【発明の詳細な説明】[Detailed description of the invention]
本発明は、内部酸化法によつて製造される銀酸
化物系の複合電気接点材料に係る。
内部酸化法によつて製造される銀−酸化物系の
複合電気接点材料としては、銀−酸化カドミウム
系例えば銀−酸化カドミウム12w／ｏより成る複
合電気接点材料が小電流乃至中電流域で優れた接
点特性を示すものとして各方面で広く用いられて
きた。
然し乍ら、近時電気及び電子機器の小型化によ
り電気接点材料に要求される接点特性が苛酷にな
つてきており、従来の銀−酸化カドミウム系の複
合電気接点材料では耐溶着性に劣り、使用に耐え
得なくなつてきた。この為、更に耐溶着性に優れ
た銀−酸化カドミウム系の複合電気接点材料が要
望されている。
銀−酸化カドミウム系の複合電気接点材料の耐
溶着性を向上させるには、内部酸化法の場合、銀
−カドミウム合金にビスマス、アンチモンを添加
し、全体の酸化物含有率を高めることが従来行わ
れていたが、このような銀−酸化カドミウム系の
複合電気接点材料は接点形状への塑性加工が困難
で、生産性に問題があつた。
本発明は上記諸事情に鑑みなされたものであ
り、従来の銀−酸化カドミウム系の複合電気接点
材料よりも優れた接点性能、とりわけ耐溶着性に
優れた複合電気接点材料を提供せんとするもので
ある。
本発明の複合電気接点材料は、銀中にカドミウ
ム0.5〜10w／ｏとすず5.5〜11w／ｏと鉄、ニツ
ケル、コバルトの内少なくとも１種0.02〜2w／
ｏとを添加して成る合金を、内部酸化せしめて成
るものである。
上記本発明の複合電気接点材料に於いて、銀中
にカドミウムの他すずと鉄族元素（鉄、ニツケ
ル、コバルト）とを添加して内部酸化する理由
は、銀−酸化カドミウムの組織中に、非常に微細
な酸化すず及び鉄族元素の酸化物が均一に分散す
ることにより耐溶着性が富むようになる。
然して本発明の複合電気接点材に於いて、銀中
に添加するカドミウムを0.5〜10w／ｏとしたの
は、0.5w／ｏ未満では酸化カドミウムの持つ特
性を十分に利用できない為であり、10w／ｏを超
えると消耗量が多くなる為である。またすずを
5.5〜11w／ｏとしたのは5.5w／ｏ未満では十分
な耐溶着性が得られず、11w／ｏを超えると接触
抵抗が高くなり、しかも塑性加工が困難となるか
らである。さらに鉄族元素の鉄、コバルト、ニツ
ケルの少くとも１種を0.01〜2w／ｏとしたの
は、0.01w／ｏ未満では内部組織を微細する効果
が乏しく、2w／ｏを超えると溶解時にうまく合
金させることができないからである。
次の本発明による複合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に
ついて説明する。
実施例 １
銀中にカドミウム5w／ｏとすず6w／ｏとニツ
ケル0.5w／ｏとを添加して成る合金の溶湯を噴
霧して１mm以下の粉粒体となし、次に９気圧、
700℃の酸素雰囲気中で内部酸化して銀−酸化カ
ドミウム−酸化すず−酸化ニツケルの複合粉末と
なし、次いで圧縮、焼結、押出、引抜加工により
直径２mmの線材となした後、リベツト加工して接
点面の直径４mmの電気接点を作つた。
実施例 ２
銀中にカドミウム2w／ｏとすず7.5w／ｏとコ
バルト0.5w／ｏを添加して成る合金の溶湯を金
型に鋳造し、次に金型より外したビレツトを押
出、引抜加工により直径２mmの線材となし、次い
で３気圧、800℃の酸素雰囲気中で内部酸化して
銀−酸化カドミウム−酸化すず−酸化コバルトの
複合線材となした後、リベツト加工して接点面の
直径４mmの電気接点を作つた。
実施例 ３
銀中にカドミウム7.5w／ｏとすず6w／ｏと鉄
0.5w／ｏを添加して成る合金の溶湯を噴霧して
１mm以下の粉粒体となし、次に９気圧、600℃
の酸素雰囲気中で内部酸化して銀−酸化カドミウ
ム−酸化すず−酸化鉄の複合粉末となし、次いで
圧縮、焼結、押出、引抜加工により直径２mmの線
材となした後、リベツト加工して接点面の直径４
mmの電気接点を作つた。
従来例 １
銀中にカドミウム11w／ｏを添加して成る合金
の溶湯を金型に鋳造し、次に金型より外したビレ
ツトを押出、引抜加工により直径２mmの線材とな
し、次いで９気圧、700℃の酸素雰囲気中で内部
酸化して銀−酸化カドミウムの複合線材となした
後、リベツト加工して接点面の直径４mmの電気接
点を作つた。
従来例 ２
銀中にカドミウム14.5w／ｏとニツケル0.5w／
ｏを添加して成る合金の溶湯を噴霧して１mm以
下の粉粒体となし、次に３気圧、600℃の酸素雰
囲気中で内部酸化して銀−酸化カドミウム−酸化
ニツケルの複合粉末となし、次いで圧縮、焼結、
押出、引抜加工により直径２mmの線材となした
後、リベツト加工して接点面の直径４mmの電気接
点を作つた。
然して上記実施例１、２、３及び従来例１、２
の電気接点を下記の試験条件にて開閉試験を行な
い、溶着発生までの開閉回数を測定し且つ接触抵
抗を測定したところ、下記の表の右欄に示すよう
な結果を得た。
試験条件
電圧 AC100V 50Hz
電流 投入電流40A、定常電流10A
開閉頻度 20回／分
負荷 ランプ
開閉回数 溶着発生まで
The present invention relates to a silver oxide-based composite electrical contact material manufactured by an internal oxidation method. As silver-oxide composite electrical contact materials produced by internal oxidation method, silver-cadmium oxide composite electrical contact materials, such as silver-cadmium oxide 12w/o, are excellent in the small to medium current range. It has been widely used in various fields to indicate contact characteristics. However, with the recent miniaturization of electrical and electronic equipment, the contact characteristics required of electrical contact materials have become more severe, and conventional silver-cadmium oxide-based composite electrical contact materials have poor welding resistance and cannot be used. It was becoming unbearable. For this reason, there is a demand for a silver-cadmium oxide composite electrical contact material that has even better welding resistance. In order to improve the welding resistance of silver-cadmium oxide composite electrical contact materials, in the case of the internal oxidation method, the conventional method was to add bismuth and antimony to the silver-cadmium alloy to increase the overall oxide content. However, such silver-cadmium oxide composite electrical contact materials were difficult to be plastically worked into a contact shape, posing problems in productivity. The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a composite electrical contact material that has superior contact performance, particularly welding resistance, than conventional silver-cadmium oxide composite electrical contact materials. It is. The composite electrical contact material of the present invention contains 0.5 to 10 w/o of cadmium, 5.5 to 11 w/o of tin, and 0.02 to 2 w/o of at least one of iron, nickel, and cobalt in silver.
It is made by internally oxidizing an alloy formed by adding o. In the composite electrical contact material of the present invention, tin and iron group elements (iron, nickel, cobalt) are added to silver in addition to cadmium for internal oxidation. The extremely fine tin oxide and iron group element oxides are uniformly dispersed, resulting in enhanced welding resistance. However, in the composite electrical contact material of the present invention, the cadmium added to the silver is set at 0.5 to 10 w/o because if it is less than 0.5 w/o, the characteristics of cadmium oxide cannot be fully utilized. This is because if the value exceeds /o, the amount of consumption increases. Suzu again
The reason for setting it to 5.5 to 11 w/o is that if it is less than 5.5 w/o, sufficient welding resistance cannot be obtained, and if it exceeds 11 w/o, the contact resistance becomes high and furthermore, plastic working becomes difficult. Furthermore, the reason why at least one of the iron group elements iron, cobalt, and nickel is set at 0.01 to 2 w/o is that if it is less than 0.01 w/o, the effect of refining the internal structure is poor, and if it exceeds 2 w/o, it will not work well during melting. This is because it cannot be alloyed. Next, in order to clarify the effects of the composite electrical contact material according to the present invention, specific examples and conventional examples thereof will be explained. Example 1 A molten metal of an alloy made by adding 5 w/o of cadmium, 6 w/o of tin, and 0.5 w/o of nickel to silver was sprayed into powder particles of 1 mm or less, and then heated to 9 atm.
It was internally oxidized in an oxygen atmosphere at 700°C to form a composite powder of silver, cadmium oxide, tin oxide, and nickel oxide, and then compressed, sintered, extruded, and drawn into a wire rod with a diameter of 2 mm, which was then riveted. An electrical contact with a contact surface diameter of 4 mm was made. Example 2 A molten alloy made of silver with 2 w/o of cadmium, 7.5 w/o of tin, and 0.5 w/o of cobalt was cast into a mold, and then the billet removed from the mold was extruded and drawn. The wire was made into a wire with a diameter of 2 mm, and then internally oxidized in an oxygen atmosphere at 3 atm and 800°C to make a composite wire of silver-cadmium oxide-tin oxide-cobalt oxide, which was then riveted to make the contact surface diameter 4 mm. I made electrical contacts. Example 3 Cadmium 7.5w/o, tin 6w/o and iron in silver
A molten alloy made by adding 0.5 w/o was sprayed to form powder of 1 mm or less, and then heated at 9 atm and 600°C.
It is internally oxidized in an oxygen atmosphere to form a composite powder of silver-cadmium oxide-tin oxide-iron oxide, and then compressed, sintered, extruded, and drawn into a wire rod with a diameter of 2 mm, and then riveted to form a contact point. Surface diameter 4
I made a mm electrical contact. Conventional Example 1 A molten alloy made of silver with 11 w/o of cadmium added was cast in a mold, and then the billet removed from the mold was extruded and drawn into a wire rod with a diameter of 2 mm, and then heated to 9 atm. After internal oxidation in an oxygen atmosphere at 700°C to form a composite wire of silver-cadmium oxide, it was riveted to produce an electrical contact with a diameter of 4 mm on the contact surface. Conventional example 2 Cadmium 14.5w/o and nickel 0.5w/o in silver
A molten alloy made by adding o is sprayed to form powder particles of 1 mm or less, and then internally oxidized in an oxygen atmosphere at 3 atm and 600°C to form a composite powder of silver-cadmium oxide-nickel oxide. , then compression, sintering,
A wire with a diameter of 2 mm was made by extrusion and drawing, and then riveted to produce an electrical contact with a diameter of 4 mm on the contact surface. However, the above-mentioned Examples 1, 2, and 3 and Conventional Examples 1 and 2
The electrical contacts were subjected to opening/closing tests under the following test conditions, and the number of openings and closings until welding occurred was measured, as well as the contact resistance. The results were as shown in the right column of the table below. Test conditions Voltage AC100V 50Hz Current Supply current 40A, steady current 10A Opening/closing frequency 20 times/min load Number of lamp opening/closing Until welding occurs
【表】
上記の表の右欄の数値で明らかなように実施例
１、２、３の複合電気接点材料にて作つた電気接
点は、従来例１、２の複合電気接点材料にて作つ
た電気接点に比し、溶着発生までの開閉回数が遥
かに多く、耐溶着性が一段と優れていることが判
る。また接触抵抗も低く安定していることが判
る。
以上詳記した通り本発明による複合電気接点材
料は、従来の銀−酸化カドミウム系の複合電気接
点材料に較べ耐溶着性が一段と優れ、接触抵抗も
低く且つ安定しているので、最近の電気及び電子
機器の小型化に判なう苛酷な使用条件にも対応で
きる接点性能を備えた画期的な複合電気接点材料
と言える。[Table] As is clear from the values in the right column of the table above, the electrical contacts made with the composite electrical contact materials of Examples 1, 2, and 3 were the same as those made with the composite electrical contact materials of Conventional Examples 1 and 2. It can be seen that compared to electrical contacts, the number of openings and closings before welding occurs is far greater, and the welding resistance is much better. It can also be seen that the contact resistance is low and stable. As detailed above, the composite electrical contact material according to the present invention has superior welding resistance and low and stable contact resistance compared to conventional silver-cadmium oxide composite electrical contact materials. It can be said to be a groundbreaking composite electrical contact material with contact performance that can withstand the harsh operating conditions associated with the miniaturization of electronic devices.