JPH0841507A - Electric sintering device - Google Patents
Electric sintering deviceInfo
- Publication number
- JPH0841507A JPH0841507A JP3361397A JP36139791A JPH0841507A JP H0841507 A JPH0841507 A JP H0841507A JP 3361397 A JP3361397 A JP 3361397A JP 36139791 A JP36139791 A JP 36139791A JP H0841507 A JPH0841507 A JP H0841507A
- Authority
- JP
- Japan
- Prior art keywords
- sintering
- energization
- powders
- pressure
- powder
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000005245 sintering Methods 0.000 title claims abstract description 26
- 239000000843 powder Substances 0.000 claims abstract description 28
- 238000003825 pressing Methods 0.000 claims description 5
- 230000010355 oscillation Effects 0.000 claims description 4
- 238000009419 refurbishment Methods 0.000 claims 1
- 239000013078 crystal Substances 0.000 abstract description 7
- 238000005056 compaction Methods 0.000 abstract 2
- 230000002159 abnormal effect Effects 0.000 description 8
- 230000002123 temporal effect Effects 0.000 description 6
- 238000001514 detection method Methods 0.000 description 5
- 238000010438 heat treatment Methods 0.000 description 5
- 230000003247 decreasing effect Effects 0.000 description 3
- 230000036962 time dependent Effects 0.000 description 2
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 210000001787 dendrite Anatomy 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- QMQXDJATSGGYDR-UHFFFAOYSA-N methylidyneiron Chemical compound [C].[Fe] QMQXDJATSGGYDR-UHFFFAOYSA-N 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 230000036961 partial effect Effects 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F2998/00—Supplementary information concerning processes or compositions relating to powder metallurgy
Landscapes
- Powder Metallurgy (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、焼結粉末に加圧と通電
を同時に加えて焼結する通電焼結装置に関するものであ
る。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric current sintering apparatus for simultaneously applying pressure and electric current to a sintered powder for sintering.
【０００２】[0002]
【従来の技術】粉末焼結は加圧プレスと加圧焼成によっ
て金属、合金、化合物等を焼結するが、前記粉末加熱に
通電加熱、粉末間放電による加熱を利用する焼結におい
ては、加圧と通電を同時に加え、両者の制御によってよ
り有効なパワー供給することが必要である。従来の加圧
制御は、塑型内の粉末に所定の加圧を行い、粉末間放電
及びジュール熱を発生させて処理し加熱するが、この加
圧制御は処理による粉末収縮に伴わせて常に一定加圧が
行えるように追従プレスして焼結する。しかしながら、
この一定加圧制御で焼結するときは、部分的に異常加熱
を生ずることがあり、結晶の異常成長を起こし、全体に
均一組織の焼結体が得られない欠点があった。2. Description of the Related Art In powder sintering, metals, alloys, compounds, etc. are sintered by pressure pressing and pressure sintering. It is necessary to apply pressure and energization at the same time and supply more effective power by controlling both. In the conventional pressurization control, the powder in the plastic mold is subjected to a predetermined pressurization to generate inter-powder discharge and Joule heat to treat and heat, but this pressurization control is always accompanied by the powder shrinkage due to the treatment. Follow press to sinter so that constant pressure can be applied. However,
When sintering is performed under this constant pressure control, abnormal heating may partially occur, abnormal crystal growth may occur, and a sintered body having a uniform structure cannot be obtained.
【０００３】[0003]
【発明が解決しようとする課題】本発明は、前記従来の
定加圧制御による欠点を防止し、常に的質な結晶組織の
良質な焼結品が得られるよう加圧と通電を制御する焼結
方法を提供するものである。DISCLOSURE OF THE INVENTION The present invention prevents the disadvantages of the conventional constant pressurization control, and controls the pressurization and energization so as to obtain a good quality sintered product having a consistent crystal structure at all times. It provides a method of tying.
【０００４】[0004]
【課題を解決するための手段】焼結室内の粉末に加圧と
通電を同時に加えて焼結する装置に於いて、前記粉末間
の通電状態を信号として粉末間の通電々圧の時間的変化
が常に所定以下になるよう前記加圧と通電を制御する制
御装置を設けたことを特徴とする。In an apparatus for sintering by simultaneously applying pressure and energization to powder in a sintering chamber, a temporal change of energization pressure between powders is made by using an energization state between the powders as a signal. Is provided with a control device for controlling the pressurization and energization so that the pressure is always below a predetermined value.
【０００５】[0005]
【作用】前記のように本発明は、粉末間の通電状態を信
号として粉末間の通電々圧の時間的変化が常に所定以下
になるよう加圧と通電を制御する制御装置を設け、例え
ば電圧が急上昇するようなときは供給パワーの減少と加
圧力の増加を行って電圧の急上昇を迎え、部分的な温度
上昇を防止するよう制御したから、これにより結晶の異
常成長を防ぎ、均一組織の焼結体が得られるものであ
る。As described above, the present invention is provided with a control device for controlling pressurization and energization such that the temporal change of energization pressure between powders is always less than a predetermined value by using the energization state between powders as a signal. When the temperature rises sharply, the supply power is decreased and the pressure is increased to control the voltage sharply, and the temperature is controlled to prevent partial temperature rise. A sintered body is obtained.
【０００６】[0006]
【実施例】以下、図面の一実施例により本発明を説明す
る。第１図において、１は筒状の塑型で上下に加圧パン
チ兼通電々極２，３を嵌挿して焼結室を形成する。４は
この焼結室に充填した焼結粉末、前記の上側加圧パンチ
２は加圧シリンダ５に連通して加圧力が作用し、下側加
圧パンチ３は基台６に固定されている。７は焼結電源
で、インバーター回路が用いられる。７１はインバータ
ートラッスで、高周波トランスが用いられ、このトラン
ス出力を整流器７２によって整流した直流を前記上下の
パンチ２，３間に通電する。７３は電源整流器で３相交
流を整流して直流電源を出力し、これを１００ＫＨｚ、
３ＭＨｚの高速スイッチングするＦＥＴスイッチ７４で
高周波パルスを発生しトランス７１に供給する。８は前
記スイッチ７４に高周波制御パルスを供給する発振制御
装置で、整流器７２の出力電圧を検出回路９１と出力電
流の検出回路９２とから入力する信号によって制御信号
を発生し、前記スイッチ７４と加圧シリンダ５を制御す
る。DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to an embodiment of the drawings. In FIG. 1, reference numeral 1 is a cylindrical plastic type in which a pressurizing punch / current-carrying electrodes 2 and 3 are vertically inserted to form a sintering chamber. Reference numeral 4 denotes a sintered powder filled in the sintering chamber, the upper pressure punch 2 is communicated with a pressure cylinder 5 to apply a pressure, and the lower pressure punch 3 is fixed to a base 6. . 7 is a sintering power source, and an inverter circuit is used. Reference numeral 71 denotes an inverter tray, which uses a high frequency transformer, and a direct current obtained by rectifying the output of the transformer by a rectifier 72 is passed between the upper and lower punches 2 and 3. A power rectifier 73 rectifies the three-phase alternating current and outputs a direct current power, which is 100 KHz,
A high-frequency pulse is generated by the FET switch 74 that performs high-speed switching at 3 MHz and is supplied to the transformer 71. Reference numeral 8 denotes an oscillation control device for supplying a high frequency control pulse to the switch 74. The oscillation control device 8 generates a control signal by a signal input from the detection circuit 91 and the output current detection circuit 92 to the output voltage of the rectifier 72, and outputs a control signal to the switch 74. The pressure cylinder 5 is controlled.
【０００７】通電焼結は、塑型１内に充填された粉末４
に対し、上下パンチ２，３によって加圧を行い、同時に
インバーター電源７によって通電を行って焼結するが、
塑型１内粉末４間の通電状態は電圧、電流を各々検出回
路９１，９２で検出することにより監視状態にあり、検
出信号のフィードバックにより制御装置８はスイッチ７
４に加えるパルス周波数を制御し、インバーター７から
の供給パワーを制御すると共に、シリンダ５の制御によ
って加圧力の制御をする。これにより粉末間の通電々圧
の時間的変化が常に所定値以下になるよう加圧と通電の
制御が行われる。例えば、粉末４間の通電々圧の上昇が
急で、その時間的変化が所定以下に増大するようなとき
は、制御装置８は制御パルスの発振周波数を下げてスイ
ッチ７４のスイッチング速度を低下させることによって
インバーター７から供給パワーを低減させる。このパワ
ー制御の応答速度はインバーター回路７により極めて高
応答で制御することができる[0007] The electro-sintering is performed by filling the powder 4 filled in the plastic mold 1.
On the other hand, the upper and lower punches 2 and 3 apply pressure, and at the same time, the inverter power supply 7 energizes to sinter,
The energization state between the powders 4 in the plastic mold 1 is in the monitoring state by detecting the voltage and the current by the detection circuits 91 and 92, respectively, and the control device 8 causes the switch 7 to switch by the feedback of the detection signal.
The pulse frequency applied to No. 4 is controlled, the power supplied from the inverter 7 is controlled, and the pressing force is controlled by controlling the cylinder 5. As a result, the pressurization and the energization are controlled so that the temporal change of the energization pressure between the powders is always below a predetermined value. For example, when the energization pressure between the powders 4 suddenly rises and its temporal change increases below a predetermined level, the control device 8 lowers the oscillation frequency of the control pulse to lower the switching speed of the switch 74. As a result, the power supplied from the inverter 7 is reduced. The response speed of this power control can be controlled with an extremely high response by the inverter circuit 7.
【０００８】又、これと共に制御装置８はシリンダ５の
制御より加圧力を増大するよう制御する。この通電と加
圧の制御によって電圧上昇が迎えられ、通電々圧の時間
的変化が常に所定値以内にあるよう制御することができ
る。この制御によって電圧の上昇が停止もしくは低下す
るようなときは、前とは逆にインバーター７からの供給
パワーを高め加圧を低下させるよう制御する。以上の通
電々圧の時間的変化が常に所定以下になる制御により、
焼結室内における充填粉末４は部分的に異常加熱を発生
することなく安定した熱処理が行われるようになり、焼
結粉末４全体が均一に加熱処理され、均一組織で焼結さ
れることになる。例えばｄＶ／ｄｔ値が従来１０４程度
変化していたものを１０〜１０１．５程度以下に制御す
る。この焼結制御によれば、特に異常結晶を生じ易いと
された炭素鉄においても、従来方式では、デンドライト
組織の部分と微細結晶との比が６％であったものが、前
記電圧の時間的変化が常に所定以内にあるよう制御した
ときは、それが約０．１％以下と均一焼結をすることが
できた。又、焼結電源に前記のような周波数が１００Ｋ
Ｈｚ〜３ＭＨｚという高周波スイッチＦＥＴによるイン
バーター電源を用いることによって、通電制御の応答は
極めて高くスイッチング速度で応答することができ、焼
結中粉末の異常加熱を防止することができる。At the same time, the control device 8 controls the cylinder 5 so as to increase the pressurizing force. By controlling the energization and pressurization, the voltage rises, and it is possible to control so that the temporal change of the energization pressure is always within a predetermined value. When the increase of the voltage is stopped or decreased by this control, the supply power from the inverter 7 is increased and the pressurization is decreased contrary to the above. By the control in which the time-dependent change of the energizing pressure is always less than a predetermined value,
The filling powder 4 in the sintering chamber is subjected to stable heat treatment without causing abnormal heating partially, and the entire sintering powder 4 is uniformly heated and sintered with a uniform structure. . For example, the dV / dt value which has conventionally changed by about 10 4 is controlled to about 10 to 10 1.5 or less. According to this sintering control, even in carbon iron which is said to be prone to abnormal crystals, in the conventional method, the ratio of the dendrite structure portion to the fine crystals was 6%, but the time dependence of the voltage was When the change was controlled so that it was always within a predetermined range, it was possible to achieve uniform sintering with a value of about 0.1% or less. In addition, the sintering power source has the above frequency of 100K.
By using the inverter power source with the high frequency switch FET of Hz to 3 MHz, the response of the energization control can be extremely high and the response can be made at the switching speed, and the abnormal heating of the powder during sintering can be prevented.
【０００９】[0009]
【発明の効果】以上のように本発明は、粉末間の通電状
態を信号として粉末間の通電々圧の時間的変化が常に所
定以下になるよう加圧と通電を制御する制御装置を設
け、焼結中の通電々圧の時間的変化が常に所定以下にな
るよう制御して焼結したから、部分的に異常加熱を発生
することがなく、したがって結晶の異常成長、異常結晶
を生ずることなく、均一組織の良質の焼結体が容易に得
られる効果を奏する。As described above, the present invention is provided with the control device for controlling the pressurization and the energization so that the temporal change of the energization pressure between the powders is always less than the predetermined value by using the energization state between the powders as a signal, Sintering was controlled so that the time-dependent change of energizing pressure during sintering was always below a predetermined level, so abnormal heating did not occur partially, and therefore abnormal crystal growth and abnormal crystals did not occur. The effect is that a good quality sintered body having a uniform structure can be easily obtained.
【００１０】[0010]
【図１】本発明の一実施例構成図である。FIG. 1 is a configuration diagram of an embodiment of the present invention.
１ 塑型 ２，３ 加圧パンチ ４ 粉末 ５ シリンダ ６ 基台 ７ インバーター電源 ８ 制御装置 ９１，９２ 電圧電流検出回路 1 Plastic type 2,3 Pressure punch 4 Powder 5 Cylinder 6 Base 7 Inverter power supply 8 Controller 91,92 Voltage / current detection circuit
Claims (2)
同時に加えて焼結する通電焼結装置に於いて、前記粉末
間の通電状態を信号として粉末間の通電々圧の時間的変
化が常に所定以下になるよう前記加圧と通電を制御する
制御装置を設けたことを特徴とする通電焼結装置。1. An electric current sintering apparatus for simultaneously applying pressure and electric current to a powder filled in a sintering chamber to sinter the powder, and the electric current between the powders is used as a signal to temporally change the electric current between the powders. An energization sintering apparatus comprising a control device for controlling the pressurization and energization so that the change is always less than a predetermined value.
け、発振周波を制御するようにしたことを特徴とする特
許請求の範囲第１項に記載の通電焼結装直。2. The energization sintering refurbishment according to claim 1, wherein the sintering power source is provided with an inverter power source to control an oscillation frequency.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3361397A JPH0841507A (en) | 1991-12-26 | 1991-12-26 | Electric sintering device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3361397A JPH0841507A (en) | 1991-12-26 | 1991-12-26 | Electric sintering device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0841507A true JPH0841507A (en) | 1996-02-13 |
Family
ID=18473413
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3361397A Pending JPH0841507A (en) | 1991-12-26 | 1991-12-26 | Electric sintering device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0841507A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1999019101A1 (en) * | 1997-10-15 | 1999-04-22 | Iap Research, Inc. | System and method for consolidating powders |
| CN100368125C (en) * | 2005-08-10 | 2008-02-13 | 东北大学 | Metal Matrix Composite Material Direct Current Heating Dynamic Sintering Hot Press Preparation Method and Device |
| CN112872360A (en) * | 2021-01-13 | 2021-06-01 | 太原理工大学 | Mixed forming method of iron-based wear-resistant material |
-
1991
- 1991-12-26 JP JP3361397A patent/JPH0841507A/en active Pending
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1999019101A1 (en) * | 1997-10-15 | 1999-04-22 | Iap Research, Inc. | System and method for consolidating powders |
| US6612826B1 (en) | 1997-10-15 | 2003-09-02 | Iap Research, Inc. | System for consolidating powders |
| US7361301B2 (en) | 1997-10-15 | 2008-04-22 | Iap Research, Inc. | System and method for consolidating powders |
| CN100368125C (en) * | 2005-08-10 | 2008-02-13 | 东北大学 | Metal Matrix Composite Material Direct Current Heating Dynamic Sintering Hot Press Preparation Method and Device |
| CN112872360A (en) * | 2021-01-13 | 2021-06-01 | 太原理工大学 | Mixed forming method of iron-based wear-resistant material |
| CN112872360B (en) * | 2021-01-13 | 2024-01-02 | 山西盛世永恒工程咨询有限公司 | Mixed forming method of iron-based wear-resistant material |
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