JPH01225505A - Isotropic pressure molding method - Google Patents

Abstract

PURPOSE:To carry out isotropic pressure molding to pressurize uniformly even a material to be molded of several tens mm or less of thickness by deaerating and sealing an inner bag containing a material to be molded mounted on a substrate, putting said inner bag in an outer bag together with a cushioning material and deaerating and sealing the outer bag. CONSTITUTION:A material to be molded 3 is mounted on a substrate 4, which is put in an inner bag 5, and the inner bag is deaerated and sealed. In that case, the inner bag 5 containing a material to be molded 3 mounted on the substrate 4 is put in the inside of a case in which a heat sealing device is placed, and the inside of said case is vacuumized, while the inside of the inner bag 5 is deaerated, and then an opening 9 of the inner bag 5 is sealed in the case. Then, the deaerated and sealed inner bag 5 is put in an outer bag 8 together with a cushioning material 7, and the outer bag 8 is deaerated and sealed. A warm water isotropic pressure molding device and the like is used for the isotropic pressure molding, and a material to be pressurized is pressurized with pressure mediums in a pressure vessel. The material to be molded with several tens mm or less of thickness can be pressurized uniformly and by pressure to prevent cracks, deformation and lamellar peeling is prevented from being generated in the sintering process of the like by said arrangement.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an isostatic pressing method. More specifically, the present invention relates to an isostatic press forming method that can uniformly press a molded object even if the thickness of the molded object is, for example, several tens of millimeters or less.

[Prior Art and Problems] Conventionally, laminated green sheets used for electronic components and the like have been formed by pressing a laminated sheet formed by stacking sheets together using, for example, a mechanical press method.

However, with the mechanical pressing method, it is difficult to uniformly press the laminated sheet.

This is because the a mechanical pressing method has a problem in that it requires complicated adjustment of the mold of the pressing device in order to uniformly press the laminated sheet.

Furthermore, if the laminated sheet is not uniformly pressed, there is a problem that the laminated sheet may crack, deform, or peel off in the process of sintering the pressed laminated sheet.

On the other hand, conventionally, a rubber press method has been used to perform isostatic pressure molding in which a molded object is uniformly pressed and molded.

However, since the "rubber press method" uses a rubber mold, it is suitable for pressure molding only objects to be molded that are several tens of mm or more in size.

Therefore, there is a problem that, for example, it is impossible to pressure-form a molded object having a size of several tens of mm or less.

The present invention has been made based on the above consideration.

That is, the object of the present invention is to form a molded object with a thickness of several tens of mm.
It is an object of the present invention to provide an isostatic pressing method capable of performing isostatic pressing in which a molded object is uniformly pressurized even if the following conditions are met.

The other purpose of the unreleased 153 is that it is a much simpler operation than the cumbersome and complicated operation required when trying to uniformly press a laminated sheet, etc. using a mechanical press method.

An object of the present invention is to provide an isostatic pressure forming method that can easily and uniformly press a layered sheet or the like.

[Means for Solving the Problem] The invention according to claim 1 for solving the problem reported by the Moeki Division provides an isostatic pressure forming method for isostatic pressure forming of a molded object, in which the object is placed on a support. A step of deaerating and sealing the interior containing the molded object, and an interior in which the molded object and the support are hermetically housed, obtained through the step. This is an isostatic pressure molding method characterized by including a step of putting the product into an exterior package together with a cushioning material and deaerating and sealing the exterior.

The molding method according to claim 1 is preferably a warm isostatic pressing method (claim 2).

The method of the present invention includes, for example, deaerating and sealing an interior containing a molded object placed on a support, which is hereinafter referred to as an interior interior step. ), the degassed and sealed inner cushioning material is placed in an exterior packaging, and the exterior packaging is degassed and sealed, hereinafter referred to as the packaging process. ) is an isostatic pressing method in which the molded object is molded by loading the degassed and sealed exterior into a pressure vessel of an isostatic pressing apparatus and isostatically pressurizing the molded object with a pressure medium. be.

The method of the present invention will be described in detail below in the order of steps.

(Interior process) For example, as shown in FIG. This is the process of deaerating and sealing.

The molded object 3 is not particularly limited as long as it needs to be pressure molded under high pressure, and materials include ceramics, non-ceramic inorganic materials, compositions of ceramics and non-ceramic inorganic materials, and organic materials. Examples include compositions of organic matter and non-ceramic inorganic matter, compositions of organic matter and non-ceramic inorganic matter, group I & compositions of organic matter, ceramics and non-ceramic inorganic matter, and organic matter.

The shape of the object to be molded 3 is in the form of a single grain of powder.

Examples include a sheet shape, a plate shape, a laminated shape of sheets or plates, and other arbitrary shapes.

For example, as the molded object 3, Pb, Ha, Ti
, Fe, Nb, Sn, Zr, W, Ce, M
Examples include a laminated sheet in which sheets made of a composition of oxides of: g, Sr, Zn, and Cd'3 and a binder are piled up.

In the present invention, the support body 4 is used to place the object 3 to be formed, reinforce the object 3 to be formed, and maintain its shape.

The support 4 is not particularly limited as long as it has a shape that can maintain the shape of the object 3 to be molded and a strength sufficient to maintain the shape of the support 4. For example, the support 4 can be If is a laminated sheet with a flat surface,
For example, the shape of the support 4 can be a flat plate, and the material of the support 4 can be metal or ceramic.

In the present invention, when the molded body 3 and the support body 4 have depressions, holes, etc., for example, by filling the depressions, holes, etc. with a material having good filling properties and mold release properties, such as silicone rubber. It is preferable that the surfaces of the object 3 and the support 4 be smooth.

The purpose of smoothing the surfaces of the object 3 and the support 4 is to prevent the interior 5 from being torn due to being drawn into the depressions, holes, etc. in the object 3 and the support 4 during pressure treatment. This is for the purpose of

The material for the interior 5 is such that the interior 6, in which the molded body 3 is hermetically housed together with the support 4, has enough strength to not be damaged during pressure treatment, and is suitable for use when using the warm isostatic pressing method. There is no particular restriction as long as the material can withstand heating by the pressure medium, for example, sheets or films made of synthetic resin such as polyethylene, polypropylene, nylon, etc.
One example is metal foil. In consideration of availability, workability, strength, cost, etc., the material for the interior 5 is preferably a laminate film having a layer made of general-purpose synthetic resins such as polyethylene, polypropylene, nylon, etc. As the material 5, a gas-permeable material, a material that occludes gas, etc. can be used, thereby making it possible to supply the necessary gas to the molded object 3 during the pressure treatment.

There is no particular restriction on the shape of the interior 5 as long as it can accommodate the molded object 3 placed on the support 4 and seal it.

The shape of the interior 5 is, for example, a bag-like one having one opening as shown in FIG. 1 (in the drawing, 10 is a heat-sealed portion).

Examples include a bag-like product having two or more openings, a folded film-like product, and a film-like product made by putting two films together.

In the present invention, the object to be molded placed on the support 4 is
For example, as shown in FIG.
The object to be formed 3 and the support 4 may be put into the interior 5 after a21, or the object to be formed 3 and the support 4 may be separated and placed into the interior 5, and then the object to be formed is 3 may be placed on the support 4.

As a method for sealing the interior 5, for example, if the interior 5 is made of a synthetic resin sheet, for example, the opening 9 of the interior 5 may be heat-sealed, or the opening 9 of the interior 5 may be sealed using ultrasonic waves. It is possible to adopt methods such as sealing,
For example, if the interior 5 is made of a synthetic resin sheet or metal foil, for example, the opening 9 of the interior 5 may be sealed with an adhesive, or the opening 9 of the interior 5 may be sealed with a blade stopper, such as a pinch. It is possible to adopt a method such as sealing.

In the present invention, as a method for sealing the interior 5, it is preferable to adopt a heat sealing method in consideration of efficiency of one operation, completeness of sealing, etc.

Further, as a method for deaerating and sealing the interior 5, for example,
A method of sealing the opening 9 of the interior 5 in a state where the inside of the interior 5 is sufficiently degassed by drawing a vacuum (degassing method 1), or
The interior 5 containing the molded object 3 that has been formed into a21 on the support 4 is placed inside a box containing a heat sealing device, and the interior 5 is sufficiently degassed by evacuating the inside of the box. For example, a method of sealing the opening 9 of the interior interior 5 (degassing method 2) may be mentioned. Degassing method 2 is preferable in consideration of ease of operation and the like.

(Exterior process) As shown in FIG. 2, in the exterior process 2, the degassed and sealed interior 5 obtained in the interior process 1 is put into the exterior 8 together with the cushioning material 7, and the exterior 8 is degassed and sealed. This is the process of

The cushioning material 7 comes into contact with the interior 5 and is used, for example, to prevent the interior 5 or the exterior 8 from being damaged by, for example, corner portions of the molded object during pressure treatment.

Furthermore, by using the cushioning material 7, the shape of the object 3 to be formed can be maintained even if some pressure is applied to the outer case 8 when the outer case 8 is taken out and put in and out of the pressure vessel of the isostatic pressure forming apparatus. It also has the effect of improving handling properties.

The material of the cushioning material 7 is not particularly limited as long as it is of a material and shape that will not damage the interior 5 or exterior 8 during pressurization, for example, it may have a thickness that provides elasticity or flexibility. Examples include a rubber sheet with a thickness of about 1 to 2 mm, a sponge sheet with a thickness of about several mm, and the like.

The method of bringing the cushioning material 7 into contact with the interior 5 is not particularly limited as long as the exterior 8 is not damaged during the pressure treatment, but for example, as shown in No. 21A, the method of bringing the interior 5 into contact with the interior 5 is Here are some ways to pinch it.

In addition, if the interior 5 or exterior 8 is not damaged during the pressure treatment, for example, even if the cushioning material 7 is applied to the entire outer surface of the interior 5, or only a part of the outer surface of the interior 5 is You may guess 7.

The exterior 8 is not particularly limited as long as the interior 5 can be placed inside the exterior 8 together with the cushioning material 7;
Materials and shapes similar to those that can be used can be used.

The method for deaerating and sealing the exterior 8 is to
It can be done in the same way as deaerating and sealing.

In the present invention, it is also possible to process a plurality of objects 3 in one cycle of isostatic pressing.

This is because a plurality of objects 3 to be molded may be placed in the interior 5, a plurality of the interior 5 may be placed in the exterior 8, and a plurality of degassing bodies 3 may be placed in the pressure vessel of the isostatic pressure forming device. This is because it may be placed in a sealed exterior.

The isostatic press forming method in the present invention is a forming force method using a hot water isostatic press machine, a hot water isostatic press laminator, a supercritical press machine, etc., in which a pressurized object is pressed by a pressure medium in a pressure vessel. It has a step of pressing. Note that the isostatic pressing method in the present invention may be a cold isostatic pressing method using a cold isostatic pressing apparatus or the like.

The warm isostatic pressing method in the present invention is a molding method that uses a hot water isostatic pressing device, a hot water isostatic laminator, a supercritical pressing device, etc. It has a process of pressurizing and heating.

In the present invention, the isostatic pressing method is preferably a warm isostatic pressing method, because in the warm isostatic pressing method, for example, when pressing a laminated sheet, the laminated sheet is uniformly pressed. Since it can be heated as well as pressed, it is possible to improve the compressibility.

The pressure vessel may have a structure that can pressurize the pressurized object by making the inside high pressure by pressurizing the pressure medium. For example, the pressure vessel has an opening and the opening is airtight. It consists of a lid that can be used to extend the blade.

The +Mi pressure medium is not particularly limited as long as it is a medium that transmits heat and pressure, and examples thereof include water, pure water, fluorine-based inert fluids, oil and the like emulsified in water.

For example, if a warm isostatic pressing method is used as the isostatic pressing method of the present invention, the object to be processed obtained in the interior process 1 and the exterior process 2 is placed in a pressure vessel, and the pressure medium in the pressure vessel is Accordingly, an operation is performed in which the object to be processed is brought to a predetermined temperature and a predetermined pressure is applied to the object to be processed for a predetermined period of time.

The molding conditions in the isostatic pressing method of the present invention are as follows.

To-be-molded object 3, support body 4. Interior 5, cushioning material 7. The predetermined time may vary depending on the material and shape of the exterior 8, so it cannot be specifically limited, but for example, the predetermined time may be 1 minute to 2 minutes.
Preferably, the predetermined temperature is within a range of 50
It is preferable that the predetermined pressure is 0″C or less, and the predetermined pressure is 10,
000 kgf/cm"G or less. Furthermore, if the materials of the interior 5 and exterior 8 are resistant to high temperatures and have gas permeability or occlude gas, they can be pressurized at high temperatures. By performing the molding, it is also possible to cause a heating reaction between the components of the pressurized object and the gas.

In the present invention, when the object to be molded is subjected to warm isostatic pressure molding, it is preferable that the object to be processed be heated in advance to near the processing temperature using a heater or the like before the molding process.

Further, in the present invention, when the pressure is reduced after the predetermined pressure is reached, it is preferable that the speed of pressure reduction is slowed to 500 kgf/c or less.

[Example] (Example 1) *Interior process* As shown in Fig. 3, the molded object 3 has a depression 11 in the center and is made of an M'' oxide of Ti-based oxide and a binder. A laminated sheet with a thickness of about 7 mm was used.

As shown in FIG. 3, a stainless steel plate having four holes 12 and having a thickness of about 10 mm was used as the support 4.

As shown in FIG. 3, the object 3 to be molded was placed on a support 4.

The depression 11 of the molded body 3 and the four holes 12 of the support body 4 are
Filled with silicone rubber.

As the interior 5, a bag was used which had one opening 9 formed by stacking and heat-sealing two laminate films each having a polyethylene layer and a nylon layer each having a thickness of 70 gm.

The object to be formed 3 is placed on the support 4, and the object to be formed 3 and the support 4 are
and into the interior 5 through the opening 9 of the interior 5, put the interior 5 into a box containing an eye seal device, evacuate the inside of the box to sufficiently deair the interior 5, and then remove the interior 5 from the interior 5. Inside interior 5
The opening 9 was heat-sealed to degas and seal.

*Exterior packaging process As the exterior packaging 8, a bag having one opening 13 made by laminating and heat-sealing two laminate films having a polyethylene layer and a nylon layer each having a thickness of about 70 fitm was used.

As the cushioning material 7, two sheets made of natural rubber and having a thickness of 5 mm were used.

An interior 5 in which a molded object placed on a support 4 was hermetically housed was sandwiched between two cushioning materials 7.

Put the interior 5 and the cushioning material 7 into the exterior 8 through the opening 13 of the exterior 8, put the exterior 8 into a box containing a heat sealing device, and evacuate the inside of the box to sufficiently degas it. Inside the box, the opening 13 of the exterior package 8 was heat-sealed to remove air.

This degassed and sealed exterior was placed in a pressure vessel of a cold isostatic pressing apparatus, and wasostatically pressurized using the pressure medium in the pressure vessel under the following conditions.

As the pressure medium, an emulsion of oil in water was used.

The pressure treatment time was 15 minutes.

It was pressurized at a pressure of 3.600 kgf/C@''G.

The isostatically pressurized, degassed, and sealed exterior was taken out of the pressure vessel, the exterior 8 and interior 5 were torn, and the crimped laminated sheet was taken out.

The crimped laminated sheet thus obtained was sintered in an electric sintering furnace, but no problems such as cracking, deformation, or delamination of the laminated sheet occurred.

(Example 2) Interior process 1 and exterior process 2 were performed in the same manner as in Example 1.

The resulting degassed exterior was placed in a pressure vessel of a warm isostatic press molding device, and wasostatically pressurized using a pressure medium in the pressure vessel under the following conditions.

Water was used as the pressure medium.

The pressure treatment time was 15 minutes.

It was pressurized at a pressure of 300 kgf/cs"G.

Heated at a temperature of 80°C.

The isostatically pressurized, degassed and sealed exterior was taken out from the pressure vessel, the exterior 8 and the interior 5 were torn, and the crimped laminated sheet was taken out.

The press-bonded laminated sheet thus obtained was sintered in an electric sintering furnace, but no problems such as cracking, deformation, or delamination of the laminated sheet occurred.

[Effect of the invention] In the conventional isostatic pressing method, the thickness of the molded object is several tens of mm.
In the following cases, isostatic pressing is impossible, but with the isostatic pressing method according to claim 1, even if the thickness of the object to be molded is several tens of mm or less, it is possible to Pressure forming can be performed.

In other words, even if the thickness of the molded object is several tens of mm or less,
The object to be molded can be pressure-bonded uniformly, and conventionally,
It is possible to eliminate problems such as cracking, deformation, or single-layer peeling of the molded object during the sintering process, etc., which occurred due to the inability to uniformly pressurize and crimp the molded object. .

Further, the isostatic pressing method according to claim 1 is a much simpler operation than the complicated operation required when trying to uniformly press a laminated sheet, etc. using a conventional mechanical pressing method. Since the laminated sheets and the like can be easily and uniformly pressed, production efficiency can be improved and production costs can be lowered compared to conventional mechanical pressing methods.

Furthermore, since it is possible to process a plurality of objects to be molded in one cycle of isostatic pressure molding, it is possible to further improve production efficiency and lower production costs.

In the isostatic pressing method according to the second aspect, the isostatic pressing method according to the first aspect can be performed using a warm isostatic pressing method in which the object to be molded can be heated.

In other words, by applying pressure uniformly while heating the molded object, it is possible to more thoroughly compress the molded object, which prevents the molded object from cracking, deforming, or delaminating during the sintering process, etc. It is possible to eliminate the problem of
It is also possible to simplify the sintering process.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing an example of the relationship between a molded object, a support, and an interior interior in the interior interior step of the isostatic pressure molding method of the present invention. FIG. 2 is an explanatory diagram showing an example of the relationship between the interior, the cushioning material, and the exterior in the exterior packaging step of the isostatic pressing method of the present invention. FIG. 3 is an explanatory view showing an example of an object to be molded, an example of a support, and an example of the relationship between the object to be molded and the support in the isostatic pressing method of the present invention. l... Interior process, 2... Exterior process, 3... Molded object, 4... Support, 5... Interior, 7... Cushioning material,
8...Exterior.

Claims (2)

[Claims] (1) In the isostatic pressure molding method of isostatically press molding a molded object, a step of deaerating and sealing the interior containing the molded object placed on a support, and An isostatic pressure molding method comprising the steps of: placing an interior in which the object to be molded and the support are hermetically housed into an exterior together with a cushioning material, and deaerating and sealing the exterior. (2) The isostatic pressing method according to claim 1, wherein the isostatic pressing is warm isostatic pressing.