JP2015124441A - Metal powder sintering body manufacturing device and metal powder sintering body manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing device and a manufacturing method of a metal powder sintering body in which an initial investment amount is low and a running cost is cheap.SOLUTION: In a process in which metal powder is printed on a thermofusing belt-shaped hoop material, and the hoop material is melted and a metal powder printing part pattern only is metal-sintered through pressing and heating the printing part from above by a high temperature heater, an arbitrary hater is heated while pressing the hoop material to a substrate surface, a sintering layer of the hoop material is formed at the position of the printing part pattern at the upper surface, and the first layer which is processed as a sheet through hoop material melting and clipping from the hoop material is fixed on the substrate The hoop material is subsequently supplied on the formed sintering layer, the metal printing part on it is pressed, heated and sintered, the sheet clipped from the hoop material is piled one by one, and hoop material supply, pressing, heating and sintering, sheet forming and piling are repeated, to manufacture a metal powder sintering body.

Description

  The present invention relates to a metal powder sintered body manufacturing apparatus and a metal powder sintered body manufacturing method.

In recent years, 3D printers have attracted attention as a technique for efficiently producing a three-dimensional structure, and inexpensive commercial machines have already appeared for 3D printers made of resin.
On the other hand, when making a metal 3D structure in the same way as a 3D printer, since the metal has a higher melting point than that of the resin, the heat source must have a high output such as a laser or a light beam that can rapidly heat a minute region. Used.
For example, Patent Document 1 discloses a technique in which a powder layer is irradiated with a light beam (laser) to sinter or melt the powder layer to form a solidified layer.

JP 2010-65259 A

Lasers, light beams, etc. can sinter metal by instantly melting metal powder with high heat of several thousand degrees Celsius and high output.
However, this requires a large amount of energy and a huge amount of equipment and energy, which requires excessive investment.
Currently, heater heat sources are used in heat sources for 3D printers made of thermoplastic resin, but the heater temperature is several hundred degrees Celsius, and many of them are simple and downsized. No body manufacturing equipment is seen.
In the heater heat source of the 3D printer made of thermoplastic resin, the result of metal sintering for melting metal powder cannot be obtained.
An object of this invention is to manufacture a metal powder sintered compact with a heater heat source cheaply.
Note that the term “sintering” as used in the present invention is not limited to sintering in a narrow sense of baking and solidifying, but refers to forming a solid from a powder including melting and solidification.

  The present invention has been made for the above purpose, and the first invention provides a 3D printer using a belt-like hoop material based on a heat-dissolvable thin woven fabric and using an ultrafine metal powder as an ink. The plotter pattern is printed on the hoop material from the XY two-dimensional software synchronized with the signal from the CAD in the form of a metal foil, and the printed part is sintered with metal by pressing and heating it with a high-heater heater. .

The present invention separates the heated part from the heated hoop material as a fixed-size sheet including the sintered part of the printed part, and makes one layer of the laminate.
Move the hoop material newly printed with the next CAD signal on the sheet and align it with the CAD signal, stack it, press and heat with a heater from above the hoop material, and sinter the printed part with metal. Then, the finished product is cut into sheets of the same size to make a second layer of a sintered sheet laminate.
The printed foil binder and the printed pattern lower hoop material are melted by heat in one layer of the laminate of the sintered sheet formed by sintering the metal foil-like printed pattern on the hoop material by heating the heater top plate. The support material supports the sintered layer by combining with the periphery of the sheet material and separating from the metal sintered portion, and the combination of the sintered layer and the support material becomes a single layer of the sintered sheet layer. And by pressing with a base from above and below, it is combined with the already formed sintered sheet layer to form a laminate of sintered sheets.

The metal foil-like printed pattern in which the XY two-dimensional metal foil-like printed pattern is laminated one layer at a time from the lower Z to the upper direction and the metal is sintered and laminated by heating and pressurizing the heater top plate. An apparatus for producing a three-dimensional metal powder sintered body by sintering metal powder on the Z axis,
Printing on the hoop material, which can be printed on the hoop material by arbitrary metal foil printing, heating the hoop material including printing to form a sintered layer having an arbitrary print pattern shape in the hoop material surface, Next process after printing Hoop material feeding, positioning, pressurization, heating, sheet separation from the hoop material, synchronizing the tact time of all operations, and supplying the hoop material intermittently A metal powder sintered body manufacturing apparatus comprising a mechanism, a pressing mechanism for pressing and heating the hoop material on a base, and a function of separating the hoop material from a sheet and fixing and laminating on the base.

According to a second aspect of the present invention, a hoop material obtained by printing metal powder into a metal foil shape is set between a pressing top plate provided with a heater for pressing and heating from above and a base, and the first hoop material is disposed within the surface of the hoop material. A sintered layer is formed, and then a new hoop material is inserted between the hoop material including the first sintered layer and the base, and the sheet is processed in the same procedure as that for forming the first sintered layer. Processing, laminating a second sintered layer on the first sintered layer,
A new hoop material is supplied onto the laminated second sintered layer by the same procedure to laminate the third sintered layer, and the sintering by including the sintered body by repeating the lamination by this procedure. After forming the laminate of sheets,
A method for producing a metal powder sintered body, wherein the unsintered portion is removed by dissolving and removing the hoop material of the laminate.
The steps of the metal powder sintered body manufacturing apparatus and manufacturing method are shown in FIGS.

  The structure of the metal powder sintered compact manufacturing apparatus of this invention.   The figure which shows a hoop material and a sheet sintering lamination process.   Completion drawing of sheet sintering lamination.   The upper pressing top plate sectional drawing which concerns on this invention.   The top view from the upper press top plate which concerns on this invention.   The base perspective figure of the 1st layer Z layer sheet | seat on a board | substrate.   Cross-sectional view of the hoop material, sheet, and base B-B ′.   The exploded view which represented typically the structure of the sintered layer of each sheet | seat of a laminated body.   Completion drawing of sintered product.

Hereinafter, an example of an embodiment for carrying out the present invention will be described with reference to the drawings.
FIG. 1 is a diagram showing a configuration of a metal powder sintered body manufacturing apparatus of the present invention in which a first step of printing on a hoop material and a second step of metal powder sintering processed by a heater pressing top plate are synchronized. It is.
FIGS. 2 to 3 are diagrams showing the lamination process and completion of the hoop material and the sintered sheet. The metal powder sintered body manufacturing apparatus according to the present invention prints an arbitrary portion of the metal powder on the hoop material 2 in the form of a metal foil. Processing, heating the hoop material to form a sintered layer of an arbitrary shape, the pressing top plate 1 provided with a heater capable of forming the sintered sheet laminates 21z to 21a, and the hoop material 2 on the base 3 A hoop material supply mechanism including a hoop material feed roller 6 and a hoop material take-up roller 7 that are synchronized with printing and intermittently supplied, and a pressing top plate 1 that presses the sheet materials 21z to 21a onto the base. It consists of a pressing mechanism. The pressing top 1 can be lifted and lowered by a top lifting / lowering support 4 and a top driving device 5.

The pressing top plate 1 is provided with an air ejection port 1b on the surface in contact with the hoop material 2, and the ejection port 1b is connected to the fusible duct 9 through the air flow passage 1a.
Thereby, the pressing top plate 1 not only presses the hoop material 2 but also has a function of pressing the sheet materials 21 z to 21 a against the upper surface of the base 3 and fixing the position of the sheet material and detaching the hoop material 2.

The structure of the pressing top plate 1 will be described in some detail with reference to FIGS. FIG. 5 shows a plan view from the bottom of the pressing top plate 1 having the heater base according to the present invention.
The central heater base can arrange a large number of heaters 1c independently, and any heater 1c can be turned on and off.
The heater 1c used in the present invention is preferably a ceramic fired dot heater. For example, when producing a sintered body made of a relatively low melting point alloy near 400 ° C. represented by tin, zinc, etc., nitriding An aluminum firing heater is preferable. For example, an aluminum nitride firing heater having a heating power of 500 W / cm ² , a heating rate of 100 ° C./sec, and a maximum temperature of 600 ° C. is optimal.
The heater can be controlled in accordance with the printing pattern, and has an air ejection opening gap 1b between independent heaters to perform sheet peeling work after heating the sheet.
FIG. 4 shows a cross section of the pressing top 1 in FIG. 5A-A ′, the airflow is communicated in the air flow passage 1a in the base, and the ejection port 1b is ejected from the ejection duct 9 as a system. The heater 1c, the hoop material, and the sheet are separated from the top plate, and synchronized with the operation of the heat cutter 1d that cuts the sheet from the hoop material. Move to the next process in order.

6 to 7 are a plan view of the base and a cross-sectional view of the base, as seen from the top through the hoop material.
A double chain line in FIG. 6 is a perspective view of the base body, and a solid line in the middle is the sheet 21z cut by the heat cutter 1d.
The peripheral double chain line round hole is a perspective view of the air ejection port 3b from the air flow passage 3a, and causes the hoop material to be lifted by the air blown from the fusible duct 9.
The difference from the upper pressing top plate is innumerable to the upper pressing top plate ejection vent that sucks and fixes the sheets 21z to 21a through the suction flow passage of 3c by the vacuum pump from the intake duct 8 in the center. An intake port 3d was provided.

Both the pressing top plate 1 and the lower base 3 are provided with outlets 1b and 3b at the outer peripheral portion of the surface, respectively, and the hoop material 2 after heat treatment is easily separated from the work table by the jets. I can do it.
As the fumarole gas, it is good to use an inert gas to prevent combustion during heating of the hoop material. The base material is ceramic, and the surface is bonded to the adhesive surface by heat welding by finishing the surface with fluorine. Prevent adhesion of etc.

Next, a process for manufacturing a metal powder sintered body using the metal powder sintered body manufacturing apparatus will be described.
The material of the hoop material 2 used in the present invention is suitably a heat-welding fiber, and a thin woven fabric such as polyamide (nylon) is appropriate, and may be supplied on the base 3 one by one as a sheet of a cut plate. In the example of the manufacturing apparatus, the hoop material 2 is processed into a hoop shape. By controlling the hoop material feed roller 6 and the hoop material take-up roller 7, the hoop material 2 can be accurately and intermittently supplied to the normal position on the base 3. It has a structure.

In order to increase the shape accuracy of the sintered body and increase the sintering speed, the printing conditions on the hoop material are important, and the printing method on the hoop material used in the present invention adopts the principle of an ink jet piezo method and vibrates. In order to steadily fix the ink on the hoop material, a separately manufactured water-soluble binding liquid is used, and the nano-level metal powder particles are uniformly mixed and the filling density is 50% or more. Perform printing work.
Further, the size of the powder metal used as the raw material of the ink is preferably about 0, 1 to 10 μm. The metal powder may be a single metal or two or more different metals, and printing is performed at the same location several times. It is desirable to increase the thickness of the metal printing portion by performing the overlapping printing, and the thickness of the hoop material 2 is 200 μm or less.

  By performing printing on the hoop material 2, the metal powder can be manufactured by a method of fixing the metal powder on the thin woven fabric with a uniform density, and the thickness is 0.1 to 10 μm or less on the thin woven fabric. In this way, the powder metal is fixed on the sheet in advance, and has the effect of dust explosion protection.

When the hoop material 2 is supplied onto the base 3, the hoop 2 is pressed and heated on the base 3 by the pressing top plate 1, cut as a sheet by the heat cutter 1d, and one layer of sintered sheets from the sheets 21z to 21a. Are stacked.
This pressing force is desirably 1 g / cm ² or more in order to efficiently promote the sintering. The upper limit pressing force needs to be set so as not to cause breakage depending on the shape and structure of the sintered body.
In synchronism with the pressing, a heating signal is sent from 3D-CAD or the like (not shown) to an arbitrary heater 1c among the heaters 1c provided on the pressing top plate 1, for example, in the surface of the first layer sheet 21z. A sintered layer 22z is formed in a portion corresponding to the heated metal printing. (Fig. 6, Fig. 7)

  The sintered layer 22z thus formed constitutes one initial layer of the sintered body 22 as the final product. The sheet 21z including the sintered layer 22z is cut out from the hoop material by the heat cutter 1d provided on the pressing top plate 1, and is formed on the base by the ejection port 1b of the pressing top plate 1 and the intake port 3d provided on the base 3. It is fixed and separated from the surface of the hoop material 2 main body and the pressing top plate 1.

When the sintered sheet 21z is fixed to the base 3, the hoop feed roller 6 and the hoop take-up roller 7 are operated to supply a new hoop material 2 onto the sintered sheet 21z on the base 3.
The pressing top plate 1 descends on the hoop material 2 and presses the hoop material 2 against the sintered sheet 21 z on the base 3. That is, a new hoop material 2 is laminated and pressed on the sintered sheet 21z. In synchronization with this, an arbitrary heater 1c and heat cutter 1d are heated in the same manner as described above, and a sheet 21y including a new sintered layer 22y is laminated on the sintered sheet 21z.

  FIG. 2 shows how these sintering operations are repeated and lamination proceeds, and FIG. 3 shows how a series of lamination sintering is completed. As a result of the repetition of the sintering operation, a sintered body 22 is built in the laminated body 21 of the formed sintered sheets.

  FIG. 10 is an exploded view schematically showing the relationship between the sintered sheet 22 and the respective layers 21a to 21z and the sintered layers 22a to 21z constituting the laminated body 21. In this example, the fact that the sintering steps (number of times of sintering) of a to z have been passed is schematically expressed.

  The sintered body 22 can be taken out by removing an unsintered portion of the laminated body 21. For example, in the case of a hoop material using a polyamide thin woven fabric (melting point: 79 to 121 ° C.), the unsintered portion is melted and removed in a 200 ° C. hot air drying furnace, thereby firing the laminate 21 with vibration. The ligature 22 can be taken out. At this time, the unsintered support material from which the thin woven fabric or the like has been removed is recycled again as a raw material of the hoop material without being discarded. At this time, there may be unsintered metal powder. It is better to work in an inert gas such as nitrogen in order not to induce an explosion.

Effect of the invention

By using the heater, the apparatus cost is lower and the running cost is lower than the conventional sintering apparatus using a laser beam. In addition, since the metal powder is processed by ink and printing, there is no risk of powder scattering or dust explosion during the sintering operation, and the working environment is good.
In the present invention, a heater heat source is used with an emphasis on cost. However, high-melting point metal processing using a beam (laser) as a heat source is possible by processing a sheet material of metal powder in advance.

DESCRIPTION OF SYMBOLS 1 Press top plate 1a Air flow path 1b Air outlet 1c Heater 1d Heat cutter 2 Hoop material 2a Hoop material advancing direction 21 Sintered sheet laminated body 21a Sintered sheet final layer 21b-21y Sintered sheet intermediate layer 21z Sintered sheet stack 22 Sintered body product 22a-22z Sintered layer 3 Base 3a Air flow path 3b Air ejection port 3c Intake air flow path 3d Inlet port 4 Press top plate lifting support DESCRIPTION OF SYMBOLS 5 Press top plate drive device 6 Hoop material delivery roller 7 Hoop material take-up roller 8 Base air intake duct 9 Foam duct 10 Base height maintenance support 11 Base height maintenance drive device 12 Metal powder printing machine

Claims (2)

The metal powder is printed on the heat-meltable belt-shaped fabric hoop material, and the hoop material is melted by pressing and heating with a high-heater heater that can be controlled from the top of the printed material. The specific dimensions including the metal sintered part of the hoop material to be bonded are fixed to the cutout base as a sheet, and a layer of hoop material printed in the same operation is stacked on this sheet and pressed from above. Heating with a top plate, and stacking one after another, a laminate of sintered sheets including a metal sintered body is completed.
It is an apparatus for producing a sintered metal powder body that is laminated and heated by pressing laminated sheets,
Pressing top plate equipped with a heater that can form a print-shaped sintered layer by heating an arbitrary printing location of the hoop material, a base that can adjust the height level according to the lamination thickness, and a sheet on the base An apparatus for producing a sintered metal powder, comprising: a hoop material supply mechanism capable of intermittently supplying a sheet; and a pressing mechanism that cuts out a sheet from the hoop material and fixes and presses the sheet on the substrate. The metal powder is printed on the hot-melting hoop, and by pressing and heating with a high-heater that can be controlled arbitrarily from the top of the printed material, the hoop material melts and only the printed pattern of the metal powder is sintered. A part of the metal-sintered hoop material is cut out as a sheet, and on this sheet, the printed hoops produced in the same operation are layered one by one, heated from above with a pressing top plate, and the sheet is cut out. By laminating one after another, a laminated body of sintered sheets including a metal sintered body is produced, and an apparatus for producing a metal powder sintered body by laminating and sintering, including the first sintered layer A new sheet is inserted between the sheet on the top and the pressing top plate, and the second sintered layer is formed on the first sintered layer in the same procedure as the first sintered layer is formed. Laminated
After supplying a new sheet material in the same procedure on the laminated sintered layer and laminating the sintered layer, after repeating the lamination by this procedure to form a laminate of the sheet material,
A method for producing a metal powder sintered body, comprising dissolving and removing the thin fabric of the laminate to remove an unsintered portion.

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