【発明の詳細な説明】[Detailed description of the invention]
本発明は封入型マグネツトスイツチ、封入型ブ
レーカー、封入型リレー等の電気接点に用いる材
料に関する。
従来、マグネツトスイツチ、ブレーカー、リレ
ー等の電気接点材料としては、耐溶着性、耐消耗
性に優れた銀−酸化カドミウム系が使用されてき
たが、何分にも材料が高価である為、低廉な銅−
酸化カドミウムの使用が考えられていた。
然し、銅−酸化カドミウムは耐溶着性について
は問題無いが、接触抵抗は銀−酸化カドミウム系
に比べ著しく劣いた。これは接点開閉時のアーク
により酸化カドミウムがカドミウムと酸素に分解
し、分解した酸素が地の銅を酸化させてしまい、
このため、接触抵抗が高く、不安定になる。そし
てこのような接触抵抗が高く不安定な状態は10〜
400Aという中電流域での使用に於いて顕著に現
われる。
本発明はかかる問題を解消すべくなされたもの
であり、高価な銀−酸化カドミウム系より成る電
気接点材料と同等の低接触抵抗、耐溶着性に優れ
た封入用電気接点材料として、前記銅−酸化カド
ミウムより成る封入用電気接点材料にかわる封入
用電気接点材料を提供せんとするものである。
本発明の封入用電気接点材料は、タンタル５〜
25w／ｏと残部銅の焼結銅合金より成るものであ
る。
本発明の封入用電気接点材料は、従来考えられ
ていた銅−酸化カドミウムより成る封入用電気接
点材料中の酸化カドミウムをタンタルに代えたも
ので、その添加量をタンタル５〜25w／ｏとした
理由は、接点開閉時のアークにより酸化物は金属
と酸素に分解されやすく、分解された酸素が下地
の銅を酸化させ、接触抵抗が高く、不安定になる
ため、酸化物を用いずまた、多少の酸化雰囲気で
も銅地より酸化しやすく、かつ高融点の元素を用
いることにより、安定した接触抵抗、耐溶着性、
耐消耗性を得る為で、タンタル5w／ｏ未満では
耐溶着性、耐消耗性が不充分であり、またタンタ
ル25w／ｏを超えると加工性が悪くなり接点形状
に加工できなくなるからである。
以下本発明の封入用電気接点材料の効果を明瞭
ならしめる為に、その具体的な実施例の封入用電
気接点材料と従来例の封入用電気接点材料により
作つた封入用電気接点の耐溶着性、接触抵抗につ
いて述べる。
〔実施例 １〕
重量比で銅粉末90％、タンタル粉末10％を混合
圧縮して30mm角（以下口と表記する）×150mm長さ
（以下ｌと表記する）の圧粉体を作り、これを真
空中900℃で焼結し、然る後溝ロール加工と真空
中900℃の熱処理を繰返し、10mm口の棒になつた
ところで真空中900℃で熱処理し、スエジング加
工と真空中900℃の熱処理を繰返して5.0mm直径
（以下と表記する）の銅−タンタル10w／ｏよ
り成る線材となし、更にこの線材を旋盤加工によ
り頭部４mm×1.2mm厚さ（以下ｔと表記する）
のリベツトとなした。
〔実施例 ２〕
重量比で銅粉末80％、タンタル粉末20％を混合
圧縮して30mm口×150mmｌの圧粉体を作り、これ
を窒素ガス雰囲気中900℃で焼結し、然る後溝ロ
ール加工と窒素ガス雰囲気中900℃の熱処理を繰
返し、10mm口の棒になつたところで、窒素ガス雰
囲気中900℃で熱処理し、スエージング加工と窒
素ガス雰囲気中900℃の熱処理を繰返して5.0mm
の銅−タンタル20w／ｏより成る線材となし、更
にこの線材を旋盤加工により頭径4mm×1.2tmmの
リベツトとなした。
〔実施例 ３〕
重量比で銅粉末95％、タンタル粉末５％を混合
圧縮して30mm口×150mmｌの圧粉体を作り、これ
を真空中900℃焼結し、然る後溝ロール加工と真
空中900℃の熱処理を繰返し、10mm口の棒になつ
たところで真空中900℃で熱処理し、スエジング
加工と真空中900℃の熱処理を繰返して5.0mmの
銅95w／ｏ−タンタル5w／ｏより成る線材とな
し、更にこの線材を旋盤加工により頭部４mm×
1.2mmｔのリベツトとなした。
〔実施例 ４〕
重量比で銅粉末75％、タンタル粉末25％を混合
圧縮して30mm口×150mmｌの圧粉体を作り、これ
を真空中900℃で焼結し、然る後溝ロール加工と
真空中900℃の熱処理を繰返し、10mm口の棒にな
つたところで真空中900℃で熱処理し、スエジン
グ加工と真空中900℃の熱処理を繰返して5.0mm
の銅75w／ｏ−タンタル25w／ｏより成る線材と
なし、更にこの線材を旋盤加工により頭部４mm
×1.2mmｔのリベツトとなした。
〔比較例 １〕
重量比で銅粉末97％、タンタル粉末３％を混合
圧縮して30mm口×150mmｌの圧粉体を作り、これ
を真空中900℃で焼結し、然る後溝ロール加工と
真空中900℃の熱処理を繰返し、10mm口の棒にな
つたところで真空中900℃で熱処理し、スエジン
グ加工と真空中900℃の熱処理を繰返して5.0mm
の銅97w／ｏ−タンタル3w／ｏより成る線材と
なし、更にこの線材を旋盤加工により頭部４mm
×1.2mmｔのリベツトとなした。
〔比較例 ２〕
重量比で銅粉末72％、タンタル粉末28％を混合
圧縮して30mm口×150mmｌの圧粉体を作り、これ
を真空中900℃で焼結し、然る後溝ロール加工を
施したが割れて加工を中断した。
〔従来例 １〕
Cu粉末88w／ｏとCdO粉末12w／ｏを混合圧縮
して30mm口×150mmｌの圧粉体を作り、これを窒
素ガス雰囲気830℃で焼結し、然る後溝ロール加
工と窒素ガス雰囲気中830℃の熱処理を繰返し、
10mm口の棒になつたところで、窒素ガス雰囲気中
830℃で熱処理し、スエージング加工と窒素ガス
雰囲気中830℃の熱処理を繰返して５mmのCu−
CdO12w／ｏより成る線材となし、更にこの線材
を旋盤加工により頭部4mm×1.2tmmのリベツトと
なした。
〔従来例 ２〕
Ag中にCd11w／ｏ溶解してAg−Cd合金の2.3
mm×2.3mmｌの粒を作り、これを酸素ガス雰囲
気中７気圧800℃で内部酸化してAg−CdO12w／
ｏの粒となし、然る後この粒を圧縮、焼結、押出
加工し、次いで線引加工と大気中700℃の熱処理
を繰返して２mmのAg−CdO12w／ｏより成る
線材となし、更にこの線材をヘツダー加工により
頭部4mm×1.2tmmのリベツトとなした。而して市
販のヒンジ型リレーに固定、可動接点をベースに
かしめ付け、試験用リレーを作りこれを夫々真空
又は不活性ガス（N2，Ar，N2−H2，Ar−H2，
He，N2−O2，Ar−O2，CO2，N2−CO2，Ar−
CO2，CO2−O2）充填容器、本例ではArガス充
填容器中に封入して、下記の試験条件にて開閉試
験を行ない電気接点の溶着回数及び接触抵抗を測
定した処、下記の表に示すような結果を得た。
試験条件
負 荷 抵抗２段切換
電 圧 100V
周波数 50Hz
電 流 投入電流40A
定常電流10A
開閉頻度 20回／分
通電時間 0.62秒
休止時間 2.35秒
接触力 20ｇ
開離力 40ｇ
開閉回数 ５万回
The present invention relates to materials used in electrical contacts such as encapsulated magnetic switches, encapsulated breakers, encapsulated relays, and the like. Conventionally, silver-cadmium oxide based materials have been used as electrical contact materials for magnetic switches, breakers, relays, etc. due to their excellent welding and abrasion resistance, but since the materials are extremely expensive, Cheap copper
The use of cadmium oxide was considered. However, although copper-cadmium oxide had no problem in welding resistance, its contact resistance was significantly inferior to that of silver-cadmium oxide. This is because cadmium oxide decomposes into cadmium and oxygen due to the arc when the contacts are opened and closed, and the decomposed oxygen oxidizes the underlying copper.
This results in high contact resistance and instability. And this unstable state with high contact resistance is 10~
This becomes noticeable when used in the medium current range of 400A. The present invention has been made to solve this problem, and uses the copper-cadmium oxide-based electrical contact material as an encapsulating electrical contact material that has the same low contact resistance and excellent adhesion resistance as the expensive silver-cadmium oxide electrical contact material. It is an object of the present invention to provide an encapsulating electrical contact material that can replace the encapsulating electrical contact material made of cadmium oxide. The electrical contact material for encapsulation of the present invention is tantalum 5-
It is made of a sintered copper alloy of 25w/o and the balance copper. The electrical contact material for encapsulation of the present invention replaces the cadmium oxide in the electrical contact material for encapsulation made of copper-cadmium oxide, which was conventionally considered, with tantalum, and the amount of tantalum added is 5 to 25 w/o. The reason is that oxides are easily decomposed into metal and oxygen by the arc that occurs when opening and closing contacts, and the decomposed oxygen oxidizes the underlying copper, resulting in high contact resistance and instability. By using an element that oxidizes more easily than copper base even in a slightly oxidizing atmosphere and has a high melting point, stable contact resistance, welding resistance,
This is to obtain wear resistance, and if the tantalum content is less than 5 w/o, the welding resistance and wear resistance will be insufficient, and if the tantalum content exceeds 25 w/o, the workability will deteriorate and it will not be possible to process it into a contact shape. In order to clarify the effects of the electrical contact material for encapsulation of the present invention, the welding resistance of electrical contacts for encapsulation made from the electrical contact material for encapsulation of specific examples and the electrical contact material for encapsulation of the conventional example will be described below. , we will discuss contact resistance. [Example 1] 90% copper powder and 10% tantalum powder by weight were mixed and compressed to make a green compact of 30 mm square (hereinafter referred to as 口) x 150 mm long (hereinafter referred to as l). sintered at 900℃ in vacuum, followed by repeated groove rolling and heat treatment at 900℃ in vacuum, and when it became a 10mm diameter bar, heat treated at 900℃ in vacuum, swaging process and heat treatment at 900℃ in vacuum. The heat treatment was repeated to create a wire made of copper-tantalum 10w/o with a diameter of 5.0 mm (hereinafter referred to as t), and this wire was further processed on a lathe to a head of 4 mm x 1.2 mm thick (hereinafter referred to as t).
It was made with rivets. [Example 2] 80% copper powder and 20% tantalum powder by weight were mixed and compressed to make a 30 mm opening x 150 mml green compact, which was sintered at 900°C in a nitrogen gas atmosphere, and the following grooves were prepared. Roll processing and heat treatment at 900°C in a nitrogen gas atmosphere are repeated until the rod has a diameter of 10 mm. Heat treatment is then performed at 900°C in a nitrogen gas atmosphere, swaging processing and heat treatment at 900°C in a nitrogen gas atmosphere are repeated until the bar has a diameter of 5.0 mm.
A wire rod made of copper-tantalum 20 w/o was made, and this wire rod was further processed on a lathe to form a rivet with a head diameter of 4 mm x 1.2 tmm. [Example 3] 95% copper powder and 5% tantalum powder by weight were mixed and compressed to make a 30 mm opening x 150 mml green compact, which was sintered at 900°C in vacuum, followed by subsequent groove rolling. Heat treatment at 900℃ in vacuum is repeated, and when it becomes a 10mm diameter bar, it is heat treated at 900℃ in vacuum, swaging processing and heat treatment at 900℃ in vacuum are repeated, and 5.0mm of copper 95w/o - tantalum 5w/o is made. This wire is then machined on a lathe to a head of 4 mm x
Made with 1.2mmt rivets. [Example 4] 75% copper powder and 25% tantalum powder by weight were mixed and compressed to make a 30 mm opening x 150 mml green compact, which was sintered at 900°C in a vacuum and processed with a trailing groove roll. Heat treatment at 900℃ in vacuum is repeated, and when the rod has a diameter of 10 mm, it is heat treated at 900℃ in vacuum, swaging processing and heat treatment at 900℃ in vacuum are repeated, and the length is 5.0 mm.
The wire rod is made of 75w/o copper and 25w/o tantalum, and then this wire is lathed to a head of 4mm.
It was made with a rivet of ×1.2mmt. [Comparative Example 1] 97% copper powder and 3% tantalum powder by weight were mixed and compressed to make a 30 mm opening x 150 mml green compact, which was sintered in a vacuum at 900°C and then processed with a trailing groove roll. Heat treatment at 900℃ in vacuum is repeated, and when the rod has a diameter of 10 mm, it is heat treated at 900℃ in vacuum, swaging processing and heat treatment at 900℃ in vacuum are repeated, and the length is 5.0 mm.
A wire made of 97w/o copper and 3w/o tantalum, and this wire was lathed to a head of 4mm.
It was made with a rivet of ×1.2mmt. [Comparative Example 2] 72% copper powder and 28% tantalum powder by weight were mixed and compressed to make a compact of 30 mm opening x 150 mml, which was sintered in a vacuum at 900°C, followed by grooved roll processing. However, it cracked and processing was interrupted. [Conventional example 1] Cu powder 88w/o and CdO powder 12w/o are mixed and compressed to make a 30mm opening x 150mml green compact, which is sintered in a nitrogen gas atmosphere at 830°C and then processed with a trailing groove roll. and repeated heat treatment at 830℃ in a nitrogen gas atmosphere.
When the rod has a 10 mm opening, place it in a nitrogen gas atmosphere.
Heat treated at 830℃, swaging process and heat treatment at 830℃ in a nitrogen gas atmosphere were repeated to form a 5mm Cu-
A wire rod made of CdO12w/o was made, and this wire rod was further processed on a lathe to form a rivet with a head size of 4 mm x 1.2 tmm. [Conventional example 2] 2.3% of Ag-Cd alloy by dissolving Cd11w/o in Ag
Ag-CdO12w/
The particles were then compressed, sintered, and extruded, and then wire drawn and heat treated at 700°C in the atmosphere were repeated to make a 2 mm Ag-CdO12w/o wire rod. The wire rod was processed into a rivet with a head size of 4 mm x 1.2 tmm by header processing. Then, a test relay was made by caulking the fixed and movable contacts to a commercially available hinge-type relay and injected into vacuum or inert gas (N 2 , Ar, N 2 −H 2 , Ar−H 2 ,
He, N 2 −O 2 , Ar−O 2 , CO 2 , N 2 −CO 2 , Ar−
CO 2 , CO 2 −O 2 ) filled container, in this example, an Ar gas filled container, and an opening/closing test was conducted under the following test conditions to measure the number of welding times and contact resistance of the electrical contacts. The results shown in the table were obtained. Test conditions Load 2-stage resistance switching Voltage 100V Frequency 50Hz Current Closing current 40A Steady current 10A Switching frequency 20 times/minute Energizing time 0.62 seconds Rest time 2.35 seconds Contact force 20g Breaking force 40g Number of switching times 50,000 times
【表】
上記の表で明らかなように実施例１，２，３，
４のリレーに於ける電気接点は、従来例１のリレ
ーに於ける電気接点よりも溶着回数が少なく、接
触抵抗が低く、また従来例２のリレーに於ける高
価な電気接点と同等に溶着回数が少なく、接触抵
抗が低く耐溶着性及び接触抵抗特性に優れている
ことが判る。比較例１のリレーに於ける電気接点
は、溶着回数が多く比較例２の線材は加工の途中
で割れが発生し加工を中断した。
以上詳記した通り本発明の封入用電気接点材料
は、貴金属を全く使用しない安価な材料であつ
て、しかも銀−酸化カドミウムより成る高価な封
入用電気接点材料と同等の優れた耐溶着性及び低
接触抵抗特性を有するので、これにとつて代わる
ことのできる画期的な封入用電気接点材料と言え
る。[Table] As is clear from the table above, Examples 1, 2, 3,
The electrical contacts in the relay No. 4 are welded less times than the electrical contacts in the relay of Conventional Example 1, and the contact resistance is lower, and the electrical contacts in the relay of Conventional Example 2 are welded as many times as the expensive electrical contacts in the relay of Conventional Example 2. It can be seen that the contact resistance is low and the welding resistance and contact resistance characteristics are excellent. The electrical contacts in the relay of Comparative Example 1 were welded many times, and the wire of Comparative Example 2 cracked during processing, and processing was interrupted. As detailed above, the electrical contact material for encapsulation of the present invention is an inexpensive material that does not use any precious metals, and has excellent welding resistance and properties equivalent to the expensive electrical contact material for encapsulation made of silver-cadmium oxide. Since it has low contact resistance characteristics, it can be said to be an innovative electrical contact material for encapsulation that can replace this.