JP4004259B2

JP4004259B2 - Friction stir welding method

Info

Publication number: JP4004259B2
Application number: JP2001290745A
Authority: JP
Inventors: 直田中; 正樹熊谷
Original assignee: Sumitomo Light Metal Industries Ltd
Current assignee: Sumitomo Light Metal Industries Ltd
Priority date: 2001-09-25
Filing date: 2001-09-25
Publication date: 2007-11-07
Anticipated expiration: 2021-09-25
Also published as: JP2003094174A

Description

【０００１】
【技術分野】
本発明は、摩擦攪拌接合方法に係り、特に、摩擦攪拌接合によって形成される接合部における接合端部の端面健全化方法に関するものである。
【０００２】
【背景技術】
近年、摩擦熱を利用して板を突合せ接合する方法の一つとして、米国特許第５４６０３１７号明細書や特表平７−５０５０９０号公報等に明らかにされている如き、摩擦攪拌接合法（ＦｒｉｃｔｉｏｎＳｔｉｒＷｅｌｄｉｎｇ）が、入熱が少なく、また接合部の強度低下や歪みの少ない接合方法として、注目を受けている。
【０００３】
そして、そのような摩擦攪拌接合方法は、具体的には、図１に例示されている如く、接合されるべき２枚の板材２ａ，２ｂよりも硬い材質のピン４を先端中心部に設けてなるロッド状の回転治具６を用い、この回転治具６を高速回転せしめつつ、その先端のピン４を、２枚の板材２ａ，２ｂの突合せ部８の部位に差し込み、相対的に該突合せ部８に沿って移動せしめることにより、それら回転せしめられるピン４や回転治具６と板材２ａ，２ｂとの間に、摩擦熱を発生せしめ、そしてその摩擦熱にて、突合せ部８の周辺部位を塑性加工可能な状態と為し、更にピン４の高速回転による攪拌作用にて、板材２ａ，２ｂの突合せ部位（８）の組織を入り交わらせ、以て溶融せしめることなく、２枚の板材２ａ，２ｂを接合せしめるものである。
【０００４】
ところで、このような摩擦攪拌接合手法に基づくところの接合開始時においては、回転治具６が、その肩部（ショルダー部）が接合されるべき板材２ａ，２ｂの端面より３mmを超える長さにおいて離れて入り込んだ位置において、板材２ａ，２ｂの板面に接触するように、板材２ａ，２ｂの突合せ部８に差し込まれて、摩擦攪拌接合操作が開始され、そして、突合せ部８に沿って、図示の如く、矢印方向に移動せしめられることによって、かかる回転治具６の後方側に、接合部１０が形成されるようになっている。そのような入り込んだ位置から接合する理由は、回転治具６の回転により攪拌されたメタルが接合されるべき板材２ａ，２ｂの端面から洩れることによる、接合部１０における接合欠陥の発生を防止することにある。
【０００５】
このため、図１にも示されている如く、接合されるべき二つの部材２ａ，２ｂの突合せ部８の接合開始端側の部分が、或る程度の長さに亘って、未接合部１２として、二つの板材２ａ，２ｂが接合されてなる接合体内に存在することとなるのである。そして、そのような未接合部１２の処理のため、摩擦攪拌接合操作が終了した後、接合体における未接合部１２部分の切断を行ったり、或いは、溶融溶接による手直しが施されることとなるのであるが、それらの後処理は、非経済的のみならず、溶融溶接の熱影響による歪みの発生や、軟化といった問題を、新たに惹起せしめることとなる。
【０００６】
一方、摩擦攪拌接合操作の接合終了時においても、上記した接合開始時と同様に、板材２ａ，２ｂの突合せ部８の接合終了端側の端面から１０mm以上余した位置（端面とショルダー部との間の距離）において、回転治具６を引き抜いて、終了せしめている。その理由は、回転治具６の回転により攪拌されたメタルが接合体の端面から漏れることによる、接合部における接合欠陥の発生を阻止することにある。そして、それにより、二つの板材２ａ，２ｂの突合せ部８に形成される接合部１０が、二つの板材２ａ，２ｂの端面に至ることはなく、接合部１０の最終尾部と板材端面との間の所定長さ部分に位置する突合せ部８が、未接合部（１２）として残り、そのため、接合操作の終了後において、そのような未接合部（１２）の存在部分を切断したり、或いは、そのような未接合部（１２）を溶融溶接することからなる手直しが施されているのであるが、それらの後処理は、非経済的のみならず、溶融溶接の熱影響による歪みの発生や軟化といった問題があり、更に、回転治具６を引き抜いた後のピン穴が、凹みとして残存する不具合も内在するものであった。
【０００７】
尤も、そのような摩擦攪拌接合操作における接合開始時や接合終了時に惹起される上記不具合を解消すべく、例えば、二つの板材２ａ，２ｂの突合せ部８における接合開始端側の端面や、接合終了端側の端面に対して、それぞれ適当なタブ板を当接せしめ、回転治具６を一方のタブ板に差し込んで、接合操作を開始せしめ、そして、突合せ部８に入り込ませて、突合せ部８を全長に亘って通過させた後、他方のタブ板まで至らしめた後、回転治具６を引き抜く手法の採用が考えられるものの、そのような手法にあっては、両端のタブ板が、二つの板材２ａ，２ｂの両端面に対して接合せしめられることとなるところから、それらタブ板の切断除去に手間がかかると共に、その切断除去に際して、接合部１０の切断面が二つの板材２ａ，２ｂの突合せ部８内に入り込んだ形態において、タブ板が除去される場合にあっては、接合体における接合部１０の強度の問題が発生し、また、端面の手直しの等の作業が新たに発生するという問題も内在することとなる。
【０００８】
また、特開２０００−４２７５９号公報においては、接合終了時の上記不具合を解消する方法として、接合終了部分に、予め捨て肉部を設けて、その捨て肉部に回転治具を逃がし、その後、かかる捨て肉部を切断除去せしめることにより、回転治具引き抜き後の穴や凹部を生じさせない摩擦攪拌接合方法が提案されている。しかしながら、そのような方法では、接合されるべき部材に捨て肉部を特別に設ける必要があるところから、そのような捨て肉部を加工するための手間が必要となることに加えて、材料コストや、その切断除去工程のコストが必然的に掛かることとなり、十分に実用的なものではないのである。
【０００９】
さらに、特開２０００−４２７６２号公報においては、パイプ同士の摩擦攪拌接合において、接合部に配置した当て部材に回転治具を逃がすことにより、回転治具引き抜き後の穴や凹部を生じさせないようにした方法が、明らかにされている。この方法では、接合材と当て部材の界面において、攪拌されたメタルの影響によって、接合材から当て部材を簡単には取り外すことが出来ない問題があり、このため、力任せに当て部材を外した場合にあっては、当て部材部分が残り、その後の修正が面倒となったり、或いは接合体部分が剥ぎ取られて、欠陥となったりして、健全な接合品を得る上において、好ましい方法といえるものではないのである。
【００１０】
【解決課題】
ここにおいて、本発明は、かかる事情を背景にして為されたものであって、その解決課題とするところは、摩擦攪拌接合の終了形態に工夫を加えることにより、健全な接合部端面を、有利に、且つ簡単に実現し得る方法を提供することにある。
【００１１】
【解決手段】
そして、本発明にあっては、摩擦攪拌接合操作での終了時において、接合終了端側における健全な接合部端面を実現すべく、接合されるべき二つの板状部材を突き合わせ、その突合せ部に対して、ロッド状の回転治具の先端に同心的に設けたピンを、該回転治具と共に一体に回転させつつ差し込み、相対的に移動させることにより、かかる突合せ部を摩擦攪拌接合せしめるに際し、該二つの板状部材における、前記突合せ部の接合終端側の端面に対して、それら板状部材よりも硬質の若しくは同様な硬さのタブ板を当接せしめると共に、該タブ板の前記突合せ部に対向する部位に、前記ピンの半径以上、前記回転治具の半径以下の凹陥深さを有する半円形乃至はＵ字形の凹所を設け、前記回転治具が前記突合せ部から該凹所を経て該タブ板に達した後、摩擦攪拌接合操作が終了せしめられるようにしたことを特徴とする摩擦攪拌接合方法を、その要旨とするものである。
【００１３】
さらに、本発明は、摩擦攪拌接合操作の終了時における、上記と同様な課題の解決を図るべく、接合されるべき二つの板状部材を突き合わせ、その突合せ部に対して、ロッド状の回転治具の先端に同心的に設けたピンを、該回転治具と共に一体に回転させつつ差し込み、相対的に移動させることにより、かかる突合せ部を摩擦攪拌接合せしめるに際し、該二つの板状部材における、前記突合せ部の接合終端側の端面に対して、それら板状部材よりも硬質の若しくは同様な硬さのタブ板を当接せしめると共に、該タブ板の前記突合せ部に対向する部位に、前記ピンの直径以上、前記回転治具の直径以下の幅と、前記ピンの半径以上、前記回転治具の半径以下の凹陥深さを有する矩形の凹所を設け、前記回転治具が前記突合せ部から該凹所を経て該タブ板に達した後、摩擦攪拌接合操作が終了せしめられるようにしたことを特徴とする摩擦攪拌接合方法をも、その要旨とするものである。
【００１４】
加えて、かかる摩擦攪拌接合操作の終了時における課題を解決するための、本発明の更に異なる他の要旨とするところは、接合されるべき二つの板状部材を突き合わせ、その突合せ部に対して、ロッド状の回転治具の先端に同心的に設けたピンを、該回転治具と共に一体に回転させつつ差し込み、相対的に移動させることにより、かかる突合せ部を摩擦攪拌接合せしめるに際し、該二つの板状部材における、前記突合せ部の接合終端側の端面に対して、それら板状部材と同様な硬さの材質のタブ板を当接せしめ、その状態において、前記回転治具が前記突合せ部から該タブ板に達するまで、摩擦攪拌接合操作を実施した後、該回転治具を形成された接合部から引き抜き、そして該回転治具の回転方向を逆方向とした後、該接合部の、前記突合せ部の接合終端面位置から前記突合せ部の接合開始端側に５mm以上の距離をもって該回転治具が位置するような部位に、該逆方向回転の回転治具のピンを差し込み、前記タブ板に達するように再度の摩擦攪拌接合操作を実施し、該回転治具の後方肩部が前記板状部材と前記タブ板との境界を通り過ぎるまで、かかる摩擦攪拌接合操作を継続せしめることを特徴とする摩擦攪拌接合方法にある。
【００１５】
そして、上述せる如き各種の摩擦攪拌接合方法に従って得られた、前記二つの板状部材の接合体にあっては、回転治具による未接合部を存在させることなく、実質的に全体に亘って完全に接合、一体化せしめられているのであるが、タブ板は、そのような接合体から、手、あるいは木槌等にて叩くことによって、簡単に折り取ることが可能であり、それ故に、摩擦攪拌接合操作の終了の後の接合体に対する仕上げ作業が簡単となることに加えて、接合部の折り取られた部分も奇麗であって、割れや切欠き等の欠陥が、接合体側の接合部内に入り込む等の問題も、悉く解消せしめられ得ることとなったのである。
【００１６】
なお、かくの如き本発明に従う摩擦攪拌接合方法にあっては、摩擦攪拌接合操作が終了せしめられた後、前記二つの板状部材の接合体から前記タブ板が取り除かれた後、接合体の接合部端面で突出するメタルが、グラインダー等の切削機にて除去せしめられることとなる。
【００１７】
【発明の実施の形態】
以下、図面を参照しつつ、本発明の構成について、更に具体的に明らかにすることとする。
【００１８】
先ず、図２には、摩擦攪拌接合操作における接合開始端側の一つの状態が示されている。そこにおいて、本発明に従う摩擦攪拌接合操作に用いられる、ピン４を先端部に同心的に設けてなるロッド状の回転治具６としては、従来と同様なものが用いられ、それぞれ接合されるべき二つの板状部材２ａ，２ｂの材質よりも硬い材料を用いて形成されており、そのため、それらピン４や回転治具６が高速回転せしめられて、二つの部材２ａ，２ｂの突合せ部８に差し込まれたり、それら板状部材２ａ，２ｂの上面に、回転治具６の下部（ショルダー部）が接触せしめられても、殆ど損耗することない非消費型の部材とされている。なお、かかるピン４及び回転治具６の軸心周りの高速回転は、従来と同様な回転駆動装置（図示せず）を用いて、容易に実現され得るものである。また、ピン４は、図３にも示される如く、従来と同様に、その軸心が法線に対して接合進行方向において角度：θをもって後傾する形態において、相対的に移動せしめられ、以て接合が進行せしめられるようになっている。
【００１９】
そして、図２においては、アルミニウム若しくはその合金等からなる公知材質の二つの板状部材２ａ，２ｂにおける突合せ部８の接合開始端側の端面に対して、タブ板２０が、その一つの端面において当接せしめられて、それら二つの板状部材２ａ，２ｂと共に位置固定に保持され、摩擦攪拌接合操作が実施されるようになっているのである。また、かかるタブ板２０は、板状部材２ａ，２ｂよりも硬質の材料にて形成され、或いは、それら板状部材２ａ，２ｂと同様な硬さの材料にて形成されているのであって、これにより、摩擦攪拌接合後に、タブ板２０の除去が、容易に行われ得るようになっている。なお、このタブ板２０が、接合されるべき板状部材２ａ，２ｂよりも軟質となると、タブ板２０のメタルも攪拌されて、それらタブ板２０と板状部材２ａ，２ｂとが強固に接合せしめられるようになるのである。
【００２０】
また、そのようなタブ板２０の板厚としては、板状部材２ａ，２ｂと同様な板厚とされる他、タブ板２０の上面の高さが、板状部材２ａ，２ｂの上面の高さの７割以上の高さにおいてセットし得るような厚さとされることとなる。なお、タブ板２０の上面の高さが、接合されるべき二つの板状部材２ａ，２ｂの上面の高さの７割未満となると、端部から湧き出るメタルを押さえるタブ板２０の役目を為さず、タブ板２０と板状部材２ａ，２ｂとの板厚差の部分からメタルが湧き出てしまう問題があり、また、タブ板２０の上面が、板状部材２ａ，２ｂの上面よりも高くなると、摩擦攪拌接合操作により、タブ板２０を優先的に攪拌してしまい、接合が困難となる問題を惹起する。
【００２１】
なお、かかる図２においては、回転治具６のピン４が差し込まれる接合開始点から、回転治具６が突合せ部８に沿って少し移動し、摩擦攪拌接合操作が少し進んで、接合部１０が接合開始部位から延びている状態が示されているが、本発明にあっては、そのような回転治具６におけるピン４の、接合開始時における差込位置が、接合開始端側の板状部材２ａ，２ｂの端面とピン４先端部における最先端位置との間の距離が３mm以下となるように設定されて、摩擦攪拌接合操作を開始するようにしているのである。なお、この際、ピン４の差込位置は、タブ板２０上には設定されないようになっている。
【００２２】
具体的には、図３の（ａ）及び（ｂ）に示されるように、回転治具６のピン４が突合せ部８に差し込まれたとき、かかるピン４の先端部における最先端位置、即ち図３（ａ）においては、ピン先端部における左端位置と、板状部材２ａ，２ｂの端面との間の距離：ｘが３mm以下となるようにして、摩擦攪拌接合操作が開始せしめられるのであり、これによって、回転治具６の回転により、攪拌されたメタルが外部に漏れるのを効果的に抑制乃至は阻止しつつ、接合開始端側における未接合部の発生を効果的に回避乃至は抑制して、接合部１０の形成が有利に実現せしめられ得ることとなるのである。なお、かかる板状部材２ａ，２ｂ端面と、ピン４先端部における最先端位置との間の距離：ｘが、３mmを超えるようになると、接合開始端側部分の攪拌が不十分となり、未接合部（１２）を惹起せしめたり、或いは欠陥を内在する接合部１０が生じたりする問題を発生させることとなる。
【００２３】
ここで、回転治具６のピン４の形状としては、図３（ａ）に示される如き台形形状の他、先端部が丸められた各種の形状も採用され得るところから、ピン４の先端部における最先端位置は、図３（ｂ）に示される如く、ピン４の傾斜操作状態も考慮して、摩擦攪拌接合操作におけるピン４の最先端の位置とし、これと板状部材２ａ，２ｂ端面との間の距離が、前記ｘとして、その値が３mm以下となるようにして、前記摩擦攪拌接合操作が開始せしめられることとなる。
【００２４】
また、回転治具６のピン４の挿入深さとしては、ピン４の先端から板状部材２ａ，２ｂの裏面までの距離：ｄが１mm以下となるようにして、摩擦攪拌接合を行うようにすることが望ましく、それは、特に、板状部材２ａ，２ｂの板厚が２mm以上の場合において有効である。なお、裏面からの距離が１mmを超えるようになると、回転治具６のピン４による攪拌作用が、板状部材２ａ，２ｂの厚さ全体に行き渡らず、その裏面近傍において、欠陥のある接合部が発生する問題が惹起され易くなる。
【００２５】
そして、かくの如き接合開始時においては、図３にも示される如く、回転治具６の肩部がタブ板２０の側にはみ出し、そのような肩部によって、接合開始端側の板状部材２ａ，２ｂ部分を攪拌する効果も発揮され得るようになるために、より良い攪拌が実現され得ることとなるのであり、以て、欠陥のない健全な接合部が端部に形成されることとなるが、特に、そのような回転治具６の肩部による攪拌作用は、板状部材２ａ，２ｂの板厚が２mmよりも薄い場合において、より一層有効に発揮せしめられ得るのである。
【００２６】
ところで、本発明は、摩擦攪拌接合操作の終了時において、タブ板と回転治具の使用態様に工夫を加えることによって、前記した従来の問題を有利に解消し得るようにしたものであって、その一例が、図４に示されている。
【００２７】
すなわち、図４においては、二つの板状部材２ａ，２ｂにおける突合せ部８の接合終端側の端面に対して、それら板状部材２ａ，２ｂよりも硬質であるか、或いはそれと同様な硬さのタブ板３０が、その一つの端面（側面）において、当接せしめられ、位置固定に保持されている。また、かかるタブ板３０の突合せ部８に対向する部位には、所定の凹陥深さを有する半円形の凹所３２が、設けられている。そして、回転治具６が、突合せ部８から、そのような凹所３２を経て、タブ板３０に到達した後、タブ板３０から回転治具６が引き抜かれることにより、摩擦攪拌接合操作が終了せしめられるようにされるのである。
【００２８】
なお、このような摩擦攪拌接合操作における接合終端側に配されるタブ板３０に設けられる凹所３２としては、図５（ａ）や（ｂ）に示される如く、半円形状のものの他、Ｕ字形状のものが採用され得るが、それら形状の凹所３２の凹陥深さ：ｙとしては、回転治具６におけるピン４の半径以上、該回転治具６の半径以下の値を有するものであって、このような凹所３２を通って、回転治具６を、突合せ部８からタブ板３０上に導くようにすることによって、摩擦攪拌接合操作の終了後におけるタブ板３０の取り除き作業が、有利に行われ得ることとなるのである。
【００２９】
すなわち、そのような凹所３２の存在によって、二つの板状部材２ａ，２ｂのピン４によるメタルの攪拌を一旦終了させる効果があるのであるが、そのような凹所３２が、回転治具６の半径よりも深い凹陥深さとなると、メタルの湧き出しが多くなって、端部に欠陥が発生する問題がある。また、そのような凹所３２の設けられていない、或いはピン４の半径よりも浅い凹陥深さ（ｙ）の凹所３２が設けられても、板状部材２ａ，２ｂとタブ板３０との間での攪拌が惹起され、それらの材質が混合されたメタルからなる接合部が、端部に形成されてしまう問題があり、そして、タブ板３０よりも板状部材２ａ，２ｂが軟質或いはほぼ同じ硬さであるところから、タブ板３０を、それら二つの板状部材２ａ，２ｂの接合体から取り除く際に、かかる接合体側で割れ易くなってしまう問題があるからである。
【００３０】
なお、かかる半円形状乃至はＵ字形状の配設位置としては、二つの板状部材２ａ，２ｂの突合せ部８の延長線上に、そのような凹所３２の中心線が位置せしめられる形態が有利に採用され、これによって、ピン４によるメタルの攪拌作用の一時的な終了効果が、有利に実現されることとなるのである。
【００３１】
尤も、かかる凹所３２としては、図５の（ａ）に示される半円形状や、（ｂ）に示されるＵ字形状のほか、図６に示される如き矩形形状を呈する凹所３２構造も、採用可能である。
【００３２】
そして、かかる矩形形状の凹所（切り欠き）３２としては、その凹陥深さ：ｙが、ピン４の半径以上、回転治具６の半径以下の値とされると共に、凹所３２の幅：ｚとしては、ピン４の直径以上、回転治具６の直径以下の値となるように、タブ板３０に形成され、二つの板状部材２ａ，２ｂの突合せ部８に対向せしめられるのである。なお、そのような凹所３２の凹陥深さ：ｙや幅：ｚが、上記した寸法未満であると、タブ板３０のメタルが端部に混合されてしまい、タブ板３０を取り除く際に、接合体（２ａ，２ｂ）側において割れ易くなってしまう問題があり、また、それらの寸法を超えた場合にあっては、凹みによる空間部に板状部材２ａ，２ｂのメタルが湧き出し易くなり、そのために、肉不足或いは欠陥を内在する接合端部となってしまう問題が惹起されるのである。
【００３３】
さらに、図７に示される摩擦攪拌接合操作における接合終了側端部の形成に際しては、先ず、二つの板状部材２ａ，２ｂにおける突合せ部８の接合終端側の端面に対して、それら板状部材２ａ，２ｂと同様な硬さのタブ板４０が、その一つの端面（側面）において当接せしめられ、その状態を固定せしめた形態において、回転治具６が突合せ部８に沿って移動せしめられ、かかる突合せ部８からタブ板４０上に達するまで、摩擦攪拌接合操作が実施される。そして、回転治具６がタブ板４０上に達した後、そこに形成された接合部１０から回転治具６が引き抜かれるのである。なお、接合部１０は、二つの板状部材２ａ，２ｂから、タブ板４０上に至るように形成されることとなる。なお、このように、回転治具６を、二つの板状部材２ａ，２ｂの突合せ部８から、タブ板４０上にまで効果的に到達させるために、それら二つの板状部材２ａ，２ｂの上面高さとタブ板４０の上面高さの差は１mm以内とすることが望ましく、これに反して、１mmを超える高さの差が存在する場合にあっては、タブ板４０と板状部材２ａ，２ｂとの境目における攪拌が不均一となって、欠陥を生じる原因となるおそれがある。
【００３４】
次いで、かかる引き抜かれた回転治具６は、先の回転方向とは逆方向に回転せしめられるようにされた後、先に形成された接合部１０の突合せ部８の接合終端面（板状部材２ａ，２ｂの端面）位置から、突合せ部８の接合開始端側に５mm以上の距離をもって、換言すれば、図７におけるタブ板４０と回転治具６との距離：Ｌが５mm以上となるような距離において、回転治具６（ピン４）が再び接合部１０に差し込まれ、そして、タブ板４０に達するように、再度の摩擦攪拌接合操作が、回転治具６の逆方向回転状態の下において、実施されるのである。そして、そのような回転治具６の後方肩部が、板状部材２ａ，２ｂとタブ板４０との境界を通り過ぎるまで、従って回転治具６が完全にタブ板４０上に位置するようになるまで、かかる摩擦攪拌接合操作が継続せしめられるのであり、そして、その後に、回転治具６がタブ板４０から引き抜かれることによって、摩擦攪拌接合操作が終了せしめられるのである。
【００３５】
なお、かかる逆方向回転の回転治具６のピン４が差し込まれる位置がＬ：５mmに満たない接合部１０に対して、ピン４の差し込みが実施され、再度の摩擦攪拌接合操作が実施される場合にあっては、タブ板４０と板状部材２ａ，２ｂとの境目に近くなり過ぎて、かかる境目における両者のメタルの混合が過度となり、そのようなタブ板４０と接合体２ａ，２ｂとの離脱に際して、その境目にて奇麗に割ることが困難となるのである。また、かかる逆回転の回転治具６による再度の摩擦攪拌接合操作にて、そのような境目を通過させることにより、該境目のメタルにメタルフローの界面が発生し、その部分において割れ易くなり、以て接合体（２ａ，２ｂ）の端面の健全性の向上に、著しく寄与せしめ得ることとなるのである。
【００３６】
また、上記の何れの方法においても、タブ板２０，３０，４０は、手或いは木槌等で、簡単に折り取ることが可能であり、以て、健全な端部が有利に実現され得るのであるが、また、必要に応じて、そのようなタブ板を取り除いた後、端面に湧き出したメタルをグラインダー等の切削機にて切削除去せしめ、端面を仕上げることも、本発明においては、有利に採用されることとなる。図８には、図６に示されるタブ板３０を用いて摩擦攪拌接合して得られた接合体より、タブ板３０を折り取り、その端部に形成される突出部（メタル）３４を、グラインダー等によって切削して、端面を仕上げて、目的とする接合体を得る形態が示されている。
【００３７】
そして、かくの如き摩擦攪拌接合手法にて得られる接合体の端部端面が、効果的に健全化せしめられることにより、本発明は、例えば、アルミニウム合金の板材や押出し材等の展伸材や鋳物を接合し、アルミニウム合金の大型材を製造する技術に有利に適用され得るのであり、また、そのようにして得られた接合材は、鉄道車両行体や自動車の外板、サブフレーム及びホイール等の部材に適しており、アルミニウム合金の大型材の接合に有利に採用され得て、その特徴を発揮するものである。
【００３８】
【実施例】
以下に、本発明の実施例を示し、本発明を更に具体的に明らかにすることとするが、本発明が、そのような実施例の記載によって何等の制約をも受けるものでないことは言うまでもないところである。また、本発明には、以下の実施例の他にも、更には上記した具体的構成以外にも、本発明の趣旨を逸脱しない限りにおいて、当業者の知識に基づいて種々なる変更、修正、改良等を加え得るものであることが理解されるべきである。
【００３９】
参考例１
板厚：４mm、板幅：３００mm、長さ：５０００mm、材質：６Ｎ０１−Ｔ５のアルミニウム合金押出型材の２枚を供試材として用い、それらの板幅方向に対向する側面を突き合わせて、テーブル上に固定せしめた。また、それら突き合わされた２枚の供試材の接合開始側の端部には、板厚：３．５mm（供試材板厚に対して８７．５％）、サイズ：５０mm×５０mmの鋼板（材質：ＳＳ４０）をタブ板として用いて、図２に示される如く突き合せて、テーブル上に固定せしめた。
【００４０】
一方、回転治具としては、肩径：１７mm、ピン長さ（高さ）：３．９mm、ピン径：３mmのものを用い、回転数：３０００ｒｐｍ、速度：５００mm／分の接合条件下において、摩擦攪拌接合を実施した。なお、回転治具先端に設けたピンを、供試材の突合せ部に挿入した際のピン先端部における最先端位置と接合開始端側の供試材端面（供試材とタブ板との当接面）との間の距離：ｘを３mmとして、差し込み、かかる摩擦攪拌接合操作を開始した。
【００４１】
その結果、回転治具は、タブ板（鋼板）に接触することなく回転し、また、２枚の供試材を接合して得られた接合材（接合体）においては、その接合開始端部から、外観上においても、健全な接合部となっていることを認めた。更に、かかる得られた接合材の頭部の引張試験を行ったところ、その引張強さは１９８ＭＰａ、継手効率は８１％と健全であり、接合部の断面マクロ組織の観察結果からしても、接合頭部において亀裂やトンネルポアーの等の欠陥はなく、健全な接合部であることを認めた。
【００４２】
参考例２
板厚：１．８mm、板幅：７２mm、長さ：３００mm、材質：５４５４−Ｏのアルミニウム板材の２枚を供試材として用い、それらを幅方向に突き合せて、摩擦攪拌接合を施すためのテーブル上に固定せしめた。また、それら供試材の接合開始側の端部には、板厚：１．３mm（供試材板厚の７２％）、サイズ：５０mm×５０mmの鉄板をタブ板として用いて突き合わせ、供試材と同様にテーブル上に固定せしめた。
【００４３】
回転治具として、肩径：１５mm、ピン長さ：１．７mm、ピン径：４mmのものを用い、回転数：１５００ｒｐｍ、速度：３００mm／分の接合条件の下において、摩擦攪拌接合操作を実施した。なお、回転治具の先端部のピンを供試材の突合せ部に挿入した際に、かかる回転治具の肩部がタブ板側にはみ出すようにして、摩擦攪拌接合操作を開始した。
【００４４】
その結果、回転治具は、タブ板としての鉄板に接触することなく回転したが、二つの供試材を接合して得られる接合材の接合開始側の端部には、若干のメタルの突出が認められた。また、接合材の頭部に対する引張試験の結果、引張強さは２３５ＭＰａであり、継手効率は９４％となり、健全であった。更に、接合部の断面マクロ組織の観察結果においても、接合頭部において亀裂やトンネルポアー等の欠陥は全く認められず、健全な接合部であることを認めた。また、接合開始側端部に認められた若干のメタル突出部は、グラインダーで仕上げることにより、外観上も健全な端面が得られた。
【００４５】
比較例１
板厚：４mm、板幅：３００mm、長さ：５０００mm、材質：６Ｎ０１−Ｔ５のアルミニウム押出型材の２枚を供試材として、それらを幅方向に突き合せてテーブル上に固定せしめた。また、それら供試材の接合開始側の端部には、板厚：２．５mm（供試材板厚の６２．５％）、サイズ：５０mm×５０mmの鉄板を突き合せてテーブル上に固定せしめた。
【００４６】
また、回転治具としては、肩径：１５mm、ピン長さ：３．９mm、ピン径：４mmのものを用い、回転数：１５００ｒｐｍ、速度：３００mm／分の接合条件の下において、摩擦攪拌接合操作を開始した。なお、ピンを挿入した際の、ピン先端部における最先端位置と供試材端面との間の距離（ｘ）は、２mmであった。
【００４７】
その結果、回転治具は、鉄板に接触することなく回転したものの、端部からのメタルの湧き出しが多く、外観上健全な接合部ではなかった。更に、接合部の断面マクロ組織の観察結果でも、接合頭部において、トンネルポアー等の多数の欠陥が存在することを認めた。
【００４８】
比較例２
板厚：４mm、板幅：３００mm、長さ：５０００mm、材質：６Ｎ０１−Ｔ５のアルミニウム押出型材の２枚を供試材として用い、それらを幅方向に突き合せてテーブル上に固定せしめた。また、それら供試材の接合開始側の端部には、板厚：３．５mm（供試材板厚の８７．５％）、サイズ：５０mm×５０mmの鉄板を突き合せて、同様に固定せしめた。また、回転治具として、肩径：１５mm、ピン長さ：２．８mm、ピン径：４mmのものを用い、回転数：１５００ｒｐｍ、速度：３００mm／分の接合条件の下において摩擦攪拌接合操作を開始した。なお、ピンを挿入した際の、ピン先端部における最先端位置と供試材端面との間の距離（ｘ）を３mmとした。
【００４９】
その結果、回転治具は、鉄板に接触することなく回転し、接合材の接合開始側端部から、外観上は健全な接合部であることを認めたが、接合部の断面マクロ組織の観察結果では、特に、接合材裏面側に接合不十分による亀裂があることを認めた。
【００５０】
実施例１
板厚：４mm、板幅：３００mm、長さ：５０００mm、材質：６Ｎ０１−Ｔ５のアルミニウム押出型材の２枚を供試材として用い、それらを幅方向に突き合せて、摩擦攪拌接合のためのテーブル上に固定せしめた。また、それら供試材の突合せ部の接合終了側の端部には、図４に示されるように、半径：２mmの半円形状の凹所を刳り抜いた板厚：４mm（供試材板厚と同じ）、サイズ：５０mm×５０mmの鋼板（材質：ＳＳ４０）を、かかる凹所が突合せ部に対向するようにして、且つ突合せ部の延長線によって凹所が二等分されるように、供試材端面に当接せしめて、供試材と同様にテーブル上に固定せしめた。
【００５１】
また、回転治具としては、肩径：１７mm、ピン長さ：３．９mm、ピン径：４mmのものを用い、回転数：１５００ｒｐｍ、速度：５００mm／分の接合条件の下において、摩擦攪拌接合操作を実施した。そして、かかる回転治具の接合方向における後方肩部が、供試材とタブ板との境目から２mmの長さでタブ板側に進んだところで、回転治具を引き抜き、摩擦攪拌接合操作を終了した。
【００５２】
かくして得られた２枚の供試材からなる接合材に付着するタブ板を、木槌を用いて取り除いたところ、接合部の終端部に若干バリが生じた形態において割れ、接合材側には、そのような割れが何等至るものではなかった。そして、そのような接合材尾部の引張試験の結果、引張強さは１９８Ｍｐａ、継手効率は８１％と健全であり、接合部の断面マクロ組織の観察結果でも、接合尾部において、亀裂やトンネルポアー等の欠陥は認められず、健全な接合部であった。なお、端部の若干のバリはグラインダーで仕上げることで、外観上も健全な端面とすることが出来た。
【００５３】
比較例３
板厚：４mm、板幅：３００mm、長さ：５０００mm、材質：６Ｎ０１−Ｔ５のアルミニウム押出型材の２枚を供試材として、それらを幅方向に突き合せて、テーブル上に固定した。また、それら供試材の突合せ部における接合終了側の端部には、凹陥深さ（ｙ）：６mmであり、Ｒ部の半径：２mmであるＵ字形状の凹所を刳り抜いた、板厚：４mm（供試材板厚と同じ）、サイズ：５０mm×５０mmの鋼板（材質：ＳＳ４０）をタブ板として用い、供試材端面に、図４に示される如く当接せしめた状態において固定した。
【００５４】
そして、回転治具として、肩径：１７mm、ピン長さ：３．９mm、ピン径：４mmのものを用い、回転数：１５００ｒｐｍ、速度：５００mm／分の接合条件の下において、摩擦攪拌接合操作を実施した。なお、その際、回転治具の接合方向後方の端部が、２枚の供試材を接合してなる接合材と、それに当接せしめたタブ板との境目から、２mm程タブ板側に進んだところで、回転治具を引き抜き、摩擦攪拌接合操作を終了せしめた。そして、このようにして得られた接合材に付着するタブ板を、木槌を用いて取り除いたところ、接合材側で割れが発生してしまい、目的とする用途の製品に使用することの出来ないものとなった。
【００５５】
実施例２
板厚：３．２mm、板幅：１００mm、長さ：１５０mm、材質：５４５４−Ｏのアルミニウム板材の２枚を供試材として用い、それら供試材を幅方向において突き合せて、摩擦攪拌接合のためのテーブル上に固定せしめた。また、それら突き合わされた供試材の接合終了側の端部には、図６に示されるように、幅（ｚ）：１５mm、凹陥深さ（ｙ）：２．０mmの矩形形状の凹所が設けられてなる、板厚：３．２mm（供試材板厚と同じ）、サイズ：５０mm×５０mmの、供試材と同材質のアルミニウム板材からなるタブ板を、その凹所が供試材の突合せ部に対向する如くして、供試材端部に当接せしめて、かかる供試材と同様に、テーブル上に固定せしめた。
【００５６】
そして、回転治具として、肩径：１５mm、ピン長さ：３．０mm、ピン径：４mmのものを用い、回転数：１５００ｒｐｍ、速度：２５０mm／分の接合条件の下において、摩擦攪拌接合操作を実施し、回転治具の接合方向後方側肩部が、接合材とタブ板の境目から２５mmだけタブ板側に進んだところで、回転治具を引き抜き、摩擦攪拌接合操作を終了せしめた。
【００５７】
かくして得られた接合材に付着するタブ板を木槌を用いて取り除いたところ、接合部の終端部分に若干のバリが生じた形態において割れ、接合材側には、何等割れが至るものではなかった。また、かかる接合材の尾部に対する引張試験の結果、引張強さは２３５ＭＰａで、継手効率は９４％と健全であり、接合部の断面マクロ組織の観察結果でも、接合尾部において、亀裂やトンネルポアー等の欠陥は無く、健全な接合部であった。更に、接合終端部における若干のバリはグラインダーで仕上げることにより、外観上も健全な端面を得ることが出来た。
【００５８】
比較例４
板厚：４mm、板幅：３００mm、長さ：５０００mm、材質：６Ｎ０１−Ｔ５のアルミニウム押出型材の２枚を供試材として、それら供試材を幅方向において突き合せて、テーブル上に固定せしめた。また、それら供試材の接合終了側の端部には、幅（ｚ）：２５mm、凹陥深さ（ｙ）：３mmの大きさの矩形の凹所を有する、板厚：４mm（供試材板厚と同じ）、サイズ：５０mm×５０mmの、供試材と同材質のアルミニウム押出型材からなるタブ板を当接せしめて、供試材と同様に、テーブル上に固定せしめた。また、回転治具として、肩径：１７mm、ピン長さ：３．９mm、ピン径：４mmのものを用い、回転数：１５００ｒｐｍ、速度：５００mm／分なる接合条件の下において、摩擦攪拌接合操作を実施した。そして、かかる回転治具の接合方向後方側肩部が、接合材とタブ板の境目から１５mmだけタブ板側に進んだところで、回転治具を引き抜くことにより、摩擦攪拌接合操作を終了せしめた。
【００５９】
このようにして得られた接合材にあっては、その接合端部からのメタルの湧き出しが多く、外観上健全な接合部ではなかった。更に、接合部の断面マクロ組織の観察結果でも、接合頭部において、トンネルポアー等の多数の欠陥があることを認めた。
【００６０】
実施例３
板厚：４mm、板幅：３００mm、長さ：５０００mm、材質：６Ｎ０１−Ｔ５のアルミニウム押出型材の２枚を供試材として用いて、それらを幅方向において突き合わせ、摩擦攪拌接合のためのテーブル上に固定せしめた。また、それら供試材の接合終了側端部には、図７に示されるように、板厚：４mm、サイズ：５０mm×５０mmの、供試材と同材質のタブ板を当接せしめて、供試材と同様に、テーブル上に固定せしめた。
【００６１】
また、回転治具としては、肩径：１７mm、ピン長さ：３．９mm、ピン径：４mmのものを用い、回転数：１５００ｒｐｍ、速度：５００mm／分の接合条件の下において、摩擦攪拌接合操作を実施した。なお、回転治具の回転は、最初は治具上から見て時計回りとした。そして、回転治具は、２枚の供試材を接合して形成される接合材とタブ板の境目からタブ板側に２５mm進んだ位置で引き抜き、その後、かかる回転治具を反時計回りに逆回転せしめ、そして、接合材側の接合部で前記境目から１０mm戻った位置に差し込んで、再度の摩擦攪拌接合をタブ板側に向かって実施し、そして、回転治具がタブ板上に至り、更に前記境目からタブ板側に２０mm進んだ位置において引き抜くことにより、摩擦攪拌接合操作を終了せしめた。
【００６２】
かくして得られた接合材に付着せるタブ板を木槌を用いて取り除いたところ、かかる接合材における接合終端部に若干のバリが生じた形態において割れ、接合体側には何等の割れも至るものではなかった。また、接合材尾部の引張試験の結果、引張強さは２００ＭＰａで、継手効率は８２％と健全であり、更に接合部の断面マクロ組織の観察結果でも、接合頭部において亀裂やトンネルポアー等の欠陥は無く、健全な接合部であることを認めた。また、そのような接合材における接合端部の若干のバリは、グラインダーで仕上げることで、外観上も健全な端面を得ることが出来た。
【００６３】
比較例５
板厚：４mm、板幅：３００mm、長さ：５０００mm、材質：６Ｎ０１−Ｔ５のアルミニウム押出型材の２枚を供試材として用い、それら供試材を幅方向に突き合せて、テーブル上に固定した。また、２枚の供試材の接合終了側の端部には、板厚：４mm、サイズ：５０mm×５０mmの、供試材と同材質のタブ板を当接せしめて、同様に固定した。そして、回転治具としては、肩径：１７mm、ピン長さ：３．９mm、ピン径：４mmのものを用い、回転数：１５００ｒｐｍ、速度：５００mm／分の接合条件下において、摩擦攪拌接合を行い、供試材の突合せ部に沿って、回転治具を移動せしめると共に、更に突合せ部からタブ板上に至るまで、進行せしめた。なお、回転治具の回転は、治具上から見て時計回りとした。また、回転治具は、供試材とタブ板の境目からタブ板側に２５mm進んだ位置で引き抜き、更にその後、反時計回りに逆回転せしめ、供試材側の接合部で前記境目から３mm戻った位置において、回転治具を再度差し込み、タブ板側に再度の摩擦攪拌接合操作を実施し、タブ板側に２５mm進んだ位置で引き抜くことにより、摩擦攪拌接合操作を終了せしめた。
【００６４】
かくして得られた接合材に付着するタブ板を、木槌を用いて、実施例２と同様に取り除いたところ、接合材側で割れが発生してしまい、目的とする用途の製品として使用することの出来ないものとなった。
【００６５】
【発明の効果】
以上の説明から明らかなように、本発明に従う摩擦攪拌接合手法によれば、接合終了端部において健全な接合部端面が、タブ板の効果的な使用によって、簡単に実現されることとなったのであり、また、そのようなタブ板の接合材からの取り外しも、簡単に且つ容易に行われ得るのであり、しかも、タブ板の取除き作業に基づくところの接合端部における欠陥の発生も、効果的に抑制乃至は防止せしめられ得て、品質の良好な接合材を有利に得ることが出来るのである。
【図面の簡単な説明】
【図１】従来の摩擦攪拌接合方法を示す説明図である。
【図２】摩擦攪拌接合方法の一つの開始形態を示す説明図である。
【図３】摩擦攪拌接合方法において、接合されるべき二つの板状部材の突合せ部に差し込まれた回転治具のピンの位置を示す説明図であって、（ａ）及び（ｂ）はそれぞれピン先端部の形状の異なる例を示す断面説明図である。
【図４】本発明に従う摩擦攪拌接合方法の一つの形態たる接合終了端側の状態を示す説明図である。
【図５】本発明に従う摩擦攪拌接合方法における接合終了端側の板状部材とタブ板との当接形態を示す平面説明図であり、（ａ）及び（ｂ）は、それぞれ、タブ板に設けられた凹所の異なる形態を示す説明図である。
【図６】図５に示されるタブ板とは異なる形状の凹所を有するタブ板を用い、それを二つの板状部材の接合終了端側の端面に当接した形態を示す平面説明図である。
【図７】本発明に従う摩擦攪拌接合方法の更に他の例を部分平面形態図として示す工程説明図である。
【図８】本発明に従う摩擦攪拌接合方法により得られた接合材からタブ板を取り除き、その接合端部の処理の例を示す部分平面説明図である。[0001]
【Technical field】
The present invention relates to a friction stir welding method, and more particularly to a method for soundening the end face of a joint end portion in a joint portion formed by friction stir welding.
[0002]
[Background]
In recent years, as one of the methods for butt-joining plates using frictional heat, as disclosed in US Pat. No. 5,460,317, Japanese Patent Publication No. 7-505090, etc., the friction stir welding method (Friction) (Stir Welding) is receiving attention as a joining method with less heat input and less strength reduction and distortion of the joint.
[0003]
In such a friction stir welding method, specifically, as illustrated in FIG. 1, a pin 4 made of a material harder than the two plates 2a and 2b to be joined is provided at the center of the tip. The rod-shaped rotating jig 6 is used, and the rotating jig 6 is rotated at a high speed, and the pin 4 at the tip is inserted into the portion of the butting portion 8 of the two plates 2a and 2b, and the butting is relatively performed. By moving along the portion 8, friction heat is generated between the pin 4 and the rotating jig 6 that are rotated and the plates 2 a and 2 b, and the peripheral portion of the butt portion 8 is generated by the friction heat. The two plate members are made into a state in which plastic working is possible, and the structure of the butted portions (8) of the plate members 2a and 2b is mixed and melted by a stirring action by high-speed rotation of the pins 4. 2a and 2b are joined.
[0004]
By the way, at the start of joining based on such a friction stir welding technique, the rotating jig 6 has a length exceeding 3 mm from the end surfaces of the plate materials 2a and 2b to which the shoulder portions (shoulder portions) are to be joined. At the position where it entered away, it was inserted into the abutting portion 8 of the plate materials 2a, 2b so as to come into contact with the plate surfaces of the plate materials 2a, 2b, the friction stir welding operation was started, and along the abutting portion 8, As illustrated, the joint 10 is formed on the rear side of the rotating jig 6 by being moved in the direction of the arrow. The reason for joining from such an intrusion position is to prevent the occurrence of joint defects in the joint portion 10 due to leakage of the metal agitated by the rotation of the rotating jig 6 from the end surfaces of the plate materials 2a and 2b to be joined. There is.
[0005]
For this reason, as shown in FIG. 1, the portion on the joining start end side of the abutting portion 8 of the two members 2a and 2b to be joined extends over a certain length to the unjoined portion 12. As a result, the two plate members 2a and 2b are present in the joined body. Then, after the friction stir welding operation is completed for such treatment of the unjoined portion 12, the unjoined portion 12 portion in the joined body is cut or reworked by fusion welding. However, these post-treatments are not only uneconomical, but also cause new problems such as distortion and softening due to the heat effect of fusion welding.
[0006]
On the other hand, at the end of the friction stir welding operation, similarly to the above-described start of bonding, a position 10 mm or more from the end surface on the end side of the butted portion 8 of the plate members 2a and 2b (the end surface and the shoulder portion). In the distance between the two, the rotation jig 6 is pulled out and finished. The reason is to prevent the occurrence of joining defects in the joint due to the metal stirred by the rotation of the rotating jig 6 leaking from the end face of the joined body. And thereby, the junction part 10 formed in the butt | matching part 8 of the two board | plate materials 2a and 2b does not reach the end surface of the two board | plate materials 2a and 2b, but between the last tail part of a junction part 10, and a board | plate material end surface. The butted portion 8 located in the predetermined length portion remains as an unjoined portion (12), and therefore, after the joining operation is finished, the existing portion of the unjoined portion (12) is cut, or Although such a rework consisting of fusion welding of the unjoined part (12) has been performed, the post-treatment thereof is not only economical, but also generation of strain and softening due to the thermal effect of fusion welding. Furthermore, the pin hole after pulling out the rotating jig 6 has a problem of remaining as a dent.
[0007]
However, in order to eliminate the above-described problems caused at the start of joining and at the end of joining in such a friction stir welding operation, for example, the end face on the joining start end side of the butting portion 8 of the two plate members 2a and 2b, or the joining end Appropriate tab plates are brought into contact with the end surfaces on the end side, the rotating jig 6 is inserted into one of the tab plates, the joining operation is started, and the joining portion 8 is entered to enter the abutting portion 8. Although it is possible to adopt a method of pulling out the rotating jig 6 after passing through the entire length and then reaching the other tab plate, in such a method, the tab plates at both ends are Since the two plate members 2a and 2b are bonded to the both end surfaces, it takes time to cut and remove the tab plates, and at the time of cutting and removing, the cut surface of the joint portion 10 has two plate members 2a and 2b. of When the tab plate is removed in the form that has entered the mating portion 8, a problem of strength of the joint portion 10 in the joined body occurs, and work such as reworking of the end face newly occurs. The problem is also inherent.
[0008]
Moreover, in JP-A-2000-42759, as a method for solving the above-described problem at the end of joining, a discarded meat portion is provided in advance at the joining end portion, and the rotating jig is allowed to escape to the discarded meat portion. There has been proposed a friction stir welding method that does not cause a hole or a recess after the rotating jig is pulled out by cutting and removing the discarded meat portion. However, in such a method, since it is necessary to specially provide a discarded meat portion on the members to be joined, in addition to the need for processing such a discarded meat portion, the material cost is also increased. In addition, the cost of the cutting and removing process is inevitably increased, and is not sufficiently practical.
[0009]
Furthermore, in Japanese Patent Laid-Open No. 2000-42762, in friction stir welding between pipes, a hole or a recess after pulling out the rotating jig is not generated by letting the rotating jig escape to the abutting member arranged at the joint. The method has been clarified. In this method, there is a problem that the abutting member cannot be easily removed from the joining material due to the influence of the agitated metal at the interface between the joining material and the abutting member. In that case, it can be said that it is a preferable method in order to obtain a sound bonded product because the abutting member portion remains and subsequent correction becomes troublesome, or the bonded body portion is peeled off and becomes defective. It is not a thing.
[0010]
[Solution]
  Here, the present invention has been made against the background of such circumstances, and the problem to be solved is friction stir welding.End ofAn object of the present invention is to provide a method capable of advantageously and easily realizing a healthy joint end face by adding a device to the end form.
[0011]
[Solution]
  And in the present invention,At the end of the friction stir welding operation, two plate-like members to be joined are brought into contact with each other in order to achieve a sound end face on the joining end side, and a rod-shaped rotating jig is placed against the abutting part. A pin provided concentrically at the tip of the two is inserted together while rotating together with the rotating jig, and moved relatively, so that the abutting portion is friction stir joined, the two plate-like members, A tab plate harder than or similar to the plate-like member is brought into contact with the end surface on the joining terminal side of the butting portion, and the pin is placed at a position facing the butting portion of the tab plate. After providing a semicircular or U-shaped recess having a recess depth not less than the radius and not more than the radius of the rotating jig, and the rotating jig reaches the tab plate through the recess from the butted portion, Friction stir welding operation The friction stir welding method, characterized in that as caused to completion, it is an gist thereof.
[0013]
Furthermore, in the present invention, at the end of the friction stir welding operation, two plate-like members to be joined are brought into contact with each other in order to solve the same problem as described above, and a rod-like rotational treatment is made against the joined portion. A pin provided concentrically at the tip of the tool is inserted while rotating together with the rotating jig and moved relatively, so that the butt portion is frictionally stirred and joined, in the two plate-like members, A tab plate harder than or similar to the plate-like member is brought into contact with the end surface on the joining end side of the abutting portion, and the pin is disposed at a portion facing the abutting portion of the tab plate. A rectangular recess having a width not less than the diameter of the rotating jig and not more than the diameter of the rotating jig and a recess depth not less than the radius of the pin and not more than the radius of the rotating jig is provided. Through the recess After reaching the tab plate, also the friction stir welding method Friction stir welding operation, characterized in that as caused to completion, it is an gist thereof.
[0014]
In addition, in order to solve the problem at the end of the friction stir welding operation, another different gist of the present invention is to butt two plate-like members to be joined and to the butt portion. A pin provided concentrically at the tip of the rod-shaped rotating jig is inserted while rotating together with the rotating jig and moved relatively, so that the abutting portion is frictionally stirred and joined. In one plate-like member, a tab plate made of a material having the same hardness as that of the plate-like member is brought into contact with the end face on the joining end side of the abutting portion, and in this state, the rotating jig is placed on the abutting portion. Until the tab plate is reached, the friction stir welding operation is carried out, and then the rotating jig is pulled out from the formed joint, and the rotational direction of the rotating jig is reversed, The meeting Insert the pin of the rotating jig in the reverse direction into the part where the rotating jig is located at a distance of 5 mm or more from the position of the joining end surface of the part to the joining start end side of the butting part. The friction stir welding operation is performed again so as to reach, and the friction stir welding operation is continued until the rear shoulder of the rotating jig passes the boundary between the plate-like member and the tab plate. Friction stir welding method.
[0015]
And in the joined body of the two plate-like members obtained in accordance with the various friction stir welding methods as described above, there is no unjoined portion due to the rotating jig, and substantially throughout. Although it is completely joined and integrated, the tab plate can be easily broken from such a joined body by hitting it with a hand or a mallet. In addition to facilitating finishing work on the joined body after the end of the friction stir welding operation, the broken part of the joined part is also beautiful, and defects such as cracks and notches are joined on the joined body side. Problems such as getting into the club could be resolved.
[0016]
In the friction stir welding method according to the present invention as described above, after the friction stir welding operation is finished, the tab plate is removed from the joined body of the two plate-shaped members, and then the joined body of the joined body is removed. The metal protruding at the joint end face is removed by a cutting machine such as a grinder.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the configuration of the present invention will be described more specifically with reference to the drawings.
[0018]
First, FIG. 2 shows one state on the welding start end side in the friction stir welding operation. Therefore, as the rod-shaped rotary jig 6 having the pin 4 concentrically provided at the tip portion, which is used for the friction stir welding operation according to the present invention, the same one as the conventional one is used and should be joined respectively. It is formed using a material harder than the material of the two plate-like members 2a and 2b. For this reason, the pin 4 and the rotating jig 6 are rotated at a high speed, and the butted portions 8 of the two members 2a and 2b are brought into contact with each other. Even if the lower part (shoulder part) of the rotating jig 6 is brought into contact with the upper surface of the plate-like members 2a and 2b, the non-consumable member is hardly worn. The high-speed rotation around the axis of the pin 4 and the rotating jig 6 can be easily realized by using a rotation driving device (not shown) similar to the conventional one. Further, as shown in FIG. 3, the pin 4 is relatively moved in a configuration in which the axis of the pin 4 is inclined backward at an angle of θ in the joining progression direction with respect to the normal, as in the prior art. As a result, the joining can proceed.
[0019]
In FIG. 2, the tab plate 20 is disposed at one end surface of the two plate-like members 2 a and 2 b made of aluminum or an alloy thereof with respect to the end surface on the joining start end side of the butting portion 8. They are brought into contact with each other and are held in a fixed position together with the two plate-like members 2a and 2b, and a friction stir welding operation is performed. Further, the tab plate 20 is formed of a material harder than the plate-like members 2a and 2b, or is formed of a material having the same hardness as the plate-like members 2a and 2b, Thus, the tab plate 20 can be easily removed after the friction stir welding. When the tab plate 20 becomes softer than the plate-like members 2a and 2b to be joined, the metal of the tab plate 20 is also stirred, and the tab plate 20 and the plate-like members 2a and 2b are firmly joined. You will be tempted.
[0020]
Further, the thickness of the tab plate 20 is the same as that of the plate members 2a and 2b, and the height of the upper surface of the tab plate 20 is the height of the upper surface of the plate members 2a and 2b. The thickness can be set at a height of 70% or more. Note that when the height of the upper surface of the tab plate 20 is less than 70% of the height of the upper surfaces of the two plate-like members 2a and 2b to be joined, the tab plate 20 serves to hold down the metal springing from the end. In addition, there is a problem that metal springs out from the plate thickness difference between the tab plate 20 and the plate-like members 2a and 2b, and the upper surface of the tab plate 20 is higher than the upper surfaces of the plate-like members 2a and 2b. Then, the tab plate 20 is preferentially stirred by the friction stir welding operation, thereby causing a problem that the joining becomes difficult.
[0021]
In FIG. 2, the rotating jig 6 slightly moves along the abutting portion 8 from the joining start point where the pin 4 of the rotating jig 6 is inserted, and the friction stir welding operation proceeds a little. In the present invention, the insertion position of the pin 4 in such a rotating jig 6 at the start of joining is the plate on the joining start end side. The friction stir welding operation is started by setting the distance between the end surfaces of the shaped members 2a and 2b and the most distal position at the tip of the pin 4 to be 3 mm or less. At this time, the insertion position of the pin 4 is not set on the tab plate 20.
[0022]
Specifically, as shown in FIGS. 3A and 3B, when the pin 4 of the rotating jig 6 is inserted into the butting portion 8, In FIG. 3 (a), the friction stir welding operation is started so that the distance between the left end position at the tip of the pin and the end faces of the plate-like members 2a and 2b: x is 3 mm or less. Thus, the rotation of the rotating jig 6 effectively prevents or suppresses the occurrence of an unjoined portion on the joining start end side while effectively suppressing or preventing the stirred metal from leaking to the outside. As a result, the formation of the joint 10 can be advantageously realized. When the distance x between the end surfaces of the plate-like members 2a and 2b and the most distal position at the tip of the pin 4 exceeds 3 mm, stirring at the joining start end side portion becomes insufficient and unbonded. This causes a problem that the part (12) is caused to occur, or that the joint part 10 having a defect is generated.
[0023]
Here, as the shape of the pin 4 of the rotating jig 6, in addition to the trapezoidal shape as shown in FIG. As shown in FIG. 3B, the most advanced position of the pin 4 is the most advanced position of the pin 4 in the friction stir welding operation in consideration of the tilting operation state of the pin 4, and the end faces of the plate-like members 2a and 2b. The friction stir welding operation is started so that the distance between the two is x and the value is 3 mm or less.
[0024]
Further, the insertion depth of the pin 4 of the rotating jig 6 is such that the distance from the tip of the pin 4 to the back surface of the plate-like members 2a and 2b: d is 1 mm or less so that friction stir welding is performed. It is desirable that this is particularly effective when the plate thickness of the plate-like members 2a and 2b is 2 mm or more. When the distance from the back surface exceeds 1 mm, the stirring action by the pin 4 of the rotating jig 6 does not reach the entire thickness of the plate-like members 2a and 2b, and there is a defective joint near the back surface. The problem that occurs is likely to be caused.
[0025]
At the start of such joining, as shown in FIG. 3, the shoulder portion of the rotary jig 6 protrudes toward the tab plate 20, and the plate-like member on the joining start end side by such a shoulder portion. Since the effect of stirring the portions 2a and 2b can also be exerted, better stirring can be realized, and therefore, a healthy joint without defects is formed at the end. However, in particular, the stirring action by the shoulder portion of the rotating jig 6 can be more effectively exhibited when the plate-like members 2a and 2b are thinner than 2 mm.
[0026]
  By the way, the present invention, MaAt the end of friction stir welding operationAndBy improving the usage of the tab plate and rotating jig, the conventional problems described above can be advantageously solved.InAn example thereof is shown in FIG.
[0027]
That is, in FIG. 4, it is harder than these plate-shaped members 2a and 2b with respect to the end surface of the joining end side of the butt | matching part 8 in two plate-shaped members 2a and 2b, or the same hardness as it. The tab plate 30 is brought into contact with one end face (side face) and is held in a fixed position. Further, a semicircular recess 32 having a predetermined recess depth is provided in a portion of the tab plate 30 facing the butting portion 8. Then, after the rotating jig 6 reaches the tab plate 30 from the abutting portion 8 through such a recess 32, the rotating jig 6 is pulled out from the tab plate 30 to complete the friction stir welding operation. It is made to be harassed.
[0028]
In addition, as the recess 32 provided in the tab plate 30 disposed on the joining terminal side in such a friction stir welding operation, as shown in FIGS. 5A and 5B, in addition to a semicircular shape, U-shaped ones can be adopted, but the concave depth of the recess 32 of these shapes: y has a value not less than the radius of the pin 4 in the rotating jig 6 and not more than the radius of the rotating jig 6 Then, by removing the tab plate 30 after completion of the friction stir welding operation, the rotating jig 6 is guided from the abutting portion 8 onto the tab plate 30 through the recess 32. Can be advantageously performed.
[0029]
That is, the presence of such a recess 32 has an effect of once ending the stirring of the metal by the pins 4 of the two plate-like members 2a and 2b. When the depth of the recess is deeper than the radius of the metal, there is a problem in that the metal protrudes more and a defect occurs at the end. Further, even if such a recess 32 is not provided or a recess 32 having a recess depth (y) shallower than the radius of the pin 4 is provided, the plate-like members 2a and 2b and the tab plate 30 Agitation between them is caused, and there is a problem that a joining portion made of a metal in which these materials are mixed is formed at the end portion, and the plate-like members 2a and 2b are softer or almost more than the tab plate 30. This is because when the tab plate 30 is removed from the joined body of the two plate-like members 2a and 2b because of the same hardness, there is a problem that the joined body is easily broken.
[0030]
The semicircular or U-shaped arrangement position is such that the center line of such a recess 32 is positioned on the extension line of the butting portion 8 of the two plate-like members 2a and 2b. This is advantageously employed, whereby a temporary end effect of the stirring action of the metal by the pin 4 is advantageously realized.
[0031]
However, as such a recess 32, in addition to the semicircular shape shown in FIG. 5A, the U-shape shown in FIG. 5B, a recess 32 structure having a rectangular shape as shown in FIG. Can be adopted.
[0032]
The rectangular recess (notch) 32 has a recess depth y that is not less than the radius of the pin 4 and not more than the radius of the rotating jig 6, and the width of the recess 32: z is formed on the tab plate 30 so as to have a value not less than the diameter of the pin 4 and not more than the diameter of the rotating jig 6, and is opposed to the abutting portions 8 of the two plate-like members 2a and 2b. In addition, when the recess depth: y or width: z of the recess 32 is less than the above-described dimensions, the metal of the tab plate 30 is mixed with the end portion, and when the tab plate 30 is removed, There is a problem that the joined body (2a, 2b) is easily broken, and if the dimensions are exceeded, the metal of the plate-like members 2a, 2b is likely to spring out into the space due to the recess. For this reason, there is a problem that the joint end portion has a lack of meat or a defect.
[0033]
Further, when forming the end portions on the joining end side in the friction stir welding operation shown in FIG. 7, first, the plate-like members are opposed to the end surfaces on the joining end side of the butting portions 8 of the two plate-like members 2a and 2b. A tab plate 40 having the same hardness as 2a and 2b is brought into contact with one end face (side face), and in a form in which the state is fixed, the rotating jig 6 is moved along the abutting portion 8. Then, the friction stir welding operation is performed from the butt 8 until the tab plate 40 is reached. Then, after the rotating jig 6 reaches the tab plate 40, the rotating jig 6 is pulled out from the joint 10 formed there. The joint 10 is formed so as to reach the tab plate 40 from the two plate-like members 2a and 2b. In this way, in order to effectively allow the rotating jig 6 to reach the tab plate 40 from the abutting portion 8 of the two plate members 2a and 2b, the two plate members 2a and 2b The difference between the upper surface height and the upper surface height of the tab plate 40 is preferably within 1 mm. On the other hand, if there is a height difference exceeding 1 mm, the tab plate 40 and the plate-like member 2a. , 2b, the agitation at the boundary is non-uniform and may cause defects.
[0034]
Next, the drawn rotating jig 6 is rotated in the direction opposite to the previous rotation direction, and then the bonding end surface (plate-like member) of the butted portion 8 of the previously formed bonding portion 10. 2a and 2b) from the position) to the joining start end side of the butting portion 8 with a distance of 5 mm or more, in other words, the distance L between the tab plate 40 and the rotating jig 6 in FIG. 7 is 5 mm or more. At a short distance, the rotary jig 6 (pin 4) is inserted into the joint 10 again, and the friction stir welding operation is repeated under the reverse rotation state of the rotary jig 6 so as to reach the tab plate 40. Is implemented. Then, until the rear shoulder of the rotating jig 6 passes the boundary between the plate-like members 2a and 2b and the tab plate 40, the rotating jig 6 is completely positioned on the tab plate 40. The friction stir welding operation is continued until the rotation jig 6 is pulled out from the tab plate 40, and the friction stir welding operation is terminated.
[0035]
In addition, the pin 4 is inserted into the joint 10 where the position of the pin 4 of the rotating jig 6 of the reverse rotation is less than L: 5 mm, and the friction stir welding operation is performed again. In that case, the boundary between the tab plate 40 and the plate-like members 2a and 2b becomes too close to each other, and the mixing of the two metals at the boundary becomes excessive, and such a tab plate 40 and the joined bodies 2a and 2b When leaving, it becomes difficult to cleanly break at the border. In addition, by passing such a boundary in the friction stir welding operation again by the rotating jig 6 of the reverse rotation, a metal flow interface is generated in the metal of the boundary, and the part easily breaks, Therefore, it is possible to remarkably contribute to the improvement of the soundness of the end face of the joined body (2a, 2b).
[0036]
In any of the above methods, the tab plates 20, 30, and 40 can be easily folded by hand or a mallet, so that a healthy end can be advantageously realized. However, if necessary, after removing such a tab plate, it is also advantageous in the present invention to finish the end surface by removing the metal that has sprung out on the end surface with a cutting machine such as a grinder. Will be adopted. In FIG. 8, from the joined body obtained by friction stir welding using the tab plate 30 shown in FIG. 6, the tab plate 30 is broken, and the protruding portion (metal) 34 formed at the end portion thereof, The form which cuts with a grinder etc., finishes an end surface, and obtains the target joined body is shown.
[0037]
And the end part end face of the joined body obtained by such a friction stir welding method is effectively sanitized, so that the present invention is, for example, a stretched material such as an aluminum alloy plate or an extruded material, The present invention can be advantageously applied to a technique for joining a casting and manufacturing a large-sized aluminum alloy material, and the joining material thus obtained can be used for railway vehicle bodies, automobile skins, subframes and wheels. It can be advantageously used for joining large materials of aluminum alloy and exhibits its characteristics.
[0038]
【Example】
Examples of the present invention will be shown below to clarify the present invention more specifically. Needless to say, the present invention is not limited by the description of such examples. By the way. In addition to the following examples, the present invention includes various changes, modifications, and modifications based on the knowledge of those skilled in the art without departing from the spirit of the present invention other than the specific configuration described above. It should be understood that improvements and the like can be added.
[0039]
  referenceExample 1
  Thickness: 4mm, width: 300mm, length: 5000mm, material: 6N01-T5 aluminum alloy extruded molds were used as test materials, but the sides facing each other in the width direction were butted on the table. It was fixed to. In addition, at the end of the joining side of the two specimens that were butted together, a steel plate of plate thickness: 3.5 mm (87.5% with respect to the specimen thickness) and size: 50 mm × 50 mm (Material: SS40) was used as a tab plate, butted together as shown in FIG. 2, and fixed on the table.
[0040]
On the other hand, a rotating jig having a shoulder diameter: 17 mm, a pin length (height): 3.9 mm, and a pin diameter: 3 mm was used under the joining conditions of a rotation speed: 3000 rpm and a speed: 500 mm / min. Friction stir welding was performed. When the pin provided at the tip of the rotating jig is inserted into the butt portion of the specimen, the tip end position at the tip of the pin and the end face of the specimen at the joining start end (the contact between the specimen and the tab plate). The distance between the contact surface and the contact surface was set to 3 mm, and the friction stir welding operation was started.
[0041]
As a result, the rotating jig rotates without coming into contact with the tab plate (steel plate), and in the joining material (joined body) obtained by joining the two test materials, the joining start end portion From this, it was confirmed that the appearance was a sound joint. Furthermore, when the tensile test of the head of the obtained joint material was performed, the tensile strength was 198 MPa, the joint efficiency was 81%, and even from the observation result of the cross-sectional macrostructure of the joint, There were no defects such as cracks and tunnel pores in the joint head, and it was confirmed that the joint was sound.
[0042]
  referenceExample 2
  In order to perform friction stir welding by using two aluminum plates of plate thickness: 1.8 mm, plate width: 72 mm, length: 300 mm, material: 5454-O as test materials, butting them in the width direction It was fixed on the table. In addition, at the end of the test material on the joining start side, a steel plate having a thickness of 1.3 mm (72% of the thickness of the test material) and a size: 50 mm × 50 mm was used as a tab plate to make a test. It was fixed on the table like the material.
[0043]
A rotating jig with a shoulder diameter of 15 mm, a pin length of 1.7 mm, and a pin diameter of 4 mm was used, and a friction stir welding operation was performed under the joining conditions of a rotational speed of 1500 rpm and a speed of 300 mm / min. did. The friction stir welding operation was started such that when the pin at the tip of the rotating jig was inserted into the abutting portion of the specimen, the shoulder of the rotating jig protruded toward the tab plate.
[0044]
As a result, the rotating jig rotated without coming into contact with the iron plate as the tab plate, but a slight amount of metal protruded from the end of the joining material obtained by joining the two specimens. Was recognized. Further, as a result of a tensile test on the head portion of the bonding material, the tensile strength was 235 MPa, and the joint efficiency was 94%, which was sound. Further, in the observation result of the cross-sectional macrostructure of the joint, no defects such as cracks and tunnel pores were observed at the joint head, and it was confirmed that the joint was sound. Further, a slight metal protrusion recognized at the end portion on the joining start side was finished with a grinder, so that a sound end face was obtained in terms of appearance.
[0045]
Comparative Example 1
Two aluminum extrusion molds having a thickness of 4 mm, a width of 300 mm, a length of 5000 mm, and a material of 6N01-T5 were used as test materials, and they were butted in the width direction and fixed on a table. In addition, an iron plate with a thickness of 2.5 mm (62.5% of the thickness of the test material) and a size of 50 mm × 50 mm is abutted and fixed to the end of the test material on the joining start side. I was damned.
[0046]
In addition, as a rotating jig, one having a shoulder diameter of 15 mm, a pin length of 3.9 mm, and a pin diameter of 4 mm was used, and friction stir welding was performed under the bonding conditions of a rotation speed of 1500 rpm and a speed of 300 mm / min. The operation has started. In addition, the distance (x) between the most advanced position in a pin front-end | tip part and a test material end surface at the time of inserting a pin was 2 mm.
[0047]
As a result, the rotating jig rotated without contacting the iron plate, but there were many metal protrusions from the end portion, and the appearance was not a healthy joint. Furthermore, the observation result of the cross-sectional macrostructure of the joint also confirmed that there were many defects such as tunnel pores in the joint head.
[0048]
Comparative Example 2
Two aluminum extrusion molds having a thickness of 4 mm, a width of 300 mm, a length of 5000 mm, and a material of 6N01-T5 were used as test materials, and they were butted in the width direction and fixed on a table. In addition, an iron plate having a thickness of 3.5 mm (87.5% of the thickness of the test material) and a size of 50 mm × 50 mm is abutted and fixed to the end of the test material on the joining start side. I was damned. Also, as a rotating jig, a shoulder diameter: 15 mm, a pin length: 2.8 mm, and a pin diameter: 4 mm are used, and a friction stir welding operation is performed under the joining conditions of a rotation speed: 1500 rpm and a speed: 300 mm / min. Started. In addition, the distance (x) between the most advanced position in a pin front-end | tip part and a test material end surface at the time of inserting a pin was 3 mm.
[0049]
As a result, the rotating jig was rotated without contacting the iron plate, and it was recognized that the appearance was a soundly joined part from the joining start side end of the joining material, but the cross-sectional macrostructure of the joined part was observed. As a result, it was confirmed that there was a crack due to insufficient bonding particularly on the back side of the bonding material.
[0050]
  Example 1
  Table for friction stir welding by using two aluminum extruded molds of plate thickness: 4 mm, plate width: 300 mm, length: 5000 mm, material: 6N01-T5 as test materials, butting them in the width direction It was fixed on the top. In addition, as shown in FIG. 4, at the end of the butt portion of these specimens, a semicircular recess with a radius of 2 mm is punched, and the thickness is 4 mm (the specimen plate). The same as the thickness), size: 50 mm × 50 mm steel plate (material: SS40), such that the recess is opposed to the butting portion, and the recess is divided into two equal parts by the extension line of the butting portion, It was made to contact | abut to the end surface of a test material, and was fixed on the table similarly to a test material.
[0051]
In addition, as a rotating jig, one having a shoulder diameter: 17 mm, a pin length: 3.9 mm, and a pin diameter: 4 mm was used, and friction stir welding was performed under the bonding conditions of a rotation speed: 1500 rpm and a speed: 500 mm / min. The operation was performed. Then, when the rear shoulder in the joining direction of the rotating jig advances to the tab plate side with a length of 2 mm from the boundary between the specimen and the tab plate, the rotating jig is pulled out and the friction stir welding operation is completed. did.
[0052]
When the tab plate adhering to the joining material composed of the two specimens thus obtained was removed using a wooden mallet, cracking occurred in the form where some burrs were formed at the terminal end of the joining portion, , Such cracks did not lead to anything. And as a result of the tensile test of such a joint material tail, the tensile strength is 198 Mpa and the joint efficiency is 81%, and the observation result of the cross-sectional macrostructure of the joint also shows cracks, tunnel pores, etc. No defects were observed, and the joint was sound. In addition, some burrs at the end were finished with a grinder, so that the end face was also sound.
[0053]
Comparative Example 3
Two aluminum extrusion molds having a thickness of 4 mm, a width of 300 mm, a length of 5000 mm, and a material of 6N01-T5 were used as test materials, which were butted in the width direction and fixed on a table. In addition, at the end of the joining portion of the test material, the end of the joining end has a recess depth (y): 6 mm, and a U-shaped recess having a radius of R part: 2 mm is punched out. Thickness: 4 mm (same as test material plate thickness), size: 50 mm x 50 mm steel plate (material: SS40) is used as a tab plate, and fixed in a state where it is in contact with the end surface of the test material as shown in FIG. did.
[0054]
A rotating jig having a shoulder diameter of 17 mm, a pin length of 3.9 mm, and a pin diameter of 4 mm was used, and a friction stir welding operation was performed under the joining conditions of a rotation speed of 1500 rpm and a speed of 500 mm / min. Carried out. At that time, the end of the rotating jig in the rear direction in the joining direction is about 2 mm from the boundary between the joining material obtained by joining the two test materials and the tab plate brought into contact with the joining material. When it advanced, the rotating jig was pulled out and the friction stir welding operation was completed. And when the tab board adhering to the joining material obtained in this way is removed using a wooden mallet, cracks occur on the joining material side, and it can be used for products of the intended use. It became nothing.
[0055]
  Example 2
  Thickness: 3.2 mm, plate width: 100 mm, length: 150 mm, material: 5454-O, two aluminum plates were used as test materials. Fixed on the table for. Further, as shown in FIG. 6, a rectangular recess having a width (z): 15 mm and a recess depth (y): 2.0 mm is provided at the end portion on the joining end side of the specimens thus abutted. Thickness: 3.2 mm (same as test material thickness), size: 50 mm x 50 mm, a tab plate made of the same aluminum material as the test material, with the recess as the test It was made to contact | abut to the end part of a test material so that it might oppose to the butt | matching part of a material, and it was made to fix on a table like this test material.
[0056]
A rotating jig having a shoulder diameter of 15 mm, a pin length of 3.0 mm, and a pin diameter of 4 mm was used, and a friction stir welding operation was performed under the joining conditions of a rotational speed of 1500 rpm and a speed of 250 mm / min. When the shoulder on the rear side in the joining direction of the rotating jig progressed to the tab plate side by 25 mm from the boundary between the joining material and the tab plate, the rotating jig was pulled out to finish the friction stir welding operation.
[0057]
When the tab plate adhering to the bonding material thus obtained was removed using a wooden mallet, cracking occurred in the form in which some burrs were generated at the terminal end of the bonding portion, and no cracking occurred on the bonding material side. It was. Moreover, as a result of a tensile test on the tail portion of the joint material, the tensile strength is 235 MPa, the joint efficiency is 94%, and the observation result of the cross-sectional macrostructure of the joint portion shows that cracks, tunnel pores, etc. There was no defect of this, and it was a healthy joint. Furthermore, by finishing some burrs at the terminal end of the joint with a grinder, it was possible to obtain a sound end face.
[0058]
Comparative Example 4
Thickness: 4 mm, width: 300 mm, length: 5000 mm, material: 6N01-T5 aluminum extruded molds were used as test materials, but these test materials were butted in the width direction and fixed on the table. It was. In addition, at the end of the specimens on the bonding end side, there is a rectangular recess having a width (z): 25 mm and a recess depth (y): 3 mm. Plate thickness: 4 mm (test material) A tab plate made of an aluminum extrusion mold of the same material as that of the test material was abutted and fixed on the table in the same manner as the test material. In addition, a rotating jig having a shoulder diameter of 17 mm, a pin length of 3.9 mm, and a pin diameter of 4 mm was used, and a friction stir welding operation was performed under the joining conditions of a rotation speed of 1500 rpm and a speed of 500 mm / min. Carried out. Then, when the shoulder portion on the rear side in the joining direction of the rotating jig advanced to the tab plate side by 15 mm from the boundary between the bonding material and the tab plate, the rotating jig was pulled out to complete the friction stir welding operation.
[0059]
In the joining material obtained in this way, there was a lot of metal springing up from the joining end portion, and it was not a joining portion that was sound in appearance. Furthermore, the observation result of the cross-sectional macrostructure of the joint also confirmed that there were many defects such as tunnel pores in the joint head.
[0060]
  Example 3
  Thickness: 4 mm, width: 300 mm, length: 5000 mm, material: 6N01-T5 aluminum extruded molds were used as test materials, but they were butted in the width direction, and on a table for friction stir welding It was fixed to. In addition, as shown in FIG. 7, a tab plate made of the same material as that of the test material having a thickness of 4 mm and a size of 50 mm × 50 mm is brought into contact with the end portion on the joining end side of the test materials, The sample was fixed on the table in the same manner as the sample material.
[0061]
In addition, as a rotating jig, one having a shoulder diameter: 17 mm, a pin length: 3.9 mm, and a pin diameter: 4 mm was used, and friction stir welding was performed under the bonding conditions of a rotation speed: 1500 rpm and a speed: 500 mm / min. The operation was performed. The rotation of the rotating jig was initially clockwise when viewed from above the jig. Then, the rotating jig is pulled out at a position 25 mm from the boundary between the joining material formed by joining two test materials and the tab plate to the tab plate side, and then the rotating jig is rotated counterclockwise. Reverse rotation was performed, and the friction stir welding was performed again toward the tab plate side by inserting it at a position 10 mm back from the boundary at the bonding portion on the bonding material side, and the rotating jig reached the tab plate. Further, the friction stir welding operation was completed by pulling out at a position advanced 20 mm from the boundary to the tab plate side.
[0062]
When the tab plate attached to the bonding material thus obtained was removed using a mallet, cracks occurred in the form in which some burrs were formed at the terminal end of the bonding material, and no cracks would occur on the bonded body side. There wasn't. Moreover, as a result of the tensile test of the joint material tail, the tensile strength is 200 MPa and the joint efficiency is sound as 82%. Further, the observation result of the cross-sectional macrostructure of the joint also shows cracks and tunnel pores in the joint head. There was no defect and it was confirmed that the joint was sound. In addition, some burrs at the joining end portion in such a joining material were finished with a grinder, and an end face that was sound in appearance could be obtained.
[0063]
Comparative Example 5
Thickness: 4 mm, width: 300 mm, length: 5000 mm, material: 6N01-T5 aluminum extruded molds were used as test materials, but these test materials were butted in the width direction and fixed on the table. did. Further, a tab plate of the same material as that of the test material having a thickness of 4 mm and a size of 50 mm × 50 mm was brought into contact with the end portion on the joining end side of the two test materials and fixed in the same manner. As the rotating jig, one having a shoulder diameter: 17 mm, a pin length: 3.9 mm, and a pin diameter: 4 mm was used, and friction stir welding was performed under the bonding conditions of a rotation speed: 1500 rpm and a speed: 500 mm / min. The rotation jig was moved along the abutting portion of the test material, and further advanced from the abutting portion to the tab plate. The rotation of the rotating jig was clockwise when viewed from above the jig. The rotating jig is pulled out at a position 25 mm from the boundary between the test material and the tab plate to the tab plate side, and then rotated counterclockwise, and 3 mm from the boundary at the joint on the test material side. In the returned position, the rotating jig was inserted again, the friction stir welding operation was performed again on the tab plate side, and the friction stir welding operation was terminated by pulling out at a position advanced 25 mm toward the tab plate side.
[0064]
  The tab plate adhering to the bonding material thus obtained was used as an example using a mallet.2When it was removed in the same manner as above, cracks occurred on the side of the bonding material, making it unusable as a product for the intended use.
[0065]
【The invention's effect】
  As is clear from the above explanation, according to the friction stir welding method according to the present invention,,ContactA healthy joint end face at the end of the joint is easily realized by the effective use of the tab plate, and it is also easy to remove such tab plate from the joint material. In addition, it is possible to effectively suppress or prevent the occurrence of defects at the joining end portion based on the tab plate removing operation, and it is advantageous to use a good quality joining material. Can be obtained.
[Brief description of the drawings]
FIG. 1 is an explanatory view showing a conventional friction stir welding method.
[Figure 2]MaOne of the friction stir welding methodsstartIt is explanatory drawing which shows a form.
[Fig. 3]MaIn a friction stir welding method, it is explanatory drawing which shows the position of the pin of the rotation jig | tool inserted in the butt | matching part of two plate-shaped members to be joined, Comprising: (a) And (b) is a pin tip part, respectively. It is sectional explanatory drawing which shows the example from which a shape differs.
FIG. 4 is an explanatory view showing a state at the end of welding end as one form of the friction stir welding method according to the present invention.
FIGS. 5A and 5B are plan explanatory views showing a contact form between a plate-like member on a joining end side and a tab plate in the friction stir welding method according to the present invention, and FIGS. It is explanatory drawing which shows the different form of the provided recess.
6 is an explanatory plan view showing a form in which a tab plate having a recess having a shape different from that of the tab plate shown in FIG. is there.
FIG. 7 is a process explanatory view showing still another example of the friction stir welding method according to the present invention as a partial plan view.
FIG. 8 is an explanatory partial plan view showing an example of processing of the joining end portion after removing the tab plate from the joining material obtained by the friction stir welding method according to the present invention.

Claims

Two plate-like members to be joined are abutted, and a pin provided concentrically at the tip of the rod-shaped rotating jig is inserted into the abutting portion while rotating together with the rotating jig, and relative By moving the butt to the friction stir welding,
In said two plate-like member, the end face of the junction termination side of the butt portion, hard or their plate-shaped member and the same hardness of the tab plate with allowed to abut than their plate-shaped member, said tab A semicircular or U-shaped recess having a recess depth not less than the radius of the pin and not more than the radius of the rotating jig is provided at a portion facing the butting portion of the plate, and the joining direction rearward of the rotating jig is provided. A friction stir welding method characterized in that the friction stir welding operation is terminated after the side shoulder portion reaches the tab plate from the butted portion through the recess.

Two plate-like members to be joined are abutted, and a pin provided concentrically at the tip of the rod-shaped rotating jig is inserted into the abutting portion while rotating together with the rotating jig, and relative By moving the butt to the friction stir welding,
In said two plate-like member, the end face of the junction termination side of the butt portion, hard or their plate-shaped member and the same hardness of the tab plate with allowed to abut than their plate-shaped member, said tab A rectangular recess having a width not less than the diameter of the pin and not more than the diameter of the rotating jig and a recess depth not less than the radius of the pin and not more than the radius of the rotating jig at a portion facing the butting portion of the plate. The friction stir welding operation is completed after the shoulder on the rear side in the joining direction of the rotating jig reaches the tab plate through the recess from the butted portion. Stir welding method.

Two plate-like members to be joined are abutted, and a pin provided concentrically at the tip of the rod-shaped rotating jig is inserted into the abutting portion while rotating together with the rotating jig, and relative By moving the butt to the friction stir welding,
In said two plate-like member, the end face of the junction termination side of the butt portion, their plate-shaped member and the tab plate material of the same hardness brought into contact, in this state, the rotary jig wherein After performing the friction stir welding operation from the abutting portion until reaching the tab plate, the rotary jig is pulled out from the formed joint portion, and the rotation direction of the rotary jig is reversed, and then the joint portion The pin of the rotating jig of the reverse rotation is inserted into a part where the rotating jig is located at a distance of 5 mm or more from the joining end surface position of the abutting part to the joining start end side of the abutting part, Repeat the friction stir welding operation so as to reach the tab plate, and continue the friction stir welding operation until the rear shoulder of the rotating jig passes the boundary between the plate-like member and the tab plate. Friction stir welding method characterized by .

After the friction stir welding operation is completed, the tab plate is removed from the joined body of the two plate-like members, and the metal protruding at the joined portion end surface of the joined body is removed by a cutting machine such as a grinder. 4. The friction stir welding method according to claim 1, wherein the friction stir welding method is removed.