JPH0783945B2 - Resistance welding electrode and method for manufacturing the same - Google Patents

Description

【発明の詳細な説明】Detailed Description of the Invention

【０００１】[0001]

【産業上の利用分野】本発明は被溶接体に加圧力を加え
つつ、通電を行う抵抗溶接技術に関し、特にこの抵抗溶
接において使用される電極の素材となる混合原料粉末、
この混合原料粉末により製造された電極及びこの電極の
製造方法に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resistance welding technique in which current is applied while applying pressure to a workpiece, and in particular, a mixed raw material powder used as a material for electrodes used in this resistance welding,
The present invention relates to an electrode manufactured from this mixed raw material powder and a method for manufacturing this electrode.

【０００２】[0002]

【従来の技術】一般に、スポット溶接又はシーム溶接等
の抵抗溶接に使用される電極には、短時間とはいえ大電
流が流れる。そして、この電極には抵抗発熱が生じると
共に、溶接部に投入した熱量の多くは電極に逃げるた
め、電極先端部の温度は400乃至700℃にも達する。従っ
て、抵抗溶接用電極材料としては、耐熱性、高温強度及
び高導電性等が要求されており、このため、従来の抵抗
溶接用電極は通常Ｃｕ−Ｃｒ合金により形成されてい
る。2. Description of the Related Art Generally, a large current flows through an electrode used for resistance welding such as spot welding or seam welding, though it is short time. Then, resistance heat is generated in this electrode, and most of the heat input to the weld escapes to the electrode, so the temperature at the tip of the electrode reaches 400 to 700 ° C. Therefore, the resistance welding electrode material is required to have heat resistance, high temperature strength, high conductivity, and the like. Therefore, the conventional resistance welding electrode is usually formed of a Cu—Cr alloy.

【０００３】[0003]

【発明が解決しようとする課題】ところで、近年、車両
等の軽量化を目的として、アルミニウム板が使用される
ことが多くなってきた。しかし、アルミニウムは熱伝導
率が高いため、電極には短時間で大電流を流す必要があ
る。このため、電極の損傷が極めて大きくなる。而し
て、Ｃｕ−Ｃｒ合金は他の従来の電極材に比して導電性
が優れているものの、アルミニウム板の抵抗溶接のよう
な過酷な使用状況下においては、必ずしも必要な特性を
十分に満足しているとはいえない。即ち、このＣｕ−Ｃ
ｒ合金は溶融Ａｌに対して濡れ易いため、その表面で脆
い合金層が生成しやすい。このため、従来のＣｕ−Ｃｒ
合金製電極はアルミニウム材の溶接に際して、寿命が短
いという欠点がある。そして、電極の寿命が短ければ電
極材のコストが高くなるだけでなく、電極の取り替え及
びドレッシングのために多大の時間と労力とを費やすこ
とになる。By the way, in recent years, aluminum plates have been increasingly used for the purpose of reducing the weight of vehicles and the like. However, since aluminum has high thermal conductivity, it is necessary to flow a large current to the electrodes in a short time. Therefore, the damage to the electrodes becomes extremely large. Although the Cu-Cr alloy has excellent conductivity as compared with other conventional electrode materials, it does not always have the necessary characteristics under severe conditions such as resistance welding of an aluminum plate. I'm not satisfied. That is, this Cu-C
Since the r alloy is easily wet with molten Al, a brittle alloy layer is likely to be formed on the surface thereof. Therefore, conventional Cu-Cr
The alloy electrode has a shortcoming that it has a short life when welding an aluminum material. If the life of the electrode is short, not only the cost of the electrode material is increased, but also a lot of time and labor are spent for replacing and dressing the electrode.

【０００４】本発明はかかる問題点において鑑みてなさ
れたものであって、導電性が優れ、溶融Ａｌに対する耐
濡れ性が優れていて、脆い合金層の生成が少なく、優れ
た寿命を持つ抵抗溶接用電極及びその製造方法を提供す
ることを目的とする。The present invention has been made in view of the above problems, and is resistance welding having excellent conductivity, excellent wettability with respect to molten Al, less formation of a brittle alloy layer, and excellent life. It is an object of the present invention to provide a use electrode and a manufacturing method thereof.

【０００５】[0005]

【課題を解決するための手段】本発明に係る抵抗溶接用
電極は、平均粒径が30μｍ以下のＣｕ粉末、Ｚｒ粉末及
びＡｇ粉末と平均粒径が10μｍ以下のＣｒ粉末の混合粉
末に平均粒径が10μｍ以下のＷ粉末を0.1〜5.0重量％混
合してなる原料粉末を焼結して得られた焼結体を有し、
前記Ｃｕ−Ｃｒ−Ｚｒ−Ａｇ混合粉末中の各粉末の配合
比は、Ｃｒ粉末が0.3〜5.0重量％、Ｚｒ粉末が0.01〜0.
3重量％、Ａｇ粉末が0.01〜0.5重量％、残部がＣｕ粉末
であることを特徴とする。The electrode for resistance welding according to the present invention has an average particle diameter of a mixed powder of Cu powder, Zr powder and Ag powder having an average particle diameter of 30 μm or less and Cr powder having an average particle diameter of 10 μm or less. A sintered body obtained by sintering a raw material powder obtained by mixing 0.1 to 5.0% by weight of W powder having a diameter of 10 μm or less,
The mixing ratio of each powder in the Cu-Cr-Zr-Ag mixed powder is 0.3 to 5.0% by weight of Cr powder and 0.01 to 0.
3% by weight, 0.01 to 0.5% by weight of Ag powder, and the balance Cu powder.

【０００６】本発明に係る抵抗溶接用電極の製造方法
は、無酸素銅からなる外層部材内に、Ｃｒ；0.3〜1.5重
量％、残部実質的にＣｕからなる銅合金の中間層部材を
挿入し、更にこの中間層部材内に、前記請求項１に記載
の原料粉末を封入し、次いで、前記中間層内を真空脱気
してビレットを製造し、その後このビレットを熱間静水
圧押出処理し、更に、溶体化処理した後、少なくとも１
サイクルの冷間加工及び焼鈍処理を実施することを特徴
とする。In the method for producing a resistance welding electrode according to the present invention, an intermediate layer member made of a copper alloy containing 0.3 to 1.5% by weight of Cr and the balance substantially Cu is inserted into an outer layer member made of oxygen-free copper. Further, the raw material powder according to claim 1 is further enclosed in the intermediate layer member, and then the intermediate layer is vacuum deaerated to produce a billet, and then the billet is subjected to hot isostatic pressing. , And at least 1 after solution treatment
It is characterized by carrying out a cycle cold working and annealing treatment.

【０００７】なお、前記Ａｇ粉末としては、Ａｇろう粉
末等も含まれる。The Ag powder includes Ag wax powder and the like.

【０００８】[0008]

【作用】本願発明者等は前述した従来技術の有する欠点
を解消するため、アルミニウム材の抵抗溶接用電極とし
て必要な強度及び熱伝導度等の特性を満足する合金材料
を開発すべく種々実験研究を行った。その結果、Ｃｕ−
Ｃｒ合金基地中にＷを分散させることにより、被溶接材
との耐濡れ性が優れた材料を得ることができることを見
いだした。In order to solve the above-mentioned drawbacks of the prior art, the inventors of the present invention have conducted various experimental studies to develop an alloy material satisfying the properties such as strength and thermal conductivity required for resistance welding electrodes of aluminum materials. I went. As a result, Cu-
It was found that by dispersing W in the Cr alloy matrix, a material having excellent wettability with the material to be welded can be obtained.

【０００９】次に、本発明に係る抵抗溶接用電極及びそ
の製造方法について更に具体的に説明する。Next, the resistance welding electrode and the method for manufacturing the same according to the present invention will be described more specifically.

【００１０】先ず、混合原料粉末を構成する各成分粉末
の添加理由及びその組成限定理由、並びに粉末粒径の限
定理由について説明する。First, the reason for adding each component powder constituting the mixed raw material powder, the reason for limiting the composition thereof, and the reason for limiting the powder particle size will be described.

【００１１】Ｃｒ粉末；0.3〜5.0重量％ 溶体化処理によって固溶したＣｒは、その後の析出焼鈍
によって、微細な金属Ｃｒとして析出し、強度の向上に
寄与する。また、固溶限を超えた含有Ｃｒは、そのまま
粉末焼結体中に残存し、一部はＣｒ₂Ｏ₃等の酸化物に変
わる。金属Ｃｒはそれ自体高融点であるため、溶融Ａｌ
の拡散を抑えると共に、Ｃｒ₂Ｏ₃は溶融Ａｌとの耐濡れ
性向上に寄与する。Ｃｒ粉末が0.3重量％未満では、析
出焼鈍を行っても析出するＣｒ量が少ないので強度の向
上は期待できず、また、Ｃｒ粉末が5.0重量％を超えて
含有されても延性の低下により溶接時の加圧によって電
極先端部に割れが発生しやすくなり、電極寿命を縮める
原因ともなる。従って、Ｃｒ粉末の含有量は0.3〜5.0重
量％とする。 Cr powder; 0.3 to 5.0 wt% Cr solid-solved by solution treatment is precipitated as fine metallic Cr by subsequent precipitation annealing, and contributes to improvement of strength. Further, the Cr content exceeding the solid solubility limit remains in the powder sintered body as it is, and a part thereof is changed to an oxide such as Cr ₂ O ₃ . Since metallic Cr itself has a high melting point, molten Al
Cr ₂ O ₃ contributes to the improvement of wettability with molten Al while suppressing the diffusion of Al. If the content of Cr powder is less than 0.3% by weight, the amount of Cr precipitated is small even if precipitation annealing is performed, so improvement in strength cannot be expected, and even if the content of Cr powder exceeds 5.0% by weight, the ductility decreases and welding occurs. The pressure applied at this time tends to cause cracks at the tip of the electrode, which may shorten the life of the electrode. Therefore, the content of Cr powder is set to 0.3 to 5.0% by weight.

【００１２】Ｚｒ粉末；0.01〜0.3重量％ Ｃｕ粉末は水アトマイズ法、ガスアトマイズ法及び電気
分解法等によって製造されるが、その製造過程で500ppm
から多い場合は5000ppm程度の酸素量を含有してしま
う。この酸素はＣｕ粉末中ではＣｕＯ及びＣｕ₂Ｏとし
て存在しているが、高温静水圧押出及びその後の熱処理
の過程で酸素との親和力が強いＣｒと結合して酸化物を
形成してしまう。これにより、本来Ｃｕ中に微細な金属
Ｃｒとして析出して強度の向上に寄与すべきＣｒ量が減
少し、所望の強度が得られなくなることがある。酸素含
有量が50ppmを超えるＣｕ粉末を使用する場合には、上
述のような酸素による弊害が発生するが、本願発明者等
は、酸素との親和力がＣｒより強く、且つ、Ｃｕに固溶
しても導電率の低下が少ないＺｒ粉末を混合することに
より、上述の弊害を防止できることを見いだした。Ｚｒ
粉末の添加量が0.01重量％未満ではその添加効果が小さ
く、Ｚｒ粉末を0.3重量％超えて含有しても、その添加
効果が飽和するばかりでなく、導電率の低下をもたら
す。従って、Ｚｒ粉末含有量は0.01〜0.3重量％とす
る。 Zr powder: 0.01 to 0.3 wt% Cu powder is manufactured by a water atomizing method, a gas atomizing method, an electrolysis method, etc., and 500 ppm in the manufacturing process.
If the content is too high, the content of oxygen is about 5000 ppm. Although this oxygen exists as CuO and Cu ₂ O in the Cu powder, it is combined with Cr, which has a strong affinity for oxygen, in the course of high temperature hydrostatic extrusion and subsequent heat treatment to form an oxide. As a result, the amount of Cr, which originally should be deposited as fine metal Cr in Cu and should contribute to the improvement of strength, decreases, and the desired strength may not be obtained. When Cu powder having an oxygen content of more than 50 ppm is used, the above-mentioned adverse effects due to oxygen occur, but the inventors of the present application have found that the affinity with oxygen is stronger than that of Cr and that it forms a solid solution with Cu. However, it has been found that the above-mentioned adverse effects can be prevented by mixing Zr powder, which has a small decrease in conductivity. Zr
If the addition amount of the powder is less than 0.01% by weight, the addition effect is small, and even if Zr powder is contained in an amount of more than 0.3% by weight, the addition effect is not only saturated, but also the conductivity is lowered. Therefore, the Zr powder content is 0.01 to 0.3% by weight.

【００１３】Ａｇ粉末；0.01〜0.5重量％ ＡｇとＣｕの共晶温度は779℃であるため、Ｃｕ粉末に
Ａｇ粉末を混合することによって、導電率を劣化させる
ことなく、焼結を促進させ、充填率を高めることができ
る。ＡｇはＡｇろうに置き換えても良く、この焼結促進
効果は何ら変わりはない。Ａｇ粉末の含有量が0.01重量
％未満では効果は小さく、0.5重量％を超えて含有して
も効果は飽和するばかりでなく、高価なＡｇの使用は無
駄となる。従って、Ａｇ粉末含有量は0.01乃至0.5重量
％とする。 Ag powder: 0.01 to 0.5 wt% Since the eutectic temperature of Ag and Cu is 779 ° C., mixing Ag powder with Cu powder promotes sintering without deteriorating conductivity, The filling rate can be increased. Ag may be replaced with Ag solder, and this sintering promoting effect is not changed at all. If the Ag powder content is less than 0.01% by weight, the effect is small, and if the Ag powder content exceeds 0.5% by weight, the effect is not only saturated, but also expensive Ag is wasted. Therefore, the Ag powder content is 0.01 to 0.5% by weight.

【００１４】Ｗ粉末；0.1〜5.0重量％ Ｗは高融点金属であり、Ａｌ等の拡散を抑える効果があ
ると共に、ＷＯ₃等の酸化物は特にＡｌ等の溶融金属に
対して優れた耐濡れ性を発揮する。加えて、導電率もそ
れ自体31％IACSとセラミックスに比較して格段に高く、
特に、アルミニウム抵抗溶接用電極の構成材料として有
用である。更に、本願発明者らの研究によると、Ｗは未
固溶のＣｒ粒子中へ拡散するため、Ｃｒ粒子の耐濡れ性
をも向上させるものである。従って、ＷとＣｒの共添に
よる相乗作用により飛躍的に耐濡れ性を向上させること
ができるものである。Ｗ粉末の含有量が0.1重量％未満
の場合はその効果が小さく、5.0重量％を超えるとその
効果が飽和するばかりでなく、延性の低下及び被削性の
低下等の電極チップ加工上の弊害が大きくなるため、好
ましくない。更に、延性の低下などにより、溶接時の加
圧によって電極先端部に割れが発生しやすくなり、電極
寿命を縮める原因ともなる。従って、Ｗ粉末の含有量は
0.1〜5.0重量％とする。 W powder; 0.1 to 5.0% by weight W is a refractory metal and has an effect of suppressing diffusion of Al and the like, and oxides such as WO ₃ have excellent wettability resistance especially to molten metals such as Al. Exert its abilities. In addition, the conductivity itself is 31% IACS, which is significantly higher than that of ceramics,
Particularly, it is useful as a constituent material of an electrode for aluminum resistance welding. Further, according to the research conducted by the inventors of the present application, W diffuses into undissolved Cr particles, so that the wettability of Cr particles is also improved. Therefore, the wettability can be dramatically improved by the synergistic effect of the co-addition of W and Cr. When the content of W powder is less than 0.1% by weight, the effect is small, and when it exceeds 5.0% by weight, the effect is not only saturated, but also the ductility and machinability are deteriorated. Is large, which is not preferable. Further, due to deterioration of ductility, cracking is likely to occur at the tip of the electrode due to the pressure applied during welding, which may shorten the life of the electrode. Therefore, the content of W powder is
0.1 to 5.0% by weight.

【００１５】Ｚｒ，Ａｇ，Ｃｕ粉末；30μｍ以下 これらの粉末の平均粒径が30μｍを超えると、後述する
電極製造方法における高温静水圧押出工程及びその後の
冷間加工工程によって充填率を97％以上にすることは難
しい。この充填率が97％未満であると、延性及び導電率
の低下が生じるため好ましくない。従って、これらの粉
末の平均粒径は30μｍ以下とする。 Zr, Ag, Cu powder; 30 μm or less When the average particle size of these powders exceeds 30 μm, the filling rate is 97% or more by the high temperature isostatic extrusion step and the subsequent cold working step in the electrode manufacturing method described later. It's difficult to do. If the filling rate is less than 97%, the ductility and the conductivity decrease, which is not preferable. Therefore, the average particle size of these powders should be 30 μm or less.

【００１６】Ｃｒ粉末；10μｍ以下 Ｃｒ粉末は、Ｃｕ中に固溶し、その後の析出焼鈍によっ
て、微細な金属Ｃｒとして析出し、強度の向上に寄与す
ると共に、未固溶のＣｒ粒子はＣｕ中に分散して溶融Ａ
ｌに対する耐濡れ性を向上させるという効果も有してい
る。Ｃｒ粉末の平均粒径が10μｍを超えると、高温静水
圧押出及びその後の溶体化処理工程を経ても、Ｃｕ中へ
の固溶が平衡状態まで到達せず、その後の析出焼鈍によ
っても所望の強度が得られなくなる。また、未固溶Ｃｒ
粒子の分散も不均一となるため、耐濡れ性の向上効果が
十分発揮されない。従って、Ｗ粉末の平均粒径は10μｍ
以下とする。 Cr powder: 10 μm or less Cr powder forms a solid solution in Cu and precipitates as fine metallic Cr by subsequent precipitation annealing, contributing to the improvement of strength, and undissolved Cr particles remain in Cu. Disperse and melt A
It also has an effect of improving wettability with respect to l. If the average particle size of the Cr powder exceeds 10 μm, the solid solution in Cu does not reach the equilibrium state even after the high temperature isostatic pressing and the subsequent solution treatment step, and the desired strength is obtained even by the subsequent precipitation annealing. Will not be obtained. In addition, undissolved Cr
Since the particles are not evenly dispersed, the effect of improving the wettability is not sufficiently exerted. Therefore, the average particle size of W powder is 10 μm
Below.

【００１７】Ｗ粉末；10μｍ以下 Ｗ粉末はＣｕ中に分散して、溶融Ａｌに対する耐濡れ性
を向上させるという効果を有しているが、平均粒径が10
μｍを超えるとこの分散が不均一となるため、その効果
が十分に発揮されない。従って、Ｗ粉末の平均粒径は10
μｍ以下とする。 W powder: 10 μm or less W powder is dispersed in Cu and has an effect of improving wettability with respect to molten Al, but has an average particle size of 10
If it exceeds μm, the dispersion becomes non-uniform, so that the effect cannot be sufficiently exhibited. Therefore, the average particle size of W powder is 10
μm or less.

【００１８】なお、本発明に係る抵抗溶接用電極の製造
に使用される混合粉末は前述の如く、Ｃｒ粉末、Ｚｒ粉
末、Ａｇ粉末及びＣｕ粉末の各金属粉末にＷ粉末を混合
した混合物に限らず、所定量のＣｒ，Ｚｒを含有するＣ
ｕ合金の粉末にＡｇ粉末及びＷ粉末を請求項２に記載の
含有量及び配合比で混合したものでも良い。その限定理
由は上述の場合と同様である。但し、Ｃｕ−Ｃｒ−Ｚｒ
合金の粒径の条件は、上述のＣｕ粉末の粒径の場合と同
一条件であり、その限定理由も同様である。The mixed powder used in the production of the resistance welding electrode according to the present invention is limited to the mixture of W powder with each metal powder of Cr powder, Zr powder, Ag powder and Cu powder as described above. C containing a predetermined amount of Cr and Zr
It is also possible to mix Ag powder and W powder with the u alloy powder in the content and compounding ratio as set forth in claim 2. The reason for the limitation is similar to the above case. However, Cu-Cr-Zr
The conditions for the grain size of the alloy are the same as those for the grain size of the Cu powder described above, and the reasons for the limitation are the same.

【００１９】本発明に係る抵抗溶接用電極は上述の組成
及び粒径の混合粉末を焼結することにより製造される。The resistance welding electrode according to the present invention is manufactured by sintering a mixed powder having the above composition and particle size.

【００２０】この場合、上述の混合粉末の焼結体を電極
の芯部に配置し、外層に無酸素銅を配置し、その中間層
として、Ｃｒが0.3〜1.5重量％であり、残部が実質的に
Ｃｕよりなる合金を配置した３層構造にすることが好ま
しい。In this case, the sintered body of the above-mentioned mixed powder is placed in the core of the electrode, oxygen-free copper is placed in the outer layer, and Cr is 0.3 to 1.5% by weight as the intermediate layer, and the balance is substantially the same. It is preferable to have a three-layer structure in which an alloy made of Cu is arranged.

【００２１】即ち、強度と耐濡れ性を必要とする芯部に
前述のＷを分散させた粉末焼結体を配し、この芯部の外
側に純銅等の高導電材を配して電極チップを構成する。
この場合、粉末焼結体は高価なものであり、できるだけ
芯部の径は小さくすることが好ましい。しかし、芯部の
径を小さくし過ぎると、苛酷な溶接条件においては、マ
ッシュルーミング等のような電極先端部の変形が生じや
すい。そこで本発明においては中間層にクロム銅を配し
て強度を向上させる。That is, the above-mentioned powder sintered body in which W is dispersed is arranged in a core portion which requires strength and wettability, and a highly conductive material such as pure copper is arranged outside the core portion to form an electrode chip. Make up.
In this case, the powder sintered body is expensive and it is preferable to make the diameter of the core portion as small as possible. However, if the diameter of the core portion is made too small, the electrode tip portion such as mash roaming is likely to be deformed under severe welding conditions. Therefore, in the present invention, chromium copper is arranged in the intermediate layer to improve the strength.

【００２２】次に、本発明に係る抵抗溶接用電極の製造
方法について説明する。先ず、無酸素銅からなる外層部
材に、前述の組成を有するＣｕ合金からなる中間層部材
を嵌入し、更に、この中間層部材内に前述の組成を有す
る混合原料粉末を充填する。そして、この混合原料粉末
を中間層部材内に封入した後、前記中間層部材内を真空
脱気してビレットを製造する。次いで、このビレットを
熱間静水圧押出処理し、更に、溶体化処理した後、少な
くとも１サイクルの冷間加工及び焼鈍処理を実施する。
これにより、本発明に係る３層構造の抵抗溶接用電極が
製造される。Next, a method of manufacturing the resistance welding electrode according to the present invention will be described. First, an outer layer member made of oxygen-free copper is fitted with an intermediate layer member made of a Cu alloy having the above-mentioned composition, and further, the mixed raw material powder having the above-mentioned composition is filled in the intermediate layer member. Then, after the mixed raw material powder is enclosed in the intermediate layer member, the inside of the intermediate layer member is vacuum deaerated to manufacture a billet. Next, this billet is subjected to hot isostatic extrusion treatment, further subjected to solution treatment, and then subjected to at least one cycle of cold working and annealing treatment.
Thus, the resistance welding electrode having a three-layer structure according to the present invention is manufactured.

【００２３】この場合に、熱間静水圧押出処理における
押出温度は、800〜1000℃とするのが好ましい。静水圧
押出温度を800〜1000℃とした理由は、1000℃より高温
では、焼結粒の粗大化が発生し、800℃より低温では粉
末の焼結が不十分となり、機械的特性及び導電率の所期
の目標達成が困難になるからである。In this case, the extrusion temperature in the hot isostatic extrusion treatment is preferably 800 to 1000 ° C. The reason why the hydrostatic extrusion temperature is set to 800 to 1000 ° C is that the sintered particles become coarser at a temperature higher than 1000 ° C, and the sintering of the powder becomes insufficient at a temperature lower than 800 ° C, resulting in insufficient mechanical properties and electrical conductivity. This is because it will be difficult to achieve the intended goal of.

【００２４】また、その後の溶体化処理温度は900〜100
0℃とするのが好ましい。このように900〜1000℃で溶体
化処理する理由は1000℃より高温では結晶粒の粗大化が
発生する芯部及び中間層のＣｕ母相中へのＣｒの固溶が
不十分となり、後工程の焼鈍工程における析出強化が不
十分となるためである。The solution treatment temperature thereafter is 900 to 100.
The temperature is preferably 0 ° C. The reason for the solution treatment at 900 to 1000 ° C. is that the solidification of Cr in the Cu matrix of the core and the intermediate layer where the crystal grains are coarsened at a temperature higher than 1000 ° C. becomes insufficient, This is because the precipitation strengthening in the annealing step is insufficient.

【００２５】溶体化処理後の冷間加工は、焼鈍処理工程
における強度の向上に寄与するＣｒの析出を促進させる
ため、20％以上の加工率とすることが望ましい。また、
焼鈍処理工程においては、400〜500℃で30分以上の熱処
理を施すことが好ましい。焼鈍温度を400〜500℃とする
理由は500℃より高温では強度が低く、450℃より低温で
は析出が不十分となり、強度及び導電率の所期の目標達
成が困難になるからである。焼鈍時間を30分以上とする
理由はＣｒを十分に析出させるためである。The cold working after the solution treatment is preferably performed at a working rate of 20% or more in order to promote the precipitation of Cr which contributes to the improvement of the strength in the annealing process. Also,
In the annealing process, it is preferable to perform heat treatment at 400 to 500 ° C. for 30 minutes or more. The reason for setting the annealing temperature to 400 to 500 ° C. is that the strength is low at a temperature higher than 500 ° C. and the precipitation becomes insufficient at a temperature lower than 450 ° C., and it becomes difficult to achieve the desired target of strength and conductivity. The reason for setting the annealing time to 30 minutes or more is to sufficiently precipitate Cr.

【００２６】更に、焼鈍後の冷間加工は強度向上に対し
て有効である。焼鈍後の冷間加工率は10〜50％が望まし
い。10％未満では加工硬化が不十分であり、50％を超え
て加工しても加工硬化が飽和すると共に、耐熱性の低下
が著しくなるからである。Further, cold working after annealing is effective for improving strength. The cold working ratio after annealing is preferably 10 to 50%. This is because if it is less than 10%, the work hardening is insufficient, and if it exceeds 50%, the work hardening is saturated and the heat resistance is significantly reduced.

【００２７】[0027]

【実施例】次に、本発明の実施例について説明する。EXAMPLES Next, examples of the present invention will be described.

【００２８】下記表１に示す成分を同表に示す配合比で
含有する混合粉末を外層が無酸素銅、中間層がＣｕ−1.
0重量％Ｃｒの組成を有するＣｕ合金からなる２層構造
（内径が89mm、中間層外径が114mm、外径が143mm）のケ
ースに封入した。但し、Ｃｒ，Ｚｒ，Ａｇ，Ｃｕの各粉
末の平均粒径は20μｍであり、Ｗ粉末の平均粒径は1μ
ｍである。The mixed powder containing the components shown in Table 1 below in the compounding ratio shown in the same table was oxygen-free copper for the outer layer and Cu-1.
It was enclosed in a case having a two-layer structure (inner diameter 89 mm, middle layer outer diameter 114 mm, outer diameter 143 mm) made of a Cu alloy having a composition of 0 wt% Cr. However, the average particle size of each powder of Cr, Zr, Ag, and Cu is 20 μm, and the average particle size of W powder is 1 μm.
m.

【００２９】[0029]

【表１】 [Table 1]

【００３０】これを真空脱気した後、850℃で１時間加
熱し、その後、静水圧押出を実施し、外径が29mmの押出
材を得た。これを950℃で１時間溶体化処理した後、直
ちに水冷した。その後、抽伸加工により外径を20mmに
し、更に425℃で５時間焼鈍した。その後、抽伸加工を
施して外径が16mmの電極材料を得た。そして、これらの
各材料の断面を観察した結果、芯部の外径が8mm、中間
層の外径が12mmであることを確認した。次いで、これら
の材料の各層のビッカース硬さ及び芯部と全体の導電率
を測定した。After degassing in vacuum, it was heated at 850 ° C. for 1 hour and then subjected to hydrostatic extrusion to obtain an extruded material having an outer diameter of 29 mm. This was subjected to solution treatment at 950 ° C. for 1 hour, and then immediately cooled with water. After that, the outer diameter was reduced to 20 mm by drawing and further annealed at 425 ° C. for 5 hours. Then, it was drawn to obtain an electrode material having an outer diameter of 16 mm. As a result of observing the cross section of each of these materials, it was confirmed that the outer diameter of the core portion was 8 mm and the outer diameter of the intermediate layer was 12 mm. Next, the Vickers hardness of each layer of these materials and the conductivity of the core and the whole were measured.

【００３１】また、抵抗溶接試験に際しては、前述の如
く、製造した外径が16mm、先端半径が6mm、先端曲率が4
0mm、長さが25mmの水冷孔付き電極チップに加工した。
被溶接材として、1.0mmの厚さのアルミニウム板（Ａｌ-
4.5重量％Ｍｇ−0.35重量％Ｃｕ）をりん酸ソーダ系液
にて酸化膜除去処理したものを用いた。これを50mmの幅
にスリットしたコイルを被溶接材として、重ね溶接を２
秒／点の速度で施し、溶接継手の引張せん断強度を20点
に２本の割合で測定した。この引張せん断強度値がＪＩ
ＳＺ3140Ｂ級（1.30KN）を１点でも下回った時の打点数
を電極寿命とした。なお、溶接機は単相交流式のものを
用いた。溶接条件は溶接電流が25KA(4サイクル）、溶接
加圧力が2.94KNである。In the resistance welding test, as described above, the manufactured outer diameter is 16 mm, the tip radius is 6 mm, and the tip curvature is 4 mm.
It was processed into an electrode chip with a water cooling hole of 0 mm and a length of 25 mm.
As a material to be welded, an aluminum plate (Al-
(4.5 wt% Mg-0.35 wt% Cu), which was subjected to an oxide film removal treatment with a sodium phosphate-based solution, was used. This is a coil that is slit into a width of 50 mm and is used as the material to be welded.
The tensile shear strength of the welded joint was measured at a rate of 2 at 20 points by applying at a speed of second / point. This tensile shear strength value is JI
The electrode life was defined as the number of dots when even one point was below the SZ3140B class (1.30KN). The welding machine used was a single-phase AC type. The welding conditions are welding current of 25KA (4 cycles) and welding pressure of 2.94KN.

【００３２】以上の評価結果を下記表２に示す。The results of the above evaluations are shown in Table 2 below.

【００３３】[0033]

【表２】 [Table 2]

【００３４】なお、比較材として市販のクロム銅合金
（Ｃｕ−1.0重量％Ｃｒ）を用いた。表２から明らかな
ように、比較例No.７〜１１は強度と導電率のバランス
が悪いため電極寿命が短い。比較例No.１２は溶融Ａｌ
に対する耐濡れ性を向上させるＷ粉末の含有量が少ない
ため、電極寿命が短い。また、比較合金No.１３はＷの
含有量が多く、溶接時に電極先端部に割れが発生するた
め、電極寿命が短くなる。A commercially available chromium-copper alloy (Cu-1.0 wt% Cr) was used as a comparative material. As is clear from Table 2, Comparative Examples Nos. 7 to 11 have a poor balance between strength and conductivity, and thus have a short electrode life. Comparative example No. 12 is molten Al
The electrode life is short because the content of the W powder that improves the wettability against is small. Further, Comparative Alloy No. 13 has a large content of W and cracks occur at the electrode tip during welding, resulting in a shorter electrode life.

【００３５】これらの比較例に対して、本実施例（No.
１〜６）の場合は強度及び導電率が優れていると共に、
溶融Ａｌに対する耐濡れ性も優れているため、電極寿命
が比較例（No.７〜１４）より著しく長い。In contrast to these comparative examples, this embodiment (No.
In the cases of 1 to 6), the strength and conductivity are excellent, and
Since the wettability against molten Al is also excellent, the electrode life is remarkably longer than that of the comparative examples (Nos. 7 to 14).

【００３６】[0036]

【発明の効果】以上説明したように、本発明に係る抵抗
溶接用電極は強度と導電率のバランスが優れているのに
加えて、特に、溶融Ａｌとの耐濡れ性が優れているた
め、アルミニウムの抵抗溶接時の電極寿命を著しく長く
することができるという優れた効果を奏する。As described above, the resistance welding electrode according to the present invention has an excellent balance of strength and conductivity, and in particular, has excellent wettability with molten Al. It has an excellent effect that the life of the electrode during resistance welding of aluminum can be remarkably extended.

Claims (4)

【特許請求の範囲】[Claims] 【請求項１】 平均粒径が30μｍ以下のＣｕ粉末、Ｚｒ
粉末及びＡｇ粉末と平均粒径が10μｍ以下のＣｒ粉末の
混合粉末に平均粒径が10μｍ以下のＷ粉末を0.1〜5.0重
量％混合してなる原料粉末を焼結して得られた焼結体を
有し、前記Ｃｕ−Ｃｒ−Ｚｒ−Ａｇ混合粉末中の各粉末
の配合比は、Ｃｒ粉末が0.3〜5.0重量％、Ｚｒ粉末が0.
01〜0.3重量％、Ａｇ粉末が0.01〜0.5重量％、残部がＣ
ｕ粉末であることを特徴とする抵抗溶接用電極。1. Cu powder having an average particle size of 30 μm or less, Zr
Sintered body obtained by sintering a raw material powder formed by mixing 0.1 to 5.0% by weight of W powder having an average particle size of 10 μm or less with a mixed powder of powder and Ag powder and Cr powder having an average particle size of 10 μm or less And the compounding ratio of each powder in the Cu-Cr-Zr-Ag mixed powder is 0.3 to 5.0 wt% for Cr powder and 0 for Zr powder.
01-0.3 wt%, Ag powder 0.01-0.5 wt%, balance C
An electrode for resistance welding, which is u powder. 【請求項２】 平均粒径が30μｍ以下のＣｕ−Ｃｒ−Ｚ
ｒ合金粉末及びＡｇ粉末の混合粉末に平均粒径が10μｍ
以下のＷ粉末を0.1〜5.0重量％混合してなる原料粉末を
焼結して得られた焼結体を有し、前記Ｃｕ−Ｃｒ−Ｚｒ
合金粉末は、Ｃｒが0.3〜5.0重量％、Ｚｒが0.01〜0.3
重量％、残部がＣｕであり、前記Ｃｕ−Ｃｒ−Ｚｒ合金
粉末とＡｇ粉末との混合粉末中のＡｇ粉末の配合比は0.
01〜0.5重量％であることを特徴とする抵抗溶接用電
極。2. Cu-Cr-Z having an average particle size of 30 μm or less
Average particle diameter of mixed powder of r alloy powder and Ag powder is 10μm
A sintered body obtained by sintering a raw material powder obtained by mixing the following W powder in an amount of 0.1 to 5.0% by weight is used.
The alloy powder contains 0.3 to 5.0% by weight of Cr and 0.01 to 0.3 of Zr.
% By weight, the balance being Cu, and the compounding ratio of the Ag powder in the mixed powder of the Cu-Cr-Zr alloy powder and the Ag powder is 0.
The electrode for resistance welding is characterized by being 01 to 0.5% by weight. 【請求項３】 前記焼結体を芯材とし、この芯材を被覆
する中間層がＣｒ；0.3〜1.5重量％及び残部実質的にＣ
ｕからなる銅合金であり、この中間層を被覆する外層が
無酸素銅からなることを特徴とする請求項１又は２に記
載の抵抗溶接用電極。3. The sintered body is used as a core material, and an intermediate layer covering the core material is Cr; 0.3 to 1.5% by weight and the balance substantially C.
The electrode for resistance welding according to claim 1 or 2, which is a copper alloy made of u, and an outer layer covering the intermediate layer is made of oxygen-free copper. 【請求項４】 無酸素銅からなる外層部材内に、Ｃｒ；
0.3〜1.5重量％及び残部実質的にＣｕからなる銅合金の
中間層部材を挿入し、更にこの中間層部材内に、前記請
求項１又は２に記載の原料粉末を封入し、次いで、前記
中間層内を真空脱気してビレットを製造し、その後この
ビレットを熱間静水圧押出処理し、更に、溶体化処理し
た後、少なくとも１サイクルの冷間加工及び焼鈍処理を
実施することを特徴とする抵抗溶接用電極の製造方法。4. An outer layer member made of oxygen-free copper, containing Cr;
An intermediate layer member of a copper alloy consisting of 0.3 to 1.5% by weight and the balance substantially Cu is inserted, and further, the raw material powder according to claim 1 or 2 is enclosed in the intermediate layer member, and then the intermediate The inside of the layer is vacuum degassed to produce a billet, and then the billet is subjected to hot isostatic extrusion treatment, further subjected to solution treatment, and then subjected to at least one cycle of cold working and annealing treatment. Method for manufacturing a resistance welding electrode.