JP6137154B2 - Spark plasma sintering method and apparatus - Google Patents

Description

  The present invention relates to a discharge plasma sintering method and apparatus used for manufacturing, for example, a thermoelectric conversion material, a high thermal conductivity material, an electronic device material, a mold material, a sputtering target material, and an abrasion resistant material.

  Conventionally, as a discharge plasma sintering apparatus of this type, a shut-off device is generally arranged in parallel in a passage communicating between a preparatory chamber and a sintering chamber arranged in parallel, and a die and a punch are placed in a predetermined atmosphere in the preparatory chamber. A powder or solid sintered material as a raw material is filled in a sintering mold made of, and the sintering mold filled with the sintering material is transferred to a sintering chamber through a passage. In the vacuum chamber, a structure that is sintered in a predetermined atmosphere such as an inert gas or a vacuum atmosphere is known.

JP 2006-131921 A

  However, in the case of the above conventional structure, since the preparation chamber and the sintering chamber are integrally arranged in parallel and the blocking device is arranged in the passage, the entire sintering apparatus is increased in size and requires a lot of installation space. The entire apparatus tends to be complicated, and the preparation chamber is intended exclusively for a sintering apparatus, although it has a glove box structure that can perform various operations under a predetermined atmosphere such as an inert gas or a vacuum atmosphere. As a result, the flexibility of use may be reduced.

  The present invention aims to solve such inconveniences. Among the present inventions, the invention of the method according to claim 1 is characterized in that the sintered mold is hermetically stored in a capsule in a deoxygenated atmosphere. The capsule is housed in a sealed chamber through an open / close door, the inside of the chamber is made into a deoxygenated atmosphere by inert gas replacement, and the capsule housed in the chamber under the deoxygenated atmosphere is opened. Then, the sintering mold in the capsule is transferred to an electric pressure and pressure sintering machine in the chamber, and the sintered material filled in the sintering mold is subjected to discharge plasma sintering (hereinafter referred to as “desorption oxygen sintering” in the chamber). It is also referred to as “SPS”).

  Further, the invention of the apparatus according to claim 2 is characterized in that a capsule capable of hermetically storing the sintered mold in a deoxygenated atmosphere, a sealed chamber having an opening / closing door capable of storing and taking out the capsule, and an inert atmosphere in the chamber. An inert gas replacement section prepared in a deoxygenated atmosphere by gas replacement, an electric pressure sintering machine that is disposed in the chamber and discharge-plasma-sinters the sintered material filled in the sintering mold, A sintering type transfer mechanism that is disposed in the chamber and that can open the capsule housed in the chamber under a deoxygenated atmosphere and transfer the sintered mold in the capsule to the energizing pressure sintering machine. The discharge plasma sintering apparatus is characterized by comprising a portion.

  According to a third aspect of the present invention, there is provided a mounting member capable of mounting and storing the capsule at a mounting position in the chamber as the sintering type transfer mechanism, and mounting on the mounting member. An unsealing mechanism for unsealing the capsule, and a transfer mechanism capable of transporting the sintering mold in the unsealed capsule to a sintering position of the energization pressure sintering machine. Further, the invention of the apparatus according to claim 4 is provided with a retracting mechanism for retracting the mounting member from the mounting position to a retracting position away from the sintering position of the energizing pressure sintering machine. The invention according to claim 5 is characterized in that a vacuum pump for promoting introduction of the inert gas into the chamber is provided. is there.

  According to a sixth aspect of the present invention, there is provided a glove box for sealing the sintered mold in the capsule in a deoxygenated atmosphere, and the seventh aspect of the present invention. The invention of this apparatus is characterized by comprising a gas circulation purification device for further reducing the oxygen concentration in the inert gas in the chamber.

  As described above, according to the present invention, the sintered mold is hermetically housed in a capsule in a deoxygenated atmosphere, and the capsule is hermetically sealed through an open / close door. The inside of the chamber is made in a deoxygenated atmosphere by inert gas replacement of the inert gas replacement part, and the capsule containing the sintered mold in the deoxygenated atmosphere is opened by the sintering type transfer mechanism part. The sintering mold in the capsule is transferred to an electric pressure sintering machine in the chamber, and the sintered material filled in the sintering mold by the electric pressure sintering machine is subjected to discharge plasma sintering in a deoxygenated atmosphere in the chamber. Highly pure and high quality because the capsule can sinter the sintered material without contacting it with the atmosphere, and it can sinter while preventing oxidation due to oxygen, contamination by dust, moisture, etc. To obtain a sintered molded product In addition, the capsule can be housed in the chamber via the open / close door, and the sintering mold can be transferred to the energizing / pressure sintering machine in the chamber by the sintering mold transfer mechanism, and the sintering mold can be energized and pressurized. It can be easily fed to the sintering machine, and the sintering mold can be accommodated in the chamber by the capsule, the entire sintering apparatus can be miniaturized, and the installation space can be reduced. And the entire apparatus can be simplified.

  In the invention according to claim 3, as the sintering type transfer mechanism, the capsule can be placed and stored at a placement position in the chamber, and placed on the placement member. Since the unsealing mechanism for unsealing the capsule and the transfer mechanism capable of transferring the sintering mold in the unsealed capsule to the sintering position of the electric pressure sintering machine, the sintering type transfer mechanism section The capsule can be simplified and the capsule housed in the chamber in a deoxygenated atmosphere is opened, and the sintered mold in the capsule is easily transferred to the sintering position of the electric pressure sintering machine in the chamber Further, in the invention according to claim 4, a retraction mechanism for retreating the placement member from the placement position to a retreat position away from the sintering position of the energizing pressure sintering machine is provided. Since it is provided, it is placed by heat generation during sintering by the current pressure sintering machine. In the invention according to claim 5, since the vacuum pump for accelerating the introduction of the inert gas into the chamber is provided, the chamber can be prevented. The above inert gas can be introduced in a short time by evacuating the gas with a vacuum pump, and workability can be improved.

  In the invention described in claim 6, since the glove box for sealing the sintering mold in the capsule in a deoxygenated atmosphere is provided, the sintering mold can be filled with the sintering material. The sintered mold can be easily sealed and stored in the capsule. Since the glove box is independent from the chamber, the entire sintering apparatus can be downsized and the glove box can be used for general purposes. A gas circulation purification apparatus that can be used, can increase the flexibility of using the glove box, and further reduces the oxygen concentration in the inert gas in the chamber. Therefore, the oxygen concentration in the inert gas in the chamber can be further reduced as necessary, or the moisture content can be adjusted and returned to the chamber to circulate the inert gas. Can be can be, obtain a high-purity and high-quality sintered molded article.

It is explanatory sectional drawing of the example of embodiment of this invention. It is explanatory drawing sectional drawing of the capsule of the embodiment of this invention. It is explanatory plane sectional drawing of the glove box of the embodiment of this invention. It is a partial explanation sectional view of an example of an embodiment of the invention. It is a partial explanation plane sectional view of an example of an embodiment of the invention. It is explanatory sectional drawing of the example of embodiment of this invention. It is explanatory sectional drawing of the example of embodiment of this invention. It is explanatory sectional drawing of the example of embodiment of this invention.

  1 to 8 show an embodiment of the present invention. Reference numeral 1 denotes a capsule, which is configured to be capable of hermetically storing the sintering mold 2 in a deoxygenated atmosphere. Of these, as shown in FIG. The die 2 is composed of a die 3 and upper and lower punches 4 and 4, and a space formed by the hole 3 a of the die 3 and the upper and lower punches 4 and 4 inserted into the hole 3 a is filled with a sintered material W, Consists of a bottom member 1a and a lid member 1b which are detachable from each other by an attachment / detachment mechanism Q. A sintering mold 2 is placed on the bottom member 1a of the capsule 1, and the lid member 1b is fastened to the bottom member 1a. The mold 2 is sealed in the capsule 1, and the lid 2b is removed from the bottom member 1a to open the sintered mold 2 from the capsule 1.

  Reference numeral 5 denotes a chamber. In this case, as shown in FIG. 5, an open / close door 5 a capable of storing and taking out the capsule 1 is disposed to form a sealed structure F.

  Reference numeral 6 denotes an inert gas replacement unit. In this case, as shown in FIG. 1, the inside of the chamber 5 is formed in a deoxygenated atmosphere by substituting an inert gas G such as argon gas. An inert gas introduction port 5b is formed on the outer wall of the gas flow channel, and the inert gas introduction port 5b is connected to an inert gas source 6b through a gas on-off valve 6a.

  Reference numeral 7 denotes an electric pressure sintering machine. In this case, as shown in FIG. 1, a pressurizing mechanism 7c is arranged in the chamber 5 and operates to pressurize the upper electrode 7a, the lower electrode 7b, and the upper electrode 7a up and down. A pulse power supply unit 7d for passing a pulse current between the upper electrode 7a and the lower electrode 7b, a control unit 7e, etc., and the pressure of the sintered material W filled in the sintering mold 2 by the punches 4 and 4 While being applied, a pulse current is passed to sinter the sintered material W by the self-heating effect and the Joule heating effect.

  Reference numeral 8 denotes a sintering type transfer mechanism. In this case, as shown in FIG. 1, the capsule 1 is disposed in the chamber 5 and opened in the chamber 5 in a deoxygenated atmosphere. The sintering mold 2 is configured to be transportable to the energizing pressure sintering machine 7.

  In this case, as the sintering type transfer mechanism unit 8, in this case, as shown in FIGS. 1, 6, 7, and 8, the capsule 1 can be placed and placed at the placement position S in the chamber 5. The member 9, the unsealing mechanism 10 for unsealing the capsule 1 placed on the placement member 9, and the sintering mold 2 in the opened capsule 1 are transferred to the sintering position B of the energizing pressure sintering machine 7. As shown in FIG. 4, the placing member 9 and the bottom member 1a of the capsule 1 are detachably provided by the attaching / detaching mechanism Q, and in addition, the above-described placing member 9 is placed on the above-described placing member 9 as shown in FIG. A retracting mechanism 12 for retracting from a position S to a retracting position T away from the sintering position B of the energizing pressure sintering machine 7 is provided. Then, the mounting member 9 is attached to the lifting shaft 9a and mounted by an artificial operation of the lifting shaft 9a. The member 9 is configured to be movable up and down from the mounting position S to the retracted position T. In the opening mechanism 10, in this case, the rotating shaft 10a is disposed on the upper outer wall of the chamber 5 by the sealing structure R, An engaging claw portion 10b is provided at the lower portion of the rotating shaft 10a, and an engaging / disengaging portion 1c that can be freely engaged with and disengaged from the engaging claw portion 10b is formed on the upper portion of the lid member 1b of the capsule 1, thereby artificially moving the rotating shaft 10a up and down. With the engaging claw portion 10b engaged with the engaging / disengaging portion 1c by operation, the rotary shaft 10a is rotated to remove the lid member 1b from the placement position S to the removal position H and lift it, thereby opening the capsule 1 In this case, the transfer mechanism 11 has a horizontal shaft 11a arranged on the side wall of the chamber 5 by a sealing structure R, and an inner end portion of the horizontal shaft 11a. A bifurcated transfer member 11b is provided on the horizontal axis 1 It is possible to transfer the sintering mold 2 on the mounting member 9 from the mounting position S to the sintering position B of the energizing pressure sintering machine 7 in a state where the sintering mold 2 on the mounting member 9 is mounted on the transfer member 11b by an artificial operation of a. doing.

  Reference numeral 13 denotes a vacuum pump. In this case, as shown in FIG. 1, a vacuum suction port 1d is formed on the outer wall of the chamber 5, and the vacuum pump 13 is connected to the vacuum suction port 1d so that the chamber 5 is evacuated. The introduction of the inert gas G is promoted.

  14 is a glove box. In this case, as shown in FIG. 3, a plurality of rubber gloves 15... Are provided, and the inside is made in a deoxygenated atmosphere by inert gas G substitution. The sintering material 2 is filled with the sintering material W with both hands, and the sintering die 2 is sealed in the capsule 1 in a deoxygenated atmosphere.

  Reference numeral 16 denotes a gas circulation purification device. In this case, as shown in FIG. 1, the oxygen concentration in the inert gas G in the chamber 5 is further reduced, or the moisture content is adjusted and returned to the chamber 5 to be inactive. The gas G is configured to circulate.

  Since this embodiment is configured as described above, the sintering mold 2 is hermetically housed in a capsule 1 in a deoxygenated atmosphere, and in this case, sintering is performed in a separately arranged glove box 14 as shown in FIG. The mold 2 is filled with the sintered material W and the sintered mold 2 filled with the sintered material W is sealed in the capsule 1, and the capsule 1 is sealed via the open / close door 5a as shown in FIG. It is housed in the chamber 5 of the structure F, and the inside of the chamber 5 is produced in a deoxygenated atmosphere by substituting the inert gas G in the inert gas replacement unit 6. The encapsulated capsule 1 is opened by the sintering mold transfer mechanism 8 as shown in FIGS. 1 to 6, and the sintering mold 2 in the capsule 1 is energized in the chamber 5 as shown in FIGS. It is transferred to the pressure sintering machine 7 and energized and pressurized as shown in FIG. The sintered material W filled in the sintering mold 2 by the binding machine 7 can be subjected to discharge plasma sintering in a deoxygenated atmosphere in the chamber 5, and the capsule 1 does not bring the sintered material W into contact with the atmosphere. It is possible to sinter, prevent oxidation due to oxygen, contamination by dust, moisture, etc., and to sinter, to obtain a sintered product of high purity and quality, and to open and close the capsule 1 The sintered mold 2 is accommodated in the mounting position S in the chamber 5 through 5a, and the sintering mold 2 is transferred to the sintering position B of the energizing pressure sintering machine 7 in the chamber 5 by the sintering mold transfer mechanism 8. The sintering mold 2 can be easily fed from the mounting position S to the sintering position B, and the sintering mold 2 can be housed in the chamber 5 by the capsule 1. The overall size can be reduced, and the installation space must be reduced. Can, it is possible to simplify the entire apparatus.

  In this case, as the sintering type transfer mechanism unit 8, in this case, as shown in FIGS. 1, 6, 7, and 8, the capsule 1 can be placed and placed at the placement position S in the chamber 5. The placing member 9, the unsealing mechanism 10 for unsealing the capsule 1 placed on the placing member 9, and the sintering mold 2 in the opened capsule 1 are placed at the sintering position B of the energizing pressure sintering machine 7. Since the transfer mechanism 11 is transportable, the bottom member 1a of the capsule 1 is placed and fixed to the placement member 9 by the attachment / detachment mechanism Q, and the lid member 1b of the capsule 1 is opened as shown in FIG. The engagement member 1c is engaged with the engaging claw portion 10b and the lid member 1b is lifted and opened while rotating the rotating shaft 10a, and the sintering die 2 is moved by the transfer member 11b of the transfer mechanism 11 as shown in FIG. Placed and transferred to the sintering position B of the energizing pressure sintering machine 7 by the pushing operation of the horizontal shaft 11a, As shown in FIG. 8, the capsule 1 can be sintered by the energization pressure sintering machine 7, can simplify the structure of the sintering type transfer mechanism 8, and is stored in the chamber 5 in a deoxygenated atmosphere. And the sintering mold 2 in the capsule 1 can be easily transferred to the sintering position B of the energizing pressure sintering machine 7 in the chamber 5, and in this case, as shown in FIG. Since the retracting mechanism 12 for retracting the mounting member 9 from the mounting position S to the retracted position T away from the sintering position B of the energizing pressure sintering machine 7 is provided, It is possible to prevent thermal damage to the mounting member 9 due to heat generated during the bonding, and in this case, as shown in FIG. 1, a vacuum pump 13 that promotes introduction of the inert gas G into the chamber 5 is provided. Therefore, the chamber 5 is evacuated by the vacuum pump 13. The can be performed in a short time the introduction of the inert gas G, it is possible to improve workability.

  In this case, as shown in FIG. 3, since the glove box 14 for sealing the sintering mold 2 in the capsule 1 in a deoxygenated atmosphere is provided, the sintering material W into the sintering mold 2 is provided. Filling and hermetically storing the sintered mold 2 in the capsule 1 can be easily performed. Since the glove box 14 has a structure independent of the chamber 5, the entire sintering apparatus can be reduced in size. The glove box 14 can be used for general purposes, and the versatility of using the glove box 14 can be improved. In this case, as shown in FIG. 1, the oxygen concentration in the inert gas G in the chamber 5 is set as follows. Since the gas circulation purification device 16 is further provided, the oxygen concentration in the inert gas G in the chamber 5 is further reduced as needed, or the amount of water is adjusted and returned to the chamber 5. Te can be circulated inert gas G, it is possible to obtain a high-purity and high-quality sintered molded article.

  The present invention is not limited to the embodiment described above, and the structure of the sintering mold 2, the energizing pressure sintering machine 7, the sintering mold transfer mechanism section 8 and the like are designed as appropriate. Yes, for example, in this case, the sintering type transfer mechanism 8 is configured to open and transfer the capsule 1 by manual operation from the outside of the chamber 5, but the lifting shaft 9a, the rotating shaft 10a and the horizontal The shaft 11a can be automatically controlled by various actuators such as an electric cylinder and a pneumatic cylinder, not artificially.

  As described above, the intended purpose can be sufficiently achieved.

W Sintered material F Sealed structure S Placement position B Sintering position T Retraction position G Inert gas 1 Capsule 2 Sintering mold 5 Chamber 5a Open / close door 6 Inert gas replacement part 7 Current pressure sintering machine 8 Sintering mold Transfer mechanism section 9 Placement member 10 Unsealing mechanism 11 Transfer mechanism 12 Retraction mechanism 13 Vacuum pump 14 Glove box 16 Gas circulation purification device

Claims (7)

  The sintered mold is hermetically housed in a deoxidized atmosphere in the capsule, the capsule is housed in a sealed chamber through an open / close door, and the inside of the chamber is prepared in a deoxygenated atmosphere by inert gas replacement. The capsule housed in the chamber under a deoxygenated atmosphere is opened, the sintering mold in the capsule is transferred to an electric pressure sintering machine in the chamber, and the sintering filled in the sintering mold A discharge plasma sintering method characterized in that a material is subjected to discharge plasma sintering (hereinafter also referred to as “SPS”) in a deoxygenated atmosphere in a chamber.   Capsule capable of hermetically storing the sintered mold in a deoxygenated atmosphere, a chamber having a closed structure having an opening / closing door capable of accommodating and taking out the capsule, and an inert gas produced in the deoxygenated atmosphere by replacing the inside of the chamber with an inert gas A replacement unit, an electric pressure sintering machine disposed in the chamber and performing discharge plasma sintering of the sintered material filled in the sintering mold, and disposed in the chamber under a deoxygenated atmosphere. And a sintering type transfer mechanism capable of opening the capsule housed in the chamber and transferring the sintering mold in the capsule to the energizing pressure sintering machine. Plasma sintering equipment.   As the sintering type transfer mechanism section, a placement member capable of placing and storing the capsule in a placement position in the chamber, an opening mechanism for opening the capsule placed on the placement member, 3. The discharge plasma sintering apparatus according to claim 2, further comprising a transfer mechanism capable of transferring the sintering mold in the opened capsule to a sintering position of the energizing pressure sintering machine.   4. The discharge plasma sintering apparatus according to claim 3, further comprising a retracting mechanism for retracting the mounting member from the mounting position to a retracting position away from the sintering position of the energization pressure sintering machine. .   The discharge plasma sintering apparatus according to any one of claims 2 to 4, further comprising a vacuum pump for promoting introduction of the inert gas into the chamber.   The discharge plasma sintering apparatus according to any one of claims 2 to 5, further comprising a glove box for sealing the sintering mold in the capsule in a deoxygenated atmosphere.   The discharge plasma sintering apparatus according to any one of claims 2 to 6, further comprising a gas circulation purification device that further reduces the oxygen concentration in the inert gas in the chamber.