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摘 要 攪拌摩擦焊技術(shù)是 90 年代發(fā)展起來(lái)的、自發(fā)明到工業(yè)應(yīng)用時(shí)間跨度最短和 發(fā)展最快的一項(xiàng)新型固相連接新技術(shù)，公認(rèn)為是最有前途和最適合航空材料以 及結(jié)構(gòu)件制造的工藝方法之一。攪拌摩擦焊（FSW）是一個(gè)相對(duì)較新的固態(tài)焊接 過(guò)程。這種連接技術(shù)具有節(jié)能，高效，環(huán)保，用途廣泛的特點(diǎn)。特別是，它可 以用于高強(qiáng)度航天鋁合金和其他金屬的合金，這些合金是很難通過(guò)常規(guī)焊接熔 焊。 FSW 被認(rèn)為是金屬連接在十年的發(fā)展中最有標(biāo)志性的成果。 [6] 本文設(shè)計(jì)出的雙攪拌軸摩擦焊焊機(jī)，總功率約 3 千瓦，適合于普通厚度的 鋁及其合金的工藝試驗(yàn)試件的焊接，攪拌摩擦頭轉(zhuǎn)速約 6000r/min，焊接速度 為 500—600mm/min，最大加工焊縫厚度 15mm，焊縫長(zhǎng)度 500mm。文中介紹了攪 拌摩擦焊焊接技術(shù)的基本原理和特點(diǎn)，概要地介紹了攪拌摩擦焊的技術(shù)優(yōu)勢(shì)、 研究現(xiàn)狀、工業(yè)應(yīng)用和發(fā)展前景。針對(duì)工藝試驗(yàn)試件攪拌摩擦焊機(jī)，主要設(shè)計(jì)、 計(jì)算和校核了設(shè)備各主要部分，均能夠滿(mǎn)足試驗(yàn)用焊機(jī)的要求。 本機(jī)器由于采用雙攪拌頭，因此相對(duì)于一般的攪拌摩擦焊焊機(jī)效率更高。 相對(duì)于一般的攪拌摩擦焊焊機(jī)，該機(jī)器也非常的經(jīng)濟(jì)和容易操作。 關(guān)鍵詞：雙攪拌軸摩擦焊；固相焊接；鋁合金焊接；焊機(jī)設(shè)計(jì) Abstract Friction stir welding (FSW) was firstly used in the 1990s, which is swiftest in development and is shortest in time from being invented to being applied, it is also treated as one of the technology that have a bright future and the most suitable for aviation and component manufacture.Friction stir welding (FSW) is a relatively new solid-state joining process. This joining technique is energy efficient, environment friendly, and versatile. In particular, it can be used to join high-strength aerospace aluminum alloys and other metallic alloys that are hard to weld by conventional fusion welding. FSW is considered to be the most significant development in metal joining in a decade. This task is to sign a machine used in laboratory. Its power is about three kilowatt, rotation rate approximately is 6000r/min, and welding speed is from 500 to 600mm/min. It can be apply to welding the aluminum and aluminum alloys. In addition, the welding thickness can’t exceed 15mm and length 500mm. In this paper, the basal principle and features of FSW is introduced, and the priority, prospect and application are also expounded. Importantly, main parts of the FSW machine was designed and calculated, the calculation results shows that the FSW machine designed in the paper can accord with the demand of the testing in laboratory. The advantage of this machine is that it is more efficient than the normal FSW machine because it has a twin-stir.Compared with other machine,it is also very cheap and easy-to-use. Key words：Twin-stir Friction welding；Solid phase welding；Aluminum alloys welding；Application prospect；Welding machine design 目 錄 摘 要 Abstract 第 1 章 緒論 ..................................................................................................................1 1.1 攪拌摩擦焊簡(jiǎn)介 ........................................................1 1.2 國(guó)內(nèi)外研究現(xiàn)狀及發(fā)展趨勢(shì) ..............................................2 1.2.1 攪拌摩擦焊技術(shù)發(fā)展歷史及研究成果 .................................................................2 1.2.2 國(guó)內(nèi)攪拌軸摩擦焊技術(shù)發(fā)展發(fā)展應(yīng)用 ................................................................3 1.2.3 攪拌摩擦焊中雙攪拌軸摩擦焊技術(shù)目前的應(yīng)用情況和前景 .............................5 1.3 本次設(shè)計(jì)的內(nèi)容和意義 ..................................................6 第 2 章 雙攪拌軸攪拌摩擦焊機(jī)設(shè)計(jì) ..........................................................................7 2.1 焊機(jī)的總體設(shè)計(jì)以及規(guī)劃 ................................................7 2.2 各部件設(shè)計(jì) ............................................................8 2.2.1 攪拌頭及夾具設(shè)計(jì) ................................................................................................8 2.2.2 攪拌系統(tǒng)功率計(jì)算 ................................................................................................9 2.2.3 攪拌系統(tǒng)傳動(dòng)齒輪設(shè)計(jì) .......................................................................................11 2.2.4 攪拌軸的設(shè)計(jì) .......................................................................................................15 2.2.5 攪拌系統(tǒng) V 帶設(shè)計(jì) ...............................................................................................20 2.2.6X-Y 工作臺(tái)設(shè)計(jì) .....................................................................................................26 2.2.7 傳動(dòng)絲杠設(shè)計(jì) .......................................................................................................27 2.2.8 減速齒輪的設(shè)計(jì) ...................................................................................................30 2.2.9 液壓缸選擇 ...........................................................................................................33 第 3 章 AUTOCAD 與 PRO/E 軟件簡(jiǎn)介 .........................................................................34 3.1 軟件簡(jiǎn)介 .........................................................................................................................34 3.2 三維模型 .........................................................................................................................35 第 4 章 總結(jié)與展望 ....................................................................................................37 參考文獻(xiàn) ...................................................................................................................38 致 謝 ........................................................................................................................39 浙江理工大學(xué)本科畢業(yè)設(shè)計(jì)（論文）文獻(xiàn)綜述報(bào)告
班 級(jí)
機(jī)械設(shè)計(jì)制造及其自動(dòng)化09(4)班
姓 名
陳偉杰
課題名稱(chēng)
雙攪拌軸攪拌摩擦焊機(jī)設(shè)計(jì)
文獻(xiàn)綜述（內(nèi)容包括國(guó)內(nèi)外本課題及相關(guān)研究現(xiàn)狀、分析及參考文獻(xiàn)目錄，字?jǐn)?shù)不少于2000字）
目 錄
1 前言
2 攪拌摩擦焊發(fā)展歷史及研究成果
3 國(guó)內(nèi)攪拌軸摩擦焊發(fā)展及應(yīng)用
4 攪拌摩擦焊縫中雙攪拌軸攪拌摩擦焊目前的應(yīng)用情況和前景
5 總結(jié)部分
參考文獻(xiàn)
（報(bào)告全文附后）
指導(dǎo)
教師
審批
意見(jiàn)
簽名：
年 月 日
雙攪拌軸攪拌摩擦焊機(jī)設(shè)計(jì)
陳偉杰(機(jī)械設(shè)計(jì)制造及其自動(dòng)化09(4)班 B09300405)
1 前言
1991年．?dāng)嚢枘Σ梁?Friction stir Welding．FSW)由英國(guó)焊接研究所(The Welding lnstirate-TWl)發(fā)明，這項(xiàng)杰出的焊接技術(shù)一步一步地為世界制造技術(shù)的進(jìn)步做出了巨大的貢獻(xiàn)。
自1991年攪拌摩擦焊(Friction stir Welding．FSW)被發(fā)明到現(xiàn)在，該項(xiàng)技術(shù)已經(jīng)在國(guó)內(nèi)外的眾多領(lǐng)域出現(xiàn)它的身影。如今，攪拌摩擦焊焊已經(jīng)在諸多制造領(lǐng)域（船舶、軌道列車(chē)、航天、航空、汽車(chē)、兵器、電子電力等）達(dá)到規(guī)?；?、工業(yè)化的應(yīng)用水平。如在船舶制造領(lǐng)域，在1996年攪拌摩擦焊就在挪威MARINE公司成功地應(yīng)用在鋁臺(tái)金快速艦船的甲板、側(cè)板等結(jié)構(gòu)件的流水線(xiàn)制造。在軌道車(chē)輛制造領(lǐng)域，日本HITACHI公司首先于1997年將攪拌摩擦焊技術(shù)應(yīng)用于列車(chē)車(chē)體的快速低成本制造。成功實(shí)現(xiàn)了大壁板鋁合金型材的工業(yè)化制造．在世界宇航制造領(lǐng)域．?dāng)嚢枘Σ梁敢呀?jīng)成功代替熔焊實(shí)現(xiàn)了大型空間運(yùn)載工具如運(yùn)載火箭和航天飛機(jī)等的大型高強(qiáng)鋁合金燃料貯箱的制造，波音公司的DELTA II型和Iv型火箭已經(jīng)全部實(shí)現(xiàn)了攪拌摩擦焊制造t并于1999年首次成功發(fā)射升空。2000年世界汽車(chē)工業(yè)，如美國(guó)TOWER汽車(chē)公司等就利用攪拌摩擦焊實(shí)現(xiàn)了汽車(chē)懸掛支架、輕合金車(chē)輪、防撞緩沖器、發(fā)動(dòng)機(jī)安裝支架以及鋁合金車(chē)身的焊接。2002年8月，美國(guó)月蝕航空公司利用FSW技術(shù)研制出了全攪拌摩擦焊輕型商用飛機(jī)，并且首次試飛成功．
至2004年9月，全世界約有130家各個(gè)行業(yè)的公司和大學(xué)、研究機(jī)構(gòu)獲得了英國(guó)焊接研究所授權(quán)的攪拌摩擦焊非獨(dú)占性專(zhuān)利許可。英國(guó)、美國(guó)、法國(guó)、德國(guó)、瑞典、日本和中國(guó)等先后獲得了該專(zhuān)利的使用權(quán)。至今為止我國(guó)先后已經(jīng)有二十多家單位。獲得了該項(xiàng)專(zhuān)利的使用權(quán)。
雙攪拌軸摩擦焊縫技術(shù)作為攪拌摩擦焊技術(shù)的一種，它的最大特點(diǎn)就是可以提高生產(chǎn)效率。同時(shí)，它也可以使得焊縫區(qū)域更大，焊接質(zhì)量更高。目前存在的雙攪拌軸一般采用兩個(gè)轉(zhuǎn)動(dòng)相反的攪拌頭同時(shí)進(jìn)行焊接。
在不久的將來(lái)，攪拌摩擦焊技術(shù)將會(huì)一直以任何一種焊接方法無(wú)法比擬的速度發(fā)展，在更多的領(lǐng)域發(fā)揮著它的作用。
2 攪拌摩擦焊縫技術(shù)發(fā)展歷史及研究成果
（1）攪拌摩擦焊的工作過(guò)程及其優(yōu)缺點(diǎn)
攪拌摩擦焊作為一項(xiàng)新型焊接方法，在很短的時(shí)間內(nèi)完成了從發(fā)明到工業(yè)化應(yīng)用的歷程。目前，在國(guó)際上還沒(méi)有針對(duì)攪拌摩擦焊公布的統(tǒng)一技術(shù)術(shù)語(yǔ)標(biāo)準(zhǔn)，在攪拌摩擦焊專(zhuān)利許可協(xié)會(huì)的影響下，業(yè)界已經(jīng)對(duì)攪拌摩擦焊方法中所涉及到的通用技術(shù)術(shù)語(yǔ)進(jìn)行了定義和認(rèn)可。圖（1）為攪拌摩擦焊需要用到的主要描述性術(shù)語(yǔ)。
圖（1）攪拌摩擦焊
攪拌摩擦焊技術(shù)所涉及到的主要技術(shù)術(shù)語(yǔ)定義如下：
攪拌頭(Pin tool)一攪拌摩擦焊的施焊工具：
攪拌頭軸肩(Tool Shoulder)一攪拌頭與工件表面接觸的肩臺(tái)部分；
攪拌針(Tool Pin)一攪拌頭插入工件的部分：
前進(jìn)側(cè)(Advanced Side)一焊接方向與攪拌頭軸肩旋轉(zhuǎn)方向一致的焊縫側(cè)面；
回轉(zhuǎn)側(cè)(Retreating Side)一焊接方向與攪拌頭軸肩旋轉(zhuǎn)方向相反的焊縫側(cè)面；
軸向壓力(Down or Axial Force)一向攪拌頭施加的使攪拌針插入工件和保持?jǐn)嚢桀^軸肩與工
件表面接觸的壓力；
下面本文就根據(jù)這些術(shù)語(yǔ)來(lái)說(shuō)明一下攪拌摩擦焊的工作過(guò)程：攪拌摩擦焊過(guò)程中，一個(gè)柱形帶特殊軸肩和針凸的攪拌頭旋轉(zhuǎn)著緩慢插入被焊接工件，攪拌頭和被焊接材料之間的摩擦剪切阻力產(chǎn)生了摩擦熱，使攪拌頭鄰近區(qū)域的材料熱塑化(焊接溫度一般不會(huì)達(dá)到和超過(guò)被焊接材料的熔點(diǎn))，當(dāng)攪拌頭旋轉(zhuǎn)著向前移動(dòng)時(shí)，熱塑化的金屬材料從攪拌頭的前沿向后沿轉(zhuǎn)移，并且在攪拌頭軸肩與工件表層摩擦產(chǎn)熱和鍛壓共同作用下，形成致密固相連接接頭。
相對(duì)于以前的電弧焊、激光焊、電子束焊等，攪拌摩擦焊的適應(yīng)性更強(qiáng)，它可以焊接所有類(lèi)型的鋁合金材料，由于攪拌摩擦焊接過(guò)程較低的焊接溫度和較小的熟輸入，一般攪拌摩擦焊接頭具有變形小、接頭性能優(yōu)異等特點(diǎn)；可以焊接目前熔焊“不能焊接”和所謂“難焊”的金屬材料如：AI．Cu(2xxx系列)、AI-Zn(7xxx系列)和Al—Li(如8090、2090和2195鋁合金)等鋁合金。但是攪拌摩擦也具有其局限性，例如：弧焊相比，缺少焊接操作的柔性；不能實(shí)現(xiàn)添絲焊接。
（2） 攪拌摩擦焊的發(fā)展
攪拌摩擦焊在其發(fā)明初期主要解決厚度1.2毫米的鋁合金板材焊接問(wèn)題；1996年，用FSW技術(shù)解決了6～12毫米的鋁、鎂、銅合金的連接．1997年實(shí)現(xiàn)了12-25毫米厚鋁合金板的攪拌摩擦焊．并且在宇航結(jié)構(gòu)件上得到應(yīng)用。1999年攪拌摩擦焊可以焊接50毫米厚的銅合金及75毫米厚度的鋁合金零件和產(chǎn)品。2004年，英國(guó)焊接研究所已經(jīng)能夠單道單面實(shí)現(xiàn)100毫米厚鋁合金板材的攪拌摩擦焊。迄今，在材料的厚度上，單道焊可以實(shí)現(xiàn)厚度為0.8～100mm鋁合金材料的焊接：雙道焊可以焊接180mm厚的對(duì)接板材。最近，又開(kāi)發(fā)了可以連接0.4mm鋁板的微型攪拌摩擦焊技術(shù)。
攪拌摩擦作為一種優(yōu)選焊接技術(shù)，已經(jīng)在從技術(shù)研究向高層次的工程化和工業(yè)化應(yīng)用階段發(fā)展。就拿國(guó)外的例子來(lái)說(shuō)：在美國(guó)的宇航制造工業(yè)、北歐的船舶制造工業(yè)、日本的高速列車(chē)制造等制造領(lǐng)域?？傊?dāng)嚢枘Σ梁敢呀?jīng)廣泛地涉及到了在船舶制造工業(yè)、航空航天工業(yè)、軌道交通及陸路交通工業(yè)、汽車(chē)工業(yè)以及兵器、建筑、電力、能源、家電等工業(yè)。
（3）攪拌摩擦焊在近年來(lái)各個(gè)領(lǐng)域取得的成就
（a）攪拌摩擦焊在船舶制造工業(yè)上的應(yīng)用
船用鋁合金采用攪拌摩擦焊可以克服其在熔焊時(shí)產(chǎn)生氣孔、裂紋等缺陷且獲得優(yōu)良的焊接接頭。目前攪拌摩擦焊在船用鋁合金的焊接方面研究應(yīng)用較多，幾乎可以焊接所有系列的鋁合金材料，已經(jīng)成功地進(jìn)行了攪拌摩擦焊的鋁合金材料包括2000系列、5000系列、6000系列、7000系列、8000系列等。對(duì)于異種材料的連接，如2024／6061、2040／7075等不同牌號(hào)鋁合金材料，攪拌摩擦焊也具有較大的優(yōu)越性，還可以實(shí)現(xiàn)鋁合金與銅合金、鋁合金與鎂合金等不同材料的焊接。另外，攪拌摩擦焊與普通摩擦焊相比，因不受軸類(lèi)零件的限制，可焊接直焊縫、角焊縫。傳統(tǒng)焊接工藝焊接鋁合金時(shí)要求對(duì)表面進(jìn)行去除氧化膜處理，并要求在48 h內(nèi)進(jìn)行焊接，而攪拌摩擦焊工藝只要在焊前去除油污即可，并對(duì)裝配要求不高。因此，攪拌摩擦焊是船用鋁合金結(jié)構(gòu)首選的連接技術(shù)。
（b）攪拌摩擦焊在航天航空工業(yè)上的應(yīng)用
在航空制造工業(yè)領(lǐng)域，攪拌摩擦焊作為飛機(jī)輕合金結(jié)構(gòu)制造技術(shù)的一種發(fā)展趨勢(shì)還處于研究開(kāi)發(fā)以及工程化階段。但是以英國(guó)焊接研究所、波音、空客以及美國(guó)月蝕公司為代表的攪拌摩擦焊技術(shù)開(kāi)發(fā)和應(yīng)用的先鋒。已經(jīng)取得了豐碩的成果。近期的研究結(jié)果表明。攪拌摩擦焊可以在飛機(jī)機(jī)翼結(jié)構(gòu)、翼盒結(jié)構(gòu)、機(jī)身結(jié)構(gòu)、艙門(mén)結(jié)構(gòu)、裙翼結(jié)構(gòu)、機(jī)艙氣密隔板以及貨物裝卸結(jié)構(gòu)等方面得到應(yīng)用。
總而言之，在航天航空工業(yè)上，攪拌摩擦焊由于技術(shù)發(fā)展歷程較短還存在許多問(wèn)題和許多可以進(jìn)步的空間。
（c）攪拌摩擦焊在高速列車(chē)鋁合金焊接的應(yīng)用
在攪拌摩擦焊之前，在焊接高速列車(chē)時(shí)一般采用熔化焊（激光一MIG復(fù)合焊和雙絲MIG雙弧焊）。在攪拌摩擦焊出現(xiàn)后，攪拌摩擦焊由于是一種無(wú)需外加焊接材料的焊接方法，因此沒(méi)有熔化焊接時(shí)選擇焊接材料的困難，也節(jié)省了焊材費(fèi)用。更重要的是沒(méi)有熔化焊接凝固時(shí)的一次結(jié)晶過(guò)程，克服了焊接高強(qiáng)鋁合金時(shí)的結(jié)晶裂紋、氣孔和夾雜傾向，不會(huì)產(chǎn)生焊縫塌陷問(wèn)題，也不會(huì)形成焊縫鑄造組織和低強(qiáng)區(qū)。有資料介紹，攪拌摩擦焊的焊接接頭與熔化焊接頭相比，在常溫和深冷狀態(tài)下的抗拉強(qiáng)度、沖擊韌度和疲勞強(qiáng)度都要提高30％一50％。
（d）攪拌摩擦焊在其他領(lǐng)域的應(yīng)用
攪拌摩擦焊除了上述3個(gè)領(lǐng)域外，還在軌道交通及陸路交通工業(yè)、汽車(chē)工業(yè)在兵器、建筑、電力、能源、家電等工業(yè)中的應(yīng)用也越來(lái)越廣泛。而且都取得了或多或少的成就。
（4） 攪拌摩擦焊的攪拌頭的現(xiàn)狀和發(fā)展趨勢(shì)
對(duì)于攪拌摩擦焊來(lái)講，它的最大優(yōu)勢(shì)就體現(xiàn)在它的攪拌頭上，所以這里不能不提及攪拌頭的現(xiàn)狀和發(fā)展趨勢(shì)。
攪拌頭是攪拌摩擦焊的關(guān)鍵,最優(yōu)攪拌頭是攪拌摩擦焊獲得高質(zhì)量接頭的前提。攪拌頭主要由軸肩和攪拌針兩部分構(gòu)成,其幾何形貌和尺寸不僅決定著焊接過(guò)程的熱輸入方式,還影響焊接過(guò)程中攪拌頭附近塑性軟化材料的流動(dòng)形式,對(duì)于給定板厚的材料來(lái)說(shuō),焊接質(zhì)量和效率主要取決于攪拌頭的形貌和幾何設(shè)計(jì)。
（a） 攪拌頭軸肩的現(xiàn)狀
軸肩在焊接過(guò)程中主要起兩種作用: ①通過(guò)與工件表面間的摩擦,提供焊接熱源; ②提供一個(gè)封閉的焊接環(huán)境,以阻止高塑性軟化材料從軸肩溢出。
圖（2）常見(jiàn)攪拌頭軸肩的類(lèi)型
圖（2）為常見(jiàn)的幾種軸肩形狀，。在焊接過(guò)程中,這種設(shè)計(jì)形式可保證軸肩端部下方的軟化材料受到向內(nèi)方向的力的作用,從而有利于將軸肩端部下方形成的軟化材料收集到軸肩端面的中心以添充攪拌針后方所形成的空腔,同時(shí),可減少焊接過(guò)程中攪拌頭內(nèi)部的應(yīng)力集中而保護(hù)攪拌針。
（b)攪拌頭的攪拌針的現(xiàn)狀
攪拌針在焊接過(guò)程中不僅通過(guò)與接合面間的摩擦來(lái)提供熱輸入,更重要的是起到機(jī)械攪拌作用,因而攪拌針的形貌和幾何尺寸影響著塑性軟化材料的流動(dòng)形式和被切削材料的體積,進(jìn)而影響接頭的力學(xué)性能。下面我們結(jié)合幾張圖來(lái)分析下幾種典型的攪拌頭：
（1）柱形攪拌頭
圖（3）為柱形攪拌頭，在攪拌摩擦焊工藝應(yīng)用的初始階段,柱形攪拌針應(yīng)用得較為廣泛,然而在焊接過(guò)程中,柱形攪拌針周?chē)能浕牧鲜艿街赶蚝缚p根部的力較弱,軟化材料的流動(dòng)性較差。
此種攪拌頭存在一下幾種問(wèn)題：(1) 耐沖擊力弱,即在焊接行走的起始瞬間攪拌針容易在針的根部斷裂，圖(3) 焊后接頭性能較差。
圖（3）柱形攪拌頭
（2）錐形螺紋攪拌針和三槽錐形螺紋攪拌針
錐形螺紋攪拌 針和三槽錐形螺紋攪拌針的共同之處是它們都呈平截頭體狀(或玻璃杯狀) ,而且都帶有螺紋。在攪拌針根部直徑相同時(shí),平截頭體狀攪拌針切削的材料比柱形的少。另外,平截頭體形狀攪拌針上的螺紋能促進(jìn)攪拌頭附近的塑性軟化材料具有向上運(yùn)動(dòng)的趨勢(shì)。如下圖（4）所示，左側(cè)為錐形螺紋攪拌針，右側(cè)為三槽錐形螺紋攪拌針
圖（4）錐形攪拌頭
（3） 外開(kāi)螺紋攪拌針
外開(kāi)螺紋攪拌針(圖5） 在靠近軸肩部分是平截頭體狀攪拌針的端部是一個(gè)三叉樣的攪拌器。這樣的形特征都是為了增加攪拌針掃過(guò)體積與攪拌針靜態(tài)體積間的差值(即增大動(dòng)、靜態(tài)體積比) ,改善軟化材料沿?cái)嚢栳槀?cè)面環(huán)向流動(dòng)路徑。外開(kāi)螺紋攪拌針適合搭
接焊和“T”形接頭焊接。
外開(kāi)螺紋攪拌針有以下特點(diǎn)：（1）提高焊接速度；（2）塔焊接時(shí)，焊接壓力減少20 % ,可明顯減少軸肩于焊縫表面上的壓入量,有效提高接頭的承載能力;（3）軟化材料流動(dòng)時(shí)的混合動(dòng)作。
圖（5）外開(kāi)螺紋攪拌針
（4）其他
除了上述三種典型的攪拌頭，攪拌摩擦焊現(xiàn)有的還有偏心圓攪拌針和偏心圓螺紋攪拌針、非對(duì)稱(chēng)攪拌針、可伸縮式攪拌針、用于搭接的兩級(jí)攪拌針。
3 國(guó)內(nèi)攪拌軸摩擦焊技術(shù)發(fā)展和應(yīng)用
2002年，北京航空制造工程研究所與英國(guó)焊接研究所正式簽署攪拌摩擦焊專(zhuān)利許可協(xié)議，并在技術(shù)合作的基礎(chǔ)上成立了中國(guó)攪拌摩擦焊中心。中國(guó)攪拌摩擦焊中心的成立標(biāo)志著攪拌摩擦焊技術(shù)正式登陸中國(guó)。中國(guó)攪拌摩擦焊中心全權(quán)代表英國(guó)焊接研究所，發(fā)售和管理中國(guó)地區(qū)(包括香港、澳門(mén)和臺(tái)灣)的攪拌摩擦焊技術(shù)專(zhuān)利許可，從此為攪拌摩擦焊技術(shù)在中國(guó)地區(qū)的發(fā)展、推廣和工業(yè)化應(yīng)用打開(kāi)了大門(mén)。
圖（6）采用攪拌摩擦焊焊接的鋁合金材壁機(jī)
圖（7）攪拌摩擦加工技術(shù)的發(fā)展
自攪拌摩擦焊進(jìn)入國(guó)內(nèi)后，較快的運(yùn)用于我國(guó)工業(yè)上的許多領(lǐng)域（船舶制造行業(yè)、航天制造工業(yè)、軌道交通行業(yè)等），這也主要取決于攪拌摩擦焊的技術(shù)優(yōu)勢(shì)。
攪拌摩擦焊的技術(shù)優(yōu)勢(shì)有以下幾點(diǎn)：
（1） 攪拌摩擦焊徹底解決了鋁合金的焊接性問(wèn)題：采用攪拌摩擦焊可以焊接所有系列的鋁合金，不存在常規(guī)焊缺陷，徹底解決了鋁合金的焊接性問(wèn)題。
（2） 攪拌摩擦焊為工業(yè)產(chǎn)品的設(shè)計(jì)提供了新的思路和途徑：攪拌摩擦焊不僅可以實(shí)現(xiàn)同種材料的連接，也可以實(shí)現(xiàn)異種材料的焊接，如鎂鋁、鋁鋼等，甚至可以將不同狀態(tài)的材料焊接在一起。
（3） 攪拌摩擦焊可以提升產(chǎn)品質(zhì)量和性能：攪拌摩擦焊接頭力學(xué)性能普遍優(yōu)于熔焊接頭，因而可以提高產(chǎn)品的質(zhì)量和性能。
（4） 攪拌摩擦焊可以降低產(chǎn)品成本、提高生產(chǎn)效率：由于攪拌摩擦焊無(wú)需填絲和保護(hù)氣，焊接過(guò)程無(wú)弧光輻射，是真正的綠色制造技術(shù)，在批量生產(chǎn)中可以節(jié)省成本和費(fèi)用
攪拌摩擦焊在國(guó)內(nèi)的應(yīng)用現(xiàn)狀，主要通過(guò)船舶制造行業(yè)、航天制造工業(yè)兩方面來(lái)介紹。首先在船舶制造行業(yè)，2006年4月，我國(guó)設(shè)計(jì)制造了國(guó)內(nèi)第一臺(tái)用于大型船用型材料拼焊的攪拌摩擦焊設(shè)備，此后，中國(guó)攪拌摩擦焊中心大力發(fā)展鋁合金型材壁板的攪拌摩擦焊制造。其次，攪拌摩擦焊在航天制造工業(yè)也發(fā)揮著重大的作用。目前，國(guó)內(nèi)對(duì)于2000系列、7000系列以及鋁鋰合金的材料制成的太空交通運(yùn)載工具都優(yōu)先采用攪拌摩擦焊。中國(guó)攪拌摩擦焊中心于‘十五’期間重點(diǎn)對(duì)航天運(yùn)載火箭攪拌摩擦焊開(kāi)展了系統(tǒng)的科研攻關(guān)，國(guó)內(nèi)的航天制造工業(yè)企業(yè)也積極采用了攪拌摩擦焊技術(shù)。 除卻上述的兩個(gè)領(lǐng)域外，攪拌摩擦焊在國(guó)內(nèi)還廣泛應(yīng)用于汽車(chē)制造業(yè)、軌道交通行業(yè)、電子電力能源行業(yè)。
上圖（7）為攪拌摩擦焊在國(guó)內(nèi)的發(fā)展趨勢(shì)。隨著攪拌摩擦焊研究、技術(shù)開(kāi)發(fā)與應(yīng)用推廣的不斷深入，基于攪拌摩擦的基本原理形成了材料鏈接、材料改姓、材料成行等多種材料加工方法。
總之，在中國(guó)，攪拌摩擦焊的研究、開(kāi)發(fā)和推廣應(yīng)用才剛剛起步，在市場(chǎng)化的環(huán)境下，通過(guò)引進(jìn)、消化、吸收和技術(shù)創(chuàng)新，攪拌摩擦得到了快速發(fā)展，尤其在航空、航天等領(lǐng)域、在國(guó)家政策和項(xiàng)目的支持下，攪拌摩擦焊必將在我國(guó)其他工業(yè)領(lǐng)域得到較快的推廣。
4 攪拌摩擦焊縫中雙攪拌軸攪拌摩擦焊目前的應(yīng)用情況和前景
1.雙攪拌軸攪拌摩擦焊的原理
雙頭攪拌摩擦焊(Twin-stir FSW)采用兩個(gè)轉(zhuǎn)動(dòng)相反的攪拌頭同時(shí)進(jìn)行焊接，由于兩個(gè)攪拌頭轉(zhuǎn)動(dòng)方向相反，產(chǎn)生的工作扭矩因相互抵消而減弱，焊接過(guò)程中采用較小的側(cè)向裝夾力就能實(shí)現(xiàn)可靠的連接。在雙攪拌頭復(fù)雜的機(jī)械力和摩擦熱的作用下，塑性金屬的流動(dòng)、焊接溫度場(chǎng)、應(yīng)力應(yīng)變場(chǎng)都將受到影響，這會(huì)對(duì)焊件性能產(chǎn)生很大的影響。下圖（8）為雙攪拌頭的一張結(jié)構(gòu)圖
2.雙攪拌摩擦焊縫的特點(diǎn)及其現(xiàn)有的種類(lèi)
圖（8）為一個(gè)電機(jī)帶動(dòng)的雙攪拌軸的三維裝配圖
（1）平行并列式雙頭(Parallel Twin-stir)攪拌摩擦焊，該方式采用兩個(gè)轉(zhuǎn)向相反的攪拌頭，按照平行并列方式排布，一同沿焊接方向移動(dòng)。這種工藝方法最適合用于焊接搭接接頭，它可以使搭接焊的缺陷出現(xiàn)在兩個(gè)焊縫之間。
（2）前后交錯(cuò)排列式雙頭(Staggered Twin-stir)攪拌摩擦焊，該方式沿焊接方向，兩個(gè)攪拌頭前后交錯(cuò)排列，并非與焊縫中心線(xiàn)平行，采用這種方式可以形成更寬的焊縫區(qū)域。兩個(gè)攪拌頭重疊區(qū)域的氧化膜將得到更好的破碎和彌散性分布。該方法的突出之處在于第二個(gè)攪拌頭位置可調(diào)，可以覆蓋前方攪拌頭的焊接區(qū)域，消除焊縫減薄。且焊縫區(qū)晶粒細(xì)化，氧化膜破碎完全，呈彌散分布。
（3）前后一字排列式雙頭(Tandem Twin-stir)攪拌摩擦焊，該方式按焊接方向，兩個(gè)攪拌頭一前一后排布，轉(zhuǎn)向相反。這種方式適用于所有FSW接頭形式，后面攪拌頭的主要作用在于對(duì)前面攪拌頭焊接后的殘留氧化膜進(jìn)行完全破碎，提高了焊接接頭質(zhì)量。這樣做的另一個(gè)優(yōu)勢(shì)是由于前面攪拌頭的作用下材料已經(jīng)軟化了，降低了對(duì)后方跟進(jìn)的攪拌頭的要求。
3.雙攪拌軸摩擦焊取得得成就
TWI采用雙攪拌軸進(jìn)行了雙頭攪拌摩擦焊焊接，試驗(yàn)中得出了在6mm厚6082-T6鋁合金一字排列式雙頭攪拌摩擦焊搭接接頭中，無(wú)論前進(jìn)側(cè)還是后退側(cè)的焊縫區(qū)域殘留氧化物均有所減少，前后交錯(cuò)排列式雙頭攪拌摩擦焊3mm厚5083-H111鋁合金搭接接頭的金相分析表明，焊接區(qū)域尺寸可達(dá)板厚度的4.3倍。
在一系列的試驗(yàn)后，事實(shí)證明了雙攪拌軸摩擦焊的優(yōu)點(diǎn)遠(yuǎn)遠(yuǎn)大于其不足之處。多頭系統(tǒng)可以確保在較小的扭矩下實(shí)現(xiàn)材料的可靠連接。采用 前后交錯(cuò)排列式雙頭攪拌摩擦焊工藝，用于材料加工和搭接焊具有獨(dú)特優(yōu)勢(shì)，而且可以在更大的對(duì)接間隙下實(shí)現(xiàn)對(duì)接接頭的可靠連接。
由此，在接下來(lái)的幾年內(nèi)，雙攪拌軸摩擦焊縫技術(shù)將會(huì)得到越來(lái)越廣泛的應(yīng)用于各個(gè)領(lǐng)域。
5 總結(jié)部分
(1) 攪拌摩擦自從誕生以來(lái)，憑借這先進(jìn)固態(tài)連接技術(shù)的優(yōu)勢(shì)正廣泛應(yīng)用于航天、汽車(chē)等鋁合金結(jié)構(gòu)件的連接制造領(lǐng)域，很大程度上取代了先前的焊熔方法，經(jīng)濟(jì)效益顯著。
(2) 我國(guó)在近年來(lái)對(duì)于攪拌摩擦焊的基礎(chǔ)方法研究、工程開(kāi)發(fā)等方面也越來(lái)越重視，一定程度上推進(jìn)了攪拌摩擦焊在我國(guó)制造領(lǐng)域業(yè)的快速發(fā)展。攪拌摩擦焊的設(shè)備和工藝也得到了不同程度的進(jìn)步。
(3) 攪拌摩擦焊憑借著在方法、材料、性能和效率、成本、環(huán)保等方面顯示出的優(yōu)越性，大大地促進(jìn)了在我國(guó)航空、航天、船舶、列車(chē)、電力等工業(yè)制造行業(yè)中的大規(guī)模工程化應(yīng)用，具有非常好的應(yīng)用前景。
(4) 雙攪拌軸摩擦焊縫技術(shù)雖然現(xiàn)在還未大面積被使用，但是在不久的將來(lái)，它將憑借著比攪拌摩擦焊更寬的焊縫區(qū)域，更高的焊接質(zhì)量，更高的生產(chǎn)效率將會(huì)使得它得到更加廣泛的應(yīng)用。
(5) 總體而言，攪拌摩擦焊以及雙攪拌軸摩擦焊縫技術(shù)將在未來(lái)發(fā)展中發(fā)揮出越來(lái)越多的優(yōu)勢(shì)。
參考文獻(xiàn)
[1] 中國(guó)機(jī)床商務(wù)網(wǎng) http://www.jic35.cn/Tech_news/Detail/3970.html
[2]鄢東洋.史清宇.吳愛(ài)萍.Juerqen Silvanus 攪拌摩擦焊應(yīng)力變形有限元模擬的研究進(jìn)展[期刊論文]-焊接 2009(1)
[3]李光.李從卿.欒國(guó)紅.董春林薄壁鋁合金攪拌摩擦焊焊接應(yīng)力變形與控制[期刊論文]-焊接 2009(1)
[4]張友壽.何建軍.謝志強(qiáng).蔣蔚翔攪拌摩擦焊接技術(shù)基礎(chǔ)及其工程應(yīng)用[期刊論文]-材料導(dǎo)報(bào) 2008(1)
[5]董春林 欒國(guó)紅 攪拌摩擦焊在中國(guó)應(yīng)用發(fā)展現(xiàn)狀概述-北京航空制造工程研究所
[6]欒國(guó)紅;柴鵬;孫成斌鈦合金的攪拌摩擦焊探索[期刊論文]-焊接學(xué)報(bào) 2005(11)
[7]柯黎明 攪拌摩擦焊工藝及其應(yīng)用[期刊論文]-工藝與新技術(shù) 2000(02)
[8]關(guān)橋輕金屬材料結(jié)構(gòu)制造中的攪拌摩擦焊技術(shù)與焊接變形控制[期刊論文]-航空科學(xué)技術(shù) 2005(04)
[9]J. J. Vagi, R. P. Meister, and M. D. Randall, DMIC Report 244, Defense Metals Information Center, Battelle Memorial Institute, August 1968.
[10]Terry Khaled, Ph.D. USA AN OUTSIDER LOOKS AT FRICTION STIR WELDING
[11]R.S. Mishraa,*, Z.Y. Mab USA FIRCTION STIR WELDING AND PROCESSING
[12] Hassan Kh A A , Norman A F. Stability of nugget zone grain structures in high strength Al alloy friction stir welds during solution treatment. Acta Materialia , 2003 , 51 (8) : 1 923～1 936
外 文 翻 譯
畢業(yè)設(shè)計(jì)題目： 雙攪拌軸攪拌摩擦焊機(jī)設(shè)計(jì)
原文1： AN OUTSIDER LOOKS AT FRICTION STIR WELDING
譯文1： 常人眼中的摩擦攪拌焊接技術(shù)
原文2： FIRCTION STIR WELDING AND PROCESSING
譯文2： 摩擦攪拌焊接技術(shù)及其發(fā)展過(guò)程
(原文1)
AN OUTSIDER LOOKS AT FRICTION STIR WELDING
BACKGROUND
4.1 Solid State Welding, Overview 2-4
FSW, the subject matter of this document, is the newest addition to friction welding (FRW), a solid state welding process. Solid state welding, as the term implies, is the formation of joints in the solid state, without fusion. Solid state welding includes processes such as cold welding, explosion welding, ultrasonic welding, roll welding, forge welding, coextrusion welding and FRW. Conventional FRW in its simplest form involves two axially aligned parts, one rotating and the other stationary. The stationary part is advanced to make contact with the other, at which point an axial force is applied and maintained to generate the frictional heat required to affect welding at the abutting surfaces and form a solid-state joint. The joint is achieved by upset forging at the elevated temperatures generated by friction. There are two FRW techniques. The first is direct / continuos drive FRW, where constant energy is provided by a source for the desired duration. The second is inertia drive FRW, where a rotating flywheel provides the required energy. A variant of the conventional techniques, radial friction welding, is used for hollow sections, such as tube and pipe. Here, a solid ring is rotated and compressed around the abutting beveled ends of the stationary pipes / tubes to be welded. A support mandrel is located at the bore, at the welding position, to prevent the collapse of the pipe / tube ends. Another variant is friction surfacing, where metal layers are deposited on a substrate. Here, a rotary consumable is brought into contact with a moving substrate to affect metal transfer from the consumable to the substrate.
4.2 Friction Stir (FS) Technology 5, 6
FSW is a member of the FS technology family. The other members of that family are FS processing for superplasticity, FS casting modification (also referred to as FTMP or friction thermomechanical processing), FS microforming, FS powder processing, FS channeling and FS processing for low temperature formability.
4.3 A Note on Aluminum Alloys
Since the majority of work reviewed in this document pertains to aluminum alloys, it is important to discuss some of the heat treatment aspects of these alloys. A three-step sequence is used to heat treat 2xxx, 6xxx and 7xxx series and other heat treatable aluminum alloys, to higher strength levels. The first step is solution heat treatment and it consists of heating to some prescribed elevated temperature (around 900 F) and soaking there for a prescribed period of time. The second step is to cool the alloy fast enough (e.g., by quenching), so as to retain the elevated temperature microstructure. As will become clear shortly, cold working, forming or straightening of quenched wrought alloys should be performed as soon as possible after quenching. The third step is aging (AKA precipitation heat treatment). Aging involves soaking the alloy for a period of time at some temperature that is lower than that used for solution treatment. For the aluminum alloys of concern here, aging is performed in the room temperature to 375 F temperature range. Aging at room temperature is referred to as natural aging. Aging at temperatures above room temperature is referred to as artificial aging. Aging causes precipitation within the grains, with the attendant increase in strength and hardness, at the expense ductility. Other properties also change as a result of aging.
4.3.1 Natural Aging
After quenching, the alloy is in the unstable -AQ temper. At room temperature, the alloy remains in that temper for a period that ranges from a few minuets to an hour or so, depending on the particular alloy. During that period, the solution treated microstructure remains as it was at the solution treatment temperature; i.e., remains unchanged. At the end of that period, the temper changes to the -W temper, also an unstable temper. This isaccompanied by changes in properties; e.g., the strength and hardness will increase and the ductility will decrease. As more precipitation occurs with time, the properties will progressively evolve; e.g., strength will progressively increase and ductility will progressively decrease with time. After a few days (or about 96 hr), 2xxx and 6xxx alloys reach a stable condition, referred to as the -T4 temper where no further property changes would take place. An additional increment of strength can be obtained in 2xxx alloys if the alloy is cold worked in the -AQ temper or during the early stages of the -W temper, and then naturally aged, for about 96 hr, to a stable condition referred to as the -T3 temper. While it is generally accepted that natural aging for 96 hr is sufficient to develop a stable temper (-T3 or -T4), it is reported, in FSW literature, that natural aging continues for over one month in AA 6013 7 and over 2.5 years in AA 2195. 8 The 7xxx alloys do not reach the stable -T3 and -T4 tempers. Rather, strength and other properties continue to evolve with time for years at room temperature; in fact, it is reported 9 that AA 7050 aluminum alloy age hardens indefinitely at room temperature. In other words, it should be assumed that 7xxx alloys remain in an unstable and evolving -W temper indefinitely, unless the alloy is artificially aged. Therefore, test results obtained in various 7xxx-W alloy investigations cannot be directly compared unless the periods of natural aging indicated (e.g., -W 0.5 hr) are the same. Unfortunately, however, researchers tend not to indicate these periods.
4.3.2 Artificial Aging
Aging at temperatures above room temperature is artificial aging. The properties constantly evolve with aging time at the aging temperature. For example, strength and hardness increase with time to some peak values, beyond which both strength and hardness decrease, with further increases in aging time; strength and hardness peaks may or may not occur at the same aging time. The decrease in strength and hardness is referred to as overaging. For a given alloy, the peak strength (hardness) values that can be achieved by artificial aging are higher than that achieved by natural aging. As the artificial aging temperature is increased, peak strength / hardness shifts to shorter times, and the loss of strength, due to overaging, occurs more rapidly. Peak strength may increase or decrease as the aging temperature increases, depending on the alloy and temperature range. Due to peak shift to shorter times and the more rapid overaging, precise time and temperature control is essential at the higher aging temperatures, to avoid undesirable overaging or underaging. []a In general, the -T4 or -W tempers maybe aged to the -T6 temper (2xxx and 6xxx alloys). The -T3 temper (2xxx alloys) maybe aged to -T8 temper. In 7xxx alloys, the -W temper may be directly aged to the -T6 or -T7 temper. Alternately, the -T6 temper may be artificially overaged to the -T7 temper. The -T7 type tempers are for enhanced corrosion performance, with some sacrifice in strength.
4.4 Abbreviations
Some abbreviations of a general nature are used throughout this document. These are presented alphabetically below, together with what they mean.
EDS: energy dispersive spectrometry. %e: percent tensile elongation. Ftu: ultimate tensile strength. Fty: tensile yield strength. GMAW: gas metal arc welding. GTAW: gas tungsten arc welding. NDI: nondestructive inspection. OM: optical microscope / microscopy. SEM: scanning electron microscope / microscopy. TEM: transmission electron microscope / microscopy.
5.0 INTRODUCTION TO FSW
A brief description of the FSW process for various types of joints is presented in 5.1. Some of the terms and conventions used in FSW are introduced in 5.2. FS welded joint profiles and the various weld zones encountered are detailed in 5.3. The issue of processing variables is tackled in 5.4. An attempt to outline the factors that control weld microstructures is presented in 5.5. Some advanced FSW concepts are discussed in 5.6. The topic of mechanical testing of welded joints is treated in 5.7.
5.1 Process Description
Brief process descriptions are given below for butt joints (5.1.1), lap joints (5.1.2) and other joint types (5.1.3). The contents of this section are based on the publications reviewed in this document. 5.1.1 Butt Joints: 4, 10-13
The two workpieces to be welded, with square mating (faying) edges, are fixtured (clamped) on a rigid backplate, Figure 1a. The fixturing prevents the workpieces from spreading apart or lifting during welding. The welding tool, consisting of a shank, shoulder and pin (Figure 1b), is then rotated to a prescribed speed and tilted with respect to the workpiece normal. The tool is slowly plunged into the workpiece material at the butt line, until the shoulder of the tool forcibly contacts the upper surface of the material and the pin is a short distance from the backplate (Figure 1c). A downward force is applied to maintain the contact and a short dwell time is observed to allow for the development of the thermal fields for preheating and softening the material along the joint line. At this point, a lateral force is applied in the direction of welding (travel direction) and the tool is forcibly traversed along the butt line (Figure 1 d), until it reaches the end of the weld; alternately, the workpieces could be moved, while the rotating tool remains stationary. Upon reaching the end of the weld, the tool is withdrawn, while it is still being rotated. As the pin is withdrawn, it leaves a keyhole at the end of the weld. Shoulder contact leaves in its wake an almost semi circular ripple in the weld track, as depicted schematically in Figure 1d.
As the tool is moved in the direction of welding, the leading edge of the pin, aided by certain other tool features, if present, forces the plasticized material, on either side of the butt line, to the back of the pin. In effect, the material
is transferred from the leading edge of the tool to the trailing edge of the pin (i.e., the material is being stirred) and is forged by the intimate contact of the shoulder and the pin profile. Some believe that the stirring motion tends to break up oxides on the faying surfaces, allowing bonding between clean surfaces. It should be noted that, in order to achieve full closure of the root, it is necessary for the pin to pass very close to the backplate, since only limited amount of deformation occurs below the pin, and then only close to the pin surface. An open root (lack of penetration) is a potential failure site. This aside, Figure 1c depicts that the tool axis and the workpiece normal are tilted with respect to each other by a small angle, θ, typically in the 2-4O range; this angle can be achieved by tilting either the tool or the workpieces. It is said that this tilting aids in the compaction of the material behind the tool, but it has the drawback of limiting the ability to execute nonlinear welds and can also limit the welding speed. 12
As a consequence of the FSW method, the start and end of the joint will not be fully welded, particularly at the end of the weld, where the keyhole is left. Furthermore, in FSW steel and other high melting alloys, a small-diameter hole is predrilled in the butt line, to lessen the forces acting on the welding tool during the plunge. It has been recommended, therefore, that the weld start and end regions be machined off. Even with the use of run-on run-off tabs, Ekman et al. 13 report that low joint strengths resulted at the workpiece / tab interfaces (Figure 2), necessitating the removal of material, approximately corresponding to the thickness of the workpiece, from either end.
5.1.2 Lap Joints 14-16
The same operational principles discussed above for butt joints apply to lap welds, except as follows. In a lap joint there is no butt line, where the tool can be plunged between the workpieces and, as such, the pin must penetrate through the top member. Furthermore, it is essential for the stirring motion to break up the scale, oxides and the other contaminants at the interface. This makes lap welds fundamentally different from butt welds. For butt welds, the primary stirring is in plane of the abutting surfaces being welded. By contrast, lap welds need out of plane stirring, across the interface of the two members being welded. This being so, Brooker et al. 14 indicate that the principal difference between a tool for lap welds and one for butt welds is the introduction of a second shoulder, located at the interface between the two details being welded (Figure 3). The lap joint publications reviewed in this document do not specifically indicate that predrilling of a start hole was required.
In lap joints, one must distinguish between the top and bottom members, since the former is in contact with the shoulder. The end of the pin must penetrate completely through the top member, and extend some distance into the bottom member. It is not required, however, that the pin end pass very close to the bottom of the bottom member, since, in contrast to butt joints, there is no root closure to be concerned about. Nevertheless, one must not underestimate the effect of the penetration distance into the lapped (bottom) member on the mechanical properties of the joint. The notches on either side of the joint (Figure 4) are potential sites for crack initiation and, as such, they have a profound effect on mechanical properties. In general, while lap joints are not as strong as butt joints, they have adequate static 14 and fatigue 16 properties to replace fastened joints.
5.1.3 Other Joint Types
FSW has been used to prepare spot joints with and without the end keyhole. Spot welds can be either of the butt or lap type. The specifics are presented in section 8. FSW has been also used to prepare T-joints 16 and corner joints, 17 Figure 5. Based on this figure, a T-joint could be viewed as a special lap joint and, as such, the notches on either side of the weld are potential crack initiation sites. Designing with T-joints is challenging, since care must be taken to avoid compression failure of the web (vertical member). Figure 5 suggests that a corner joint is in essence either a special butt joint (butt configuration) or a special lap joint (rabbet configuration). Apart from the above types of joint, FSW has been used to prepare, among others, fillet welds 18 and hem joints. 19 Not much technical information is published on the T, corner, fillet or hem joints and, as such, they will not be considered any further in this document.
5.2 Conventions & Terminology
Following the convention used by Colligan, 11 we define the advancing and retreating sides of a FS weld as follows. The side of the welding tool where surface motion (due to spinning) is in the same direction as the travel direction is referred to as the advancing side. The opposite side, where surface motion opposes the travel direction, is referred to as the retreating side. Some authors refer to the advancing and retreating sides as the shear and flow sides, respectively; this terminology, however, will not be used here. Figure 6 depicts the advancing and retreating sides in a butt weld, together with some other commonly used FSW terminology. As indicated in section 5.1.1, the tool and workpiece are tilted, by an angle θ, with respect to each other. Colligan 11 and Hirano et al. 18 indicate that the tilt is away from the travel direction, as shown in Figure 7. This tilt gives rise to a shoulder plunge, P, defined by Cederqvist et al., 15 as shown in Figure 7; P = 0.5 D sin θ, where D is the shoulder diameter. It is to be noted that the shoulder plunge defined above is for the case where the middle of tool contacts the workpiece; other researchers may use different approaches. The terms and definitions
discussed above and depicted in Figures 6 and 7 apply to all types of FS welded joints. However, the terms advancing and retreating sides, leading and trailing edges, and travel direction are not applicable to spot welds, since no travel is involved. The term joint profile is used throughout this document, for all types of joints. Joint profile is the shape of the outermost boundary of the weld that borders the base metal and it includes the face and root of the weld. Joint profile can be discerned by preparing a weld cross section, perpendicular to the length of the weld, and viewing it as shown in Figure 8 for butt and lap joints.
The terms face, root and toe of the weld, Figure 9, are used with butt joints and occasionally with other types of joints. The terms overmatching and undermatching, respectively, indicate a weld that is stronger than the base metal and a base metal that is stronger than the weld. The term penetration ligament is occasionally used in conjunction with FS welded butt joints. The penetration ligament, as defined by Ding and Oelgoetz, 20 is the distance from the tip (end) of the pin to the backside of the workpiece. Another term that appears in FS welded butt joints is the kissing bond. According to Oosterkamp et al., 21 a kissing bond is a descriptive term for two surfaces lying extremely close together, but not close enough for the majority of the original surface asperities to have deformed sufficiently to affect the formation of atomic bonds. Kissing bonds are extremely difficult to detect by most of the NDI methods that are commonly used for weld inspection. Depending on their location and extent, kissing bonds can have a detrimental effect on fatigue life, impact properties and through thickness load carrying capacity. A third term frequently used with butt joints is joint efficiency. Joint efficiency is defined as the ratio (Ftu)joint / (Ftu)base metal, expressed as a percentage. The ultimate strength of the base metal must be obtained in the same direction in which the joint is tested, using specimens from the same heat; base metal minimum (design)
strength should not be used here. Therefore, if the joint is tested in the longitudinal direction of the product, then the ultimate base metal strength in the longitudinal direction must be used. Similarly, the ultimate base metal transverse strength must be used if the joint is tested in the transverse direction of the product. Note that, so far, we have been referring to the longitudinal and transverse directions of the base metal product. There is also the issue of weld orientation with respect to test direction; i.e., the longitudinal-weld and transverse-weld testing
configurations, to be discussed in section 5.7 and the Appendix. Figure 10 depicts the various weld orientation-working direction combinations in butt welded sheet and plate products. For dissimilar metal butt welding, joint efficiency is computed on the basis of the strength of the weakest member of the dissimilar couple.
Author： Terry Khaled, Ph.D.
Country：U.S.A
Provenance: terry.khaled@faa.gov
（譯文1） 常人眼中的攪拌摩擦焊
背景：
4.1固體焊接，概述：
FSW是本文的主要說(shuō)明對(duì)象，是除了摩擦焊（FRW）外，最新的固態(tài)焊接技術(shù)。固態(tài)焊接，顧名思義，是在固體狀態(tài)下形成的焊縫，并且沒(méi)有沒(méi)有融合。固態(tài)焊接包括以下類(lèi)型，如冷焊接，爆炸焊接，超聲波焊接，滾焊，鍛焊，共擠焊接和FRW。在其最簡(jiǎn)單的形式中的常規(guī)的FRW涉及兩個(gè)軸向?qū)R的部分，一個(gè)旋轉(zhuǎn)和一個(gè)固定。固定的元件提前與其他元件接觸，在該點(diǎn)施加一軸向力，并保持以產(chǎn)生所需的摩擦熱使與相鄰接面形成固態(tài)焊縫。這個(gè)焊縫是通過(guò)高溫摩擦產(chǎn)生的。FRW有兩個(gè)技術(shù)。第一個(gè)是連續(xù)驅(qū)動(dòng)FRW，為了滿(mǎn)足設(shè)計(jì)好的持續(xù)性，恒定能量由一個(gè)源提供。第二個(gè)是慣性驅(qū)動(dòng)FRW的，其中的旋轉(zhuǎn)飛輪提供所需的能量。徑向摩擦焊接是傳統(tǒng)技術(shù)的一個(gè)延伸，用于空心型材料，如管和管道。這里，固體環(huán)是通過(guò)旋轉(zhuǎn)來(lái)焊接固定管/管道周?chē)?/div>
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