JPH03290374A - Production of sintered article - Google Patents
Production of sintered articleInfo
- Publication number
- JPH03290374A JPH03290374A JP2087560A JP8756090A JPH03290374A JP H03290374 A JPH03290374 A JP H03290374A JP 2087560 A JP2087560 A JP 2087560A JP 8756090 A JP8756090 A JP 8756090A JP H03290374 A JPH03290374 A JP H03290374A
- Authority
- JP
- Japan
- Prior art keywords
- binder
- degreasing
- weight
- vacuum
- sintering
- 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
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 10
- 238000005238 degreasing Methods 0.000 claims abstract description 57
- 239000011230 binding agent Substances 0.000 claims abstract description 52
- 238000002347 injection Methods 0.000 claims abstract description 23
- 239000007924 injection Substances 0.000 claims abstract description 23
- 239000012298 atmosphere Substances 0.000 claims abstract description 18
- 238000010438 heat treatment Methods 0.000 claims abstract description 16
- FLKPEMZONWLCSK-UHFFFAOYSA-N diethyl phthalate Chemical compound CCOC(=O)C1=CC=CC=C1C(=O)OCC FLKPEMZONWLCSK-UHFFFAOYSA-N 0.000 claims abstract description 14
- 239000005038 ethylene vinyl acetate Substances 0.000 claims abstract description 13
- 229920001200 poly(ethylene-vinyl acetate) Polymers 0.000 claims abstract description 13
- 238000005245 sintering Methods 0.000 claims abstract description 13
- 229920006244 ethylene-ethyl acrylate Polymers 0.000 claims abstract description 11
- 239000000203 mixture Substances 0.000 claims abstract description 10
- 239000004793 Polystyrene Substances 0.000 claims abstract description 9
- 239000000919 ceramic Substances 0.000 claims abstract description 9
- 239000002184 metal Substances 0.000 claims abstract description 9
- 229910052751 metal Inorganic materials 0.000 claims abstract description 9
- 239000004203 carnauba wax Substances 0.000 claims abstract description 8
- 235000013869 carnauba wax Nutrition 0.000 claims abstract description 8
- 239000000314 lubricant Substances 0.000 claims abstract description 8
- 239000004014 plasticizer Substances 0.000 claims abstract description 8
- 239000012188 paraffin wax Substances 0.000 claims abstract description 7
- MQIUGAXCHLFZKX-UHFFFAOYSA-N Di-n-octyl phthalate Natural products CCCCCCCCOC(=O)C1=CC=CC=C1C(=O)OCCCCCCCC MQIUGAXCHLFZKX-UHFFFAOYSA-N 0.000 claims abstract description 6
- BJQHLKABXJIVAM-UHFFFAOYSA-N bis(2-ethylhexyl) phthalate Chemical compound CCCCC(CC)COC(=O)C1=CC=CC=C1C(=O)OCC(CC)CCCC BJQHLKABXJIVAM-UHFFFAOYSA-N 0.000 claims abstract description 6
- WRIDQFICGBMAFQ-UHFFFAOYSA-N (E)-8-Octadecenoic acid Natural products CCCCCCCCCC=CCCCCCCC(O)=O WRIDQFICGBMAFQ-UHFFFAOYSA-N 0.000 claims abstract description 4
- LQJBNNIYVWPHFW-UHFFFAOYSA-N 20:1omega9c fatty acid Natural products CCCCCCCCCCC=CCCCCCCCC(O)=O LQJBNNIYVWPHFW-UHFFFAOYSA-N 0.000 claims abstract description 4
- QSBYPNXLFMSGKH-UHFFFAOYSA-N 9-Heptadecensaeure Natural products CCCCCCCC=CCCCCCCCC(O)=O QSBYPNXLFMSGKH-UHFFFAOYSA-N 0.000 claims abstract description 4
- 239000005642 Oleic acid Substances 0.000 claims abstract description 4
- ZQPPMHVWECSIRJ-UHFFFAOYSA-N Oleic acid Natural products CCCCCCCCC=CCCCCCCCC(O)=O ZQPPMHVWECSIRJ-UHFFFAOYSA-N 0.000 claims abstract description 4
- 235000021355 Stearic acid Nutrition 0.000 claims abstract description 4
- QXJSBBXBKPUZAA-UHFFFAOYSA-N isooleic acid Natural products CCCCCCCC=CCCCCCCCCC(O)=O QXJSBBXBKPUZAA-UHFFFAOYSA-N 0.000 claims abstract description 4
- QIQXTHQIDYTFRH-UHFFFAOYSA-N octadecanoic acid Chemical compound CCCCCCCCCCCCCCCCCC(O)=O QIQXTHQIDYTFRH-UHFFFAOYSA-N 0.000 claims abstract description 4
- OQCDKBAXFALNLD-UHFFFAOYSA-N octadecanoic acid Natural products CCCCCCCC(C)CCCCCCCCC(O)=O OQCDKBAXFALNLD-UHFFFAOYSA-N 0.000 claims abstract description 4
- ZQPPMHVWECSIRJ-KTKRTIGZSA-N oleic acid Chemical compound CCCCCCCC\C=C/CCCCCCCC(O)=O ZQPPMHVWECSIRJ-KTKRTIGZSA-N 0.000 claims abstract description 4
- 239000008117 stearic acid Substances 0.000 claims abstract description 4
- 239000000843 powder Substances 0.000 claims description 25
- 239000004698 Polyethylene Substances 0.000 claims description 10
- 239000004743 Polypropylene Substances 0.000 claims description 10
- 229920000573 polyethylene Polymers 0.000 claims description 10
- -1 polypropylene Polymers 0.000 claims description 10
- DOIRQSBPFJWKBE-UHFFFAOYSA-N dibutyl phthalate Chemical compound CCCCOC(=O)C1=CC=CC=C1C(=O)OCCCC DOIRQSBPFJWKBE-UHFFFAOYSA-N 0.000 claims description 9
- 238000001746 injection moulding Methods 0.000 claims description 9
- 239000005042 ethylene-ethyl acrylate Substances 0.000 claims description 7
- 229920001155 polypropylene Polymers 0.000 claims description 7
- 238000002156 mixing Methods 0.000 claims description 4
- 238000000034 method Methods 0.000 abstract description 33
- 238000005336 cracking Methods 0.000 abstract description 7
- 229920002223 polystyrene Polymers 0.000 abstract description 6
- 239000000463 material Substances 0.000 abstract 2
- 230000000694 effects Effects 0.000 description 16
- 239000007789 gas Substances 0.000 description 10
- 239000013078 crystal Substances 0.000 description 8
- 238000000465 moulding Methods 0.000 description 7
- 229920005992 thermoplastic resin Polymers 0.000 description 5
- 238000002844 melting Methods 0.000 description 4
- 230000008018 melting Effects 0.000 description 4
- 239000002994 raw material Substances 0.000 description 4
- 239000001993 wax Substances 0.000 description 4
- 229920005989 resin Polymers 0.000 description 3
- 239000011347 resin Substances 0.000 description 3
- 238000005979 thermal decomposition reaction Methods 0.000 description 3
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 description 2
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 230000000052 comparative effect Effects 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- 230000002950 deficient Effects 0.000 description 2
- 239000011261 inert gas Substances 0.000 description 2
- 239000012778 molding material Substances 0.000 description 2
- 239000012299 nitrogen atmosphere Substances 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 229910001030 Iron–nickel alloy Inorganic materials 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 238000004898 kneading Methods 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 229910001004 magnetic alloy Inorganic materials 0.000 description 1
- 230000014759 maintenance of location Effects 0.000 description 1
- 239000006082 mold release agent Substances 0.000 description 1
- 239000010802 sludge Substances 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 230000008961 swelling Effects 0.000 description 1
- 239000011800 void material Substances 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Abstract
Description
【発明の詳細な説明】
［産業上の利用分野］
本発明は金属またはセラミックス粉末と熱可塑性樹脂及
びワックスを主成分とするバインダーを混合して射出成
形法を利用して三次元的に複雑形状で高精度の焼結品を
量産的に製造する方法に関するものである。Detailed Description of the Invention [Industrial Application Field] The present invention involves mixing metal or ceramic powder with a binder mainly composed of thermoplastic resin and wax, and molding the mixture into a three-dimensionally complex shape using an injection molding method. The present invention relates to a method for mass-producing high-precision sintered products.
［従来の技術］
一般に、射出成形を利用し、脱脂及び焼結工程を経て金
属またはセラミックスの焼結品を製造する方法において
、脱脂工程は常圧あるいは加圧した大気中または不活性
ガス雰囲気中で行われ、膨れ防止の観点から真空中では
行われなかった。[Prior Art] Generally, in a method of manufacturing sintered metal or ceramic products through a degreasing and sintering process using injection molding, the degreasing process is performed in normal pressure, pressurized air, or inert gas atmosphere. It was not done in a vacuum to prevent blistering.
また、従来の射出成形用バインダーを使用した射出成形
体の脱脂は三次元的に複雑な形状を有し、高い寸法精度
が要求される場合には、脱脂時の変形や割れを防止する
ために射出成形体をセラミックス（例えばアルミナ）等
の不活性粉末中に埋めて脱脂していた。In addition, when degreasing an injection molded product using a conventional injection molding binder, it has a three-dimensionally complex shape and high dimensional accuracy is required. The injection molded body was buried in an inert powder of ceramics (for example, alumina) and degreased.
［発明が解決しようとする課題］
射出成形体の特徴は三次元的に複雑な形状の製品を高い
寸法精度で量産できることにある。[Problems to be Solved by the Invention] A feature of injection molded products is that products with three-dimensionally complex shapes can be mass-produced with high dimensional accuracy.
これまでの常圧あるいは加圧した大気中または不活性ガ
ス雰囲気中での脱脂では、バインダーの分解ガスが射出
成形体の周囲に停滞し、成形体中に残存しているバイン
ダー成分と反応して変形が生じるために成形体の間隔を
十分にあけなければならず、従って、炉の装入量が制限
された。また、速い昇温速度では変形や割れ、膨れなど
が生じるために１〜ｂ
ならず、このため脱脂に長時間を要していた。In conventional degreasing in normal pressure, pressurized air, or inert gas atmosphere, the decomposed gas of the binder stagnates around the injection molded product and reacts with the binder components remaining in the molded product. The compacts had to be spaced far enough apart for deformation to occur, thus limiting the furnace loading. Furthermore, if the temperature is increased at a high rate, deformation, cracking, blistering, etc. occur, and the degreasing process takes a long time.
また、不活性粉末中に射出成形体を埋めて変形や割れな
どを防止する方法もあるが、脱脂後に射出成形体の表面
に付着した不活性粉末を除去する作業に長時間を要し、
工業的な方法ではなかった。Another method is to bury the injection molded body in inert powder to prevent deformation and cracking, but this method requires a long time to remove the inert powder that has adhered to the surface of the injection molded body after degreasing.
It wasn't an industrial method.
そこで、不活性粉末中に埋めずに脱脂炉に多量の射出成
形体を装入することが可能であり、できる限り速い昇温
速度で変形や割れを生じることなく脱脂できる脱脂方法
及びそれに適したバインダーの開発が望まれていた。Therefore, it is possible to charge a large amount of injection molded products into a degreasing furnace without burying them in inert powder, and a degreasing method that can be degreased at the fastest possible temperature increase rate without causing deformation or cracking, and a degreasing method suitable for this purpose. The development of a binder was desired.
より速い速度で脱脂する方法として特開昭６４２８３０
３号公報には磁性合金粉末と熱可塑性樹脂を含有する射
出成形体を真空雰囲気で脱脂する方法が開示されている
。しかし、該公報に開示された真空脱脂法は昇温速度が
２〜ｂ
速く、金属粉末やセラミックス粉末と慣用のバインダー
からなる射出成形体の脱脂に適用すると、膨れや変形や
割れを生じて寸法精度の高い焼結品を量産することはで
きない。Japanese Patent Application Laid-open No. 642830 as a method for degreasing at a faster speed
No. 3 discloses a method of degreasing an injection molded body containing magnetic alloy powder and a thermoplastic resin in a vacuum atmosphere. However, the vacuum degreasing method disclosed in the publication has a temperature increase rate of 2 to 10% faster, and when applied to degreasing an injection molded article made of metal powder or ceramic powder and a conventional binder, it causes blistering, deformation, and cracking, resulting in dimensional defects. It is not possible to mass produce highly precise sintered products.
従って、本発明の目的はこれらの課題を解決した焼結品
の製造方法を提供することにある。Therefore, an object of the present invention is to provide a method for manufacturing a sintered product that solves these problems.
［課題を解決するための手段］
即ち、本発明は金属またはセラミックス粉末とバインダ
ーを混合して射出成形し、得られた射出成形体を脱脂し
、焼結することからなる焼結品の製造方法において、前
記バインダーがエチレン酢酸ビニル共重合体（ＥＶＡ）
またはエチレン−エチルアクリレート共重合体（ＥＥＡ
）またはそれら両者を５〜４０重量％、ポリプロピレン
（ｐｐ＞またはアタクチックポリプロピレン（Ａ Ｐ
Ｐ ）またはそれら両者を５〜４０重量％、ポリスチレ
ン（ｐｓ）またはポリエチレン（ＰＥ）またはそれら両
者を５〜４０重量％、パラフィンワックスまたはカルナ
バワックスまたはそれら両者を２０〜７０重量％、及び
ジエチルフタレート（ＤＥＰ）、ジブチルフタレート（
ＤＢＰ）、ジオクチルフタレート（Ｄ ＯＰ ＞からな
る群から選択された可塑剤、ステアリン酸、オレイン酸
からなる群から選択された滑剤またはそれら両者を１５
重量％未満配合してなり、脱脂工程が射出成形体を１ト
ール以下の真空中で、昇温速度５〜ｂ
まで加熱してバインダー成分の４０〜９５重量％を脱脂
することからなり、且つ焼結が昇温を真空雰囲気で開始
し、昇温過程でＡｒガス雰囲気に置換することよりなる
ことを特徴とする焼結品の製造方法に係る。[Means for Solving the Problems] That is, the present invention provides a method for producing a sintered product, which comprises mixing metal or ceramic powder and a binder, injection molding the mixture, degreasing the obtained injection molded product, and sintering the mixture. wherein the binder is ethylene vinyl acetate copolymer (EVA)
or ethylene-ethyl acrylate copolymer (EEA
) or both of them in an amount of 5 to 40% by weight, polypropylene (pp>) or atactic polypropylene (AP
5 to 40% by weight of polystyrene (PS) or polyethylene (PE) or both, 20 to 70% by weight of paraffin wax or carnauba wax or both, and diethyl phthalate ( DEP), dibutyl phthalate (
DBP), a plasticizer selected from the group consisting of dioctyl phthalate (DOP), a lubricant selected from the group consisting of stearic acid, oleic acid, or both.
The degreasing step consists of heating the injection molded article in a vacuum of 1 torr or less at a temperature increase rate of 5 to b to degrease 40 to 95 percent by weight of the binder component, and The present invention relates to a method for manufacturing a sintered product, characterized in that the sintering process starts with raising the temperature in a vacuum atmosphere, and replacing the atmosphere with an Ar gas atmosphere during the temperature raising process.
［作 用］
本発明の第１の特徴である真空中ての脱脂には以下のよ
うな作用がある。[Function] Degreasing in vacuum, which is the first feature of the present invention, has the following effects.
バインダー成分中で比較的融点の低い（４０〜１００℃
）ワックス系バインダーは融点以上の温度で液体状にな
り、減圧下において粉末粒子間を拡散して表面に浸み出
し、脱脂炉内に蒸発揮散し、真空ポンプにより炉外に排
出される。Among the binder components, it has a relatively low melting point (40 to 100℃
) The wax binder becomes liquid at a temperature above its melting point, diffuses between powder particles under reduced pressure, oozes out to the surface, evaporates into the degreasing furnace, and is discharged outside the furnace by a vacuum pump.
また、比較的融点の高い樹脂系バインダーは成形体内部
で分解ガス化し、ワックス系バインダーが除去された空
隙を通って成形体外部に排出される。Further, the resin binder having a relatively high melting point is decomposed and gasified inside the molded body, and is discharged to the outside of the molded body through the void where the wax binder has been removed.
以上のように、真空中での脱脂はバインダー成分を積極
的に成形体外部に排出する効果があるので、脱脂中の成
形体の軟化を抑制し、変形を生じることなく短時間で脱
脂でき、脱脂炉の装入量も真空ポンプの排気能力を増す
ことにより炉の有効容積−杯に射出成形体を装入するこ
とができる６本発明方法において、脱脂工程に使用する
ことが好適である真空脱脂の条件は、射出成形体を１ト
ール以下の真空中で、昇温速度５〜ｂ時間で２５０〜５
００℃まで加熱し、それによってバインダー成分の４０
〜９５重量％を脱脂することにある。As mentioned above, degreasing in a vacuum has the effect of actively discharging the binder component to the outside of the molded object, so it suppresses the softening of the molded object during degreasing, and allows degreasing in a short time without causing deformation. By increasing the evacuation capacity of the vacuum pump, the charging capacity of the degreasing furnace can be increased so that the injection molded products can be charged into the effective volume of the furnace. The conditions for degreasing are as follows: the injection molded product is placed in a vacuum of 1 torr or less, at a heating rate of 5 to 5 hours, and at a temperature of 250 to 5
00°C, thereby reducing the binder component to 40°C.
The purpose is to degrease up to 95% by weight.
本発明における真空脱脂において、脱脂条件を上記のよ
うに限定した理由について、まず真空度が１トールを超
えると前記のような真空の効果が十分に得られず、成形
体に膨れや変形が発生する。Regarding the reason why the degreasing conditions are limited as described above in the vacuum degreasing of the present invention, firstly, if the degree of vacuum exceeds 1 Torr, the above-mentioned vacuum effect cannot be obtained sufficiently, causing blistering and deformation of the molded product. do.
次に、昇温速度は５℃／時間未満では脱脂に長時間を要
し、工業的ではない。また、１００℃／時間を超えると
急激な成形体の軟化と急激なバインダーのガス分解のた
めに成形体に膨れや変形が発生する。Next, if the heating rate is less than 5° C./hour, degreasing takes a long time and is not industrially practical. Furthermore, if the temperature exceeds 100° C./hour, the molded product will rapidly soften and the binder will rapidly decompose into gas, causing swelling and deformation of the molded product.
更に、脱脂率が４０重量％未満であると、後の焼結工程
で膨れや変形が発生することがあり、また、焼結炉の汚
染の問題もあり好ましくない。Furthermore, if the degreasing rate is less than 40% by weight, blistering and deformation may occur in the subsequent sintering process, and there is also the problem of contamination of the sintering furnace, which is not preferable.
方、脱脂率が９５重量％を超えると脱脂体の強度が不足
し、後の作業により脱脂体を破損する恐れがある。この
４０〜９５重量％の脱脂率を得るために本発明バインダ
ーを使用すると２５０〜５００℃の脱脂温度が必要であ
る。以上の理由により脱脂条件を限定した。On the other hand, if the degreasing rate exceeds 95% by weight, the strength of the degreased body will be insufficient and there is a risk that the degreased body will be damaged during subsequent operations. When the binder of the present invention is used to obtain a degreasing rate of 40 to 95% by weight, a degreasing temperature of 250 to 500°C is required. For the above reasons, the degreasing conditions were limited.
次に、本発明方法に使用するバインダーは本出願人が既
に出願（特開昭１−１３９２５４号）しているものであ
り、以下のような作用がある。Next, the binder used in the method of the present invention has already been filed by the present applicant (Japanese Patent Application Laid-Open No. 139254/1989), and has the following effects.
該バインダーには、エチレン酢酸ビニル共重合体（ＥＶ
Ａ）またはエチレン−エチルアクリレート共重合体（Ｅ
ＥＡ）またはそれら両者を５〜４０重量％添加配合する
。ＥＶＡ及びＥＥＡは熱可塑性樹脂であり、加熱流動性
が良いために原料粉末及びバインダーよりなる混合物を
成形する際に良好な成形性を付与することができる。ま
た、得られる成形体の強度を高め、熱安定性が高いため
に、真空脱脂中に他の成分が低温で分解して除去される
間に成形体の形状を保持する作用を有する。The binder includes ethylene vinyl acetate copolymer (EV
A) or ethylene-ethyl acrylate copolymer (E
EA) or both thereof in an amount of 5 to 40% by weight. EVA and EEA are thermoplastic resins, and because they have good heat fluidity, they can provide good moldability when molding a mixture consisting of raw material powder and a binder. Furthermore, since the strength of the resulting molded product is increased and the thermal stability is high, it has the effect of maintaining the shape of the molded product while other components are decomposed and removed at low temperatures during vacuum degreasing.
ＥＶＡ及び／またはＥＥＡの添加配合量が５重量％未満
の場合には、効果が現れず、また、それらの添加配合量
が４０重量％を超えると脱脂中に多量の分解ガスを生じ
、成形体中に膨れや割れを生ずることがあり、焼結体中
にも残留して焼結体の特性を劣化させることがあるため
に好ましくない
また、本発明方法に使用するバインダーには、ポリプロ
ピレン（ｐｐ）またはアタクチックポリプロピレン（Ａ
Ｐ Ｐ ）を５〜４０重量％添加配合する。If the amount of EVA and/or EEA added is less than 5% by weight, no effect will be exhibited, and if the amount added exceeds 40% by weight, a large amount of decomposed gas will be generated during degreasing, and the molded product will be damaged. The binder used in the method of the present invention does not contain polypropylene (pp. ) or atactic polypropylene (A
P P ) is added in an amount of 5 to 40% by weight.
ＰＰ及びＡＰＰも上述のＥＶＡ及びＥＥＡと同様に熱可
塑性樹脂であり、同様の作用をもつが、ＥＶＡ及びＥＥ
Ａよりも粘着性が高く、成形体の強度を高めるほか、軟
化点も高いために、脱脂中に成形体の形状を保持するの
に特に効果的である。PP and APP are also thermoplastic resins like the above-mentioned EVA and EEA, and have similar effects, but EVA and EE
It has higher adhesiveness than A, increases the strength of the molded product, and has a higher softening point, so it is particularly effective in maintaining the shape of the molded product during degreasing.
ＰＰ及び／またはＡＰＰの添加配合量も５重量％未満の
場合には効果が現れず、また、それらの添加配合量が４
０重量％を超えると成形時の流動性が悪化し、流動性を
良くするために高い温度で成形すると、他の低い熱分解
温度のバインダー成分の蒸発を招くために好ましくない
。If the amount of PP and/or APP added is less than 5% by weight, no effect will be seen;
If it exceeds 0% by weight, the fluidity during molding will deteriorate, and if molding is performed at a high temperature to improve the fluidity, other binder components having a low thermal decomposition temperature will evaporate, which is not preferable.
更に、本発明方法に使用するバインダーには、ポリスチ
レン（ＰＳ）またはポリエチレン（ＰＥ）またはそれら
両者を５〜４０重量％添加配合する。Further, the binder used in the method of the present invention contains polystyrene (PS), polyethylene (PE), or both in an amount of 5 to 40% by weight.
ＰＳ及びＰＥも熱可塑性樹脂であるか、軟化点がＥＶＡ
及びＥＥＡとｐｐ及びＡＰＰの間の温度であり、これら
との共存において脱脂時のバインダーの熱分解が徐々に
進行するために、バインターの急激な熱分解に起因する
成形体の変形や割れ、膨れを防止する。また、ＰＳは樹
脂系バインダーの中でも特に脱脂性が良く、成形体の軟
化による変形を生しることなく脱脂する効果を有する。PS and PE are also thermoplastic resins or have a softening point of EVA
The temperature is between EEA, pp and APP, and thermal decomposition of the binder during degreasing progresses gradually in the coexistence of these, so the molded product may be deformed, cracked, or bulged due to rapid thermal decomposition of the binder. prevent. Furthermore, PS has particularly good degreasing properties among resin binders, and has the effect of degreasing the molded article without causing deformation due to softening.
ＰＳ及び／またはＰＥの添加配合量も５重量％未満では
効果が現れず、また、それらの添加配合量が４０重量％
を超えるとＥ Ｖ ＡやＥＥＡと同様の結果を生じるた
めに好ましくない。また、ＰＳは粘着性が悪いために過
剰の添加は成形体の強度を低下させることがある。If the amount of PS and/or PE added is less than 5% by weight, no effect will be seen, and if the amount of added PS and/or PE is less than 5% by weight,
Exceeding this is not preferable because results similar to EVA and EEA will occur. Furthermore, since PS has poor adhesiveness, excessive addition may reduce the strength of the molded product.
また、本発明方法に使用するバインダーには、パラフィ
ンワックスまたはカルナバワックスまたはそれら両者を
２０〜７０重量％添加配合する。Further, the binder used in the method of the present invention contains 20 to 70% by weight of paraffin wax, carnauba wax, or both.
パラフィンワックス及びカルナバワックスは成形時のコ
ンパウンドの流動性を高め、原料粉末とバインダーとの
濡れ性を向上させて成形体中に原料粉末を均一に分散さ
せる効果を有する。更に、これらの成分は脱脂時に成形
体中を拡散して表面に浸み出し、蒸発揮散するという樹
脂系バインダー成分と異なる脱脂機構を有し、樹脂系バ
インダー成分がガス分解して成形体外部に排出される抜
は道を形成するために成形体を破損することなく脱脂さ
れる。カルナバワックスはワックス系バインダーの中で
も低温での強度が高く、融点も高いために成形体の形状
を保持するのに効果的である。Paraffin wax and carnauba wax have the effect of increasing the fluidity of the compound during molding, improving the wettability between the raw material powder and the binder, and uniformly dispersing the raw material powder in the molded body. Furthermore, these components have a different degreasing mechanism from the resin binder component in that they diffuse through the molded body during degreasing, seep out to the surface, and evaporate. The discharged sludge is degreased to form a channel without damaging the molded body. Carnauba wax has the highest strength at low temperatures among wax-based binders and has a high melting point, so it is effective in maintaining the shape of molded products.
パラフィンワックス及び／またはカルナバワックスの添
加配合量が２０重量％未満では効果が十分に得られず、
また、それらの配合量が７０重量％を超えると粘着性が
低いために成形性が悪化し、脱脂中の保形性が低下して
成形体に変形が生じることがあるために好ましくない。If the amount of paraffin wax and/or carnauba wax added is less than 20% by weight, sufficient effects cannot be obtained;
Moreover, if the blending amount thereof exceeds 70% by weight, moldability deteriorates due to low tackiness, and shape retention during degreasing may deteriorate, resulting in deformation of the molded product, which is not preferable.
本発明に使用するバインダーには、更に可塑剤または滑
剤またはそれら両者を１５重量％まで添加配合すること
ができる。The binder used in the present invention may further contain up to 15% by weight of a plasticizer, a lubricant, or both.
可塑剤としては例えばジエチルフタレート（ＤＥＰ）、
ジブチルフタレート（Ｄ Ｂ Ｐ ）またはジオクチル
フタレート（Ｄ ＯＰ ）などを使用することができる
。可塑剤は上述の各底弁の相溶性を向上させてバインダ
ーの均質化に効果があり、成形時のコンパウンドの流動
性を向上させる作用を有する。Examples of plasticizers include diethyl phthalate (DEP),
Dibutyl phthalate (D B P ) or dioctyl phthalate (D OP ) and the like can be used. The plasticizer has the effect of improving the compatibility of the above-mentioned bottom valves and homogenizing the binder, and has the effect of improving the fluidity of the compound during molding.
なお、上記可塑剤は単独で、または２種以上を併用して
使用することができる。In addition, the said plasticizer can be used individually or in combination of 2 or more types.
滑剤としては例えばステアリン酸、オレイン酸などを使
用することができる。滑剤は成形時の型離れが悪い場合
には、離型剤としても効果がある。As the lubricant, for example, stearic acid, oleic acid, etc. can be used. A lubricant is also effective as a mold release agent when mold release during molding is difficult.
なお、上記滑剤は単独で、または２種以上を併用して使
用することもできる。Note that the above lubricants can be used alone or in combination of two or more.
可塑剤及び／または滑剤の添加配合量が１５重量％以上
になると、成形体の強度が低下し、脱脂時に変形が生じ
ることがあるために好ましくない。If the added amount of the plasticizer and/or lubricant exceeds 15% by weight, the strength of the molded product may decrease and deformation may occur during degreasing, which is not preferable.
上記配合をもつバインダーは金属粉末例えばステンレス
鋼粉末、Ｆｅ−３ｉ、Ｆｅ−Ｎｉ等の合金粉末、Ｆｅ、
Ｃｕ等の純金属粉末及びセラミックス粉末例えばアルミ
ナ粉末、ジルコニア粉末等のような原料粉末から射出成
形法を用いて焼結晶を製造する際のバインダーとして好
適なものであり、本発明方法による焼結晶の製造に際し
、バインダーを脱脂する工程として使用される真空脱脂
において特に有効である。The binder having the above composition may be a metal powder such as a stainless steel powder, an alloy powder such as Fe-3i or Fe-Ni, Fe,
It is suitable as a binder when producing sintered crystals using injection molding method from pure metal powder such as Cu and ceramic powder such as alumina powder, zirconia powder, etc. It is particularly effective in vacuum degreasing, which is used as a process for degreasing the binder during manufacturing.
即ち、該バインダーを真空脱脂に適用した場合、従来使
用されていた慣用のバインダーを真空脱脂に使用する場
合よりもはるかに有効であり、金属粉末やセラミックス
粉末の射出成形体から変形や割れなどのない三次元的に
複雑形状で寸法精度の高い焼結晶を量産するために最適
である。In other words, when this binder is applied to vacuum degreasing, it is much more effective than when using a conventional binder for vacuum degreasing, and it eliminates deformation, cracking, etc. from injection molded bodies of metal powder and ceramic powder. It is ideal for mass producing sintered crystals with three-dimensionally complex shapes and high dimensional accuracy.
更に、本発明方法では、真空脱脂を行った射出成形体を
焼結するに当たり、昇温を真空雰囲気中で開始し、昇温
過程でＡｒガス雰囲気に置換することからなる操作を使
用することが好ましい。なお、真空雰囲気中の焼結から
Ａｒガス雰囲気への置換は真空雰囲気で昇温しながら１
０５０〜１３００℃程度の範囲内で行うことができる。Furthermore, in the method of the present invention, when sintering the injection molded body that has been vacuum degreased, it is possible to use an operation consisting of starting the temperature increase in a vacuum atmosphere and replacing it with an Ar gas atmosphere during the temperature increase process. preferable. In addition, the replacement from sintering in a vacuum atmosphere to an Ar gas atmosphere is performed while increasing the temperature in a vacuum atmosphere.
It can be carried out within a range of about 050 to 1300°C.
なお、置換温度は得られる焼結晶の寸法精度や炭素含有
量等の条件によって適宜選定することができる。Note that the substitution temperature can be appropriately selected depending on conditions such as the dimensional accuracy and carbon content of the obtained fired crystal.
この操作を使用することにより、真空脱脂済の射出成形
体を真空雰囲気中で昇温し、ＣＯガス反応を十分に進行
させて成形体中の炭素含有量を所望の量以下とした後、
Ａｒガス雰囲気に置換して前記成形体の構成成分の蒸発
を防止することができ、それによって得られる焼結晶の
寸法のバラツキを少なくすることができ、高精度焼結晶
を工業的規模で量産することができる。なお、この焼結
方法については、本出願人が既に特許出願している（特
願昭１−２１７４７２号）。By using this operation, the temperature of the vacuum-degreased injection molded body is raised in a vacuum atmosphere, and the CO gas reaction is sufficiently advanced to reduce the carbon content in the molded body to a desired amount or less.
By replacing the atmosphere with Ar gas atmosphere, it is possible to prevent the constituent components of the compact from evaporating, thereby reducing the variation in the dimensions of the obtained sintered crystals, and making it possible to mass-produce high-precision sintered crystals on an industrial scale. be able to. The present applicant has already filed a patent application for this sintering method (Japanese Patent Application No. 1-217472).
［実 施 例］ 以下に実施例を挙げて本発明方法を更に説明する。[Example] The method of the present invention will be further explained below with reference to Examples.
実施例１
原料粉末として平均粒径が８，５μｍの５ＵＳ３０４Ｌ
水アトマイズ粉末を用い、これに第１表のＮ０１１のバ
インダー組成であるＥＶＡ３０重量％、ＰＰ１５重量％
、ＰＥ１５重量％、パラフィンワックス２０重量％、カ
ルナバワックス２０重量％からなるバインダーを９．０
重量％添加して二軸式混練機を用いて１７０°Ｃの温度
で１時間混練して均質化した後にロールミルでシート化
し、粉砕して平均５１の射出成形用材料を製造した。Example 1 5US304L with an average particle size of 8.5 μm as raw material powder
Using water atomized powder, add 30% by weight of EVA and 15% by weight of PP, which is the binder composition of N011 in Table 1.
, 9.0% by weight of a binder consisting of 15% by weight of PE, 20% by weight of paraffin wax, and 20% by weight of carnauba wax.
% by weight was added and homogenized by kneading for 1 hour using a twin-screw kneader at a temperature of 170°C, and then sheeting was formed using a roll mill and pulverized to produce an injection molding material having an average size of 51.
得られた射出成形用材料を射出成形機を用いて第１図に
正面図、第２図に断面図を示す薄板と円筒を組み合わせ
た形状に射出成形した。図中の寸法はｄ＋＝ｄ２＝１５
ｍｍ、ｄ、＝８１Ｂ、ｄ、＝ ｌｖ＋＋、ｈ、＝７．５
ｎｕａ、ｔｚ＝２ｍｍである。The obtained injection molding material was injection molded using an injection molding machine into the shape of a combination of a thin plate and a cylinder, the front view of which is shown in FIG. 1 and the sectional view shown in FIG. Dimensions in the diagram are d+=d2=15
mm, d, = 81 B, d, = lv++, h, = 7.5
nua, tz=2 mm.
得られた射出成形体を脱脂炉に装入し、炉内を真空排気
（約０．０１）−ル）しながら昇温速度５０℃／時で３
５０℃まで加熱して脱脂した。The obtained injection molded product was placed in a degreasing furnace, and heated at a heating rate of 50°C/hour for 3 hours while the furnace was evacuated (approximately 0.01 mm).
It was heated to 50°C to degrease it.
次に、得られた脱脂成形体を焼結炉を用いて約１０−’
）−ルの真空中において、昇温速度２００℃／時で１２
００℃まで昇温し、次に、炉内をアルゴンガスに置換し
た後に更に２００℃／時で１３５０℃まで昇温しで１時
間保持することにより焼結晶を得た。Next, the obtained degreased molded body was heated in a sintering furnace for about 10-'
)-12 in vacuum at a heating rate of 200°C/hour.
The temperature was raised to 00°C, and then, after replacing the inside of the furnace with argon gas, the temperature was further raised to 1350°C at 200°C/hour and held for 1 hour to obtain baked crystals.
この方法により得られた焼結晶は割れや変形などは見ら
れず、理論密度の９５％以上の密度を有するものであっ
た。The fired crystal obtained by this method showed no cracks or deformation, and had a density of 95% or more of the theoretical density.
実施例２
本発明方法において、上記バインダーの真空脱脂による
効果を示すために、第１表に示すバインダー組成、添加
量の成形体を第１表に示す脱脂条件で３５０°Ｃまで加
熱して脱脂した。Ｎ０１１〜７が本発明方法によるもの
であり、Ｎｏ、８〜１４が比較例である。Example 2 In the method of the present invention, in order to demonstrate the effect of vacuum degreasing of the binder, molded bodies having the binder composition and additive amount shown in Table 1 were degreased by heating to 350°C under the degreasing conditions shown in Table 1. did. Nos. 011 to 7 are those obtained by the method of the present invention, and Nos. 8 to 14 are comparative examples.
なお、Ｎｏ、３及び９は本発明範囲外のバインダーの使
用例であり、Ｎｏ、１０はＮｏ、１のバインダーを用い
て本発明範囲外の昇温速度で脱脂した例で、Ｎｏ、１１
〜１４はＮｏ、１のバインダーを用いてＮ２雰囲気中で
脱脂炉への装入量と昇温速度を変えた例である。Note that No. 3 and 9 are examples of using binders outside the scope of the present invention, No. 10 are examples in which the binder of No. 1 was used for degreasing at a heating rate outside the scope of the present invention, and No. 11
-14 are examples in which binder No. 1 was used and the charging amount to the degreasing furnace and the temperature increase rate were changed in an N2 atmosphere.
得られたそれぞれの脱脂体について第２図のり、の寸法
を測定し、下記の式に基づいて脱脂体変形率を求めた結
果と良品率を第１表に併記する。For each of the obtained degreased bodies, the dimensions shown in FIG.
ｈｌ ：射出成形体寸法
ｈ′、：脱脂体寸法
その結果、本発明による脱脂方法では、いずれの例でも
脱脂体変形率は０．１％未満であり、はとんど変形がな
く、１００％良品が得られる。hl: Injection molded body size h': Degreased body size As a result, in the degreasing method according to the present invention, the degreased body deformation rate is less than 0.1% in all cases, and there is almost no deformation, and it is 100%. Good quality products can be obtained.
比較例では、まず、Ｎｏ、８及び９においては脱脂体変
形率が大きく、良品は得られながった。In the comparative examples, first, in Nos. 8 and 9, the degreased body deformation rate was large, and good products could not be obtained.
次に、Ｎｏ、１０の例では、急激なバインダー分解ガス
の発生のためにフクレが発生し、良品が得られなかった
。Next, in example No. 10, blistering occurred due to the sudden generation of binder decomposition gas, and a good product could not be obtained.
また、Ｎｏ、１１〜１４のＮ２雰囲気中で脱脂した例で
は、昇温速度５℃／時において１００個の装入量では変
形はほとんどなく、１００％良品が得られたが（Ｎｏ、
１１）、装入量が５００個（Ｎ。In addition, in the examples of Nos. 11 to 14 degreased in an N2 atmosphere, there was almost no deformation at a charging rate of 100 pieces at a heating rate of 5°C/hour, and 100% non-defective products were obtained (No.
11), the charging amount is 500 pieces (N.
１２〉、１０００個（Ｎｏ、１３）と多くなるに従い変
形が発生し、良品率も低下した。また、昇温速度５０°
Ｃ／時（Ｎｏ、１４＞では変形が発生し、良品が得られ
なかった。12> and 1000 pieces (No. 13), deformation occurred and the non-defective rate also decreased. Also, the heating rate is 50°
C/hour (No, 14>) deformation occurred and a good product could not be obtained.
また、Ｎｏ、１〜７で得られた脱脂成形体を実施例１と
同様の方法により焼結したところ、寸法精度のよい焼結
晶が得られた６
／
［発明の効果］
以上説明したように本発明方法を用いることにより割れ
や変形などを生じることなく、焼結品を製造することが
できる。また、脱脂工程では、それぞれの成形体の間隔
をつめて脱脂炉に装入しても変形が生じないために脱脂
炉の装入量が増加し、昇温速度も速くできるので脱脂に
要するコストが大幅に低減できる。Further, when the degreased molded bodies obtained in Nos. 1 to 7 were sintered in the same manner as in Example 1, sintered crystals with good dimensional accuracy were obtained.6/ [Effects of the Invention] As explained above. By using the method of the present invention, a sintered product can be manufactured without cracking or deformation. In addition, in the degreasing process, even if the molded bodies are closely spaced and charged into the degreasing furnace, no deformation occurs, so the amount charged into the degreasing furnace increases, and the rate of temperature rise can be increased, reducing the cost required for degreasing. can be significantly reduced.
従って、三次元的に複雑形状で高い寸法精度が要求され
る焼結品を量産的に製造することができる。Therefore, it is possible to mass-produce sintered products that have three-dimensionally complex shapes and require high dimensional accuracy.
第１図は実施例で説明した射出成形体の正面図であり、
第２図は第１図に示す射出成形体の断面図である。FIG. 1 is a front view of the injection molded product explained in the example,
FIG. 2 is a sectional view of the injection molded article shown in FIG. 1.
Claims (1)
て射出成形し、得られた射出成形体を脱脂し、焼結する
ことからなる焼結品の製造方法において、前記バインダ
ーがエチレン酢酸ビニル共重合体（ＥＶＡ）またはエチ
レン−エチルアクリレート共重合体（ＥＥＡ）またはそ
れら両者を５〜４０重量％、ポリプロピレン（ＰＰ）ま
たはアタクチックポリプロピレン（ＡＰＰ）またはそれ
ら両者を５〜４０重量％、ポリスチレン（ＰＳ）または
ポリエチレン（ＰＥ）またはそれら両者を５〜４０重量
％、パラフィンワックスまたはカルナバワックスまたは
それら両者を２０〜７０重量％、及びジエチルフタレー
ト（ＤＥＰ）、ジブチルフタレート（ＤＢＰ）、ジオク
チルフタレート（ＤＯＰ）からなる群から選択された可
塑剤、ステアリン酸、オレイン酸からなる群から選択さ
れた滑剤またはそれら両者を１５重量％未満配合してな
り、脱脂工程が射出成形体を１トール以下の真空中で、
昇温速度５〜１００℃／時間で２５０〜５００℃まで加
熱してバインダー成分の４０〜９５重量％を脱脂するこ
とからなり、且つ焼結が昇温を真空雰囲気で開始し、昇
温過程でＡｒガス雰囲気に置換することよりなることを
特徴とする焼結品の製造方法。1. A method for producing a sintered product comprising mixing a metal or ceramic powder and a binder, injection molding the mixture, degreasing the obtained injection molded product, and sintering the mixture, wherein the binder is an ethylene vinyl acetate copolymer (EVA). or 5-40% by weight of ethylene-ethyl acrylate copolymer (EEA) or both, 5-40% by weight of polypropylene (PP) or atactic polypropylene (APP) or both, polystyrene (PS) or polyethylene (PE). ) or both, 20 to 70% by weight of paraffin wax or carnauba wax or both, and diethyl phthalate (DEP), dibutyl phthalate (DBP), and dioctyl phthalate (DOP). The plasticizer, stearic acid, oleic acid, or a lubricant selected from the group consisting of less than 15 wt.
Sintering consists of heating to 250-500°C at a heating rate of 5-100°C/hour to degrease 40-95% by weight of the binder component, and sintering starts with heating in a vacuum atmosphere, and during the heating process. A method for producing a sintered product, comprising replacing the atmosphere with an Ar gas atmosphere.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2087560A JPH03290374A (en) | 1990-04-03 | 1990-04-03 | Production of sintered article |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2087560A JPH03290374A (en) | 1990-04-03 | 1990-04-03 | Production of sintered article |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH03290374A true JPH03290374A (en) | 1991-12-20 |
Family
ID=13918376
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2087560A Pending JPH03290374A (en) | 1990-04-03 | 1990-04-03 | Production of sintered article |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH03290374A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH06122902A (en) * | 1992-06-02 | 1994-05-06 | Advanced Materials Technol Pte Ltd | Injection-moldable metallic material, and production of injection-molded metallic article |
| BE1007035A3 (en) * | 1993-04-28 | 1995-02-21 | Vito | Method for removing a binding agent in powdered injection moulding |
| JP2003193108A (en) * | 2002-12-09 | 2003-07-09 | Seiko Epson Corp | Method for manufacturing metallic sintered compact |
| JP2012062221A (en) * | 2010-09-16 | 2012-03-29 | Tdk Corp | Method for producing sintered compact |
| JP2014218082A (en) * | 2013-05-07 | 2014-11-20 | コマディール・エス アー | Mixer or method of mixing raw material with powder metallurgy binder for injection moulding composition and the powder metallurgy binder |
-
1990
- 1990-04-03 JP JP2087560A patent/JPH03290374A/en active Pending
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH06122902A (en) * | 1992-06-02 | 1994-05-06 | Advanced Materials Technol Pte Ltd | Injection-moldable metallic material, and production of injection-molded metallic article |
| US5397531A (en) * | 1992-06-02 | 1995-03-14 | Advanced Materials Technologies Pte Limited | Injection-moldable metal feedstock and method of forming metal injection-molded article |
| BE1007035A3 (en) * | 1993-04-28 | 1995-02-21 | Vito | Method for removing a binding agent in powdered injection moulding |
| JP2003193108A (en) * | 2002-12-09 | 2003-07-09 | Seiko Epson Corp | Method for manufacturing metallic sintered compact |
| JP2012062221A (en) * | 2010-09-16 | 2012-03-29 | Tdk Corp | Method for producing sintered compact |
| JP2014218082A (en) * | 2013-05-07 | 2014-11-20 | コマディール・エス アー | Mixer or method of mixing raw material with powder metallurgy binder for injection moulding composition and the powder metallurgy binder |
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