【発明の詳細な説明】[Detailed description of the invention]
本発明はAg―酸化物電気接点材料の製造方法
に関するものである。
内部酸化法によるAg―酸化物電気接点材料は、
耐消耗性を向上させる為にAg中の酸化物を均一
微細に分散する必要がある。
従来、Ag―酸化物接点材料としては、Agに固
溶する元素、Sn，Cd，Zn，In，Mn，Sb等を主
添加成分としてAg中に固溶させ、内部酸化させ
た接接点材料が知られていた。そして、これらの
Ag合金の内部酸化後の酸化物の分散を均一微細
にする為に副添加成分としてAg中に固溶しにく
いNi，Co，Fe，Cr，Si等を添加していた。
ところでAg中にNi，Co，Fe，Cr，Si等を添
加するには、Ag粉とNi，Co，Fe，Cr，Si等の
粉の焼結合金作つた後これを溶融Ag合金中に投
入し、Ni，Co，Fe，Cr，Si粉をAg中に添加し
て、溶解、鋳造、線引きをした後の、このワイヤ
ーを切断して内部酸化しているが、これではAg
中にNi，Co，Fe，Cr，Si等を均一微細に分散さ
せることが難しく、従つて前記酸化物の分散を均
一微細に行うことも困難であつた。
本発明はかかる実情に鑑みなされたもので、
Ag中に酸化物を均一微細に分散させるためのAg
―酸化物電気接点材料の製造方法を提供せんとす
るものである。
本発明のAg―酸化物電気接点材料の製造方法
はAg―酸化物電気接点材料の製造方法において、
Ag固溶体にSi1〜４重量％が添加された合金を溶
融噴霧して粉粒体組織中にAg―Si共晶組織を析
出させ、然る後当該粉粒体を内部酸化することを
特徴とするものである。
本発明のAg―酸化物電気接点材料の製造方法
において、Ag中にSiを添加する理由について説
明すると、SiはAgに固溶しないがAgと共晶を作
りやすいので、溶融噴霧して粉粒体となすことに
より、Ag―Sn、Ag―Zn、Ag―Cd、Ag―In、
Ag―Sb等のSn，Zn，Cd，In，Sbの主添加成分
元素の１種若しくは２種以上をAg中に固溶させ
た組織中にAg―Si共晶を析出させ、このAg―Si
共晶析出層が内部酸化時にSn，Zn，Cd，In，Sb
等の主添加成分元素の酸化粒の肥大成長を妨げ、
Ag中の酸化粒の大きさを整え、均一微細な酸化
物分散組織が得られるからである。つまりSiと
Agに固溶する元素の共存によりそれらの酸化物
分散組織は均一微細となり、結果として電気接点
使用時の耐消耗性が著しく向上するものである。
然してSiの添加量を１〜４重量％としたのは１重
量％未満では主添加成分元素の酸化粒の局所的な
肥大成長が生じやすくなり、４重量％を超えると
主添加成分元素の電気接点特性が阻害されるから
である。
次に本発明のAg―酸化物電気接点材料の製造
方法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）
下表に示す成分組成の試料No.１乃至７の原材料
を溶解し、これを溶融噴霧して粒径１mm以下の粉
粒体となした後、９気圧、760℃の酸素雰囲気中
で内部酸化してAg―酸化物電気接点材料を作り、
これら電気接点材料を圧縮、焼結、押出しにより
ワイヤーとなした後、このワイヤーから接点面の
直径５mmのリベツト型電気接点を作り、断面組織
を実体顕微鏡（100倍）で観察した上、これをマ
グネツトスイツチに組込み、下記の試験条件にて
消耗試験を行つた。
試験条件
電圧 交流220V
電流 40A
開閉頻度 10回／分
開閉回数 10万回
The present invention relates to a method for producing an Ag-oxide electrical contact material. Ag-oxide electrical contact material produced by internal oxidation method is
In order to improve wear resistance, it is necessary to uniformly and finely disperse the oxides in Ag. Conventionally, Ag-oxide contact materials include contact materials in which elements that are dissolved in Ag, such as Sn, Cd, Zn, In, Mn, and Sb, are dissolved in Ag as main additives and internally oxidized. It was known. And these
In order to make the dispersion of oxides uniform and fine after internal oxidation of Ag alloys, Ni, Co, Fe, Cr, Si, etc., which are difficult to dissolve in Ag, were added as sub-additional components. By the way, in order to add Ni, Co, Fe, Cr, Si, etc. to Ag, it is necessary to make a sintered alloy of Ag powder and powders of Ni, Co, Fe, Cr, Si, etc., and then pour this into the molten Ag alloy. However, after adding Ni, Co, Fe, Cr, and Si powders to Ag and melting, casting, and wire drawing, the wire is cut and internally oxidized, but in this method, Ag
It has been difficult to uniformly and finely disperse Ni, Co, Fe, Cr, Si, etc. therein, and it has also been difficult to uniformly and finely disperse the oxides. The present invention was made in view of such circumstances,
Ag for uniformly and finely dispersing oxides in Ag
- It aims to provide a method for manufacturing oxide electrical contact materials. The method for producing an Ag-oxide electrical contact material of the present invention includes:
It is characterized by melting and spraying an alloy in which 1 to 4% by weight of Si is added to an Ag solid solution to precipitate an Ag--Si eutectic structure in the powder structure, and then internally oxidizing the powder and particle structure. It is something. In the method for producing the Ag-oxide electrical contact material of the present invention, the reason why Si is added to Ag is that although Si does not form a solid solution in Ag, it easily forms a eutectic with Ag. Ag-Sn, Ag-Zn, Ag-Cd, Ag-In,
Ag-Si eutectic is precipitated in a structure in which one or more of the main additive elements of Sn, Zn, Cd, In, and Sb such as Ag-Sb are dissolved in Ag, and this Ag-Si
During internal oxidation, the eutectic precipitated layer forms Sn, Zn, Cd, In, and Sb.
It prevents the enlargement of oxidized grains of main additive elements such as
This is because the size of the oxide grains in Ag can be adjusted and a uniform and fine oxide-dispersed structure can be obtained. In other words, Si and
Due to the coexistence of solid-dissolved elements in Ag, the oxide dispersion structure becomes uniform and fine, and as a result, wear resistance when used as an electrical contact is significantly improved.
However, when the amount of Si added is set to 1 to 4% by weight, if it is less than 1% by weight, local enlarged growth of oxidized grains of the main added component element tends to occur, while if it exceeds 4% by weight, the electrical This is because the contact characteristics are inhibited. Next, in order to clarify the effects of the method for producing an Ag-oxide electrical contact material of the present invention, specific examples and conventional examples thereof will be described. (Example) After melting the raw materials of Samples No. 1 to 7 with the component compositions shown in the table below and melting and spraying them to form powder with a particle size of 1 mm or less, the raw materials were heated in an oxygen atmosphere at 9 atmospheres and 760°C. internal oxidation to create Ag-oxide electrical contact material,
After forming these electrical contact materials into wires by compression, sintering, and extrusion, a rivet-type electrical contact with a contact surface diameter of 5 mm was made from this wire, and the cross-sectional structure was observed using a stereomicroscope (100x magnification). It was incorporated into a magnetic switch and a wear test was conducted under the following test conditions. Test conditions Voltage: AC 220V Current: 40A Opening/closing frequency: 10 times/min Number of opening/closing: 100,000 times
【表】
（従来例）
上表に示す成組成の試料No.１乃至７の原材料を
溶解、鋳造、線引きして直径３mmのワイヤーとな
し、このワイヤーを３mm間隔で切断して直径３
mm、長さ３mmの粒体となした。その後は実施例と
同一方法で接点面の直径５mmのリベツト型電気接
点を作り断面組織を実体顕微鏡（100倍）で観察
した上、上記試験条件にて消耗試験を行つた。
上記実施例と従来例の結果は下表の通りであ
る。[Table] (Conventional example) The raw materials of samples No. 1 to 7 with the composition shown in the table above are melted, cast, and drawn into wires with a diameter of 3 mm, and this wire is cut at 3 mm intervals to create wires with a diameter of 3 mm.
mm, and the length was 3 mm. Thereafter, a rivet-type electrical contact with a contact surface diameter of 5 mm was made using the same method as in the example, and the cross-sectional structure was observed using a stereomicroscope (100x magnification), and a wear test was conducted under the above test conditions. The results of the above embodiment and conventional example are shown in the table below.
【表】
上記の表の分散組織と消耗量の結果で明らかな
ように本発明の実施例の電気接点は、従来例の電
気接点に比し、酸化物の分散組織が均一微細であ
り、その結果として消耗量がはるかに少なく、耐
消耗性に優れていることが判る。これはひとえに
Ag合金の固溶体の組織中にAg―Si共晶組織が析
出し、このAg―Si共晶析出層が内部酸化時にAg
合金中のSn，Zn，Cd，In，Sb等の主添加成分元
素の酸化粒の肥大成長を妨げ、Ag中の酸化粒の
大きさを整え、均一微細な酸化物の分散組織する
からにほかならない。
以上詳記した通り本発明のAg―酸化物電気接
点材料の製造方法は、従来の製造方法によつて得
られたAg―酸化物電気接点材料に比し消耗量が
少なく、耐消耗性に優れているので、Ag―酸化
物電気接点材料の製造方法にとつて画期的なもの
と言える。[Table] As is clear from the results of the dispersion structure and amount of wear in the table above, the electrical contacts of the embodiments of the present invention have a uniform and fine dispersion structure of oxides, compared to the electrical contacts of the conventional example. As a result, it can be seen that the amount of wear is much smaller and the wear resistance is excellent. This is all
An Ag-Si eutectic structure precipitates in the solid solution structure of the Ag alloy, and this Ag-Si eutectic precipitate layer becomes Ag during internal oxidation.
In addition, it prevents the enlargement of oxide grains of main additive elements such as Sn, Zn, Cd, In, and Sb in the alloy, adjusts the size of oxide grains in Ag, and creates a uniform and fine oxide dispersion structure. No. As detailed above, the method for producing the Ag-oxide electrical contact material of the present invention has less wear and excellent wear resistance than Ag-oxide electrical contact materials obtained by conventional production methods. Therefore, it can be said to be a revolutionary method for producing Ag-oxide electrical contact materials.