JPS62267402A - Production of porous metallic body by activated sintering - Google Patents
Production of porous metallic body by activated sinteringInfo
- Publication number
- JPS62267402A JPS62267402A JP10940886A JP10940886A JPS62267402A JP S62267402 A JPS62267402 A JP S62267402A JP 10940886 A JP10940886 A JP 10940886A JP 10940886 A JP10940886 A JP 10940886A JP S62267402 A JPS62267402 A JP S62267402A
- Authority
- JP
- Japan
- Prior art keywords
- molding
- sintering
- porous
- binder
- strength
- 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.)
- Granted
Links
- 238000005245 sintering Methods 0.000 title claims abstract description 31
- 238000004519 manufacturing process Methods 0.000 title claims description 12
- 239000000843 powder Substances 0.000 claims abstract description 20
- 239000011230 binding agent Substances 0.000 claims abstract description 13
- 238000007569 slipcasting Methods 0.000 claims abstract description 7
- 229910052751 metal Inorganic materials 0.000 claims description 31
- 239000002184 metal Substances 0.000 claims description 31
- 230000004913 activation Effects 0.000 claims description 2
- 230000003647 oxidation Effects 0.000 abstract description 25
- 238000007254 oxidation reaction Methods 0.000 abstract description 25
- 239000011148 porous material Substances 0.000 abstract description 14
- 238000000465 moulding Methods 0.000 abstract description 12
- BOTDANWDWHJENH-UHFFFAOYSA-N Tetraethyl orthosilicate Chemical compound CCO[Si](OCC)(OCC)OCC BOTDANWDWHJENH-UHFFFAOYSA-N 0.000 abstract description 6
- 238000010438 heat treatment Methods 0.000 abstract description 6
- 230000001590 oxidative effect Effects 0.000 abstract description 6
- 239000002002 slurry Substances 0.000 abstract description 6
- 238000001035 drying Methods 0.000 abstract description 5
- 239000000203 mixture Substances 0.000 abstract description 3
- 229910002549 Fe–Cu Inorganic materials 0.000 abstract description 2
- 238000001816 cooling Methods 0.000 abstract description 2
- 238000000034 method Methods 0.000 description 16
- 238000006722 reduction reaction Methods 0.000 description 13
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 11
- 239000002923 metal particle Substances 0.000 description 7
- 239000002245 particle Substances 0.000 description 6
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 5
- 229910044991 metal oxide Inorganic materials 0.000 description 5
- 150000004706 metal oxides Chemical class 0.000 description 5
- 239000001301 oxygen Substances 0.000 description 5
- 229910052760 oxygen Inorganic materials 0.000 description 5
- 230000007423 decrease Effects 0.000 description 4
- 229910052742 iron Inorganic materials 0.000 description 4
- 239000007789 gas Substances 0.000 description 3
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 2
- ATUOYWHBWRKTHZ-UHFFFAOYSA-N Propane Chemical compound CCC ATUOYWHBWRKTHZ-UHFFFAOYSA-N 0.000 description 2
- 239000000956 alloy Substances 0.000 description 2
- 229910045601 alloy Inorganic materials 0.000 description 2
- 239000000919 ceramic Substances 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000004898 kneading Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 2
- 239000004215 Carbon black (E152) Substances 0.000 description 1
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 1
- 230000001476 alcoholic effect Effects 0.000 description 1
- 229910021529 ammonia Inorganic materials 0.000 description 1
- 239000010953 base metal Substances 0.000 description 1
- 229910002091 carbon monoxide Inorganic materials 0.000 description 1
- 238000004581 coalescence Methods 0.000 description 1
- 238000005056 compaction Methods 0.000 description 1
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 230000008602 contraction Effects 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- 238000007710 freezing Methods 0.000 description 1
- 230000008014 freezing Effects 0.000 description 1
- 229910002804 graphite Inorganic materials 0.000 description 1
- 239000010439 graphite Substances 0.000 description 1
- 229930195733 hydrocarbon Natural products 0.000 description 1
- 150000002430 hydrocarbons Chemical class 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 239000000314 lubricant Substances 0.000 description 1
- 238000003754 machining Methods 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 239000011812 mixed powder Substances 0.000 description 1
- 238000010068 moulding (rubber) Methods 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 229920003023 plastic Polymers 0.000 description 1
- 239000001294 propane Substances 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000011946 reduction process Methods 0.000 description 1
- -1 rubber molding Substances 0.000 description 1
- RMAQACBXLXPBSY-UHFFFAOYSA-N silicic acid Chemical compound O[Si](O)(O)O RMAQACBXLXPBSY-UHFFFAOYSA-N 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000009849 vacuum degassing Methods 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〕
本発明は金属多孔質体の製造法とりわけ活性化焼結によ
る金属多孔質体の製造法に関するものである。DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for producing a porous metal body, particularly a method for producing a porous metal body by activated sintering.
金属多孔質体を得る場合、従来では一般に金属粉末に潤
滑材又は／及びバインダを添加混合し、この混合物を金
型に充填し高圧縮力を加えて圧粉体を作り、この圧粉体
を還元性雰囲気中で加熱焼結する方法が採られていた。Conventionally, when obtaining a porous metal body, a lubricant and/or a binder is generally added and mixed with metal powder, this mixture is filled into a mold, and a high compression force is applied to create a green compact. A method of heating and sintering in a reducing atmosphere was used.
しかし、この方法は、圧粉体の装造に錐雌の金型と大容
量のプレスなど設備を必要とするため、製造コストが高
価となり、また、金型製作上の制約や流動性などの面か
ら、複雑な形状や高さの大きな金属多孔質体の製造が難
しいという問題があった。However, this method requires equipment such as a conical female mold and a large-capacity press to prepare the powder compact, resulting in high manufacturing costs and problems such as mold manufacturing constraints and fluidity. From this point of view, there was a problem in that it was difficult to manufacture porous metal bodies with complicated shapes and large heights.
この対策としては、成形法として圧粉成形でなく、金属
粉とバインダをスラリー状にしてスリップキャスティン
グのような流し込み成形する手法を採り、この成形体を
焼結する方法が考えられる。As a countermeasure to this problem, a method of forming the metal powder and binder in a slurry form, instead of powder compaction, using a method such as slip casting, and then sintering the formed body may be considered.
しかしながら、この場合には、無加圧成形であることか
ら、成形体の気孔率が約５０％と圧粉体のそれに対し約
２倍以上高く、そのためこの方式では焼結が容易に進行
せず、所期の機械的強度を得がたいという問題がある。However, in this case, since pressureless molding is used, the porosity of the compact is about 50%, which is about twice as high as that of the green compact, so sintering does not proceed easily with this method. However, there is a problem in that it is difficult to obtain the desired mechanical strength.
本発明は前記のような問題点を解決するために研究して
創案されたもので、その目的とするところは、気孔が微
細に散在した良好な強度の金属多孔質体を簡単かつ安価
に製造することができる方法を提供することにある。The present invention was developed through research to solve the above-mentioned problems, and its purpose is to easily and inexpensively produce a porous metal body with good strength and finely scattered pores. Our goal is to provide a way to do so.
この目的を達成するため１本発明は、無加圧成形の利点
を生かしつつ同時にその難点である低焼結性を予備酸化
と還元工程の組合せにより回避して適切な活性化焼結を
行うようにしたもので、すなわち、金属粉末とバインダ
との混合試料をスリップキャストにより成形し、この成
形体を酸化処理してから還元性雰囲気中で加熱焼結する
ことを特徴とするものである。In order to achieve this object, the present invention utilizes the advantages of non-pressure forming and at the same time avoids its disadvantage of low sinterability by a combination of preliminary oxidation and reduction process to perform appropriate activation sintering. That is, the method is characterized in that a mixed sample of metal powder and a binder is molded by slip casting, and this molded body is oxidized and then heated and sintered in a reducing atmosphere.
このような本発明によれば、成形行程においてプレスな
どの大掛りな加圧設備を必要とせず、マスターモデル、
製品サンプルあるいはせいぜい雌型などを使用するだけ
で簡単に成形できる。また。According to the present invention, there is no need for large press equipment such as a press in the molding process, and the master model,
It can be easily molded by using a product sample or at most a female mold. Also.
この成形体段階で気孔率が大であっても、予備酸化処理
により金属粒子が膨張して相互の接触面積が大きくなり
、基地が互いに連結されるため、次の還元性雰囲気で加
熱することにより焼結が著しく促進される。そして、前
記予備酸化処理での金属粒子の膨張・連結で金属粒子間
の空孔が埋められるとともに気孔の合体化が生ずるため
気孔が閉じられ、残存する気孔も還元時の収縮で絞り出
され、分散微細化する。これらにより高強度な金属多孔
質体が得られる。Even if the porosity is large at this compact stage, the metal particles expand due to the preliminary oxidation treatment, increasing the mutual contact area and connecting the bases with each other. Sintering is significantly accelerated. Then, the pores between the metal particles are filled by the expansion and connection of the metal particles in the preliminary oxidation treatment, and the pores are closed due to the coalescence of the pores, and the remaining pores are also squeezed out by contraction during the reduction, Refine dispersion. A high-strength metal porous body can be obtained by these methods.
以下本発明の詳細な説明する。The present invention will be explained in detail below.
本発明による金属多孔質体の製造法は、下記の基本工程
からなっている。The method for producing a porous metal body according to the present invention consists of the following basic steps.
■金属粉末にバインダを添加し、混練してスラリー状試
料を作り、これをスリップキャステング法により成形し
、無加圧成形体を得る工程■無加圧成形体を酸化処理す
る工程
■酸化処理した無加圧成形体を還元焼結する工程詳述す
ると、まずＩの工程において、「金属粉末」は酸化性の
ものたとえば鉄またはその合金（Ｆｅ−Ｃｕ等）、Ｎｉ
、 Ｃｏの１種又は２種以上が効果的に利用される。こ
の金属粉末には、スリップキャスティング時の成形性を
確保し、乾燥クラックや焼結時のクラックを防止するた
め、ファイバーを適量添加してもよいにの目つぶれは後
に研削や研摩を行うことで除去され、多孔性を再生でき
る。■A process of adding a binder to metal powder and kneading it to make a slurry sample, which is then molded by the slip casting method to obtain a non-pressure compact.■A process of oxidizing the non-pressure compact.■A process of oxidizing the non-pressure compact. To explain the process of reducing and sintering the non-pressure compact, first, in step I, the "metal powder" is an oxidizing material such as iron or its alloy (Fe-Cu, etc.), Ni
, Co, or more are effectively used. In order to ensure formability during slip casting and prevent cracks during drying and sintering, an appropriate amount of fiber may be added to this metal powder. removed and the porosity can be regenerated.
次にバインダは、金属粉末に流動性と成形性を与えると
共に気孔を形成するためのもので、金属粉末と化学反応
を起こさず、乾燥時またはそれ以降の加熱で成形体中か
ら気散する性質の液体であり、その代表例としては加水
分解エチルシリケートすなわちアルコール性シリカゾル
（以下単にエチルシリケートと称す）またはこれと同効
の特性を有する物質が挙げられる。このバインダは金属
粉末に対し１通常１０〜３０％添加される。Next, the binder is used to provide fluidity and moldability to the metal powder, as well as to form pores.It has the property of not causing a chemical reaction with the metal powder, and evaporating from the molded body during drying or subsequent heating. A typical example thereof is hydrolyzed ethyl silicate, ie, alcoholic silica sol (hereinafter simply referred to as ethyl silicate), or a substance having the same properties as this. This binder is usually added in an amount of 10 to 30% based on the metal powder.
上記原料は計量後混ぜ合わされ、攪拌あるいは振動を加
えることで混練され、スラリー状試料となる。このスラ
リー状試料は次いで真空脱泡などにより混入エアを除去
した後、製造目的の形状寸法、模様などを所望の型に流
し込み、固化させる。The above raw materials are weighed, mixed, and kneaded by stirring or vibration to form a slurry sample. This slurry-like sample is then subjected to vacuum defoaming or the like to remove mixed air, and then poured into a desired mold with the desired shape, size, pattern, etc. for manufacturing purposes, and solidified.
これは、たとえば製造目的製品が通気性の型であれば、
型枠中にマスターモデルや製品サンプルを配して行えば
よいし、それ以外の機械部品などにあっては雌型のキャ
ビティを利用すればよい、固化後は型から取り出し、要
すれば、自然乾燥、加熱あるいは冷凍などの強制乾燥を
行うもので、これにより、無加圧成形体が得られる。For example, if the product to be manufactured is of a breathable type,
This can be done by placing a master model or product sample in the mold, or by using a female cavity for other mechanical parts. This method performs forced drying such as drying, heating, or freezing, and thereby a non-pressure molded product can be obtained.
次に本発明は、■のように無加圧成形体を酸化処理する
。これは、具体的には、酸化性雰囲気中で、かつ後述す
る還元焼結よりも低い温度で加熱することである。酸化
性雰囲気は最も簡便には大気が使用されるが、要すれば
酸素富化の雰囲気としてもよい。Next, in the present invention, the non-pressure molded product is subjected to oxidation treatment as in (2). Specifically, this means heating in an oxidizing atmosphere and at a lower temperature than the reduction sintering described below. The atmosphere is most conveniently used as the oxidizing atmosphere, but an oxygen-enriched atmosphere may be used if necessary.
この酸化処理の温度と時間は、金属粉末の酸化特性、製
造する金属多孔質体の寸法諸元、およびに金属多孔質体
に求められる気孔率と必要強度の相関を考慮して適宜設
定するが、有機バインダを用いた場合にはこの工程にお
いてバインダが消失・除去され、気孔率の大きな多孔体
が得られる。The temperature and time of this oxidation treatment are determined as appropriate, taking into account the oxidation characteristics of the metal powder, the dimensions of the porous metal body to be manufactured, and the correlation between the porosity and required strength of the porous metal body. When an organic binder is used, the binder disappears and is removed in this step, resulting in a porous body with a high porosity.
金属粉末が鉄またはその合金の場合には、通常、処理温
度は３００〜６５０℃、処理時間は１〜３６０＋ｉｎの
範囲から選択すればよい、一般に多孔質体の強度は気孔
率に指数関数的に依存している。When the metal powder is iron or its alloy, the processing temperature is usually selected from the range of 300 to 650°C, and the processing time is selected from the range of 1 to 360+ inches.In general, the strength of the porous body is exponentially proportional to the porosity. dependent.
したがって、強度より気孔率が要求される場合たとえば
通気性の型のような場合には、処理温度と処理時間の少
なくとも一方のパラメータを減少側に制御すればよく、
強度が重視される場合には。Therefore, in cases where porosity is required more than strength, such as in the case of breathable molds, it is sufficient to control at least one of the processing temperature and processing time to the lower side.
When strength is important.
処理温度と処理時間の少なくとも一方のパラメータを増
大側に制御すればよい。It is sufficient to control at least one of the processing temperature and processing time to increase the parameter.
温度条件については、処理温度があまり高温では酸化膜
中の酸素の拡散が早く、酸化膜の成長速度が早いため、
成形体内部に酸素が供給されにくくなり、内部は気孔率
が高いまま酸化が進行しなくなる。低温側では酸化膜の
成長が緩やかであるため、雰囲気中の酸素が内部まで移
動し、中心部まで酸化焼結が進み全体として強度上昇が
図られる。この特性を利用することで内部と外部での気
孔率をコントロールすることができる。Regarding temperature conditions, if the processing temperature is too high, oxygen in the oxide film will diffuse quickly and the growth rate of the oxide film will be fast.
Oxygen is difficult to be supplied to the inside of the molded body, and oxidation does not proceed while the porosity remains high inside. Since the growth of the oxide film is slow on the low temperature side, oxygen in the atmosphere moves to the inside, oxidation sintering progresses to the center, and the overall strength is increased. By utilizing this property, the porosity inside and outside can be controlled.
次いで、■のように酸化処理を終えた成形体を還元焼結
する。これは、具体的には還元性雰囲気中で、焼結金属
の融点Ｔｍの０．５〜０．８倍の温度範囲、たとえば純
鉄の場合、Ｔｍ ＝１５３５℃とすると約７７０〜１２
３０℃の範囲の温度条件で加熱することにより行われる
が、本発明の場合、後述のように焼結性が良いため、比
較的低温でまた短時間で実施することができる。Next, as in (2), the oxidized compact is reduced and sintered. Specifically, this is within a temperature range of 0.5 to 0.8 times the melting point Tm of the sintered metal in a reducing atmosphere, for example, in the case of pure iron, if Tm = 1535°C, it is approximately 770 to 12
This is carried out by heating at a temperature in the range of 30°C, but in the case of the present invention, since the sinterability is good as described later, it can be carried out at a relatively low temperature and in a short time.
還元性雰囲気は水素ガス、アンモニア分解ガスなどが使
用されるが、鉄系粉末の場合、補助的ｔこメタンやプロ
パンなどの炭化水素系ガスあるいは一酸化炭素などの添
加雰囲気あるいは、黒鉛粉末や黒鉛を添加したセラミッ
クス粉中にバッキングして還元を促進あるいはさらに加
炭をすることも可能である。この還元焼結工程は前記酸
化処理とともにバッチ火炉あるいはコンベア式、プッシ
ャ一式などの連続炉で行えばよい。Hydrogen gas, ammonia decomposition gas, etc. are used as reducing atmospheres, but in the case of iron-based powders, supplementary hydrocarbon gases such as methane and propane, or added atmospheres such as carbon monoxide, or graphite powder or graphite gases are used. It is also possible to accelerate the reduction or further carburize by backing it in the ceramic powder to which it has been added. This reduction sintering step may be performed together with the oxidation treatment in a batch furnace or a continuous furnace such as a conveyor type or a pusher set.
この還元焼結工程で目的とする金属多孔質体が得られ、
冷却後そのままあるいは機械加工を施すことで製品とな
る。また、要すれば、還元焼結時または焼結後、成形体
に異種金属を含浸あるいは溶浸してもよく、これにより
密度が向上し、強度が増加する。Through this reduction sintering process, the desired porous metal body is obtained,
After cooling, it becomes a product either as is or by machining. Furthermore, if necessary, the compact may be impregnated or infiltrated with a different metal during or after the reduction sintering, thereby increasing the density and strength.
第１図は本発明による焼結挙動を模式的に示すもので、
たとえばバインダとしてエチルシリケートを使用し、ス
リップキャスティングし固化した段階では、第１図（ａ
）のように成形体を構成する金属粒子１，１はわずかに
点状に接触するだけで、金属粒子１，１の周りを粗大な
空孔２，２が取り巻いている。そのため、成形体はきわ
めてポーラスであり、これをそのまま還元焼結しても焼
結は容易に進行せず、高温かつ長時間を要する。FIG. 1 schematically shows the sintering behavior according to the present invention.
For example, when ethyl silicate is used as a binder and is slip casted and solidified,
), the metal particles 1, 1 constituting the molded body are in only point contact, and the metal particles 1, 1 are surrounded by coarse pores 2, 2. Therefore, the molded body is extremely porous, and even if it is subjected to reduction sintering as it is, sintering does not proceed easily and requires a high temperature and a long time.
しかし１本発明のように、還元焼結の前段として積極的
に酸化処理を行えば、第１図（ｂ）のように金属粒子１
，１は酸素との反応で金属酸化粒子１’、’１’ に変
化し、この酸化の際の体積膨張と金属酸化粒子１’ 、
１’の焼結により、連結基地３に変容する。それと同時
に、第１図（ａ）における金属粒子１，１間の空孔２，
２が金属酸化粒子１’ 、１’ により埋められるとと
もに、空孔の合体化が生ずるため閉空孔２′となる。However, if oxidation treatment is actively performed as a pre-stage of reduction sintering as in the present invention, as shown in FIG. 1(b), metal particles 1
, 1 changes into metal oxide particles 1', '1' by reaction with oxygen, and the volume expansion during this oxidation and metal oxide particles 1',
By sintering 1', it transforms into a connecting base 3. At the same time, the holes 2 between the metal particles 1 and 1 in FIG. 1(a),
2 is filled with metal oxide particles 1', 1', and the pores coalesce to form closed pores 2'.
このような金属酸化粒子１’ 、１’の連結基地３が得
られた状態で次に還元が行われるため、還元反応が著し
く促進され、金属酸化粒子１’ 、１’は金属に還元さ
れながら基地金属の流動により収縮し、これにより、第
１図（ｃ）、（ｄ）のごとく焼結の進行とともに、空孔
は絞られる形で分散微細化され１組織の緻密な多孔質体
となるものである。Since the reduction is then carried out in a state where the connecting base 3 of such metal oxide particles 1', 1' is obtained, the reduction reaction is significantly promoted, and the metal oxide particles 1', 1' are reduced to metal while being reduced. It contracts due to the flow of the base metal, and as a result, as sintering progresses, the pores are narrowed and dispersed to become finer, forming a dense porous body with one structure. It is something.
次に本発明の実施例を示す。 Next, examples of the present invention will be shown.
実施例１
■下記第１表の粒度分布（％）の還元鉄粉を用い、これ
にエチルシリケートを１５％添加後、振動混練すること
でスラリー化し、真空脱泡後、雌型に流し込み、脱型後
自然乾燥してφ１０ Ｘ ２０ｍｍの無加圧成形体を得
た。Example 1 ■ Using reduced iron powder with the particle size distribution (%) shown in Table 1 below, add 15% of ethyl silicate to it, make a slurry by vibration kneading, and after vacuum degassing, pour into a female mold and degas. After molding, the product was air-dried to obtain a non-pressure molded product of φ10 x 20 mm.
第 １ 表
■次いで無加圧成形体を、大気雰囲気下で３００〜６５
０℃の保持温度範囲で、保持時間を０．１５，６０，３
６０ｍ１ｎにとって酸化処理した。Table 1 ■Then, the non-pressure molded product was heated to 300 to 65
In the holding temperature range of 0℃, holding time is 0.15, 60, 3
It was oxidized to 60mln.
得られた酸化処理成形体の圧縮強度と開気孔率の関係を
調べた結果を示すと第２図のとおりである。この第２図
から明らかなように、酸化処理を行わない無加圧成形体
にあっては、開気孔率（含水率として測定）が４５％、
圧縮強度１０ｋｇｆ／Ｃｉである。これに対し、酸化処
理を行った場合、開気孔率は低下し、圧縮強度は大きく
上昇する。その上昇度合いは、保持時間および保持温度
に対応する。FIG. 2 shows the results of examining the relationship between compressive strength and open porosity of the obtained oxidized molded body. As is clear from Fig. 2, the open porosity (measured as water content) of the non-pressure molded body without oxidation treatment is 45%,
The compressive strength is 10 kgf/Ci. On the other hand, when oxidation treatment is performed, the open porosity decreases and the compressive strength increases significantly. The degree of increase corresponds to the holding time and holding temperature.
気孔率は５００℃Ｘ ３６０ｍ１ｎの保持の場合に最も
減少していることから、この温度での酸化が著しいもの
と判断される。 ５５０”Ｃでは１５ｍ１ｎ保持まで強
度が向上し、それ以上の温度では、気孔率はｌ５−２１
％、強度は３５０−５００ｋｇｆ／ｊ （７）範囲テホ
ぼ一定値を示している。 ５５０’Ｃ以上の場合、成形
体の表面のみに緻密な酸化層が形成されるために内部ま
で十分な酸化が進行せず、試料全体の強度上昇は認めら
れない、但し、工程■の処理により表面のみが緻密な成
形体を臨む場合にはこの温度での処理も有効となる。Since the porosity decreases the most when the temperature is maintained at 500° C. and 360 ml, it is judged that oxidation is significant at this temperature. At 550"C, the strength increases to 15m1n, and at higher temperatures, the porosity decreases to 15-21
%, the strength is 350-500 kgf/j (7) It shows a constant value within the range. If the temperature is 550'C or higher, a dense oxidized layer is formed only on the surface of the compact, so oxidation does not progress to the inside sufficiently, and no increase in the strength of the entire sample is observed.However, due to the treatment in step Treatment at this temperature is also effective when facing a molded product whose surface is dense.
■次に、酸化処理条件５５０’ＣＸ ３６０ｍ１ｎのも
のにつイテ、７５０℃、９５０”Ｃ，１０５０”ｌ、テ
水素雰囲気中ニテ還元焼結を実施した。(2) Next, reduction sintering was carried out under oxidation treatment conditions of 550'C x 360ml at 750°C, 950''C, 1050''l in a hydrogen atmosphere.
その結果を示すと、第３図のとおりであり、酸化処理を
施さないものは、７５０’Ｃではほとんど焼結せず、強
度も低い、これに対し１本発明を採用したものは、同一
温度の焼結で４−３倍以上の強度を示し、したがって同
一強度を得るためには、たとえば焼結温度で約２００℃
低く、焼結時間で約１７６に短縮できることがわがる。The results are shown in Fig. 3, and the one without oxidation treatment hardly sintered at 750'C and had low strength.In contrast, the one with the present invention applied at the same temperature shows 4-3 times more strength when sintered, so to obtain the same strength, for example, the sintering temperature must be about 200°C.
It can be seen that the sintering time can be reduced to about 176.
このような結果の差異が生じたのは、酸化処理を行わな
い試料では、ただ単に鉄粉接触点の形状改良つまり球状
化により強度が上昇するのに対し、本発明は前述のよう
に酸化処理により接触面積の増加、気孔率の減少が得ら
れ、この状態で還元が行われるためである。The reason for this difference in results is that in the case of samples without oxidation treatment, the strength increases simply by improving the shape of the iron powder contact point, that is, by making it spherical, whereas in the present invention, the strength increases simply by improving the shape of the iron powder contact point, that is, by making it spherical. This is because the contact area increases and the porosity decreases, and reduction takes place in this state.
また、 １１５０℃Ｘ ６０＋ｉｉｎ処理により得られ
た金属多孔質体のミクロ組織を示すと第４図（ａ）のと
おりである、第４図（ｂ）は酸化処理を行わずに還元焼
結した金属多孔質体のミクロ組織を示すものである。こ
れらを比較して明らかなように、酸化処理を行わなかっ
たものは大きな気孔が全体に散在して焼結が進行してい
ないが１本発明の場合は、気孔が細かく分散して微細化
しており、さらにその形状も角が取れて球状化している
。In addition, the microstructure of the metal porous body obtained by the 1150°C It shows the microstructure of a porous body. As is clear from comparing these, large pores are scattered throughout the product without oxidation treatment and no sintering progresses, whereas in the case of the present invention, the pores are finely dispersed and become finer. Furthermore, its shape is rounded and spherical.
実施例２
Ｎｉアトマイズ粉（−２００メツシユ）にエチルシリケ
ートを１４％添加して、実施例１と同様な手法により多
孔質体を製造した。５００℃Ｘ６ｈｒの予備酸化後、１
１５０℃で３０ｍ１ｎ焼結したところ、未処理の試料の
圧縮強度１０４１０４Ｏ／ａＪ（気孔率３６％）のもの
が圧縮強度３１８０ｋｇｆ／ｄ （気孔率３２％）へと
゛約３倍の強度上昇を得ることができた。Example 2 A porous body was produced in the same manner as in Example 1 by adding 14% ethyl silicate to Ni atomized powder (-200 mesh). After preliminary oxidation at 500°C for 6 hours, 1
When sintering 30ml at 150°C, the untreated sample with a compressive strength of 104,104 O/aJ (porosity: 36%) became compressive strength of 3,180 kgf/d (porosity: 32%), an increase of approximately 3 times in strength. was completed.
なお、Ｆｅ−８％Ｃｕの混合粉を用いて実施例１と同様
な手法で処理した試料は１．６３００ｋｇｆ／ａＩｔ（
気孔率３０％）が得られた。In addition, the sample treated in the same manner as in Example 1 using Fe-8%Cu mixed powder had a yield of 1.6300 kgf/aIt (
A porosity of 30% was obtained.
以上説明した本発明によるときには、スリップキャステ
ィング法による無加圧成形のメリットを生かしつつ、同
時にその弱点をカバーして気孔が微細に分散した高強度
な金属多孔質体を容易に製造できるという優れた効果が
得られる。According to the present invention as described above, while taking advantage of the advantages of non-pressure forming using the slip casting method, at the same time it is possible to easily manufacture a high-strength metal porous body with finely dispersed pores by covering its weaknesses. Effects can be obtained.
本発明はプラスチックの真空成形、ゴム成形、陶磁器成
形などをはじめとする各種通気性・吸水性の型材や、各
種多孔質機械部品構造用部品等の製造に利用することが
できる。The present invention can be used to manufacture various types of breathable and water-absorbing mold materials, including vacuum molding of plastics, rubber molding, ceramic molding, etc., and structural parts of various porous mechanical parts.
第１図は本発明の活性化焼結による金属多孔質体の製造
法における成形体の焼結挙動を模式的に示す説明図、第
２図は酸化処理を行った場合の圧縮強度と気孔率の関係
を示すグラフ、第３図は還元焼結に及ぼす酸化処理の影
響を示すグラフ、第４図（ａ）は本発明により得られた
金属多孔質体のミクロ組織写真（Ｘ６７）、第４図（ｂ
）は酸化処理を行わない金属多孔質体のミクロ組織写真
（Ｘ６７）である。Figure 1 is an explanatory diagram schematically showing the sintering behavior of a molded body in the method of manufacturing a porous metal body by activated sintering of the present invention, and Figure 2 is a diagram showing compressive strength and porosity when oxidation treatment is performed. Figure 3 is a graph showing the influence of oxidation treatment on reduction sintering, Figure 4 (a) is a microstructure photograph (X67) of the porous metal body obtained by the present invention, Figure (b
) is a microstructure photograph (X67) of a metal porous body that is not subjected to oxidation treatment.
Claims (1)
より成形し、この成形体を乾燥後酸化処理してから還元
性雰囲気中で加熱焼結することを特徴とする活性化焼結
による金属多孔質体の製造法。A porous metal body is produced by activation sintering, which is characterized in that a mixed sample of metal powder and a binder is molded by slip casting, and this molded body is dried, oxidized, and then heated and sintered in a reducing atmosphere. Manufacturing method.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10940886A JPS62267402A (en) | 1986-05-15 | 1986-05-15 | Production of porous metallic body by activated sintering |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10940886A JPS62267402A (en) | 1986-05-15 | 1986-05-15 | Production of porous metallic body by activated sintering |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS62267402A true JPS62267402A (en) | 1987-11-20 |
| JPH0478681B2 JPH0478681B2 (en) | 1992-12-11 |
Family
ID=14509491
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP10940886A Granted JPS62267402A (en) | 1986-05-15 | 1986-05-15 | Production of porous metallic body by activated sintering |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS62267402A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0219430A (en) * | 1988-07-08 | 1990-01-23 | Sintokogio Ltd | Production of metallic porous body |
| JPH0413803A (en) * | 1990-05-07 | 1992-01-17 | Godo Imono Gijutsu:Kk | Method for injection-compacting metal powder |
| KR100367655B1 (en) * | 2000-02-10 | 2003-01-10 | 김성균 | Process for Making Porous Metals and Alloys |
| WO2007013712A1 (en) * | 2005-07-27 | 2007-02-01 | Korea Research Institute Of Chemical Technology | Preparation method of metallic membranes |
| WO2018212554A1 (en) * | 2017-05-16 | 2018-11-22 | 주식회사 엘지화학 | Method for manufacturing metal foam |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS49115010A (en) * | 1973-02-22 | 1974-11-02 |
-
1986
- 1986-05-15 JP JP10940886A patent/JPS62267402A/en active Granted
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS49115010A (en) * | 1973-02-22 | 1974-11-02 |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0219430A (en) * | 1988-07-08 | 1990-01-23 | Sintokogio Ltd | Production of metallic porous body |
| JPH0413803A (en) * | 1990-05-07 | 1992-01-17 | Godo Imono Gijutsu:Kk | Method for injection-compacting metal powder |
| KR100367655B1 (en) * | 2000-02-10 | 2003-01-10 | 김성균 | Process for Making Porous Metals and Alloys |
| WO2007013712A1 (en) * | 2005-07-27 | 2007-02-01 | Korea Research Institute Of Chemical Technology | Preparation method of metallic membranes |
| WO2018212554A1 (en) * | 2017-05-16 | 2018-11-22 | 주식회사 엘지화학 | Method for manufacturing metal foam |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0478681B2 (en) | 1992-12-11 |
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