JPS6248737B2

JPS6248737B2 -

Info

Publication number: JPS6248737B2
Application number: JP57143844A
Authority: JP
Inventors: Isao Okutomi; Hideo Suzuki; Shigeaki Sekiguchi; Ikuo Matsura
Original assignee: Tokyo Shibaura Electric Co Ltd
Current assignee: Toshiba Corp
Priority date: 1982-08-19
Filing date: 1982-08-19
Publication date: 1987-10-15
Also published as: JPS5935643A

Description

[Detailed description of the invention]

〔発明の技術分野〕本発明は、粉末治金法（焼結法）による接点材
料の製造方法に係り、特に均質な接点特性を有す
る焼結型接点材料の製造方法に関する。〔発明の技術的背景とその問題点〕接点に要求される特性としては、(イ)耐電圧が高
いこと、(ロ)しや断性がよいこと、(ハ)耐消耗性がよ
いこと、(ニ)接触抵抗が低く安定していること、な
どがある。しかしながら、これらの特性の全てを
満足する接点材料を得ることは現実にはなかなか
困難である。したがつて現実の接点においては、
使用される回路あるいは機器が要求する特に重要
な特性を優先させ、他の特性を幾分犠牲にしてい
るのが実情である。なかでも、Ｗ等の耐アーク性成分とCu、Ag等
の高導電性成分とからなり、両者の混合粉末の粉
末治金法による合金化、あるいは前者の仮焼体
（多孔質焼結体）に後者を溶浸させることにより
得られる焼結型接点材料は、耐電圧特性および耐
消耗性が優れており、現在広く使用されている
が、この接点材料にも耐溶着性、しや断性、接触
抵抗特性等の点において未だ不満足な点がある。
したがつて、上記した主要成分材に加えて、Bi、
Pb、Te、Sb等の耐溶着性成分あるいはNi、Fe、
Co、Ｂ等の焼結性改善成分等からなる補助成分
材を添加して、上記諸特性を改善する試みも検討
されている。これら補助成分材の添加は、それなりに効果的
なものであるが、それによる焼結型接点材料の特
性の改善は必ずしも満足すべきものとはいいがた
い。それは、接触抵抗、耐電圧性、耐溶着性、し
や断特性に影響するさい断電流値等の特性がばら
つき、不安定となることである。上述した焼結型接点材料の特性の不安定性は、
本発明者らの当初の研究によれば、焼結型接点で
あるための接触面における表面荒れ、焼結過程に
おける補助成分材の揮発等による逸散などの要因
が寄与しているものと考えられた。しかしなが
ら、本発明者らが更に研究した結果、上記特性の
ばらつきの少なからぬ部分が、補助成分材の添加
量が少量であることに伴い生ずる分布の不均一性
に起因することが見出された。すなわち、主要成
分材の与える接点材料の基本的特性を損なわずに
諸特性の改善を行うためには加えられる補助成分
材の添加量は、通常、数％ないしそれ以下の少な
いし微量である。ところが、従来は、このような
少量の補助成分材粉末を大量の主要成分材粉末と
一括して混合していたため、両粉末を充分に微細
化し、また両者の充分な混合を行つたつもりであ
つても、補助成分材が製品中に偏析して接点特性
のばらつきの原因となつていることが判明した。〔発明の目的〕本発明は、上述した粉末治金法による焼結型接
点材料の製造技術における欠点に鑑み、主要成分
材の与える基本的特性を維持しつつ少量添加され
る補助成分材の効果を効果的に発揮させて均質に
特性の改善された焼結型接点材料を製造するため
の方法を確立することを目的とする。〔発明の概要〕本発明者らは、上述した補助成分材の接点材料
中における偏析を避けるためには、主要成分材と
の最初の混合過程が重要な影響を有することを見
出した。すなわち、少量の補助成分材粉末と大量
の主要成分材粉末とを一括混合するのではなく、
最初は補助成分材粉末と主要成分材粉末とをほぼ
等量混合し、その後、更に所定配合となるように
残部の主要成分材粉末と混合して得た混合粉末を
粉末治金に供することにより、接触抵抗、耐電圧
性、耐溶着性、さい断電流値等のばらつきが著し
く減少することが見出された。本発明の接点材料
の製造方法の第１は、このような知見に基づくも
のであり、より詳しくは、高導電性成分と耐アー
ク性成分とからなる主要成分材と、溶着防止成分
および焼結性改善成分より選ばれた補助成分材
と、の混合粉末を粉末治金法によつて合金化して
接点材料を製造するに際し、まず、補助成分材粉
末とこれとほぼ同量の主要成分材の一部の粉末と
を混合して１次混合粉末を得、この１次混合粉末
と残余の主要成分材粉末とを混合して混合粉末を
得、これを粉末治金に供することを特徴とするも
のである。また、上述の主要成分材と補助成分材の初期の
等量混合に伴なう効果は、耐アーク性成分を主成
分とする仮焼結体に溶浸させるべき溶浸材の形成
のための混合工程に適用しても製品接点材料に顕
著に現われることが見出された。すなわち、本発
明の接点材料の製造方法の第２は、耐アーク性成
分単独又はこれと高導電性成分もしくは焼結性改
善成分との混合粉末の成形体からなる多孔質成形
体と、高導電性成分と溶着防止成分との混合粉末
の成形体からなる溶浸材成形体とを積層し、積層
体を加熱して溶融した溶浸材を多孔質成形体に含
浸させて接点材料を製造するに際し、溶浸材成形
体形成用混合粉末を得るために、まず溶着防止成
分粉末とこれとほぼ同量の高導電性成分とを混合
して１次混合粉末を得、この１次混合粉末と残余
の高導電性成分粉末とを混合することを特徴とす
るものである。以下、本発明を更に詳細に説明する。以下の記
載において、組成を表わす「％」は特に断らない
限り重量基準とする。〔発明の具体的説明〕本発明法で原料として使用する主要成分材は、
高導電性成分と耐アーク性成分とからなる。高導
電性成分としては、Cu、Agあるいはこれらの両
者を組合せて、通常、接点材料の15〜65％をなす
量で用いられる。また耐アーク性成分としては、
Ｗ、Mo、Cr、WC、MoC、Cr₃C₂等が、上記高導
電性成分および後述する補助成分材の残部をなす
量で用いられる。一方、補助成分材は、溶着防止成分および焼結
性改善成分より選ばれる。溶着防止成分として
は、Bi、Pb、Te、Sb等が、また、焼結性改善成
分としては、Ni、Fe、Co、Ｂ等が挙げられる。
これら補助成分は、一般に接点材料の10％以下の
量で使用されるが、本発明の効果は特に３％以下
の微量で添加されたときに顕著である。本発明の第１の方法にしたがい、まず上記補助
成分材粉末とこれとほぼ同量の主要成分材の一部
の粉末とを混合して１次混合粉末を得る。ここで
ほぼ同量とは、補助成分材粉末と主要成分材粉末
との重量比が６：４〜４：６の範囲を包含する趣
旨で用いる。また混合すべき主要成分材の一部
は、高導電性成分および耐アーク性成分の混合物
あるいはいずれか一方のみのどちらでもよい。混
合装置としては、リボンブレンダー、Ｖ型ブレン
ダー、回転円筒型ブレンダー等の通常の粉体混合
装置に加えてボールミル、擂潰機等の摩砕効果を
伴なう混合装置が効果的に使用できる。次いで、上記１次混合粉末の全部あるいは一部
を取り出して、これを残余の主要成分材粉末と混
合して粉末治金用の原料粉末を得る。接点材料中
における主要成分成材と補助成分材の量比が大で
ある場合には、この１次混合粉末と残余の主要成
分材粉末との混合自体を複数の工程に分けること
もできる。すなわち、まず１次混合粉末と残余の
主要成分材粉末の一部とを混合し、この混合粉末
と更に残る主要成分材粉末とを混合する工程を繰
り返すことができる。一般に、ｎ次混合粉末（ｎ
＝１、２……）と残余の主要成分材粉末とを混合
して（ｎ＋１）次混合粉末を得る場合、混合すべ
き粉末相互の量比は１：５以内であることが好ま
しい。但し、主要成分材粉末と補助成分材粉末と
を最初に混合して第１次混合粉末を得るとき程の
影響は少ない。上記混合を行うにあたつての主要成分材粉末お
よび補助成分材粉末の粒径は一般に細かい程好ま
しく、150μ以下、特に100μ以下が好ましい。ま
た主要成分材粉末と補助成分材粉末との粒径（針
状の場合は長さ）の比も近似していることが好ま
しく、一般に１：10〜10：１の範囲、特に１：３
〜３：１の範囲が好ましい。このようにして得られた混合粉末を、たとえば
１〜10トン／cm²の圧力で圧粉成形し、非酸化性雰
囲気中1000〜1300℃程度の温度で焼結する等の通
常の粉末治金法により接点材料が得られる。また、本発明の第２の方法では、溶浸を伴う焼
結型接点材料の製造方法に関し、上記第１の方法
における粉体混合の均質化の手法を溶浸材を構成
する高導電性粉末と溶着防止成分粉末との混合に
適用するものである。すなわち、この第２の方法においては、まず、
溶着防止成分粉末とこれとほぼ同量の高導電性成
分粉末とを混合して１次混合粉末を得、これを更
に溶浸材を構成する残余の高導電性成分粉末と混
合して溶浸材形成用混合粉末を得る。この１次混
合粉末から溶浸材形成用混合粉末を得るための混
合を複数の工程で行うことができることも第１の
方法と同様である。このようにして得られた溶浸材形成用混合粉末
を圧粉成形して溶浸材成形体を得る。この溶浸材
成形体を更に焼結に付してもよいが、その必要性
はない。一方、これとは別に、耐アーク性成分単独また
はこれと高導電性成分および／または焼結性改善
成分および／またはパラフイン等のバインダー兼
気孔形成材の粉末をたとえば１〜10トン／cm²で圧
粉成形し、非酸化性雰囲気中1000〜1200℃で焼結
して空隙率50〜80容量％程度の仮焼結体からなる
多孔質成形体を得る。次いで前記溶浸材成形体とこの多孔質成形体と
を積層し、更に非酸化性雰囲気中1100〜1300℃に
加熱することにより溶浸材を溶融させ多孔質成形
体中に含浸させたのち固化させ必要に応じて整形
加工することにより第２の方法による接点材料が
得られる。このように溶浸材は、一旦溶融後多孔
質成形体に含浸する過程を伴うにも拘らず、その
原料粉末混合工程における混合の適否は製品接点
材料の特性にまで影響する。以下、実施例、比較例により、本発明を更に具
体的に説明する。〔発明の実施例、比較例〕比較例１平均粒径３μのＷ粉末に１％のパラフインを加
え２トン／cm²のプレス圧にて圧縮し所定形状に成
形後、水素雰囲気中約1150℃で焼結して所定の空
隙率を有する仮焼結体を得た。一方、所定割合のCu粉末（平均粒径40μ）と
Sb粉末（平均粒径40μ）とを擂潰機を用い1400r.
p.m.の条件で20分間混合し、得られた混合粉末
を１トン／cm²の圧力でプレスして溶浸材圧粉成形
体を得た。次いで、上記で得られた仮焼結体（厚さ約５
mm）上に溶浸材成形体（厚さ約2.5mm）を重ね、
両者を水素雰囲気中1200゜で60分間保持すること
により仮焼結体への溶浸を行い、冷却固化して目
標組成Ｗ（残）−Cu（25.3％）−Sb（0.11％）の
接点素材を得た。このようにして得られた900個の接点素材の全
数について導電率を測定したところ平均値が33.8
％I.A.C.S.に対して、第９・10分位が41.8％I.A.
C.S.、第１・10分位が36.2％I.A.C.S.であつた
（表−１）。次いで導電率によつて900個の接点素材を３つ
のグループに区別した。すなわち、導電率が高い
グループから低いグループへと順に第１、第２、
第３グループと区別し、それぞれのグループから
10個ずつの接点素材を抜取り、化学分析によつて
Sb量を測定した。各グループについて最大、最
小の値を下表−１に示す。一方、導電率によつて区別した上記第１、第
２、第３のグループから抜き取りで代表素材を定
め、耐溶着性および絶縁破壊特性を測定した。耐溶着性は、素材を一対の径2.5mmφの円板状
試料に加工し、更にその一方を平板のまま、他方
を100Rの球面にしたものを対向させ100Kgの荷重
を加え7.2KV×31KAの短時間通電後に一対の試
料間の引きはずしに要する力をもつて測定した。
一方、絶縁破壊特性は、同じく径2.5mmφの平面
状接点素材と、先端が1.5Rの球面を有する径３
mmφの純銅円柱を0.5mm離して対向させたときの
絶縁破壊電圧を測定して評価した。試料をかえて
行つた各６回の測定の結果の分布状況をあわせて
表−１に記す。実施例１溶浸材形成用混合粉末を以下のようにして得た
以外は全く比較例−１と同様にして900個の接点
素材を得た。すなわち、まず150ｇのSb粉末と同量のCu粉末
をボールミル（ステンレス製ポツト）により50r.
p.m.の条件で60分間混合して１次混合粉末を得
た。次いで、この１次混合粉末に追加のCu粉末
を加え、ステンレス製ポツトに入れて、ボールミ
ルにより、50r.p.m.の条件で60分間混合し同量の
Cuを数次にわたり加え最終的に25.3Kgの混合粉
末を得た。この混合粉末を１トン／cm²の圧力でプ
レスして溶浸材成形体を得、更にこの溶浸材成形
体を用いる以外は比較例−１と同様にして同一目
標組成の接点素材を得た。得られた900個の接点素材について、比較例−
１と同様にして行つた特性評価結果をあわせて表
−１に記す。実施例２ 950個の仮焼結体を作製した。溶浸材形成用混合粉末は、次のようにして得
た。すなわち、500ｇのSb粉末と同量のCu粉末を
実施例−１で用いたボールミルを用い、同様な条
件で混合して１次混合粉末を得た。次いで、この
１次混合粉末から300ｇを取出し、これに１Kgの
Cu粉末を加え、擂潰機により1400r.p.m.の条件
で30分間混合して２次混合粉末を得、更にその全
量に５KgのCu粉末を同様の条件で混合して３次
混合粉末を得、更に19.15KgのCu粉末を加えて同
様の条件で混合することにより計25.45Kgの４次
混合粉末を得た。この４次混合粉末を用いて実施
例−１と同様にして950個の溶浸材成形体を得
た。これら溶浸材成形体と上記仮焼結体とより比較
例−１と同様にして同一目標組成の接点素材を得
た。得られた接点素材について、比較例−１および
実施例−１と同様にして行つた特性評価の結果も
併せて表−１に示す。 [Technical Field of the Invention] The present invention relates to a method for manufacturing a contact material using a powder metallurgy method (sintering method), and particularly to a method for manufacturing a sintered contact material having homogeneous contact characteristics. [Technical background of the invention and its problems] Characteristics required for contacts include (a) high withstand voltage, (b) good breakability, (c) good wear resistance, (d) Contact resistance is low and stable. However, it is actually quite difficult to obtain a contact material that satisfies all of these characteristics. Therefore, at the point of contact with reality,
The reality is that particularly important characteristics required by the circuit or equipment used are given priority, at the expense of some other characteristics. Among these, it consists of arc-resistant components such as W and highly conductive components such as Cu and Ag, and alloying of a mixed powder of both by powder metallurgy, or a calcined body (porous sintered body) of the former is possible. The sintered contact material obtained by infiltrating the latter with the latter has excellent withstand voltage characteristics and wear resistance, and is currently widely used. However, there are still some unsatisfactory points in terms of contact resistance characteristics, etc.
Therefore, in addition to the above-mentioned main component materials, Bi,
Welding resistant components such as Pb, Te, Sb or Ni, Fe,
Attempts have also been made to improve the above-mentioned properties by adding auxiliary components consisting of sinterability improving components such as Co and B. Although the addition of these auxiliary components is effective in its own way, it cannot be said that the improvement in the properties of the sintered contact material is necessarily satisfactory. This is because properties such as contact resistance, voltage resistance, welding resistance, and shearing current values that affect shearing characteristics vary and become unstable. The instability of the properties of the sintered contact material mentioned above is due to
According to the inventors' initial research, it is believed that factors such as surface roughness on the contact surface due to the sintered contact and dissipation due to volatilization of auxiliary component materials during the sintering process are thought to be contributing factors. It was done. However, as a result of further research by the present inventors, it was discovered that a considerable part of the variation in the above characteristics was due to the non-uniformity of the distribution that occurred due to the small amount of auxiliary component material added. . That is, in order to improve various properties of the contact material without impairing the basic properties provided by the main component material, the amount of the auxiliary component material added is usually a small to trace amount of several percent or less. However, in the past, such a small amount of auxiliary component material powder was mixed with a large amount of main component material powder at once, and it was thought that both powders were made sufficiently fine and that they were sufficiently mixed. However, it was found that auxiliary component materials segregated in the product and caused variations in contact characteristics. [Object of the Invention] In view of the drawbacks in the manufacturing technology of sintered contact materials using the powder metallurgy method described above, the present invention aims to improve the effects of auxiliary component materials added in small amounts while maintaining the basic properties provided by the main component materials. The purpose of this study is to establish a method for producing a sintered contact material with uniformly improved properties by effectively exhibiting the following properties. [Summary of the Invention] The present inventors have discovered that the initial mixing process with the main component material has an important influence in order to avoid segregation of the above-mentioned auxiliary component material in the contact material. In other words, rather than mixing a small amount of auxiliary component material powder and a large amount of main component material powder all at once,
Initially, the auxiliary component material powder and the main component material powder are mixed in approximately equal amounts, and then further mixed with the remaining main component material powder to obtain a predetermined mixture, and the resulting mixed powder is subjected to powder metallurgy. It was found that variations in contact resistance, voltage resistance, welding resistance, cutting current value, etc. were significantly reduced. The first method of manufacturing a contact material of the present invention is based on such knowledge, and more specifically, the first method for manufacturing a contact material of the present invention is based on the above knowledge. When producing a contact material by alloying a mixed powder of the auxiliary component material selected from the properties improving components using the powder metallurgy method, first, the auxiliary component material powder and approximately the same amount of the main component material are mixed together. A primary mixed powder is obtained by mixing some of the powders, and this primary mixed powder is mixed with the remaining main component material powder to obtain a mixed powder, which is then subjected to powder metallurgy. It is something. In addition, the effect associated with the initial mixing of equal amounts of the main component material and the auxiliary component material described above is effective for forming the infiltrant material to be infiltrated into the preliminary sintered body whose main component is the arc-resistant component. It has been found that even when applied to the mixing process, it appears prominently in product contact materials. That is, the second method for producing a contact material of the present invention is to prepare a porous compact made of a powder compact of an arc-resistant component alone or a mixed powder of this and a highly conductive component or a sinterability improving component, and a highly conductive component. A contact material is manufactured by laminating an infiltrant molded body consisting of a molded body of a mixed powder of an adhesive component and a welding prevention component, and heating the laminate to impregnate the porous molded body with the molten infiltrant. In order to obtain a mixed powder for forming an infiltrant compact, first, a welding prevention component powder and approximately the same amount of a highly conductive component are mixed to obtain a primary mixed powder, and this primary mixed powder and It is characterized by mixing with the remaining highly conductive component powder. The present invention will be explained in more detail below. In the following description, "%" representing the composition is based on weight unless otherwise specified. [Specific description of the invention] The main ingredients used as raw materials in the method of the present invention are:
It consists of a highly conductive component and an arc-resistant component. As the highly conductive component, Cu, Ag, or a combination of both is usually used in an amount that makes up 15 to 65% of the contact material. In addition, as arc-resistant components,
W, Mo, Cr, WC, MoC, Cr ₃ C ₂ and the like are used in amounts forming the highly conductive component described above and the remainder of the auxiliary component materials described below. On the other hand, the auxiliary component material is selected from a welding prevention component and a sinterability improving component. Welding prevention components include Bi, Pb, Te, Sb, etc., and sinterability improving components include Ni, Fe, Co, B, etc.
These auxiliary components are generally used in an amount of 10% or less of the contact material, but the effects of the present invention are particularly remarkable when they are added in a trace amount of 3% or less. According to the first method of the present invention, first, the auxiliary component material powder and approximately the same amount of powder of a part of the main component material are mixed to obtain a primary mixed powder. Here, "substantially the same amount" is used to mean that the weight ratio of the auxiliary component material powder and the main component material powder is in the range of 6:4 to 4:6. Further, a part of the main components to be mixed may be a mixture of a highly conductive component and an arc-resistant component, or only one of them. As the mixing device, in addition to ordinary powder mixing devices such as a ribbon blender, V-type blender, and rotating cylindrical blender, mixing devices with a grinding effect such as a ball mill and a crusher can be effectively used. Next, all or part of the primary mixed powder is taken out and mixed with the remaining main component material powder to obtain a raw material powder for powder metallurgy. If the ratio of the main component to the auxiliary component in the contact material is large, the mixing itself of the primary mixed powder and the remaining main component powder can be divided into multiple steps. That is, it is possible to repeat the process of first mixing the primary mixed powder and a portion of the remaining main component material powder, and then mixing this mixed powder with the remaining main component material powder. Generally, n-order mixed powder (n
= 1, 2...) and the remaining main component material powder to obtain the (n+1)-order mixed powder, it is preferable that the ratio of the amounts of the powders to be mixed is within 1:5. However, the effect is less than when the primary mixed powder is obtained by first mixing the main component material powder and the auxiliary component material powder. In performing the above-mentioned mixing, the particle size of the main component material powder and the auxiliary component material powder is generally preferably as fine as possible, and is preferably 150 μm or less, particularly 100 μm or less. It is also preferable that the ratio of the particle size (length in the case of acicular shape) of the main component material powder and the auxiliary component material powder is similar, generally in the range of 1:10 to 10:1, particularly 1:3.
A range of 3:1 is preferred. The mixed powder obtained in this way is compacted at a pressure of 1 to 10 tons/cm ² and sintered at a temperature of about 1000 to 1300°C in a non-oxidizing atmosphere. A contact material is obtained by the method. In addition, in the second method of the present invention, regarding a method for manufacturing a sintered contact material that involves infiltration, the method of homogenizing the powder mixing in the first method is applied to the highly conductive powder constituting the infiltration material. It is applied to the mixing of the powder and the welding prevention component powder. That is, in this second method, first,
A primary mixed powder is obtained by mixing the welding prevention component powder and approximately the same amount of highly conductive component powder, and this is further mixed with the remaining highly conductive component powder that constitutes the infiltrant material for infiltration. A mixed powder for material formation is obtained. Similar to the first method, mixing for obtaining a mixed powder for forming an infiltrant material from this primary mixed powder can be performed in a plurality of steps. The thus obtained mixed powder for forming an infiltrant is compacted to obtain an infiltrant molded body. This infiltrant compact may be further subjected to sintering, but this is not necessary. On the other hand, separately from this, the arc-resistant component alone or together with the highly conductive component and/or sinterability improving component and/or powder of a binder and pore-forming material such as paraffin is added at a rate of, for example, 1 to 10 tons/cm ² . The powder is compacted and sintered at 1000 to 1200°C in a non-oxidizing atmosphere to obtain a porous molded body consisting of a pre-sintered body with a porosity of about 50 to 80% by volume. Next, the infiltrant molded body and this porous molded body are laminated, and the infiltrant is melted by heating to 1100 to 1300°C in a non-oxidizing atmosphere, impregnated into the porous molded body, and then solidified. A contact material according to the second method is obtained by processing the contact material according to the second method. As described above, although the infiltrant involves the process of once melting and then impregnating the porous molded body, the suitability of mixing in the raw material powder mixing step affects the characteristics of the product contact material. Hereinafter, the present invention will be explained in more detail with reference to Examples and Comparative Examples. [Examples and Comparative Examples of the Invention] Comparative Example 1 1% paraffin was added to W powder with an average particle size of 3μ, compressed with a press pressure of 2 tons/cm ² and molded into a predetermined shape, and then heated at approximately 1150°C in a hydrogen atmosphere. A pre-sintered body having a predetermined porosity was obtained. On the other hand, with a predetermined proportion of Cu powder (average particle size 40μ)
Sb powder (average particle size 40μ) was crushed at 1400 rpm using a crusher.
After mixing for 20 minutes under pm conditions, the obtained mixed powder was pressed at a pressure of 1 ton/cm ² to obtain an infiltrant powder compact. Next, the temporary sintered body obtained above (thickness of about 5
Overlay the infiltration material molded body (approximately 2.5 mm thick) on top of the
By holding both in a hydrogen atmosphere at 1200° for 60 minutes, the pre-sintered body is infiltrated, cooled and solidified to form a contact material with the target composition W (remainder) - Cu (25.3%) - Sb (0.11%). I got it. When we measured the conductivity of all 900 contact materials obtained in this way, the average value was 33.8.
Compared to %IACS, the 9th and 10th deciles are 41.8%IA
CS, the 1st and 10th deciles had an IACS of 36.2% (Table 1). The 900 contact materials were then divided into three groups based on their conductivity. In other words, the first, second, and
Distinguish from the third group, and from each group
Ten contact materials were extracted and chemically analyzed.
The amount of Sb was measured. The maximum and minimum values for each group are shown in Table 1 below. On the other hand, representative materials were selected from the first, second, and third groups, which were differentiated based on electrical conductivity, and their welding resistance and dielectric breakdown characteristics were measured. Welding resistance was tested by processing the material into a pair of disc-shaped specimens with a diameter of 2.5 mm, and then placing one of the specimens as a flat plate and the other with a 100R spherical surface facing each other, and applying a load of 100Kg to the specimen. The force required to separate the pair of samples after energization for a short time was measured.
On the other hand, the dielectric breakdown characteristics are the same as those for a flat contact material with a diameter of 2.5 mmφ and a diameter of 3 with a 1.5 R spherical tip.
The dielectric breakdown voltage was measured and evaluated when pure copper cylinders of mmφ were placed facing each other with a distance of 0.5 mm. Table 1 also shows the distribution of the results of six measurements performed with different samples. Example 1 900 contact materials were obtained in the same manner as in Comparative Example-1 except that the mixed powder for forming the infiltrant was obtained as follows. That is, first, 150g of Sb powder and the same amount of Cu powder were mixed in a ball mill (stainless steel pot) for 50r.
The mixture was mixed for 60 minutes under pm conditions to obtain a primary mixed powder. Next, additional Cu powder was added to this primary mixed powder, placed in a stainless steel pot, and mixed for 60 minutes at 50 rpm using a ball mill to add the same amount of Cu powder.
Cu was added several times to obtain a final mixed powder weighing 25.3 kg. This mixed powder was pressed at a pressure of 1 ton/cm ² to obtain an infiltrant molded body, and a contact material with the same target composition was obtained in the same manner as Comparative Example 1 except for using this infiltrant molded body. Ta. Comparative example of the obtained 900 contact materials
The results of the characteristic evaluation conducted in the same manner as in 1 are also shown in Table 1. Example 2 950 pre-sintered bodies were produced. The mixed powder for forming an infiltrant was obtained as follows. That is, 500 g of Sb powder and the same amount of Cu powder were mixed under the same conditions using the ball mill used in Example-1 to obtain a primary mixed powder. Next, take out 300g from this primary mixed powder and add 1kg to it.
Add Cu powder and mix for 30 minutes at 1400 rpm using a crusher to obtain a secondary mixed powder, and further mix 5 kg of Cu powder to the entire amount under the same conditions to obtain a tertiary mixed powder. Furthermore, 19.15 kg of Cu powder was added and mixed under the same conditions to obtain a total of 25.45 kg of quaternary mixed powder. Using this quaternary mixed powder, 950 infiltrant molded bodies were obtained in the same manner as in Example-1. A contact material having the same target composition was obtained in the same manner as in Comparative Example 1 using these infiltrant molded bodies and the above-mentioned temporary sintered body. Table 1 also shows the results of characteristic evaluations performed on the obtained contact materials in the same manner as Comparative Example 1 and Example 1.

【表】表−１の結果を見ると、溶浸材原料の混合を従
来の方法によつて行つた比較例−１の接点におい
ては、軽い溶着が発生したり、あるいは絶縁破壊
電圧値が低下するグループが存在するなど特性の
ばらつきが大であり、またこの特性のばらつき
は、導電率のばらつき、Sb量のばらつきとも対
応しており本発明法により微量成分を厳密に制御
することの重要性を示している。比較例２ 390ｇのAg粉末（平均粒径５μ）、600ｇのWC
粉末（平均粒径３μ）、10ｇのTe粉末（平均粒径
15μ）を擂潰機により1400r.p.m.の条件で混合
し、混合粉末を得た。この混合粉末を1.5トン／
cm²の圧力で成形し、1200℃水素雰囲気中で１時間
焼結して接点素材を得た。この素材より径８mm、
厚さ４mmの接点片を切り出し、200V×100Aで５
×10⁴回の開閉テストを行つたところ、41回の溶
着を発生した。50個の接点片について導電率分布
は59〜45％I.A.C.S.の範囲を示した。実施例３ 10ｇのAg粉末と、10ｇのTe粉末とを擂潰機に
より1400r.p.m.の条件で混合して、１次混合粉末
を得た。次いでこの１次混合粉末に80ｇのAg粉
末を加えて混合して２次混合粉末を、更に100ｇ
のAg粉末を加えて混合して３次混合粉末を、更
に200ｇのAg粉末と600ｇのWC粉末とを加えて混
合して、結果として比較例−２と全体組成を同じ
くする混合粉末を得た。途中の混合条件は、１次
混合粉末を得るための条件と同じである。得られた混合粉末について、比較例−２と同様
にして接点素材を得、また同様の条件での特性評
価を行つたところ、溶着発生回数は２回と大巾に
減少し、また導電率分布は60〜57％I.A.C.S.の範
囲となつた。これら溶着発生回数の低下および導
電率のばらつきの減少も、微量の被助成分材であ
るTeの均一分散の効果と考えられる。比較例３ Cu−65％ MoC−0.5％ Bi−0.1％ Ni接点の
製造のために、688ｇのCu粉末（平均粒径40
μ）、1300ｇのMoC粉末（平均粒径３μ）、10ｇ
のBi粉末（平均粒径40μ）および２ｇのNi粉末
（平均粒径30μ）を擂潰機により1400r.p.m.で30
分の条件で混合して混合粉末を得た。この混合粉
末を1.0トン／cm²の圧力で圧粉成形後、水素雰囲
気中1200℃で焼結して400個の接点片を得た。これら接点片について求めたさい断電流値およ
び化学分析値の分布は後表−２に示す通りであ
る。実施例４２ｇのNi粉末と同量のCu粉末とを乳鉢による
手混合の条件で混合して１次混合粉末を得た。そ
れぞれ同様な混合条件により、この１次混合粉末
と10ｇのMoC粉末とを混合して２次混合粉末
を、この２次混合粉末と10ｇBi粉末とを混合して
３次混合粉末を得た。更にこの３次混合粉末と
686ｇのCu粉末を擂潰機により1400r.p.m.で30分
間混合し４次混合粉末を得た。更に、この４次混合体と1290ｇのMoC粉末と
を混合して５次混合粉末を、逐次得た。このようにして得た５次混合粉末を原料として
比較例−３と同様にして400個の接点片を得、さ
い断電流値および化学分析値の分布を求めた。結
果は、比較例−３の結果とともに下表−２に示
す。[Table] Looking at the results in Table 1, it can be seen that in the contacts of Comparative Example 1, in which the infiltrant raw materials were mixed using the conventional method, light adhesion occurred or the dielectric breakdown voltage value decreased. There is a large variation in properties, such as the presence of groups that are similar to those of other groups, and this variation in properties also corresponds to variation in conductivity and variation in the amount of Sb. Therefore, it is important to strictly control trace components using the method of the present invention. It shows. Comparative example 2 390g of Ag powder (average particle size 5μ), 600g of WC
powder (average particle size 3μ), 10g Te powder (average particle size
15 μ) were mixed using a crusher at 1400 rpm to obtain a mixed powder. 1.5 tons of this mixed powder/
It was molded under a pressure of cm ² and sintered at 1200°C in a hydrogen atmosphere for 1 hour to obtain a contact material. Diameter 8mm from this material,
Cut out a contact piece with a thickness of 4 mm and connect it to 5 at 200V x 100A.
×10 When the opening/closing test was performed ⁴ times, welding occurred 41 times. The conductivity distribution for 50 contact pieces showed a range of 59-45% IACS. Example 3 10 g of Ag powder and 10 g of Te powder were mixed using a crusher at 1400 rpm to obtain a primary mixed powder. Next, 80g of Ag powder was added to this primary mixed powder and mixed to form a secondary mixed powder, which was further mixed with 100g.
200g of Ag powder and 600g of WC powder were added and mixed to obtain a mixed powder having the same overall composition as Comparative Example-2. . The mixing conditions during the process are the same as those for obtaining the primary mixed powder. Regarding the obtained mixed powder, a contact material was obtained in the same manner as in Comparative Example 2, and the characteristics were evaluated under the same conditions. As a result, the number of welding occurrences was significantly reduced to 2, and the conductivity distribution was The IACS ranged from 60 to 57%. The reduction in the number of occurrences of welding and the reduction in variation in conductivity are also considered to be the effects of the uniform dispersion of a small amount of Te, which is a supporting component. Comparative Example 3 For the production of Cu-65% MoC-0.5% Bi-0.1% Ni contacts, 688 g of Cu powder (average particle size 40
μ), 1300g MoC powder (average particle size 3μ), 10g
of Bi powder (average particle size 40 μ) and 2 g of Ni powder (average particle size 30 μ) were crushed at 1400 r.pm using a crusher.
A mixed powder was obtained by mixing under the conditions of 1 minute. This mixed powder was compacted at a pressure of 1.0 ton/cm ² and then sintered at 1200° C. in a hydrogen atmosphere to obtain 400 contact pieces. The distribution of cutting current values and chemical analysis values determined for these contact pieces are shown in Table 2 below. Example 4 2 g of Ni powder and the same amount of Cu powder were mixed by hand in a mortar to obtain a primary mixed powder. Under similar mixing conditions, this primary mixed powder and 10 g of MoC powder were mixed to obtain a secondary mixed powder, and this secondary mixed powder and 10 g of Bi powder were mixed to obtain a tertiary mixed powder. Furthermore, this tertiary mixed powder
686 g of Cu powder was mixed using a crusher at 1400 rpm for 30 minutes to obtain a quaternary mixed powder. Further, this quaternary mixture and 1290 g of MoC powder were mixed to sequentially obtain a quintic mixed powder. Using the quintic mixed powder thus obtained as a raw material, 400 contact pieces were obtained in the same manner as in Comparative Example 3, and the distribution of cutting current values and chemical analysis values were determined. The results are shown in Table 2 below along with the results of Comparative Example 3.

【表】なお、さい断特性は、直径８mm、厚さ４mmで、
一方は平面、他方は20mmＲの球面をなす一対の接
点をサージインピーダンス200ΩのL.C.回路に組
み込み、実効値44Aの交流を与え接触圧10Kgで
300回開閉した際のさい断電流値の分布を求めた
ものである。上表−２の結果も本発明の方法によれば少量成
分のばらつきが少く、これに対応してさい断電流
値のばらつきも少いことがわかる。参考例１〜４ 0.15％Bi−64.85％TiC−35％Cuの混合焼結体
の製造過程における原料粉末粒径の影響をBi粉末
の粒径（細長粒子は長さ）を下表−３のように変
化させて調べた。混合は、まず15ｇのBi粉末（平均粒径40μ）
と、同量のCu粉末（平均粒径40μ）とをボール
ミルにより50r.p.m.の条件で混合して１次混合粉
末を得、これに30ｇのTiC粉末（平均粒径30μ）
を加え、ボールミルにより50r.p.m.の条件で混合
し、これに更に所定組成の原料粉末を与えるため
に必要な3485ｇのCu粉末および6455ｇのTiC粉
末とを擂潰機により1400r.p.m.の条件で混合して
３次混合粉末を得た。この３次混合粉末を用い２
トン／cm²の圧力で成形し、更に水素雰囲気中1300
℃で１時間の焼結により寸法、直径30mm、厚さ６
mmの焼結体を得、その表面を顕微鏡観察して偏析
度の調査を行つた。結果は下表−３に示す通りで
あつた。[Table] The cutting characteristics are 8 mm in diameter and 4 mm in thickness.
A pair of contacts, one of which is a flat surface and the other a spherical surface of 20 mmR, are incorporated into an LC circuit with a surge impedance of 200 Ω, and an AC with an effective value of 44 A is applied at a contact pressure of 10 kg.
This figure shows the distribution of cutting current values when the circuit is opened and closed 300 times. The results shown in Table 2 above also show that according to the method of the present invention, there is little variation in minor components, and correspondingly, there is also little variation in the cutting current value. Reference Examples 1 to 4 The influence of the raw material powder particle size in the manufacturing process of a mixed sintered body of 0.15% Bi - 64.85% TiC - 35% Cu is determined by measuring the particle size of Bi powder (length for elongated particles) as shown in Table 3 below. I investigated by changing it as follows. First, mix 15g of Bi powder (average particle size 40μ)
and the same amount of Cu powder (average particle size 40 μ) were mixed in a ball mill at 50 rpm to obtain a primary mixed powder, and to this was added 30 g of TiC powder (average particle size 30 μ).
and mixed with a ball mill at 50 rpm, and further mixed with 3485 g of Cu powder and 6455 g of TiC powder, which are necessary to give a raw material powder of a predetermined composition, with a crusher at 1400 rpm. A tertiary mixed powder was obtained. Using this tertiary mixed powder,
Molding at a pressure of ton/cm ² and further in a hydrogen atmosphere at a pressure of 1300
By sintering for 1 hour at ℃, the dimensions are 30 mm in diameter and 6 mm in thickness.
A sintered body of mm in diameter was obtained, and its surface was observed under a microscope to investigate the degree of segregation. The results were as shown in Table 3 below.

【表】上記結果より使用する原料粉末の粒径は150μ
以下であることが好ましいことがわかる。参考例５〜９ 2.1％Te−50％Cr−47.9％Cuの混合焼結体の製
造過程における原料粉末粒径比の影響をTeおよ
びCu粉末の粒径を変化させて調べた。混合は、
まず42ｇのTe粉末（平均粒径40〜150μ）と同量
のCu粉末（平均粒径10〜150μ）と更に同量のCr
粉末（平均粒径40μ）とをボールミルにて50r.p.
m.で60分混合の条件で混合して１次混合粉末を
得、これを更に所定組成の原料粉末を与えるため
に必要な量のCu粉末の一部150ｇおよびCr粉末の
必要な量の一部150ｇとを擂潰機により1400r.p.
m.の条件で混合して２次混合粉末を得た。２次
混合体に更に所定の原料粉末を与えるためCu粉
末の残部766ｇ、Cr粉末の残部808ｇとを擂潰機
により1400r.p.m.の条件で混合して第３次混合粉
末を得た。この３次混合粉末を用い、４トン／cm²
の圧力で成形し、更に真空中1400℃で１時間の焼
結を行い、直径30mm、厚さ５mmの焼結体を得た。
この焼結体の表面の顕微鏡調査によるTeの偏析
度評価結果は、下表−４の通りであつた。[Table] From the above results, the particle size of the raw material powder used is 150μ
It can be seen that the following is preferable. Reference Examples 5 to 9 The influence of the raw material powder particle size ratio in the manufacturing process of mixed sintered bodies of 2.1% Te-50% Cr-47.9% Cu was investigated by changing the particle sizes of Te and Cu powders. The mixture is
First, add 42g of Te powder (average particle size 40 to 150μ), the same amount of Cu powder (average particle size 10 to 150μ), and the same amount of Cr powder.
powder (average particle size 40μ) in a ball mill at 50r.p.
m. under mixing conditions for 60 minutes to obtain a primary mixed powder, which is further mixed with 150g of Cu powder and 150g of Cr powder required to give a raw material powder of a predetermined composition. 150g and crushed at 1400r.p.
A secondary mixed powder was obtained by mixing under the conditions of m. In order to further provide a predetermined raw material powder to the secondary mixture, the remaining 766 g of Cu powder and the remaining 808 g of Cr powder were mixed using a crusher at 1400 rpm to obtain a tertiary mixed powder. Using this tertiary mixed powder, 4 tons/cm ²
The molded body was molded under a pressure of 1,400° C. and sintered for 1 hour in a vacuum at 1400° C. to obtain a sintered body with a diameter of 30 mm and a thickness of 5 mm.
The results of evaluating the degree of segregation of Te by microscopic examination of the surface of this sintered body were as shown in Table 4 below.

〔Effect of the invention〕

上述したように本発明によれば、粉末治金法に
よる焼結型接点材料の製造において、主要成分材
粉末に比べて微量加えられる補助成分材の偏析に
伴なう接点特性の不安定性の問題を、特に初期の
混合態様に配慮して効果的に解決し、これにより
補助成分材の添加効果を効果的に発揮させて、接
触抵抗、耐電圧性、耐溶着性、しや断特性などの
接点特性の安定した接点材料を与えることが可能
になる。 As described above, according to the present invention, in the production of sintered contact materials by powder metallurgy, the problem of instability of contact characteristics due to segregation of auxiliary component materials added in a small amount compared to the main component powder can be solved. We have effectively solved this problem by paying particular attention to the initial mixing conditions, and by doing so, we have effectively brought out the effects of adding auxiliary ingredients and improved contact resistance, voltage resistance, welding resistance, shearing properties, etc. It becomes possible to provide a contact material with stable contact characteristics.

Claims

[Claims] 1. A mixed powder of a main component material consisting of a highly conductive component and an arc-resistant component, and an auxiliary component material selected from a welding prevention component and a sinterability improving component is processed by powder metallurgy. Therefore, when manufacturing a contact material by alloying, first, a primary mixed powder is obtained by mixing an auxiliary component material powder with approximately the same amount of a part of the main component material powder, and this primary mixed powder is A method for manufacturing a contact material, which comprises mixing the remaining main component material powder to obtain a mixed powder, and subjecting the mixed powder to powder metallurgy. 2. The primary mixed powder and the remaining main component material powder are mixed in multiple steps. First, the primary mixed powder and a portion of the remaining main component material powder are mixed, and then this mixed powder and the remaining main component material powder are mixed. 2. The method according to claim 1, wherein the component material powder is mixed with the component material powder. 3 Highly conductive component is at least one of Cu and Ag
The arc-resistant components are W, Mo, Cr,
The method according to claim 1 or 2, comprising at least one of Ti, WC, MoC, Cr ₃ C ₂ and TiC. 4 The welding prevention component consists of at least one of Bi, Pb, Te, and Sb, and the sinterability improving component consists of Ni,
The method according to any one of claims 1 to 3, comprising at least one of Fe, Co, and B. 5. The method according to any one of claims 1 to 4, wherein the particle size of the main component material powder and the auxiliary component material powder is 150μ or less. 6 Among the main component material powder and the auxiliary component material powder, the particle size ratio of the larger to the smaller is 1 to 1.
A method according to any of claims 1 to 5, wherein the ratio is 10:1. 7 Claims 1 to 6 in which the content of the auxiliary component material in the product contact material is 3% by weight or less
The method described in any of the paragraphs. 8 A porous molded body made of a powder mixture of an arc-resistant component alone or a highly conductive component or a sinterability improving component, and a molded body of a mixed powder of a highly conductive component and a welding prevention component. In order to obtain a mixed powder for forming an infiltrant molded body when manufacturing a contact material by laminating a porous molded body with an infiltrant molded body and heating the laminate to impregnate the porous molded body with the melted infiltrant. First, a welding prevention component powder and approximately the same amount of highly conductive component powder are mixed to obtain a primary mixed powder,
A method for producing a contact material, which comprises mixing this primary mixed powder and the remaining highly conductive component powder.