【発明の詳細な説明】[Detailed description of the invention]
本発明は、電気接点材料に係り、特に銀−ニツ
ケル系の電気接点材料の改良に関する。
従来より銀系の電気接点材料としては、銀−酸
化カドミウムに代表される銀−酸化物系、銀−ニ
ツケル、銀−タングステンに代表される銀−金属
系、銀−カーボンに代表される銀−非金属系の接
点材料が使用されてきた。
特に銀−ニツケルの接点材料は、極めて加工性
が良く、また比較的接触抵抗が低く安定している
ので、小電流乃至中電流域に於けるスイツチ、リ
レー、電磁継電器等に於ける電気接点に広く用い
られてきた。
然し乍ら、この銀−ニツケルの接点材料より成
る電気接点は、接触時或いは開離時のアークエネ
ルギーが接点の一点に集中し易く、それ故消耗、
移転が多く、接点寿命が短いものである。
本発明はかかる問題を解消すべくなされたもの
で、体記銀−ニツケルの接点材料よりも耐消耗
性、耐溶着性に優れ且つ抵接触抵抗性を同等に維
持せしめた電気接点材料を提供せんとするもので
ある。
本発明の電気接点材料は、ニツケル10〜60重量
％、リチウム、ナトリウム及びカリウムの各酸化
物の内から１種もしくは２種以上を合計で0.0001
〜0.3重量％及び残部銀から成るものである。
本発明の電気接点材料に於いて、銀中にニツケ
ルを添加するのは、耐溶着性、低接触抵抗性を備
える為で、10重量％（以下、「w/o」とという。
未満では耐溶着性が不十分であり、60w／ｏを超
えると接点表面にニツケル酸化物の厚い層ができ
て接触抵抗が増大するので、10〜60w/oが好適で
ある。
また銀−ニツケル中にリチウム、ナトリウム及
びカリウムの各酸化物の内から１種もしくは２種
以上を分散させるのは、このアルカリ金属の酸化
物が熱電子放出の際の仕事凾数が小さく、非常に
放電し易い化合物である為、極く少量分散するこ
とにより、電気接点の接触及び開離時にこれらの
化合物に先駆的にアークを発生させ、アークを一
点に集中するのを避けて接点表面全体に分散し、
均一に少量ずつ消耗できるからであつて、
0.00001w/o未満ではその効果が無く、0.3w/oを
超えるとアーク放電が切れない状態となり、耐消
耗、耐溶着性に悪影響を及ぼすので、0.0001〜
0.3w/oが好適である。
次に本発明による具体的な実施例と従来例につ
いて説明する。
実施例 １
平均粒径10μの化学銀粉74.9995w/oと、平均粒
径7μのカーボニルニツケル粉25w/oと、平均粒径
10μの酸化リチウム粒0.0005w/oとをＶ型混合機
を用いて３時間混合した後、Arガス雰囲気中900
℃で予備焼結し、圧縮焼結を２回以上繰返して直
径50mmのビレツトを得た。このビレツトを熱間押
出し、冷間引抜きを繰返して線材となした後、ヘ
ツダー加工して頭部径５mm、頭部厚さ１mm、脚部
径2.5mm、脚部高さ2.5mmの固定接点と、頭部径４
mm、頭部厚さ1.1mm、脚部径2.8mm、脚部高さ1.6mm
の可動接点を得た。
実施例 ２
平均粒径10μの化学銀粒69.75w/oと、平均粒径
7μのカーボニルニツケル粒30w/oと、平均粒径1μ
の酸化リチウム0.25w/oとをＶ型混合機を用いて
混合し、ボールミルを用いて粉砕した後、圧縮焼
結を行つて直径50mmのビレツトを得た。このビレ
ツトを熱間押出し、冷間引抜きを繰返して線材と
なした後ヘツダー加工して頭部径５mm、頭部厚さ
１mm、脚部径2.5mm、脚部高さ2.5mmの固定接点と
頭部径４mm、頭部厚さ1.1mm、脚部径2.8mm、脚部
高さ1.6mmの可動接点を得た。
実施例 ３
平均粒径10μｍの化学銀粉44.95重量％と、平均
粒径7μｍのカーボニルニツケル粉55重量％と、
平均粒径1μｍの酸化カリウム0.05重量％とをＶ型
混合機を用いて混合し、ボールミルを用いて粉砕
した後、圧縮焼結を行つて直径50mmのビレツトを
得た。このビレツトを熱間押出し、冷間引抜きを
繰返して線材となした後ヘツダー加工して頭部径
５mm、頭部厚さ１mm、脚部径2.5mm、脚部高さ2.5
mmの固定接点と頭部径４mm、頭部厚さ1.1mm、脚
部径2.8mm、脚部高さ1.6mmの可動接点を得た。
実施例 ４
平均粒径10μｍの化学銀粉44.995重量％と、平
均粒径7μｍのカーボニルニツケル粉50重量％と、
平均粒径1μｍの酸化ナトリウム0.005重量％とを
Ｖ型混合機を用いて混合し、ボールミルを用いて
粉砕した後、圧縮焼結を行つて直径50mmのビレツ
トを得た。このビレツトを熱間押出し、冷間引抜
きを繰返して線材となした後ヘツダー加工して頭
部径５mm、頭部厚さ１mm、脚部径2.5mm、脚部高
さ2.5mmの固定接点と頭部径４mm、頭部厚さ1.1
mm、脚部径2.8mm、脚部高さ1.6mmの可動接点を得
た。
実施例 ５
平均粒径10μｍの化学銀粉64.9重量％と、平均
粒径7μｍのカーボニルニツケル粉35重量％と、
平均粒径1μｍの酸化ナトリウム0.05重量％、酸化
カリウム0.05重量％とをＶ型混合機を用いて混合
し、ボールミルを用いて粉砕した後、圧縮焼結を
行つて直径50mmのビレツトを得た。このビレツト
を熱間押出し、冷間引抜きを繰返して線材となし
た後ヘツダー加工して頭部径５mm、頭部厚さ１
mm、脚部径2.5mm、、脚部高さ2.5mmの固定接点と
頭部径４mm、頭部厚さ1.1mm、脚部径2.8mm、頭部
高さ1.6mmの可動接点を得た。
実施例 ６
平均粒径10μｍの化学銀粉59.84重量％と、平均
粒径7μｍのカーボニルニツケル粉40重量％と、
平均粒径1μｍの酸化リチウム0.08重量％、酸化カ
リウム0.08重量％とをＶ型混合機を用いて混合
し、ボールミルを用いて粉砕した後、圧縮焼結を
行つて直径50mmのビレツトを得た。このビレツト
を熱間押出し、冷間引抜きを繰返して線材となし
た後ヘツダー加工して頭部径５mm、頭部厚さ１
mm、脚部径2.5mm、脚部高さ2.5mmの固定接点と脚
部径４mm、脚部厚さ1.1mm、脚部径2.8mm、脚部高
さ1.6mmの可動接点を得た。
実施例 ７
平均粒径10μｍの化学銀粉79.999重量％と、平
均粒径7μｍのカーボニルニツケル粉20重量％と、
平均粒径1μｍの酸化リチウム0.0005重量％、酸化
ナトリウム0.0005重量％とをＶ型混合機を用いて
混合し、ボールミルを用いて粉砕した後、圧縮焼
結を行つて直径50mmのビレツトを得た。このビレ
ツトを熱間押出し、冷間引抜きを繰返して線材と
なした後ヘツダー加工して頭部径５mm、頭部厚さ
１mm、脚部径2.5mm、脚部高さ2.5mmの固定接点と
脚部径４mm、脚部厚さ1.1mm、脚部径2.8mm、脚部
高さ1.6mmの可動接点を得た。
実施例 ８
平均粒径10μｍの化学銀粉84.76重量％と、平均
粒径7μｍのカーボニルニツケル粉15重量％と、
平均粒径1μｍの酸化リチウム0.08重量％、酸化ナ
トリウム0.08重量％、酸化カリウム0.08重量％と
をＶ型混合機を用いて混合し、ボールミルを用い
て粉砕した後、圧縮焼結を行つて直径50mmのビレ
ツトを得た。このビレツトを熱間押出し、冷間引
抜きを繰返して線材となした後ヘツダー加工して
頭部径５mm、頭部厚さ１mm、脚部径2.5mm、脚部
高さ2.5mmの固定接点と頭部径４mm、頭部厚さ1.1
mm、脚部径2.8mm、脚部高さ1.6mmの可動接点を得
た。
従来例
平均粒径10μの化学銀粉75w/oと平均粒径7μの
カーボニルニツケル粉25w/oとをＶ型混合機を用
いて混合した後、圧縮焼結を２回以上繰返して直
径50mmのビレツトを得た。このビレツトを熱間押
出し冷間引抜きを繰返して線材となした後、ヘツ
ダー加工して頭部径５mm、頭部厚さ１mm、脚部径
2.5mm、脚部高さ2.5mmの固定接点と、頭部径４
mm、頭部厚さ1.1mm、脚部径2.8mm、脚部高さ1.6mm
の可動接点を得た。
然してこれら実施例１〜８及び従来例の各接点
９組を下記の試験条件にて、耐溶着試験、耐消
耗・接触抵抗試験を行つた処、下記の表の右欄に
示すような結果を得た。
耐溶着試験条件
電 圧：AC100V、50Hz
電 流：投入電流40A
定常電流10A
負 荷：抵抗負荷
開閉頻度：20回／分
開閉回数：20万回
耐消耗・接触抵抗試験条件
電 流：30A
電 圧：AC100V 50Hz
負 荷：抵抗負荷
開閉頻度：１回／１秒
開閉回数：20万回
The present invention relates to electrical contact materials, and particularly to improvements in silver-nickel electrical contact materials. Traditionally, silver-based electrical contact materials include silver-oxide systems represented by silver-cadmium oxide, silver-metal systems represented by silver-nickel and silver-tungsten, and silver-metal systems represented by silver-carbon. Non-metallic contact materials have been used. In particular, silver-nickel contact materials are extremely easy to work with and have relatively low and stable contact resistance, making them ideal for electrical contacts in switches, relays, electromagnetic relays, etc. in the small to medium current range. It has been widely used. However, in electrical contacts made of silver-nickel contact materials, arc energy tends to concentrate at one point of the contact when making contact or breaking, and therefore wears out and
There is a lot of relocation and the contact life is short. The present invention has been made to solve these problems, and provides an electrical contact material that has better abrasion resistance and welding resistance than silver-nickel contact materials, and maintains contact resistance equivalent to that of silver-nickel contact materials. That is. The electrical contact material of the present invention contains 10 to 60% by weight of nickel and one or more of oxides of lithium, sodium, and potassium in a total amount of 0.0001%.
~0.3% by weight and the balance silver. In the electrical contact material of the present invention, nickel is added to silver to provide welding resistance and low contact resistance, and is 10% by weight (hereinafter referred to as "w/o").
If it is less than 60 w/o, the welding resistance will be insufficient, and if it exceeds 60 w/o, a thick layer of nickel oxide will be formed on the contact surface and the contact resistance will increase, so 10 to 60 w/o is preferable. Furthermore, dispersing one or more of lithium, sodium, and potassium oxides in silver-nickel is because these alkali metal oxides have a very small work force when emitting thermionic electrons. Since these compounds are easily discharged, by dispersing them in a very small amount, these compounds generate an arc in advance when the electrical contact contacts and opens, avoiding concentrating the arc in one point and spreading it over the entire contact surface. distributed in
This is because it can be consumed uniformly and in small amounts,
If it is less than 0.00001w/o, there is no effect, and if it exceeds 0.3w/o, the arc discharge will not be cut off, which will have a negative effect on wear resistance and welding resistance.
0.3w/o is suitable. Next, specific embodiments according to the present invention and conventional examples will be described. Example 1 Chemical silver powder 74.9995w/o with an average particle size of 10μ, carbonyl nickel powder 25w/o with an average particle size of 7μ, and average particle size
After mixing 10μ lithium oxide particles with 0.0005w/o using a V-type mixer for 3 hours,
Preliminary sintering was carried out at ℃, and compression sintering was repeated two or more times to obtain a billet with a diameter of 50 mm. This billet is repeatedly hot-extruded and cold-drawn to form a wire rod, and then processed into a header to form a fixed contact with a head diameter of 5 mm, head thickness of 1 mm, leg diameter of 2.5 mm, and leg height of 2.5 mm. , head diameter 4
mm, head thickness 1.1mm, leg diameter 2.8mm, leg height 1.6mm
A movable contact was obtained. Example 2 Chemical silver grains 69.75w/o with an average particle size of 10μ and an average particle size of
7μ carbonyl nickel grain 30w/o and average particle size 1μ
The mixture was mixed with 0.25 w/o of lithium oxide using a V-type mixer, pulverized using a ball mill, and compression sintered to obtain a billet with a diameter of 50 mm. This billet is repeatedly hot-extruded and cold-drawn to form a wire rod, and then processed into a header to form a fixed contact and a head with a head diameter of 5 mm, head thickness of 1 mm, leg diameter of 2.5 mm, and leg height of 2.5 mm. A movable contact with a part diameter of 4 mm, a head thickness of 1.1 mm, a leg diameter of 2.8 mm, and a leg height of 1.6 mm was obtained. Example 3 44.95% by weight of chemical silver powder with an average particle size of 10 μm, 55% by weight of carbonyl nickel powder with an average particle size of 7 μm,
The mixture was mixed with 0.05% by weight of potassium oxide having an average particle size of 1 μm using a V-type mixer, pulverized using a ball mill, and then compressed and sintered to obtain a billet with a diameter of 50 mm. This billet was repeatedly hot extruded and cold drawn to make a wire rod, and then processed into a header with a head diameter of 5 mm, head thickness of 1 mm, leg diameter of 2.5 mm, and leg height of 2.5 mm.
A fixed contact with a diameter of 4 mm and a movable contact with a head diameter of 4 mm, a head thickness of 1.1 mm, a leg diameter of 2.8 mm, and a leg height of 1.6 mm were obtained. Example 4 44.995% by weight of chemical silver powder with an average particle size of 10 μm, 50% by weight of carbonyl nickel powder with an average particle size of 7 μm,
The mixture was mixed with 0.005% by weight of sodium oxide having an average particle size of 1 μm using a V-type mixer, pulverized using a ball mill, and then compressed and sintered to obtain a billet with a diameter of 50 mm. This billet is repeatedly hot-extruded and cold-drawn to form a wire rod, and then processed into a header to form a fixed contact and a head with a head diameter of 5 mm, head thickness of 1 mm, leg diameter of 2.5 mm, and leg height of 2.5 mm. Part diameter 4mm, head thickness 1.1
A movable contact with a leg diameter of 2.8 mm and a leg height of 1.6 mm was obtained. Example 5 64.9% by weight of chemical silver powder with an average particle size of 10 μm, 35% by weight of carbonyl nickel powder with an average particle size of 7 μm,
0.05% by weight of sodium oxide and 0.05% by weight of potassium oxide with an average particle size of 1 μm were mixed using a V-type mixer, pulverized using a ball mill, and then compressed and sintered to obtain a billet with a diameter of 50 mm. This billet was repeatedly hot extruded and cold drawn to form a wire rod, and then processed into a header with a head diameter of 5 mm and a head thickness of 1 mm.
A fixed contact with a leg diameter of 2.5 mm, a leg height of 2.5 mm, and a movable contact with a head diameter of 4 mm, a head thickness of 1.1 mm, a leg diameter of 2.8 mm, and a head height of 1.6 mm were obtained. Example 6 59.84% by weight of chemical silver powder with an average particle size of 10 μm, 40% by weight of carbonyl nickel powder with an average particle size of 7 μm,
0.08% by weight of lithium oxide and 0.08% by weight of potassium oxide having an average particle size of 1 μm were mixed using a V-type mixer, pulverized using a ball mill, and compression sintered to obtain a billet with a diameter of 50 mm. This billet was repeatedly hot extruded and cold drawn to form a wire rod, and then processed into a header with a head diameter of 5 mm and a head thickness of 1 mm.
A fixed contact with a leg diameter of 2.5 mm, a leg height of 2.5 mm, and a movable contact with a leg diameter of 4 mm, a leg thickness of 1.1 mm, a leg diameter of 2.8 mm, and a leg height of 1.6 mm were obtained. Example 7 79.999% by weight of chemical silver powder with an average particle size of 10 μm, 20% by weight of carbonyl nickel powder with an average particle size of 7 μm,
0.0005% by weight of lithium oxide and 0.0005% by weight of sodium oxide having an average particle size of 1 μm were mixed using a V-type mixer, pulverized using a ball mill, and compression sintered to obtain a billet with a diameter of 50 mm. This billet is repeatedly hot-extruded and cold-drawn to form a wire rod, and then processed into a header to form fixed contacts and legs with a head diameter of 5 mm, head thickness of 1 mm, leg diameter of 2.5 mm, and leg height of 2.5 mm. A movable contact with a part diameter of 4 mm, a leg part thickness of 1.1 mm, a leg part diameter of 2.8 mm, and a leg part height of 1.6 mm was obtained. Example 8 84.76% by weight of chemical silver powder with an average particle size of 10 μm, 15% by weight of carbonyl nickel powder with an average particle size of 7 μm,
0.08% by weight of lithium oxide, 0.08% by weight of sodium oxide, and 0.08% by weight of potassium oxide with an average particle size of 1 μm are mixed using a V-type mixer, pulverized using a ball mill, and then compressed and sintered to obtain a diameter of 50 mm. I got a billet. This billet was repeatedly hot extruded and cold drawn to make a wire rod, and then processed into a header to form a fixed contact and a head with a head diameter of 5 mm, head thickness of 1 mm, leg diameter of 2.5 mm, and leg height of 2.5 mm. Part diameter 4mm, head thickness 1.1
A movable contact with a leg diameter of 2.8 mm and a leg height of 1.6 mm was obtained. Conventional example: After mixing 75w/o of chemical silver powder with an average particle size of 10μ and 25w/o of carbonyl nickel powder with an average particle size of 7μ using a V-type mixer, compression sintering is repeated two or more times to create a billet with a diameter of 50mm. I got it. This billet is repeatedly hot-extruded and cold-drawn to form a wire rod, and then processed into a header with a head diameter of 5 mm, a head thickness of 1 mm, and a leg diameter.
2.5mm, leg height 2.5mm fixed contact and head diameter 4
mm, head thickness 1.1mm, leg diameter 2.8mm, leg height 1.6mm
A movable contact was obtained. However, when welding resistance tests and abrasion resistance/contact resistance tests were conducted on each of the nine sets of contacts of Examples 1 to 8 and the conventional example under the following test conditions, the results shown in the right column of the table below were obtained. Obtained. Welding resistance test conditions Voltage: AC100V, 50Hz Current: Supply current 40A Steady current 10A Load: Resistive load Switching frequency: 20 times/min Switching frequency: 200,000 times Wear resistance/contact resistance test conditions Current: 30A Voltage : AC100V 50Hz Load: Resistive load Switching frequency: 1 time/1 second Number of switching: 200,000 times
【表】
上記の表で明らかなように実施例１〜８のリベ
ツト型接点は、従来例のリベツト型接点と同等の
低接触抵抗を有し、耐溶着、耐消耗性については
一段と優れていることが判る。
以上詳記した通り本発明の電気接点材料は、従
来の銀−ニツケルより成る電気接点材料に比べ消
耗、溶着が極めて耐消耗、耐溶着性が一段と優
れ、接触抵抗は同等に低く安定しているので、従
来の銀−ニツケルより成る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言える。[Table] As is clear from the table above, the rivet-type contacts of Examples 1 to 8 have low contact resistance equivalent to the conventional rivet-type contacts, and are even better in terms of welding resistance and abrasion resistance. I understand that. As detailed above, the electrical contact material of the present invention is extremely resistant to abrasion and welding compared to conventional electrical contact materials made of silver and nickel, and has superior abrasion and welding resistance, and the contact resistance is equally low and stable. Therefore, it can be said to be an epoch-making product that can replace the conventional electrical contact material made of silver-nickel.