JPS5964702A - High-frequency sintering method of compressed body of metal powder - Google Patents
High-frequency sintering method of compressed body of metal powderInfo
- Publication number
- JPS5964702A JPS5964702A JP17142482A JP17142482A JPS5964702A JP S5964702 A JPS5964702 A JP S5964702A JP 17142482 A JP17142482 A JP 17142482A JP 17142482 A JP17142482 A JP 17142482A JP S5964702 A JPS5964702 A JP S5964702A
- Authority
- JP
- Japan
- Prior art keywords
- heating
- graphite
- compact
- sintering
- powdery body
- 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
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
- B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
- B22F3/10—Sintering only
Landscapes
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Mechanical Engineering (AREA)
- Powder Metallurgy (AREA)
Abstract
Description
【発明の詳細な説明】
この発明は金属粉末の圧粉体における高周波焼結方法に
関するものである◎
従来、金属粉末の圧粉体の焼結方法としては電気炉加熱
がある@
然し、電気炉加熱の場合、一度に多量の圧粉体を焼結で
きる長所はあるものの、焼結温度までの昇温や焼結保持
時間等の面で時間がかかるので、機械加工工程との同期
化が難しく効率的な生産が行なえないという問題があっ
た。[Detailed Description of the Invention] This invention relates to a method for high-frequency sintering of a green compact of metal powder.◎ Conventionally, electric furnace heating has been used as a method for sintering a green compact of metal powder. In the case of heating, although it has the advantage of being able to sinter a large amount of compacted powder at once, it takes time to raise the temperature to the sintering temperature and the sintering holding time, making it difficult to synchronize with the machining process. There was a problem that efficient production could not be carried out.
そこで、このような問題を解決するものとして高周波誘
導加熱があるが、この場合には電気炉加熱よりも短時間
で焼結が行なえるので金属粉末の焼結には適している。Therefore, high-frequency induction heating is available as a solution to such problems, but in this case, sintering can be performed in a shorter time than electric furnace heating, so it is suitable for sintering metal powder.
然し、この方法では第(3)図の従来例に示すように室
温から200度位までの加熱に全加熱時間の40%程度
を要してお沙、この加熱時間の短縮が要望されていた。However, with this method, as shown in the conventional example in Figure (3), it takes about 40% of the total heating time to heat from room temperature to about 200 degrees, and there has been a desire to shorten this heating time. .
即ち、・加熱コイル1より発っせられる高周波電流の圧
粉体2に対する浸透深さPは材料の透磁率μ、比抵抗ρ
(μΩ・α)、周波数f (Hz)より求められ、とれ
は次式で表わされる。That is, the penetration depth P of the high frequency current emitted from the heating coil 1 into the green compact 2 is determined by the magnetic permeability μ and specific resistance ρ of the material.
(μΩ·α) and the frequency f (Hz), and the deviation is expressed by the following formula.
通常、圧粉体2の比抵抗は鋼に比べて非常に大 □
きいので高周波電流の浸透深ざPは深くなる。つまりこ
れは単位体積あたりのパ戒力密度が低くなることを示し
ておシ、従って圧粉体の抵抗が大きい :ときには
温度丑昇率は当然小さくなると考えられ □る0
ところが、圧粉体の抵抗は第1図に示すように脱ロ一温
度が600度位までは温度の上昇とともに減少し、室温
から200度位までは特に減少が太きい。Normally, the specific resistance of the powder compact 2 is much higher than that of steel □
Since the current is small, the penetration depth P of the high-frequency current becomes deep. In other words, this indicates that the pressure force density per unit volume becomes low, and therefore the resistance of the compact is large.In some cases, the rate of temperature increase is naturally considered to be small. As shown in FIG. 1, the resistance decreases as the temperature increases until the de-rotation temperature reaches about 600 degrees, and the decrease is particularly large from room temperature to about 200 degrees.
このようなことから第(3)図に示すように圧粉体2の
温既丑昇率は200°C位までは低くそれ以後は急激に
土昇するものと考えられる。For this reason, as shown in Figure (3), it is considered that the temperature rise rate of the compact 2 is low until about 200°C and then rises rapidly.
従って、以上のようなことから圧粉体2の焼結時間を短
Aidするためには電気炉による脱ロ一工程を設けて圧
6J体の抵抗t1を予め低くしておくか200度程匿ま
での昇゛温を補助する手段を設ければよいことがわかる
が、M者の場合脱ロ一工程を7.1新たに設けなければ
ならないといつ欠点があり、後者の場合には適当な補助
手段がないという欠点があった・
そこで、本発明では、伺ら特別な工程を設けることなく
簡11iなる手段の付設によって圧粉体の焼結時間を短
縮することができる金属粉末の圧粉体における高周波焼
結方法の提供を目的とするもの本発明ではと記目的を達
成するために、焼結される圧粉体の内側又は外側に加熱
促進材を設けるを
とともに、この加熱促進材と圧粉体ど高周波によって同
時に加熱して加熱促進材かりの熱伝導及び輻射加熱によ
り圧粉体の加熱を促進することを特徴とするものである
。Therefore, from the above, in order to shorten the sintering time of the compact 2, it is necessary to provide a de-rolling process using an electric furnace and lower the resistance t1 of the compact 6J compact in advance, or to heat it by about 200 degrees. It can be seen that it is sufficient to provide a means to assist in raising the temperature to There was a drawback that there was no auxiliary means. Therefore, in the present invention, we have developed a compacted metal powder that can shorten the sintering time of the compacted powder by adding a simple means without requiring any special process. The purpose of the present invention is to provide a method for high-frequency sintering in a powder body.In order to achieve the above objects, a heating accelerating material is provided inside or outside of a green compact to be sintered, and the heating accelerating material and This method is characterized in that the powder compact is simultaneously heated by high frequency waves, and the heating of the compact is promoted by heat conduction using a heating accelerator and radiant heating.
以下、本発明を具体化した一実施例を図面により詳細に
説明する。Hereinafter, one embodiment embodying the present invention will be described in detail with reference to the drawings.
まず、嶋周波焼結装置4の全体の構成を示す第(2)図
において、5は円柱状に形成された炉体を示しており、
これの側周面とには加熱コイμmがその全周にわたって
設けられている。First, in FIG. (2) showing the overall configuration of the Shima Shuha sintering device 4, 5 indicates a cylindrical furnace body,
A heating coil μm is provided on the side peripheral surface of this over the entire circumference.
2は炉体5の内部に設置嘔れだ、金属粉を圧縮成形した
圧粉体で、本実施例では円筒状に形成されたものを示し
ている。Reference numeral 2 denotes a powder compact formed by compression molding metal powder, which is installed inside the furnace body 5, and is shown in this embodiment as having a cylindrical shape.
6は本発明の挟部となる力11熱促進部材である。Reference numeral 6 denotes a heat accelerating member 11 which serves as the sandwiching portion of the present invention.
この加熱促進部材6は本例で′は軸心部に設けられた円
柱状■グラファイト6と、これを密閉すべく設けられた
中空円柱状の保護部材7とから構成されている。保護部
材7はセラミックにて形成されており、これとグラファ
イト6との間は真空か又はN2ガスが封入された状態等
にされている。なお、前記グラファイト6は保護部材7
によシ密閉しておかなければ使用により消耗するが、こ
れを消耗品として必要に応じて交換するのであれば保護
部材7はなくてもよい。In this example, the heating promotion member 6 is composed of a cylindrical graphite 6 provided at its axial center, and a hollow cylindrical protection member 7 provided to seal it. The protection member 7 is made of ceramic, and the space between it and the graphite 6 is kept in a vacuum state or filled with N2 gas. Note that the graphite 6 is a protective member 7.
If it is not kept tightly sealed, it will wear out with use, but if it is a consumable item and will be replaced as needed, the protective member 7 may be omitted.
8は炉体5の下部に設けられた、酸化防止用の尊囲気ガ
ス(RXガス、AXガス等)を取り入れるための導入孔
、9は炉体5の北部に設けられた酸化防止用のガスを排
出するための排出孔である。Reference numeral 8 denotes an inlet hole provided in the lower part of the furnace body 5 to take in ambient air gas (RX gas, AX gas, etc.) for preventing oxidation, and 9 refers to a gas for preventing oxidation provided in the northern part of the furnace body 5. This is a discharge hole for discharging water.
以上のような構成において、加熱コイμmよυ高周波(
@束)を発生させると圧粉体2が加熱されると同時にグ
ラファイト6も力ロ熱される。In the above configuration, the heating coil μm to υ high frequency (
When the powder (bundle) is generated, the green compact 2 is heated and at the same time, the graphite 6 is also heated.
ところで、グラファイト6の抵抗値は圧粉体2よシもは
るかに小さく、一方圧粉体には第(3)図に示すように
加熱当初は特に抵抗が大きいのでグラファイト6(D温
度上昇率は圧粉体2よりも大きくなる。このため、グラ
ファイト6は圧粉体2よシもはるかに温度が高くなるの
で圧粉体には加熱コイA71によって加熱されると同時
にグラファイト6からの輻射熱及び熱伝導によって加熱
が助長される。By the way, the resistance value of graphite 6 is much smaller than that of powder compact 2. On the other hand, as shown in Figure (3), the resistance of graphite 6 is particularly large at the beginning of heating, so graphite 6 (D temperature increase rate is The graphite 6 becomes larger than the compact 2. Therefore, the temperature of the graphite 6 becomes much higher than that of the compact 2, so the compact is heated by the heating coil A71 and at the same time receives radiant heat and heat from the graphite 6. Heating is aided by conduction.
これを密度6.5g/cm重さ50gの圧粉体を用いて
周波数10KHz、電力15i(w及び201/幅の割
付でN2ガスを供給した状態において1200度の焼結
温度に達っするまでの時間と温度の関係を従来と比較し
た結果は第(3)図に示すようになった。即ちこの比較
結果よシ焼結時間が約65%短縮てれることが確認でき
た。This was carried out using a powder compact with a density of 6.5 g/cm and a weight of 50 g at a frequency of 10 KHz and a power of 15 i (w and a width of 201/width) while supplying N2 gas until a sintering temperature of 1200 degrees was reached. The results of comparing the relationship between time and temperature with that of the conventional method are shown in Figure (3).In other words, it was confirmed from this comparison result that the sintering time was reduced by about 65%.
このように本実施例では圧粉体2の内[1!Iにグラフ
1イト6を設けることによって加熱コイμmからの高周
波による加熱と加熱促進材6からの熱伝導及び輻射熱に
よる加熱との相乗効果により、よシ一層加熱が促進され
るので、圧粉体の焼結温度までの昇温時間を短縮できる
わけである。とくに、本実施例ではグラフフィト6は加
熱コイ/I/1の内側に設けられているのでこのグラフ
ァイト6の加熱には圧粉体2の刀0熱にオリ川石れない
漏減磁束を利用することができる。このため、エネルギ
ーの効率的な利用ができるのでより一層効果的な加熱を
行うことができる。In this way, in this embodiment, [1! By providing the graphite 6 on I, heating is further promoted due to the synergistic effect of heating by high frequency from the heating coil μm and heating by heat conduction and radiant heat from the heating accelerator 6. This means that the time required to raise the temperature to the sintering temperature can be shortened. In particular, in this embodiment, since the graphite 6 is provided inside the heating coil/I/1, the leakage and demagnetization flux that is not generated by the heat of the powder compact 2 is used to heat the graphite 6. be able to. Therefore, energy can be used efficiently and heating can be performed even more effectively.
即ち本発明では特許請求の範囲に記載された方法により
きわめて簡単なる手段の付設によって圧粉体の焼結時間
を従来よりもより一層短縮することができるという優れ
た特徴がちる。That is, the present invention has an excellent feature in that the sintering time of the green compact can be further shortened compared to the conventional method by adding extremely simple means by the method described in the claims.
図面は本発明の一実施例を示すもので、第1図は圧粉体
の予備焼結温度に対する比抵抗の変化を示すグラフ、第
2図は本発明の一実施例を示す断面図、第6図は従来例
と本爽施例の焼結温度までの加熱時間と温度の関係を示
すグラフである。
2・・・圧粉体 6・・・加熱促進材4・
・・高周波焼結装置
出 願 人 トヨタ自動車株式会社
代理人 弁理士岡田英彦The drawings show an embodiment of the present invention; FIG. 1 is a graph showing changes in specific resistance of a green compact with respect to preliminary sintering temperature; FIG. 2 is a sectional view showing an embodiment of the present invention; FIG. 6 is a graph showing the relationship between heating time to sintering temperature and temperature for the conventional example and the present example. 2... Green compact 6... Heating accelerator 4.
...Induction sintering device applicant Hidehiko Okada, Toyota Motor Corporation agent and patent attorney
Claims (1)
するに際し、圧粉体の内側又は外側に加熱促進材を設け
るとともに、この加熱促進材と圧粉体とを高周波によっ
て同時に加熱して加熱促進材からの熱伝導及び輻射加熱
によシ圧粉体の加熱を促進することを特徴とする金属粉
末の圧粉体における高周波焼結方法。1 When sintering a compact of metal powder by high-frequency induction heating, a heating accelerator is provided inside or outside the compact, and the heating accelerator and the compact are simultaneously heated by high frequency to accelerate the heating. A method for high-frequency sintering of a metal powder green compact, characterized by promoting heating of the green compact by heat conduction from the material and radiant heating.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP17142482A JPS5964702A (en) | 1982-09-30 | 1982-09-30 | High-frequency sintering method of compressed body of metal powder |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP17142482A JPS5964702A (en) | 1982-09-30 | 1982-09-30 | High-frequency sintering method of compressed body of metal powder |
Publications (1)
Publication Number | Publication Date |
---|---|
JPS5964702A true JPS5964702A (en) | 1984-04-12 |
Family
ID=15922871
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP17142482A Pending JPS5964702A (en) | 1982-09-30 | 1982-09-30 | High-frequency sintering method of compressed body of metal powder |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS5964702A (en) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2003013112A (en) * | 2001-04-26 | 2003-01-15 | Daido Steel Co Ltd | Apparatus for manufacturing complex metallic member |
CN108883470A (en) * | 2016-04-01 | 2018-11-23 | 株式会社Lg化学 | The method for manufacturing metal foam |
CN111375758A (en) * | 2020-04-23 | 2020-07-07 | 王伟东 | Sintering method of titanium or titanium alloy powder |
CN111495348A (en) * | 2020-04-23 | 2020-08-07 | 王伟东 | Preparation method of porous photocatalyst filter screen |
WO2020217331A1 (en) * | 2019-04-24 | 2020-10-29 | 住友電工焼結合金株式会社 | Manufacturing system and manufacturing method for sintered compact |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS49130537A (en) * | 1973-04-21 | 1974-12-13 | ||
JPS58224291A (en) * | 1982-06-21 | 1983-12-26 | ティーディーケイ株式会社 | Baking method and baking device |
-
1982
- 1982-09-30 JP JP17142482A patent/JPS5964702A/en active Pending
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS49130537A (en) * | 1973-04-21 | 1974-12-13 | ||
JPS58224291A (en) * | 1982-06-21 | 1983-12-26 | ティーディーケイ株式会社 | Baking method and baking device |
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2003013112A (en) * | 2001-04-26 | 2003-01-15 | Daido Steel Co Ltd | Apparatus for manufacturing complex metallic member |
CN108883470A (en) * | 2016-04-01 | 2018-11-23 | 株式会社Lg化学 | The method for manufacturing metal foam |
JP2019510883A (en) * | 2016-04-01 | 2019-04-18 | エルジー・ケム・リミテッド | Method of manufacturing metal foam |
US11298745B2 (en) | 2016-04-01 | 2022-04-12 | Lg Chem, Ltd. | Method for manufacturing metal foam |
WO2020217331A1 (en) * | 2019-04-24 | 2020-10-29 | 住友電工焼結合金株式会社 | Manufacturing system and manufacturing method for sintered compact |
JPWO2020217331A1 (en) * | 2019-04-24 | 2021-12-23 | 住友電工焼結合金株式会社 | Sintered body manufacturing system and manufacturing method |
CN111375758A (en) * | 2020-04-23 | 2020-07-07 | 王伟东 | Sintering method of titanium or titanium alloy powder |
CN111495348A (en) * | 2020-04-23 | 2020-08-07 | 王伟东 | Preparation method of porous photocatalyst filter screen |
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