外文翻譯--常人眼中的攪拌摩擦焊

1、<p><b>　　外 文 翻 譯</b></p><p>　　畢業(yè)設(shè)計題目： 雙攪拌軸攪拌摩擦焊機設(shè)計 </p><p>　　原文1： AN OUTSIDER LOOKS AT FRICTION STIR WELDING

2、 </p><p>　　譯文1： 常人眼中的摩擦攪拌焊接技術(shù) </p><p><b>　　(原文1)</b></p><p>　　AN OUTSIDER LOOKS AT FRICTION STIR WELDING </p>

3、<p>　　BACKGROUND</p><p>　　4.1 Solid State Welding, Overview 2-4 </p><p>　　FSW, the subject matter of this document, is the newest addition to friction welding (FRW), a solid state welding p

4、rocess. 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 we

5、lding, forge welding, coextrusion welding and FRW. Conventional FRW in its simplest form involves two axially aligned parts, one rotating and the other stationary. T</p><p>　　4.2 Friction Stir (FS) Technolog

6、y 5, 6 </p><p>　　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 thermomecha

7、nical processing), FS microforming, FS powder processing, FS channeling and FS processing for low temperature formability. </p><p>　　4.3 A Note on Aluminum Alloys </p><p>　　Since the majority of

8、 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

9、 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 p

10、eriod of time. The second step is to co</p><p>　　4.3.1 Natural Aging </p><p>　　After quenching, the alloy is in the unstable -AQ temper. At room temperature, the alloy remains in that temper for

11、 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

12、 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 </p><p>　　4.3.2 Artificial Aging </p>

13、;<p>　　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 pea

14、k 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

15、 to as overaging. For a given alloy, the peak strength (hardness) values t</p><p>　　4.4 Abbreviations </p><p>　　Some abbreviations of a general nature are used throughout this document. These ar

16、e presented alphabetically below, together with what they mean. </p><p>　　EDS: energy dispersive spectrometry. %e: percent tensile elongation. Ftu: ultimate tensile strength. Fty: tensile yield strength. GMA

17、W: 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 / micro

18、scopy.</p><p>　　5.0 INTRODUCTION TO FSW </p><p>　　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 introd

19、uced 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 i

20、s 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.</p><p>　　5.1 Process Description </p><p>　　Brief process

21、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 &l

22、t;/p><p>　　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 durin

23、g 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 mater

24、ial at the butt line, until the shoulder of the tool forcibly contacts the upper </p><p>　　As the tool is moved in the direction of welding, the leading edge of the pin, aided by certain other tool features,

25、 if present, forces the plasticized material, on either side of the butt line, to the back of the pin. In effect, the material </p><p>　　is transferred from the leading edge of the tool to the trailing edge

26、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

27、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 o</p>

28、<p>　　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 a

29、lloys, 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. Eve

30、n with the use of run-on run-off tabs, Ekman et al. 13 report that low jo</p><p>　　5.1.2 Lap Joints 14-16 </p><p>　　The same operational principles discussed above for butt joints apply to lap w

31、elds, 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 stirri

32、ng 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</p><p&

33、gt;　　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

34、 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,

35、one must not underestimate the effect of the penetration distance</p><p>　　5.1.3 Other Joint Types </p><p>　　FSW has been used to prepare spot joints with and without the end keyhole. Spot welds

36、 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

37、 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</p><p>　　5.

38、2 Conventions & Terminology </p><p>　　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

39、 (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

40、authors refer to the advancing and retreating sides as the shear and flow sides, respectively; this terminology, ho</p><p>　　discussed above and depicted in Figures 6 and 7 apply to all types of FS welded jo

41、ints. 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 docu

42、ment, 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 discer</p><p>　

43、　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 th

44、e 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

45、 the distance from the tip (end) of the pin to the backside o</p><p>　　strength should not be used here. Therefore, if the joint is tested in the longitudinal direction of the product, then the ultimate base

46、 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 hav

47、e been referring to the longitudinal and transverse directions of the base metal product. There is also the issue of weld orientation with respe</p><p>　　configurations, to be discussed in section 5.7 and th

48、e 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 stren

49、gth of the weakest member of the dissimilar couple. </p><p>　　Author： Terry Khaled, Ph.D.</p><p>　　Country：U.S.A</p><p>　　Provenance: terry.khaled@faa.gov </p><p>　　（譯文

50、1） 常人眼中的攪拌摩擦焊</p><p><b>　　背景：</b></p><p>　　4.1固體焊接，概述：</p><p>　　FSW是本文的主要說明對象，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，并且沒有沒有融合。固態(tài)焊接包括以下類型，如冷焊接，爆炸焊接，

51、超聲波焊接，滾焊，鍛焊，共擠焊接和FRW。在其最簡單的形式中的常規(guī)的FRW涉及兩個軸向?qū)R的部分，一個旋轉(zhuǎn)和一個固定。固定的元件提前與其他元件接觸，在該點施加一軸向力，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。這個焊縫是通過高溫摩擦產(chǎn)生的。FRW有兩個技術(shù)。第一個是連續(xù)驅(qū)動FRW，為了滿足設(shè)計好的持續(xù)性，恒定能量由一個源提供。第二個是慣性驅(qū)動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)的一個延伸，用于空心型材料

52、，如管和管道。這里，固體環(huán)是通過旋轉(zhuǎn)來焊接固定管/管道周圍。支持芯棒位于孔焊接位置，以防止管材/管兩端的崩潰。另一種是摩擦堆焊，其中金屬層被沉積在襯底上。在這里，一個旋轉(zhuǎn)的托板被帶進接觸移動的基板，用于原材料到廢料的金屬轉(zhuǎn)移。</p><p><b>　　4.2攪拌摩擦技術(shù)</b></p><p>　　FSW是FS技術(shù)的一種。該技術(shù)的其他種類有處理超塑性FS，F(xiàn)S鑄造

53、修改（也稱為為FTMP或摩擦熱加工），精微FS，F(xiàn)S粉加工，F(xiàn)S引導(dǎo)和FS處理低溫成形性。</p><p>　　4.3 關(guān)于鋁合金的闡述</p><p>　　由于大部分的工作在本文檔中涉及評論鋁合金，所以有必要討論這些合金的熱處理方面。以較高的強度水平的前提下，三個步驟可運用于加熱2xxx的，6xxx和7xxx系列和其他的可熱處理的鋁合金系列。第一步是固溶熱處理，它包括加熱到一定的溫度下（

54、大約900 F）和一段時間的浸泡。第二個步驟是，以足夠快的速度冷卻合金（例如，通過淬火），以保留高溫下的顯微組織。因此在淬火后，快速結(jié)晶，冷卻，成型或者鍛造成合金都需要盡快進行。第三個步驟是老化（AKA析出熱處理）。老化涉及把合金浸泡在一些是低于固溶處理的溫度一段時間。像這里關(guān)注的鋁合金，在室溫到375 F溫度范圍內(nèi)進行老化。在室溫下老化被稱為為自然老化。老化在室溫以上的溫度下被稱為作為人工老化。老齡化導(dǎo)致晶粒內(nèi)有沉淀，隨之強度和硬度的

55、增強，費用也會增加。其他性能也會因為老化而改變。</p><p>　　4.3.1 自然老化</p><p>　　淬火后，合金有不穩(wěn)定的-AQ狀態(tài)。該合金在室溫下，保持在該回火的周期范圍從幾分鐘到一個小時左右，這取決于合金的特性。在此期間，對待微觀結(jié)構(gòu)的解決方法和之前對待時處于溫度一樣。在這個過程結(jié)束后，這種特性轉(zhuǎn)變?yōu)?W，也是一個不穩(wěn)定性質(zhì)。這是伴隨著性能變化的，例如，增加強度和硬度，延展

56、性會降低。隨著越來越多的沉淀隨著時間的推移出現(xiàn)，產(chǎn)品的性能將逐步演變;例如，強度逐漸增加，并隨著時間的推移會使得延展性變?nèi)?。幾天后（約96小時），2xxx和6XXX系列合金達(dá)到穩(wěn)定狀態(tài)，簡稱為-T4性質(zhì)，之后合金將不再變化。一次額外的回火可以得到2xxx的合金強度遞增，如果合金冷加工在-AQ狀態(tài)或在早期的-W狀態(tài)中回火，然后自然老化約96小時，以一個穩(wěn)定的情況被稱為-T3態(tài)。雖然人們普遍認(rèn)為，自然老化96小時是足夠形成一個穩(wěn)定的狀態(tài)（-

57、T3或-T4），據(jù)報道，在FSW資料里，自然老化在AA60137時持續(xù)1個多月和在AA 2195.8持續(xù)2.5年。在-T3和-T4狀態(tài)下，7xxx系列合金達(dá)不到穩(wěn)定強度。然而，強度和其他特征在室溫下隨時間演變多年；事實上，據(jù)報道，AA7050鋁合金在室溫下老話變硬是無限期。換言之</p><p>　　4.3.2 人工老化</p><p>　　在室溫以上的溫度下的老化是人工老化。伴隨著老化時

58、間和老化溫度的改變，這些性能屬性不斷變化。例如，強度和硬度隨時間增加到峰值，超過這個峰值強度和硬度降低，與老化時間的進一步增加，強度和硬度峰可能會或可能不會發(fā)生在相同的老化時間。強度和硬度的下降，被稱為“過度老化”。對于一個給定的合金，峰值強度（硬度）的值，可以通過人工老化來實現(xiàn)，并且會高于自然老化。隨著人工老化溫度的增加，峰值強度/硬度轉(zhuǎn)移到更短的時間，甚至于強度的損失，都?xì)w咎于過度老化，過度老化也會更迅速地發(fā)生。伴隨老化溫度的增加，

59、峰值強度可能會增加或減，這取決于合金和溫度范圍。由于高峰變短和過度老化的加速，精確的時間和溫度的控制在較高的老化溫度下是至光重要的，以避免不良的的過度老化。 在一般情況下，-T4或-W可能會老化成為-T6狀態(tài)（2xxx和6XXX合金）。 -T3也許會老化成為（2XXX合金）-T8狀態(tài)。對于7xxx系列合金， -W狀態(tài)可直接老化成為T6-T7狀態(tài)。另外，-T6狀態(tài)可能由于人為過度老化成為-T7型的狀態(tài)。-T7型狀態(tài)具有抗腐蝕的性能。<

60、;/p><p><b>　　4.4縮略語</b></p><p>　　本文件使用一些縮寫語。這些縮寫語連同他們的意思都是按字母順序在下面排列。</p><p>　　5.0 FSW簡介 不同類型的接頭的FSW過程的簡要說明，在5.1出現(xiàn)。FSW使用的條款和約定在5.2。 FS焊接接頭的概況和遇到的各種焊接區(qū)5.3中詳述。 解決處理變量的問題在5.

61、4。試圖勾勒出控制焊縫微觀結(jié)構(gòu)的因素在5.5。5.6關(guān)于 FSW一些先進的概念進行了討論。5.7為處理焊接接頭的力學(xué)性能測試。</p><p>　　5.1流程說明 下面給出對接接頭過程的簡要描述（5.1.1），搭接接頭（5.1.2）和其他聯(lián)合類型（5.1.3）。這部分內(nèi)容是基于本文件審查的出版物。</p><p>　　5.1.1對接接頭：</p><p>　

62、　兩個工件，配合（搭接）邊緣被焊接圖1a。裝夾的工件在焊接過程中處于分開或解除。焊接工具，包括一個柄部，肩部和引腳（圖1b），然后按一個規(guī)定的速度旋轉(zhuǎn)，并相對于工件的法線傾斜。該工具被慢慢地陷入工件材料，直到該工具的肩部強行接觸的材料的上表面（圖1c）。一個施加向下的力并保持接觸很短的停留時間，可以觀察到預(yù)熱和軟化材料沿接合線的方向的發(fā)展。在這時，橫向力被施加在焊接的方向（行進方向），并且工具被強制穿過并沿對接線（圖1四），直到它到達(dá)結(jié)

63、尾的焊縫;交替地移動，工件旋轉(zhuǎn)工具停止工作，工件保持靜止。當(dāng)?shù)竭_(dá)最終的焊縫，該工具被撤回，而它仍然是旋轉(zhuǎn)的。由于引腳被撤回，它留下一個鎖孔作為結(jié)束時的焊縫。肩部接觸也會留下，在其身后的幾乎半圓形漣漪在焊縫痕跡，示意圖1d所示。由于是在刀具移動的方向上焊接，引腳的前緣，借助于若干其他的工具，強制將塑化的材料，將對接線任一側(cè)上向后面的引腳移動。該材料被有效的通過轉(zhuǎn)移的工具從前緣到引腳的后緣（即，正在攪拌的材料），通過緊密接觸的肩與銷照成一

64、個輪廓。有些人認(rèn)為，攪拌運動往往會使接合面和清潔的表面之間生產(chǎn)氧化物。值得一提的是，為了實現(xiàn)全封閉，引腳通過靠近背板是必要</p><p>　　5.1.2搭接接頭 同一個運行流程原則適用于上面討論的對接接頭搭接焊縫，除以下情況。在搭接接頭沒有對接行，其中該工具可以陷入工件，像這樣，引腳必須貫通頂端部件。此外，不可避免的產(chǎn)生攪拌運動分離的界面處的破壞面，氧化物和其它污染物。這使得從根本上不同于對接焊縫的搭接

65、焊縫。對于對接焊縫，主攪拌是在平面的抵接表面處進行。相比之下，搭接焊縫需要充分平面攪拌，跨越接口被焊接的兩個構(gòu)件。正因為如此，布魯克等人表示搭接焊縫和一個用于對接焊縫的工具之間的主要區(qū)別是是否引入第二臺肩位于焊接（圖3）的兩個細(xì)節(jié)之間的界面處。關(guān)于搭接的重述在本文檔中并沒有特別提到起始孔在鉆前是需要。在搭接處，必須區(qū)分頂部和底部，因為前者是與肩接觸。頂端部件的銷的端部必須完全通過，并進入底部部件延伸一段距離。然而，它不是必需的，該銷端

66、通過非常接近的底部件的底部，因為，在對接接頭相反時不存在封閉現(xiàn)象。然而，一個不能低估的搭接部件（底部）的滲透距離會影響到對接接頭的機械性能。接頭兩側(cè)的槽口（圖4）會有裂紋出現(xiàn)，正因為如此，他們的力學(xué)性能更具有深遠(yuǎn)的影響。在一般情況下，對接接頭的搭接接頭不強，他們有足夠的靜態(tài)和疲勞。</p><p>　　5.1.3其他聯(lián)合類型 FSW已用于制備焊縫與未經(jīng)端鎖孔?？梢允屈c焊，對接或搭接類型。在第8節(jié)中的細(xì)節(jié)。

67、FSW也已有T-接頭和角接接頭，圖5?；谠搱D中，T型接頭可以看作是一個特殊的搭接接頭用于焊縫的任一側(cè)上的凹口，因此，會產(chǎn)生潛在的裂紋。T-接頭的設(shè)計是具有挑戰(zhàn)性的，因為必須小心，以避免壓縮的故障（垂直構(gòu)件）。圖5表明，在本質(zhì)上是特殊的對接接頭（尾部配置）或一個特殊的搭接（槽口配置）的角接頭。除了上述類型的聯(lián)合，F(xiàn)SW已經(jīng)具備，其中包括角焊縫和下擺縫以及沒有太多技術(shù)信息發(fā)布的T，角，圓角下擺縫上。</p><p>

68、;　　5.2約定和術(shù)語 柯利根為我們定義了一個FS焊縫的前進和后退的兩側(cè)使用的原則，如下。焊接工具時，其中表面運動（由于紡絲）是在相同的方向上的行進方向被稱為前進側(cè)的側(cè)面。相反，側(cè)表面運動，其中相對的行進方向，被稱為為退避側(cè)。一些作者將前進和后退的側(cè)面作為剪切和流量的面，但是，這將不被用在本文中。圖6描繪了前進和后退的側(cè)面中的對接焊縫，連同其他一些常用的FSW術(shù)語。如上第5.1.1節(jié)中，刀具和工件傾斜一個角度θ?？屏指虷ira

69、no等人表明傾斜是在遠(yuǎn)離的行進方向上，如在圖7中示出。這種傾斜的肩部由Cederqvist等定義的。如在圖7中所示，P = 0.5 D*sinθ，其中D是肩直徑。要注意的是，上述定義在肩陷入，工具中間部分接觸工件的情況下;其他研究人員可能使用不同的方法。，如圖6和7，適用于所有類型的FS焊接接頭。然而，前進和后退側(cè)，前緣和后緣面，和行進方向是不適用于點焊，由于沒有涉及行進。全文都會運用接頭術(shù)語在所有類型的連接。接頭的輪廓是最外面的代加工