manufacturing a metal honeycomb using an ultraviolet curable resin, extremely high pressure and high load are required to avoid such skipping.
That is, when manufacturing a honeycomb core having a small cell size, if the release agent is applied with a thickness as thick as about 30 μm or more, pressurization in a vacuum furnace for diffusion bonding in the bonding process should be performed at an extremely high pressure. Then, for example, if the base material is pressed from above and below with a high load of 1 kg / mm ² or more, the occurrence of skipping is avoided. That is, it is possible to avoid skipping by making up for the lack of contact and adhesion between the base materials by applying a high pressure, thereby improving the bonding strength and eliminating the unbonded portions.
However, in a general vacuum furnace, it is difficult to apply such high pressure and high load, and it is necessary to incorporate a very expensive flat press or a hydrostatic press (HIP), and it is difficult to increase the size. Manufacturing a honeycomb core having a large overall size becomes difficult. Thus, fourthly, problems have been pointed out in terms of cost and overall size.

Fifth, whether the base material is stainless steel or an aluminum alloy, the binder in the applied release agent, that is, the UV curable resin, is applied all at once during diffusion bonding between the base materials in the vacuum furnace in the joining process. It was also pointed out that the process was interrupted due to thermal decomposition and evaporation.
In other words, the inside of the vacuum furnace is maintained in a constant vacuum atmosphere, but if the degree of vacuum drops significantly during the diffusion bonding process by pressurization and heating, it is attached to protect the equipment. The device is activated to interrupt the diffusion bonding process. In diffusion bonding between the base materials in the vacuum furnace, since the binder contained in the release agent is made of an ultraviolet curable resin, a considerable portion is ashed and remains as ash by pressing and heating. However, there are parts that decompose, evaporate and disappear.
Such thermal decomposition and evaporation are performed at a time due to the fact that one type of UV curable resin has been used in the past, and the degree of vacuum in the vacuum furnace is greatly deteriorated rapidly. There were a lot of things to do.
Therefore, it has been pointed out that the safety device is activated and the diffusion bonding process is often interrupted, resulting in a production efficiency problem. Thus, fifthly, a problem that the diffusion bonding process is often interrupted has been pointed out.

Sixthly, in order to avoid such an interruption of the diffusion bonding process, it is often performed for the sake of convenience to turn off the safety device so as not to operate and to continue the diffusion bonding process without interruption. It was. For example, under such circumstances, if thermal decomposition and evaporation of a binder made of an ultraviolet curable resin are performed all at once, oxygen O is released and diffusion bonding is performed in a bad atmosphere where the degree of vacuum is greatly reduced. Will be heated. Further, ash obtained by ashing a binder made of an ultraviolet curable resin, that is, ash mainly composed of carbon C remains.
As a result, non-reducible film-like carbides, oxides, and other compounds are likely to react, generate, break out, and become coarse on the surface of the base material made of stainless steel or aluminum alloy. .
That is, when the base material is stainless steel, the remaining ash reacts with the stainless steel base material at the time of diffusion bonding or in a high temperature environment after the carburization to cause carburization, so that the carbon C is chromium in the stainless steel. It reacts with Cr to generate chromium carbide, which causes embrittlement of the base metal, high temperature oxidation, intergranular corrosion, and the like. When the base material is an aluminum alloy, for example, the evaporation of contained magnesium Mg is inhibited, so that the oxide film made of alumina Al ₂ O ₃ is not broken, dispersed, or re-formed and diffused. There will be a problem with the joining itself.
In any case, products such as carbides, oxides, and other compounds on the surface of the base material cause embrittlement of the base material, high-temperature oxidation, intergranular corrosion, and the like.
Honeycomb cores made of stainless steel or aluminum alloy as a base material for cell walls are often used in such high-temperature environments or corrosive environments, causing embrittlement, high-temperature oxidation, intergranular corrosion, etc. Was considered highly undesirable. Thus, sixthly, problems such as embrittlement, high-temperature oxidation, and intergranular corrosion have been pointed out.

In view of such circumstances, the present invention has been made to solve the problems of this type of conventional example in the recently developed method for manufacturing a metal honeycomb of a stretch method by diffusion bonding, and is made of ceramic powder. Adopting a release agent containing a release powder, a binder made of a prepolymer of UV curable resin having different thermal decomposition and evaporation temperatures, and a diluent made of a monomer of an ester UV curable resin. .
And by adopting such a mold release agent, firstly, it does not dry during the application of the mold release agent, and is cured within a short time with ultraviolet rays, thereby improving workability, and secondly No harmful volatilization or evaporation, and thirdly, the thickness of the release agent can be reduced, and skipping is avoided, and fourthly, the pressure during diffusion bonding is low and low load. Fifth, thermal decomposition and evaporation of the binder and diluent are performed at a slow speed, avoiding interruption of the diffusion bonding process, and sixth, diffusion bonding in a bad atmosphere with a reduced degree of vacuum An object of the present invention is to propose a method for manufacturing a metal honeycomb in which the formation of carbides, oxides and the like is avoided without heating for the purpose.

<About Claim>
The technical means of the present invention for solving such a problem is as follows. That is, in this method for manufacturing a metal honeycomb, first, a foil-like stainless steel or a foil-like aluminum alloy containing magnesium is used as a base material, a release agent is left on the base material, and the background is left in a line shape. Apply and cure with UV light.
Next, by stacking a plurality of the base materials in a positional relationship in which the exposed background left in the form of a streak between the release agents is shifted by a half pitch, and then pressurizing and heating. The base material is diffusion-bonded in the form of a streak between the ground surfaces in contact with each other. Then, by applying a tensile force in the stacking direction, the base material is used as a cell wall, and a honeycomb core is obtained which is a planar aggregate of a large number of hollow columnar cells partitioned by the cell wall. .
In such a method for manufacturing a metal honeycomb, as the release agent, a release powder comprising a ceramic powder having a particle size of 5 μm or more and 60 μ% or less and a particle size of 5 μm or less, and an evaporation temperature by thermal decomposition And a binder made of a prepolymer of two different types of UV curable resins and a diluent made of a monomer of an ester UV curable resin.

<About the action>
Since the manufacturing method of the metal honeycomb of the present invention is as described above, it is as follows. First, the stainless steel or aluminum alloy, which is a foil-like base material, is applied with a release agent applied and cured with ultraviolet rays while leaving the background in a streak shape. Is diffusion-bonded in a line shape. When the base material is an aluminum alloy, first, the contained magnesium evaporates to destroy and disperse the oxide film on the surface of the ground, so that the aluminum is exposed to the surface of the ground and diffusion bonding becomes possible. Thereafter, the stacked and diffusion-bonded base material is stretched to produce a honeycomb core as a planar aggregate of cells partitioned by the cell wall using the base material as a cell wall.
And the mold release agent used with this manufacturing method does not dry first during application | coating operation | work, and hardens | cures easily after the fact. That is, the prepolymer or monomer of the ultraviolet curable resin used as a binder or diluent for the release agent is cured by being irradiated with ultraviolet rays to become a polymer.
Next, this release agent is made by first using ceramic powder having a particle size of 5 μm or less and a content of 60% by weight or less as the release powder. In addition, the UV curable resin used as the binder partly decomposes, evaporates and disappears by the pressurization and heating at the beginning of diffusion bonding, and the rest becomes ash. The ash is compressed and filled in the gaps between the ceramic powders. Is done. Since the monomer of the ester UV curable resin is used as the diluent, the viscosity is lowered.
As a result, the release agent can be applied with a thin application thickness at the time of application, and the application thickness can be further reduced at the time of diffusion bonding. Therefore, the stacked base materials are diffusion-bonded by reliably contacting, abutting, and closely adhering between the strips exposed in a line shape between the release agents.
In this release agent, two types of ultraviolet curable resins having different thermal decomposition and evaporation temperatures are used, and an ester-based ultraviolet curable resin is used.
Therefore, in the diffusion bonding, this mold release agent is thermally decomposed and evaporated at a gradually different speed for each of these components, thereby preventing the diffusion bonding process from being interrupted.

  As described above, the metal honeycomb manufacturing method according to the present invention includes a mold release powder made of ceramic powder, a binder made of a prepolymer of an ultraviolet curable resin having different thermal decomposition and evaporation temperatures, and an ester-based ultraviolet cure. By adopting a mold release agent containing a diluent made of a monomer of the mold resin, the following effects of the first, second, third, fourth, fifth, sixth, etc. are exhibited.

First, it is not dried during the application of the release agent, and is cured and dried with ultraviolet rays in a short time, so that workability is improved. In this metal honeycomb manufacturing method, an ultraviolet curable resin prepolymer is used as a binder of a release agent to be applied, and an ultraviolet curable resin monomer is used as a diluent.
Therefore, as in the above-described conventional example in which an ultraviolet curable resin is not used as a release agent, that is, in this conventional example in which a general binder is dissolved in an organic solvent, the release agent is applied. The solvent during the application work does not dry, volatilize or evaporate, the mold release agent is easy to use, the application work of the mold release agent is simplified and the workability is improved.
Furthermore, the ultraviolet curable resin used as a binder in this release agent is easily cured and dried by being exposed to ultraviolet rays. In other words, as in the above-mentioned conventional example in which an ultraviolet curable resin is not used as a release agent, the applied release agent is dried with hot air in a drying furnace for a long time, and the organic solvent is volatilized and evaporated. , There is no need to make it disappear. The ultraviolet curable resin of the release agent is cured and dried easily and easily in a very short time by passing ultraviolet rays. Therefore, it becomes easy to use the release agent also from this surface, the application work of the release agent is simplified and the workability is improved.

Second, there is no volatilization or evaporation harmful to the human body. In other words, in this type of conventional example in which an ultraviolet curable resin is not used as the release agent, the organic solvent in the release agent is volatilized, evaporated, and disappeared by drying. System solvents are harmful to the human body and often have local exhaust ventilation.
On the other hand, the release agent used in the method for manufacturing the metal honeycomb does not use an organic solvent which is dangerous when volatilized or evaporated as described above, and is excellent in safety and has a local exhaust device. Is also unnecessary and is excellent in cost.

Third, the thickness of the release agent applied during diffusion bonding can be reduced, and skipping is avoided. That is, in this method for manufacturing a metal honeycomb, first, ceramic powder having a particle size of 5 μm or less and a content rate limited to 60% by weight or less is used as the release powder of the release agent. Can be made thinner.
In addition, since a monomer of an ester UV curable resin is used as a diluent for the release agent to be applied, the viscosity of the release agent is low, and the release agent can be applied thinly. . That is, similarly to this type of conventional example using an ultraviolet curable resin as a binder, the release agent can be applied with a thinner coating thickness at the time of application.
Thus, in this metal honeycomb manufacturing method, the coating thickness of the release agent can be reduced to less than 30 μm, for example, about 20 μm, and diffusion bonding is performed under such a thin coating thickness. . Therefore, the base material is surely diffusion-bonded in the form of a line, and, as in the above-described conventional example, the application thickness of the release agent is about 30 μm or more, resulting in bonding. Insufficient strength and occurrence of unjoined parts are prevented.
Therefore, in the manufactured honeycomb core, as in the conventional example of this type described above, the occurrence of so-called skipped portions where the cells are not reliably partitioned by the cell walls is avoided. Improve the quality. In particular, even a honeycomb core having a small cell size such as a cell size of 10 mm or less is manufactured while avoiding the occurrence of skipping.
In addition, when applying the release agent, it is not necessary to consider the application thickness to be as thin as possible. Therefore, various coating methods and printing methods can be freely selected as the application method. The mold application operation is simplified and facilitated.

Fourthly, pressurization during diffusion bonding can be performed under low pressure and low load. That is, when manufacturing a honeycomb core having a small cell size as in the above-described conventional example, pressurization in a vacuum furnace or the like for diffusion bonding is performed, for example, at 1 kg / mm ^2. It is not necessary to carry out under the above high load and high pressure. That is, it is not necessary to incorporate a flat press in a vacuum furnace or the like or to perform an isostatic press (HIP).
As described above, in this method for manufacturing a metal honeycomb, diffusion bonding can be surely performed even under a low pressure and a low load by using a conventional vacuum furnace or the like. Therefore, it is excellent in cost, and it is easy to increase the size of a vacuum furnace or the like, and a honeycomb core having a large overall size can be easily manufactured.

Fifthly, the thermal decomposition and evaporation of the release agent binder and diluent are performed at a slow speed, and the interruption of the diffusion bonding process is avoided. That is, in the metal honeycomb manufacturing method of the present invention, prepolymers of UV curable resins having different thermal decomposition and evaporation temperatures are used as binders for the release agent to be applied, and ester UV curable resins are used as diluents. These monomers are used.
Therefore, in the diffusion bonding between the base materials, the thermal decomposition and evaporation by pressurization and heating are performed at different temperatures, respectively, and the thermal decomposition and evaporation of the release agent are performed at a gradually slow speed.
That is, similarly to the above-described conventional example using an ultraviolet curable resin, one type of ultraviolet curable resin is thermally decomposed and evaporated at a time, so that, for example, the degree of vacuum in a vacuum furnace is abrupt. It is also possible to prevent the diffusion bonding process from being interrupted due to the deterioration of the operation and the attached safety device.
Thus, according to this method for manufacturing a metal honeycomb, interruption of the diffusion bonding process is avoided, and problems in production efficiency are eliminated.

Sixth, there is no need for heating for diffusion bonding in a bad atmosphere where the degree of vacuum is reduced, and generation of carbides, oxides, and the like is avoided.
That is, in the method for manufacturing a metal honeycomb according to the present invention, as described above, in the diffusion bonding, for example, it is avoided that the vacuum degree in the vacuum furnace is rapidly deteriorated, and the attached safety device is operated. There are few.
Therefore, as in the case of this type of conventional example using an ultraviolet curable resin, the safety device is not turned off so as not to operate due to the progress of the diffusion bonding process. Therefore, as in the conventional example of this type described above, as a result of heating for diffusion bonding in a bad atmosphere with a reduced degree of vacuum, carbides, oxides, and other compounds are formed on the surface of the base material. , No reaction, no formation, no folding, no coarsening.

Therefore, for example, when the base material is stainless steel, carburization, generation of chromium carbide, and the like are avoided. For example, when the base material is an aluminum alloy, the oxide film made of alumina is destroyed and not formed. In addition, the formation of carbides, oxides, other compounds, and the like on the surface of the base material that can cause embrittlement, high-temperature oxidation, intergranular corrosion, and the like of the base material is prevented.
Therefore, even if the manufactured honeycomb core is used in a high temperature environment or a corrosive environment, the base material, that is, cell wall embrittlement, high temperature oxidation, intergranular corrosion, etc. are not induced and can be used without any trouble. It becomes.
As described above, the effects exerted by the present invention are remarkably large, such as all the problems existing in this type of conventional example are solved.

Hereinafter, the present invention will be described in detail based on embodiments of the invention shown in the drawings. 1, 2, 3, and 4 are provided for explaining the embodiment of the present invention.
1 is a perspective explanatory view, (1) FIG. 1 shows a prepared base material, (2) FIG. 1 shows a state where a release agent is applied, (3) FIG. The figure shows the state of diffusion bonding, and the figure (5) shows the state of slicing. FIG. 2 is a perspective explanatory view, (1) FIG. 2 shows a stretched state, (2) FIG. 2 shows a trimmed state, and (3) FIG. 3 shows a main part of the obtained honeycomb core.
FIG. 3 is an enlarged front view, (1) shows a state where a release agent is applied, and (2) shows a state during diffusion bonding. FIG. 4 is a front explanatory view of the main part. (1) FIG. 4 shows a state before diffusion bonding between stainless steel base materials, and (2) FIG. 4 shows diffusion bonding between the same base materials. (3) Figure shows the state before the aluminum alloy base metal is diffusion bonded, (4) Figure shows the state immediately before the base metal is diffusion bonded ( 5) The figure shows the state after the base metal has been diffusion bonded.

First, the release agent 1 will be described. In the method for manufacturing a metal honeycomb according to the present invention, the following release agent 1 is employed.
This mold release agent 1 is applied and used in advance so as to set the non-joining part 3 when diffusion-bonding a foil-like stainless steel as a base material 2 or a foil-like aluminum alloy containing magnesium Mg. (See FIG. 1). The release agent 1 essentially contains a release powder and a binder, and further contains a diluent, a solvent, a dispersant, an antifoaming agent, and the like as appropriate.
(Release agent 1 = release powder + binder + others)

First, the release powder of the release agent 1 will be described. As the mold release powder, ceramic powder is used, and a powder having a low reactivity with the base material 2 such as stainless steel or aluminum alloy and having an excellent mold release effect between the base materials 2 is selectively used. That is, it is used to prevent diffusion bonding between stainless steel as the base material 2 and between aluminum alloys.
For example, among the compounds of elements such as iron Fe, chromium Cr, nickel Ni, and carbon C constituting the stainless steel of the base material 2, the chromium oxide Cr ₂ O ₃ is thermodynamically stable. It is more thermodynamically stable. For example, by heating at about 800 ° C. to 1200 ° C. for diffusion bonding, oxygen O of the oxide does not react with chromium Cr to become chromium oxide Cr ₂ O ₃ .
Even when the aluminum alloy is used as the base material 2, the ceramics are thermodynamically stable in accordance with the above. In particular, the diffusion bonding when the aluminum alloy is used as the base material 2 is comparatively 500 ° C. to 600 ° C. Since it is performed by heating at a low temperature, it becomes more stable. As such ceramics, specifically, boron nitride BN, yttria stabilized zirconia Y ₂ O ₃ —ZrO ₂ , magnesia stabilized zirconia MgO—ZrO ₂ , alumina Al ₂ O ₃ , magnesia MgO, calcia CaO, silica SiO ₂ , ceria Ce ₂ O ₃ , yttria Y ₂ O ₃ , tria ThO _{2 and the} like are appropriately selected and used.

Among these ceramics, oxides of Group 3A elements and rare earth elements in the periodic table (long periodic table) are typically used. That is, among the elements, group 3A elements such as scandium Se, yttrium Y, lanthanoid elements La to Lu, and actinoid elements Ac to Lr have low standard free energy of formation and are thermodynamically stable. Among elemental compounds such as nitrides, oxides, sulfides, chlorides, carbides, and the like, oxides have a low standard free energy of formation and are thermodynamically stable.
Accordingly, oxides of Group 3A elements such as ceria Ce ₂ O ₃ , yttria Y ₂ O ₃ , tria ThO _{2 and the} like are suitable, and in particular, yttria Y ₂ O ₃ is most suitable in terms of cost. That is, an oxide of a group 3A element such as yttria Y ₂ O ₃ is not reduced by heating and does not react with the base material 2 during diffusion bonding of the base material 2 made of stainless steel or aluminum alloy. Even in a high temperature environment of ℃ or higher, it does not reduce and react with the base material 2. Yttria Y ₂ O ₃ is widely used in various applications.
In the mold release agent 1, ceramic powder obtained by pulverizing such ceramics is used as the mold release powder. The ceramic powder is 5% by weight or more and 60% by weight or less and has a particle size of 5 μm or less.
First, the particle size of the ceramic powder is 5 μm or less, and if it exceeds 5 μm, the size of the particle size becomes an obstacle and the release agent 1 cannot be applied thinly.
The ceramic powder is contained in the release agent 1 at a ratio of at least 5% by weight. If the content is less than 5% by weight, the release effect as the release agent 1 is insufficient. Furthermore, the ceramic powder is contained in the release agent 1 at a ratio of 60% by weight or less, and if the content exceeds 60% by weight, the ceramic powder is too much to be liquefied as the release agent 1. , Making the paste difficult, and it becomes impossible to apply thinly as the release agent 1.
The mold release agent 1 essentially contains such a ceramic powder as a mold release powder.

And in the release agent 1 of this invention, the binder which consists of the prepolymer of two types of ultraviolet curable resin from which the evaporation temperature by thermal decomposition differs with the mold release powder which consists of ceramic powder, the monomer of ester type ultraviolet curable resin And a diluent.
(Release agent 1 = release powder + 2 types of binders + diluent + others)

Such a release agent 1 will be further described in detail. In this release agent 1, first, two types of prepolymers (at the time of application) of ultraviolet curable resins having different thermal decomposition and evaporation temperatures are used as binders for ceramic powder as a release powder.
First, in order to make it possible to apply the ceramic powder as the release agent 1 as the release agent 1 and to apply and fix the binder so that the ceramic powder does not peel off or fall off from the base material 2 after being applied as the release agent 1. Used as glue.
As such a binder, for example, a photopolymerizable amino prepolymer (oligomer) is contained in the release agent 1 at a ratio of 5 wt% to 20 wt%, and photopolymerization is performed. An epoxy-based prepolymer (oligomer) is contained in the release agent 1 at a ratio of 10 wt% to 35 wt%. In each case, when a light, that is, an ultraviolet ray is applied, a prepolymer is used which undergoes a polymerization reaction, cures and dries, and becomes a polymer (including oligomer).
These two types of ultraviolet curable resins are contained in amounts substantially commensurate as described above. For each content, the minimum content is set so that it can function as a binder / glue, and the maximum content takes into account the diluent content described below and is heated during subsequent diffusion bonding. It is set so that the amount of polymer ashing is not excessive.
By the way, these two types of ultraviolet curable resins (polymers) have different evaporation temperatures due to thermal decomposition. That is, due to the subsequent heating at the beginning of diffusion bonding, a part of these two kinds of ultraviolet curable resins (polymers) is thermally decomposed and evaporated, and the rest is ashed. Two kinds of ultraviolet curable resins having different thermal decomposition and evaporation temperatures are used. For example, the photopolymerizable amino polymer and the photopolymerizable epoxy polymer described above have greatly different thermal decomposition and evaporation temperatures.

Moreover, in this mold release agent 1, a solvent is not used like this kind of conventional example mentioned above. And in this mold release agent 1, the monomer of ester type ultraviolet curable resin is used as a diluent. That is, for the first time in the release agent 1 using an ultraviolet curable resin as a binder, an ester-based monomer is employed as a diluent. That is, the release agent 1 contains an ester monomer as a photopolymerizable diluent at a ratio of 15 wt% to 45 wt%. When light, that is, ultraviolet rays, is applied, a monomer that is polymerized and cured to become a polymer is used.
The diluent adjusts the viscosity so that the release agent 1 can be applied (lowers the viscosity), thereby enabling the release agent 1 to be applied with a thin application thickness T (see FIG. 3). Therefore, it is used. Therefore, it is necessary that the content is at least 15% by weight, and the maximum content is 45% by weight or less because of the relationship with the content of other release powder and binder.
Further, the mold release agent 1 contains a photoreaction initiator of 1 wt% or more and 10 wt% or less, and if necessary, a dispersant or an antifoaming agent is added up to 10 wt% as a limit. , Is contained. The dispersing agent is mixed so that the ceramic powder as the releasing powder in the releasing agent 1 is not aggregated, bonded or solidified, and the antifoaming agent is mixed to prevent foaming when the releasing agent 1 is applied. . As such a dispersant or antifoaming agent, for example, an organic solvent such as methanol is representative. Such a dispersant or antifoaming agent is contained in the release agent 1 at a ratio of 0% by weight to 10% by weight.
Thus, the release agent 1 of the present invention comprises 5% by weight or more and 60% by weight or less of a ceramic powder as a release powder, 5% by weight or more and 20% by weight or less of a binder, and 10% by weight or more different therefrom. 35 wt.% Or less binder, 15 wt.% Or more and 45 wt.% Or less diluent, 1 wt.% Or more and 10 wt.% Or less photoinitiator, 0 wt.% Or more and 10 wt. It contains a foaming agent and the like. The release agent 1 of the present invention is as described above.

Now, as described above, the release agent 1 includes the ceramic powder as the release powder, the ultraviolet curable resin as the binder, the ultraviolet curable resin as the diluent, the photoreaction initiator, the dispersant, the antifoaming agent, etc. Based on the predetermined content ratio, it is appropriately blended and blended.
(Release agent 1 = release powder + 2 types of binders + diluent + others)
That is, the release agent 1 is blended and prepared by mixing and dispersing the release powder in a binder dissolved and diluted with a diluent. At that time, in order to obtain the optimum viscosity for the coating method described below, the content of the release powder, diluent and the like is adjusted, and thus the viscosity of the release agent 1 is adjusted. In any case, the release agent 1 is in the form of a liquid or paste having a certain degree of viscosity, but may be emulsified.

Here, a method of applying the release agent 1 will be described. The release agent 1 is applied to the base material 2 by a coating method or a printing method.
The coating method is to mask the strip-shaped diffusion bonding target portions 4 in advance, and then apply the release agent 1 to the non-bonding portions 3 by spraying, dipping, dipping, etc., and then masking. This is done by removing. As the printing method, stencil printing such as screen printing, intaglio printing such as transfer roll printing, letterpress printing, and the like are used. The screen printing is suitable for performing after the base material 2 is cut to a predetermined length, but of course, it is performed by roll-to-roll (while the strip-shaped base material 2 before cutting is flowing between the rolls). Printing) and transfer roll printing is suitable for roll-to-roll printing.
By such an application method such as a coating method or a printing method, the release agent 1 is applied to the base material 2 while leaving the background 5 in a line shape ((2) in FIG. 1 or FIG. 3). (1) Refer to the figure). The application thickness T (see FIG. 3) of the release agent 1 to the base material 2 is actually a limit value that can be generally controlled by about 30 μm at the time of application, regardless of the application method. However, theoretically, at least about 0.5 μm is necessary from the viewpoint of the mold release effect at the time of diffusion bonding. The release agent 1 is applied in this way. The release agent 1 is as described above.

Such a release agent 1 is employed in the method for manufacturing a metal honeycomb according to the present invention. The release agent 1 contains a release powder made of a predetermined ceramic powder, a binder made of an ultraviolet curable resin, a diluent made of an ultraviolet curable resin, and others, and is applied by a coating method or a printing method. The
Next, a method for manufacturing a metal honeycomb using such a release agent 1 will be described in the order of manufacturing steps. That is, in this metal honeycomb manufacturing method, (1) preparation step, (2) coating step, (3) UV step, (4) stacking step, (5) bonding step, (6) stretching step, (7) The honeycomb core H is manufactured by a stretching method that sequentially follows the cleaning process and the like.

First, (1) the preparation process will be described. In this manufacturing method, first, a base material 2 is prepared as shown in FIG.
In view of being provided for the manufacture of the honeycomb core H, the base material 2 is made of a thin foil having a thickness of 200 μm or less, or an aluminum alloy containing magnesium Mg.
As is well known, stainless steel is made by adding 10% or more of chromium Cr to iron Fe, and in many cases, nickel Ni, carbon C, and others are added, resulting in heat resistance, high temperature strength, oxidation resistance, and corrosion resistance. , Excellent processability, etc. Aluminum alloys containing magnesium Mg are also excellent in heat resistance, high temperature strength, corrosion resistance, workability, etc., and it is known that 6000 series alloys and 5000 series alloys represented by A6951 are particularly excellent in strength. It has been.
And the foil-shaped base material 2 which consists of such stainless steel or aluminum alloy is cut | disconnected for every fixed width | variety and fixed length, after washing | cleaning by degreasing etc. as needed, after rolling in strip | belt shape. The cutting to a certain length may be performed after the (2) coating step and (3) UV step described below, regardless of the illustrated example.
The surface 5 of the aluminum alloy base material 2 is usually covered with an oxide film 6 (see FIG. 4 (3)), and immediately after cleaning, the oxide film 6 is oxidized. The formed oxide film 6 is made of alumina Al ₂ O ₃ . (1) In the preparation step, such a base material 2 is prepared.

Next, (2) the coating process will be described. In this manufacturing method, as shown in FIG. 1 (2) and FIG. 3 (1), the release agent 1 is then applied. That is, the mold release agent 1 is applied to the base material 2 prepared in the above-described (1) preparation step while leaving the background 5 in a line shape. The release agent 1 has the configuration described in detail above, and is applied at a predetermined application thickness T by various application methods.
Then, the mold release agent 1 has a constant width and pitch while leaving an interval so as to leave a background 5 as a diffusion bonding target portion 4 (node portion) in a line shape with a constant width and pitch with respect to the base material 2. For example, the portion applied along the width direction and thus the part to which the release agent 1 is applied becomes the non-joining portion 3 of the base material 2. In the illustrated example, the release agent 1 is applied to only one surface (surface) of the base material 2 at a constant width and pitch, and only such base material 2 is stacked, bonded, and stretched as described below. Will be.
It should be noted that the mold release agent 1 may be applied at a constant width and pitch on both surfaces (front and back surfaces) of the base material 2 regardless of the illustrated example. The base material 2 to which the release agent 1 is applied and the base material 2 on which both sides of the release agent 1 are not applied at all are sequentially stacked and then joined and stretched. (2) In the application step, the release agent 1 is thus applied.

Next, (3) UV process will be described. In this manufacturing method, (2) the base material 2 coated with the release agent 1 in the coating step is then cured and dried. That is, the base material 2 to which the release agent 1 is applied is immediately sent to the ultraviolet (UV) irradiation section, and passes through the ultraviolet and is irradiated with the ultraviolet.
Then, the prepolymer or monomer of the binder or diluent UV curable resin contained in the applied release agent 1 by such ultraviolet rays is polymerized and cured, dried, and polymer (including Oligomer). The mold release agent 1 is firmly fixed to the base material 2. (3) In the UV process, the release agent 1 is thus cured and dried.

Next, (4) the stacking process will be described. In this manufacturing method, as shown in FIG. 1 (3), the base material 2 is stacked (see also FIG. 3 (2)). That is, after the release agent 1 is applied in the above-described (2) application step, and (3) the base material 2 in which the release agent 1 is cured and dried in the UV step, a plurality of the release materials are then released. The background 5 exposed in the form of a streak between 1 is stacked in a positional relationship shifted by a half pitch.
For example, about 400 base materials 2 are stacked vertically in a block shape, and in this case, the background 5 left in the form of a line on one side is left and right between the upper and lower base materials 2 in the illustrated example. Positioning is performed in a positional relationship shifted from each other by a half pitch. (4) In the stacking process, the base material 2 is stacked in this way.

Next, (5) joining process will be described. In this manufacturing method, as shown in FIG. 1 (4) and FIG. 3 (2), next, diffusion bonding between the base materials 2 is performed. That is, the base material 2 stacked in a block shape in the above-described (4) stacking step is pressed and heated to diffuse and join in the form of a line between the contacting ground surfaces 5.
Such diffusion bonding will be further described in detail. The stacked block-shaped base material 2 is restrained by an appropriate jig and applied with a necessary load, and is carried into a vacuum furnace or the like and heated at a predetermined temperature and time. Diffusion bonding is performed in the solid phase.

First, this solid phase diffusion bonding is performed by the following a. Temperature, b. Load, c. Atmosphere, d. It is performed under conditions such as time. Each of these conditions varies depending on the specific configuration contents / material of the base material 2 and other conditions, but is often set as follows.
a. The temperature condition is set to about 800 ° C. to 1200 ° C. when the base material 2 is stainless steel, and is set to about 500 ° C. to 600 ° C. when the base material 2 is an aluminum alloy. 2 is heated.
b. Load condition, even if the aluminum alloy may base material 2 is stainless steel, are set from 0.1 g / mm ² to about 10 g / mm ^2, preform 2 which is a heavy product is pressurized with.
c. The atmospheric condition is typically a vacuum atmosphere, and this solid phase diffusion bonding is often performed by carrying the stacked base material 2 into a vacuum furnace. In addition, a reducing atmosphere, an inert gas atmosphere, a reduced pressure atmosphere added with argon Ar, and the like are also possible. In these cases, respective dedicated furnaces are used.
d. The time condition is set to about 5 minutes to 10 hours, and the stacked base material 2 is heated and pressurized in this set time for example in a vacuum furnace.
Such a. Temperature, b. Load, c. Atmosphere, d. Solid phase diffusion bonding is performed under conditions such as time.
Accordingly, the ground surface 5 exposed in the shape of a line between the release agents 1 that set the non-joining part 3 of the base material 2 is brought into contact with, contacted with, or brought into close contact with each other as the diffusion joining target part 4. In the illustrated example, the base material 2 stacked and opposed to each other vertically is applied with the ground surface 5 exposed in the shape of a line on the surface of the lower base material 2 and the release agent 1 on the back surface of the upper base material 2. Without being exposed to the entire surface 5, the diffusion contact portion 4 is brought into contact with, contacted with, or brought into close contact with.
Then, between the diffusion bonding target portions 4 of the ground 5, atoms diffused and moved at the grain interface with respect to the metal elements constituting the stainless steel and the aluminum alloy of the base material 2, and thus stacked in a block shape. Between the base materials 2, solid phase diffusion bonding is performed in a line shape.

FIGS. 4A and 4B show the progress of the main part of such solid phase diffusion bonding when the base material 2 is made of stainless steel. FIGS. 4 (3), 4 (5), and 5 (5) show the progress of the main part of such solid phase diffusion bonding when the base material 2 is made of an aluminum alloy containing magnesium Mg. It is shown.
That is, as shown in FIG. 4 (3), the surface of the base material 2 made of an aluminum alloy is firmly and stably covered with the oxide film 6 before the solid phase diffusion bonding. . Then, as shown in FIG. 4 (4), the magnesium Mg contained in the aluminum alloy as the base material 2 (simple at about 400 ° C. in a vacuum) by applying pressure and heating for solid phase diffusion bonding. However, the oxide film 6 is vaporized and evaporated to destroy and disperse the oxide film 6. Accordingly, as shown in FIG. 4 (5), the aluminum Al of the aluminum alloy of the base material 2 is exposed in a pure state, and the intended solid phase diffusion bonding proceeds.
In such solid phase diffusion bonding, in order to promote thermal decomposition, evaporation, and disappearance of a binder or diluent made of an ultraviolet curable resin (polymer) contained in the release agent 1, that is, heat them as much as possible. In order to make it decompose, evaporate, and disappear, it is good to hold once at the thermal decomposition temperature.
That is, at the initial stage of solid phase diffusion bonding, the heating temperature is temporarily maintained as it is at the thermal decomposition temperature of the used UV curable resin (about 300 to 600 ° C. when the base material 2 is stainless steel). In the case where the base material 2 is an aluminum alloy, it is temporarily held at about 300 ° C. to 400 ° C.). By holding the heating temperature at such a thermal decomposition temperature in the initial stage during heating and heating, the binder or diluent made of the ultraviolet curable resin in the release agent 1 can be thermally decomposed, evaporated and lost. Promoted. After that, when the heating is further advanced and the temperature rises to reach the above-described temperature condition, solid phase diffusion bonding is started.
Thus, if the thermal decomposition of the binder or diluent in the release agent 1 is promoted in the initial stage before the start of the solid phase diffusion bonding, the atmosphere at the start of the subsequent solid phase diffusion bonding is cleaned. There are advantages that can be kept. (5) In the bonding step, diffusion bonding is performed in this way.

Next, (6) the extending process will be described. In this manufacturing method, next, after slicing is performed as shown in FIG. 1 (5), stretching is performed as shown in FIG. 2 (1).
That is, the base material 2 stacked in a block shape and diffusion-bonded in the shape of a line in the above-described (5) bonding step is first sliced along the length direction and cut into a necessary size. . This slicing is performed by a method using, for example, a water jet, wire discharge, a band saw, a cutting grindstone, or the like. In the figure, 7 is the slicing tool.
Then, the block-shaped base material 2 sliced to a necessary size in this way is stretched by applying a tensile force in the stacking direction D. That is, the base material 2 stacked in a block shape and diffusion-bonded in a line shape is stretched by applying a tensile force along the upper and lower stacking directions D in the drawing. Accordingly, each base material 2 is bent in the vertical direction along the edge of the line-shaped diffusion bonding target portion 4 and is not bonded to the mold release agent 1 other than the diffusion bonding target portion 4. The part 3 is separated and separated vertically so as to spread with extension. (6) The extension process is performed in this way.

Next, (7) the cleaning process will be described. In this manufacturing method, next, the honeycomb core H obtained by the expansion step (6) in FIG. 2 (1) shown in FIG. 2 has an outer peripheral portion as shown in FIG. 2 (2). Is trimmed, cut and trimmed to the required size. Trimming is performed by a method according to the slice described above.
The manufactured honeycomb core H is then washed by air blow, water washing or the like, and the remaining ceramic powder, which is the release powder of the release agent 1, and the ash of the binder are removed. (7) In the cleaning process, cleaning is performed in this way.

In this metal honeycomb manufacturing method, such (1) preparation step, (2) coating step, (3) UV step, (4) stacking step, (5) joining step, (6) stretching step, (7 ) The honeycomb core H is manufactured by a stretching method that sequentially follows the cleaning process and the like.
As shown in FIGS. 2 (2) and 2 (3), the honeycomb core H manufactured in this way is made of a base material made of stainless steel or aluminum alloy that is diffusion-bonded in the form of a line, with the cell wall 8 And a planar assembly of a large number of hollow columnar cells 9 partitioned by the cell walls 8.
In this honeycomb core H, stainless steel or aluminum alloy is used as the base material 2 of the cell wall 8, and the cell wall 8 is formed by diffusion bonding by heating and pressurizing the base material 2. Joined in the shape of a line. The cross-sectional shape of the cell wall 8 and the cell 9 is typically the regular hexagonal shape shown in the figure, but regardless of this, the vertically long or horizontally long hexagonal shape, other hexagonal shapes, trapezoidal shapes, substantially rectangular shapes, and other various types Shapes are also possible.
In many cases, the honeycomb core H is used as a honeycomb sandwich panel by joining the surface plates to the cell end faces as both opening end faces. The honeycomb core H and the honeycomb sandwich panel, like general ones, are excellent in weight ratio strength, light weight, high rigidity and strength, excellent rectifying effect, and large surface area per unit volume. The honeycomb sandwich panel has excellent planar accuracy, heat retention, sound insulation and the like.
The honeycomb core H further utilizes the basic properties of stainless steel and aluminum alloy as the base material 2 and is excellent in heat resistance, high temperature strength, oxidation resistance, corrosion resistance, workability, and the like. Used for structural materials for vehicles, structural parts, and various other applications. In this metal honeycomb manufacturing method, such a honeycomb core H is manufactured.

The present invention is configured as described above. Therefore, it becomes as follows. In the method for manufacturing a metal honeycomb of the present invention, first, (1) stainless steel as a base material 2 prepared in the preparation step and an aluminum alloy containing magnesium Mg have an ultrathin foil shape with a thickness of 200 μm or less. (2) In the coating process, the release agent 1 is applied while leaving the background 5 in the form of a line. (3) After being cured and dried in the UV process, (4) In the stacking process, it is shifted by half a pitch. Thus, a plurality of sheets are stacked, and (5) in the joining step, diffusion bonding is performed by pressurizing and heating in a vacuum furnace or the like (FIGS. 1A, 1B, 2C, 3D). (Refer to Fig. 4 and Fig. 3 (1), (2), etc.).
That is, the ground surface 5 exposed in the shape of a line between the mold release agents 1 of the base material 2 becomes a diffusion bonding target portion 4 and contacts, abuts, and adheres to each other, thereby forming a stainless steel or aluminum alloy of the base material 2 With respect to the metal element to be diffused, atoms are diffused and moved at the grain interface, whereby the stacked base materials 2 are diffusion-bonded (see FIGS. 4A and 4B). When the base material 2 is an aluminum alloy, the magnesium Mg contained therein evaporates to destroy and disperse the oxide film 6 covering the surface 5 of the aluminum alloy, so that the aluminum Al is pure. In this state, it is exposed to the background 5 and the above-described diffusion bonding is possible (see (3), (4), (5), etc. in FIG. 4)).
After that, the base material 2 thus stacked and diffusion-bonded is stretched by applying a tensile force in the stacking direction D in the (6) extension step, so that the base material 2 is diffused in a line shape. While being bent along the edge of the bonding target portion 4, the non-bonding portion 3 covered with the release agent 1 is separated and separated (see FIG. 2 (1)).
In this way, the honeycomb core H, which is a planar aggregate of a large number of hollow columnar cells 9 partitioned by the cell wall 8 using the base material 2 made of stainless steel or aluminum alloy as the cell wall 8, is manufactured. (See (2), (3), etc. in FIG. 2). The manufactured honeycomb core H is cleaned in (7) cleaning step.

Now, in the manufacturing method of the metal honeycomb of the present invention, the following release agent 1 is employed. That is, in the present invention, together with a release powder made of ceramic powder, a binder made of two types of UV curable resin prepolymers having different thermal decomposition and evaporation temperatures, and a diluent made of an ester UV curable resin monomer The mold release agent 1 containing these is employ | adopted.
Then, (1) the release agent 1 prepared in the preparation process and (2) applied in the application process is first (3) UV-cured resin is cured and dried (polymerized) in the UV process, and then ( 4) After the stacking process (5) During the joining process, that is, during diffusion bonding between the base materials 2 after stacking, a part of the ultraviolet curable resin is thermally decomposed by the initial pressurization and heating. It evaporates and disappears, and the remainder is incinerated and remains as ash. (7) The release powder and ash are removed in the cleaning step.
Then, in the manufacturing method of the metal honeycomb of this invention, it becomes like the following 1st, 2nd, 3rd, 4th, 5th, 6th.

First, in the method for manufacturing a metal honeycomb according to the present invention, an ultraviolet curable resin prepolymer is used as the binder of the release agent 1. Further, as a diluent for the release agent 1, a monomer of an ultraviolet curable resin is used. And these are basically hard to evaporate at room temperature.
Therefore, (2) binder, solvent, diluent, etc. contained in the release agent 1 to be applied during the application process to the base material 2 by the printing method or coating method of the release agent 1 in the application step. However, it does not dry, volatilize or evaporate under a temperature of less than 100 ° C., that is, in a temperature environment where the coating operation is performed (see FIG. 1 (2) and FIG. 3 (1)). ).
The release agent 1 applied in the application step (2) is not dried during the application operation in this way, and is easily cured and dried by applying ultraviolet rays in the next (3) UV step. That is, the prepolymer and the monomer of the ultraviolet curable resin used as the binder or diluent of the release agent 1 can easily and easily be passed within a short time by passing ultraviolet rays in the UV process. Furthermore, it becomes a cured and dried polymer (including oligomer).

Secondly, in the method for manufacturing a metal honeycomb of the present invention, the prepolymer or monomer of the ultraviolet curable resin contained in the release agent 1 and used as a binder or a diluent is used in (3) UV process. Curing and drying by applying UV light. That is, no organic solvent harmful to the human body when volatilized or evaporated is used in the release agent 1.
Incidentally, the ultraviolet curable resin contained in the mold release agent 1 is used in the subsequent (5) bonding step (see FIG. 1 (4) and FIG. 3 (1)), at the beginning of diffusion bonding. Most of it is ashed by pressurization and heating. Part of it is thermally decomposed and evaporated, but even if it is sucked into the human body, it is not as harmful as an organic solvent.

Thirdly, in the method for manufacturing a metal honeycomb of the present invention, the release agent 1 used is firstly a. Since the ceramic powder having a particle size of 5 μm or less and a content rate set to 60% by weight or less is used as the release powder, (2) in the coating process, it can be applied with a thin coating thickness T ((2 in FIG. 1). ) Refer to Figure (1) in Figure 3).
b. A part of the ultraviolet curable resin used as a binder or diluent of the release agent 1 is thermally decomposed, evaporated, and disappeared by pressurization and heating at the beginning of diffusion bonding in the (5) bonding step.
c. The remaining incinerated ash has no strength and is less than half of its volume, and is compressed and filled in the gaps between the ceramic powders by pressurization for diffusion bonding to a level that can be virtually ignored (Fig. 1 ( 4) See FIG. 1 and FIG. 3 (1)).
As a result, at the start stage next to the initial stage of diffusion bonding, the entire coating thickness T is made extremely thin compared to (2) during the coating process.
D. In the mold release agent 1, 15 wt% or more of an ester UV curable resin monomer is used as a diluent, and the viscosity is lowered. Therefore, in the coating process, coating can be performed with a coating thickness T that is 30% by weight or more thinner than before (see FIG. 1 (2) and FIG. 3 (1)).

These a. b. c. d. Thus, the mold release agent 1 can be applied with a thinner application thickness T at the time of (2) application in the application step, and (5) the application thickness T at the time of diffusion bonding in the connection step is more than that at the time of application. Can be reduced thinly. That is, the release agent 1 can be applied with a thin application thickness T of less than 30 μm at the time of application in the application step (2) (see FIG. 1 (2) and FIG. 3 (1)), (5) At the start of diffusion bonding in the bonding process (see FIG. 1 (4) and FIG. 3 (2)), the coating thickness T is further reduced further, for example, a coating thickness of about 20 μm. T can also be set.
Thus, the mold release agent 1 has an extremely thin coating thickness T at the start of diffusion bonding in the (5) bonding step. Therefore, the stacked base material 2 is obstructed by the coating thickness T of the left and right mold release agents 1 between the upper and lower ground surfaces 5 exposed in a line shape between the left and right mold release agents 1. However, the pressure, heating, and contact with each other are surely brought into contact, contact, and close contact (see FIG. 3 (2), FIG. 4 (2), FIG. 4 (5), etc.). Accordingly, the stacked base materials 2 are reliably diffusion-bonded to each other in a line shape.
That is, (5) in the joining step, the coating thickness T of the release agent 1 becomes an obstacle, and the ground surface 5 which is the diffusion joining target portion 4 of the base material 2 is not closely contacted, abutted, or closely adhered. Insufficient strength or occurrence of unbonded parts (for the manufactured honeycomb core H, occurrence of skipping in which the cells 9 are not reliably partitioned by the cell walls 8) is reliably avoided. The These points are particularly prominent when manufacturing a honeycomb core H having a small cell size S such as a cell size S (see FIG. 2 (3)) of 10 mm or less, for example.

Fourthly, in the method for manufacturing a metal honeycomb of the present invention, the application thickness T of the release agent 1 is not obstructed between the stacked base materials 2 in the (5) joining step as described above. Between each other, diffusion bonding is reliably performed in a line shape. Therefore, pressurization during diffusion bonding can be performed under a relatively low pressure and a low load.
That is, based on the general premise that the thickness of the base material 2 is 200 μm or less, as described above, the base material is stacked in blocks with a low load of about 0.1 g / mm ² to 10 g / mm ^2. By pressurizing 2, diffusion bonding is reliably performed between the base materials 2. On the other hand, if the application thickness T of the release agent 1 remains at about 30 μm or more, it is ensured that the background 5 of the base material 2 is not disturbed by the application thickness T of the release agent 1. In order to achieve proper contact, contact, close contact and reliable diffusion bonding, it is necessary to apply pressure with a high load of about 1 kg / mm ² . These points are particularly noticeable when manufacturing a honeycomb core H having a small cell size S such as a cell size S of 10 mm or less.

Fifth, in the method for manufacturing a metal honeycomb of the present invention, two types of UV curable resin prepolymers having different thermal decomposition and evaporation temperatures are used as the binder of the release agent 1, and an ester type is used as the diluent. UV curable resin monomers are used.
Thus, (2) About the mold release agent 1 apply | coated at an application | coating process, three types of components from which thermal decomposition and evaporation temperature differ are mixed.
Therefore, in the diffusion bonding between the base materials 2 in the (5) bonding step, such three kinds of ultraviolet curable resins are pressurized and heated in a vacuum furnace, for example, so that each has a different temperature. In turn, it decomposes and evaporates (of course, a significant portion is ashed and remains as ash).
That is, when viewed as the mold release agent 1 as a whole, thermal decomposition and evaporation are performed slowly at a gradually slow speed in a wide temperature range.

By the way, in the (5) bonding process, a vacuum furnace maintained in a constant vacuum atmosphere is typically used. However, in this vacuum furnace, if the degree of vacuum deteriorates during the diffusion bonding process, the apparatus protection is performed. Therefore, a safety device that operates is attached, and when the safety device is activated, the diffusion bonding process is interrupted. (In the case of atmospheric conditions such as a reducing atmosphere, an inert gas atmosphere, and a reduced pressure atmosphere, the same applies to each dedicated furnace. The same applies hereinafter.)
If the ultraviolet curable resin of the release agent 1 is thermally decomposed and evaporated all at once, for example, the degree of vacuum in the vacuum furnace deteriorates and the complete apparatus may be operated.
On the other hand, in the present invention, the thermal decomposition and evaporation are performed gradually and gradually at a slow speed, so that the deterioration of the vacuum degree is minimized, and the safety device is activated during the diffusion bonding process. There is little risk of it.

Sixth, in the method for manufacturing a metal honeycomb of the present invention, as described above, in the diffusion bonding in the (5) bonding step, for example, it is avoided that the vacuum degree in the vacuum furnace is suddenly deteriorated, and the attached safety is provided. The device is rarely activated.
Therefore, for practical convenience, the safety device does not turn off so as not to operate due to the progress of the diffusion bonding process.
As described above, the diffusion bonding between the base materials 2 in the (5) bonding step is performed in a vacuum furnace maintained in a constant vacuum atmosphere as expected. As a result, accompanying the pressurization and heating, film-like carbides, oxides, and other compounds do not react, generate, break out, and become coarse on the surface of the base material 2.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory perspective view for explaining a metal honeycomb manufacturing method according to an embodiment of the present invention; (1) FIG. 2 shows a prepared base material, and (2) FIG. (3) shows the stacked state, (4) shows the diffusion bonded state, and (5) shows the sliced state. FIG. 2 is a perspective explanatory view for explaining the embodiment of the invention, (1) FIG. 3 shows a stretched state, (2) FIG. 3 shows a trimmed state, and (3) FIG. 3 shows the obtained honeycomb core. The main part is shown respectively. It is a front enlarged view with which explanation of an embodiment of the invention is given, (1) figure shows the state which applied a mold release agent, and (2) figure shows the state at the time of diffusion joining. BRIEF DESCRIPTION OF THE DRAWINGS It is front explanatory drawing of the principal part with which description of embodiment of the invention is provided, (1) The figure is the state before the stainless steel base material is diffusion-bonded, (2) The figure is the base material FIG. 3 (3) shows the state before diffusion bonding between the aluminum alloy base materials, and FIG. 4 (4) shows the state after diffusion bonding between the base materials. FIG. 5 shows the state immediately before, after the base material is diffusion-bonded.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Mold release agent 2 Base material 3 Non-joining part 4 Diffusion joining object part 5 Background 6 Oxide film 7 Slicing tool 8 Cell wall 9 Cell D Stacking direction H Honeycomb core Mg Magnesium S Cell size T Coating thickness

Claims (1)

After foil-like stainless steel or magnesium-containing foil-like aluminum alloy is used as a base material, a release agent is applied to the base material while leaving the background in the form of a streak, and cured by applying ultraviolet rays. ,
A plurality of the base materials are stacked in a positional relationship in which the exposed background left in the form of a streak between the release agents is shifted by a half pitch, and then the base material is pressed and heated, whereby After the material is diffused and joined in the form of a streak between the contacted surfaces,
A metal honeycomb which is obtained by applying a tensile force in the stacking direction and extending the base material as a cell wall to obtain a honeycomb core as a planar aggregate of a large number of hollow columnar cells partitioned by the cell wall In the manufacturing method of
As the mold release agent, a mold release powder made of ceramic powder having a particle size of 5% by weight to 60% by weight and a particle size of 5 μm or less, and two kinds of UV curable resin prepolymers having different evaporation temperatures by thermal decomposition And a diluent made of a monomer of an ester-based ultraviolet curable resin is used.

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