【発明の詳細な説明】[Detailed description of the invention]
(産業上の利用分野)
本発明は電気接点材料に係り、特にAg−Sn合
金を内部酸化した電気接点材料の改良に関する。
(従来技術とその問題点)
Ag−Sn合金を内部酸化した電気接点材料は、
耐溶着性に優れているとされているが、今だ充分
とは云えないものである。
この為内部酸化による酸化Snの含有量を増や
してさらに耐溶着性を向上させることが考えられ
るが、Sn5.5wt%以上含んでいると内部酸化が困
難となるものである。従つて耐溶着性を一層向上
させることが不可能であつた。また耐消耗性につ
いても充分満足できるものではなかつた。即ち
Ag−Sn合金の内部酸化の組織はSn酸化物が粒
界、或いは層状に析出していて、不均一な為耐消
耗性が劣るものであつた。
そこで本発明者は、従来のAg−Sn合金を内部
酸化した電気接点材料を改善すべく鋭意攻究の結
果、Ag−Sn合金中にNiを添加することにより内
部酸化するSnの添加量を増加し、酸化Snを増や
して耐溶着性を向上させ、さらにInとBiを添加
することにより耐消耗性を向上させた電気接点材
料を見い出したものである。
(問題点を解決するための手段)
本発明の電気接点材料は、Sn6〜15wt%、Ni1
〜10wt%、InとBiを0.1〜10wt%の範囲内で合計
が30wt%以下と、残部Agよりなる材料が内部酸
化されたものである。
本発明の電気接点材料に於いて、Snの添加量
を6〜15wt%としたのは、Sn6wt%未満では優
れた耐溶着性が得られず、15wt%を超えるとNi
の添加によつても内部酸化が困難となるからであ
る。またNiの添加量を1〜10wt%としたのは、
Ni1wt%未満ではSnを内部酸化させることが困
難であり、10wt%を超えるとSn内部酸化を促進
させるには多すぎるし、また合金の加工性が悪く
なるからである。さらにInとBiを添加する理由
は、内部酸化後のSnの酸化物を均一にして耐溶
着性を改善させる為で、その合計が0.1wt%未満
では耐溶着性を改善させることができず、10wt
%を超えると内部酸化が困難となり、また酸化後
のAg中の酸化物の析出が大きすぎて耐消耗性を
阻害するからである。
然して上記各添加物の合計を30wt%以下とし
たのは、30wt%を超えると内部酸化後のAg−酸
化物系合金がもろくなり、耐消耗性を阻害するか
らである。
次に本発明による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と従来例とによ
り作つた電気接点のインチング試験による消耗
量、溶着回数について述べる。
(実施例)
下表の左欄に示す成分組成のNo.1〜16の本発明
の実施例及びNo.17及び18の従来例は、夫々溶解鋳
造(或いは粉末冶金法)により板材を製作し、ろ
う付けをし易くする為に片面に銀を圧着し、圧延
加工にて1mm厚の板になして7.5φmmに各々プレス
で打抜き、700℃6気圧の酸素雰囲気中で120時間
内部酸化して得た電気接点材料であつて、これら
電気接点材料を夫々銅合金台材にろう付してリレ
ー用電気接点を作り、これらリレー用電気接点を
下記の試験条件にてインチング試験を行つて耐消
耗量、耐溶着回数を測定したところ下表の右欄に
示すような結果を得た。
インチング試験条件
接点寸法 7.5φmm×1.0tmm
電 圧 230V
電 流 175A
力 率 0.84
通電時間 15Hz
開閉頻度 20回/分
試験回数 5万回
(Industrial Application Field) The present invention relates to electrical contact materials, and particularly to improvements in electrical contact materials in which Ag-Sn alloy is internally oxidized. (Prior art and its problems) Electrical contact materials made by internally oxidizing Ag-Sn alloy are
Although it is said to have excellent welding resistance, it is still not sufficient. For this reason, it may be possible to further improve the welding resistance by increasing the content of Sn oxide through internal oxidation, but if the Sn content exceeds 5.5 wt%, internal oxidation becomes difficult. Therefore, it has been impossible to further improve the welding resistance. Further, the abrasion resistance was not fully satisfactory. That is,
The internal oxidation structure of Ag-Sn alloys is non-uniform, with Sn oxides precipitated at grain boundaries or in layers, resulting in poor wear resistance. Therefore, as a result of intensive research to improve electrical contact materials made by internally oxidizing conventional Ag-Sn alloys, the present inventors increased the amount of internally oxidized Sn by adding Ni to Ag-Sn alloys. However, we have discovered an electrical contact material that has improved welding resistance by increasing Sn oxide, and has improved wear resistance by adding In and Bi. (Means for solving the problem) The electrical contact material of the present invention contains Sn6 to 15wt%, Ni1
~10wt%, In and Bi within the range of 0.1 to 10wt%, with a total of 30wt% or less, and the balance being Ag, which is internally oxidized. In the electrical contact material of the present invention, the amount of Sn added is set to 6 to 15 wt% because if Sn is less than 6 wt%, excellent welding resistance cannot be obtained, and if it exceeds 15 wt%, Ni
This is because internal oxidation becomes difficult even with the addition of . In addition, the reason why the amount of Ni added was 1 to 10 wt% was
This is because if Ni is less than 1wt%, it is difficult to internally oxidize Sn, and if it exceeds 10wt%, it is too much to promote Sn internal oxidation and the workability of the alloy deteriorates. Furthermore, the reason for adding In and Bi is to make the Sn oxide uniform after internal oxidation and improve the welding resistance.If the total amount is less than 0.1wt%, the welding resistance cannot be improved. 10wt
%, internal oxidation becomes difficult and the precipitation of oxides in Ag after oxidation is too large, impairing wear resistance. However, the reason why the total amount of each of the above additives is 30 wt% or less is that if it exceeds 30 wt%, the Ag-oxide alloy after internal oxidation becomes brittle and the wear resistance is impaired. Next, in order to clarify the effects of the electrical contact material according to the present invention, the amount of wear and the number of weldings performed by inching tests of electrical contacts made according to specific examples and conventional examples will be described. (Example) In the embodiments of the present invention Nos. 1 to 16 and the conventional examples Nos. 17 and 18 of the component compositions shown in the left column of the table below, plate materials were manufactured by melt casting (or powder metallurgy method), respectively. In order to make it easier to braze, silver was crimped on one side, rolled into 1mm thick plates, punched into 7.5φmm pieces using a press, and internally oxidized for 120 hours at 700℃ in an oxygen atmosphere of 6 atm. These electrical contact materials were each brazed to a copper alloy base material to make electrical contacts for relays, and these electrical contacts for relays were subjected to an inching test under the following test conditions to determine their wear resistance. When the amount and the number of times of welding resistance were measured, the results shown in the right column of the table below were obtained. Inching test conditions Contact dimensions: 7.5φmm× 1.0t mm Voltage: 230V Current: 175A Power factor: 0.84 Energizing time: 15Hz Opening/closing frequency: 20 times/min Number of tests: 50,000 times
【表】
上記表の右欄の示す数値で明らかなように本発
明による電気接点材料にて作つた各リレー用電気
接点は、従来の電気接点に比し、消耗量が減少し
ていて耐消耗性に優れ、また溶着発生回数は零と
なつて耐溶着性に優れていることが判る。
(発明の効果)
以上詳記した通り本発明の電気接点材料は、耐
消耗性、耐溶着性に優れているので、従来のAg
−酸化Sn電気接点材料にとつて代わることので
きる画期的なものと云える。[Table] As is clear from the values shown in the right column of the table above, the electrical contacts for relays made from the electrical contact material of the present invention have reduced wear and wear resistance compared to conventional electrical contacts. Furthermore, the number of occurrences of welding was zero, indicating that it has excellent welding resistance. (Effects of the Invention) As detailed above, the electrical contact material of the present invention has excellent wear resistance and welding resistance, so it
- It can be said to be an epoch-making product that can replace Sn oxide electrical contact materials.