外文翻譯--航空工業(yè)焊接的新趨勢(shì)

1、<p>　　航空工業(yè)焊接的新趨勢(shì)</p><p>　　麻省理工學(xué)院 帕特里西奧樓門德斯</p><p><b>　　摘要:</b></p><p>　　焊接在航空業(yè)正經(jīng)歷著令人振奮的發(fā)展。廣泛應(yīng)用計(jì)算機(jī)和改善設(shè)備和設(shè)計(jì)新材料塑造的方式焊接，是實(shí)施過程和產(chǎn)品正在設(shè)計(jì)的主要要方法。有一種普遍的趨勢(shì)，減少鉚釘在在飛機(jī)結(jié)構(gòu)組件的使用有一種

2、普遍的趨勢(shì). 擴(kuò)散焊和激光，電子束焊接是在加入材料情況下使用的。軍用飛機(jī)的電子束焊接在加入鈦合金下使用，并且有擴(kuò)大趨勢(shì).大型商業(yè)飛機(jī)的激光束焊接，慢慢取代鉚釘在大部份機(jī)身上使用, 航天工業(yè)也顯示:航空業(yè)界承諾一些新的進(jìn)程的發(fā)展.其中包括：攪拌摩擦焊接和變極性等離子弧焊，這已經(jīng)被應(yīng)用火箭的關(guān)鍵部件上, 目前, 鑄件在飛機(jī)有日益增加的趨勢(shì),這樣開辟了新的機(jī)遇和挑戰(zhàn). 而一些進(jìn)程，包括擴(kuò)散焊接鋁合金和線性摩擦加入葉片盤。似乎并沒有得到廣泛應(yīng)用

3、. 本文側(cè)重于焊接的基礎(chǔ)，就其影響的焊接航空組件，以及對(duì)趨勢(shì)的行業(yè)的預(yù)計(jì)，因此是一項(xiàng)基本的水平。維修焊接，無損檢測(cè)，釬焊是本文章討論的范圍。</p><p><b>　　導(dǎo)言:</b></p><p>　　焊接的過程，就是人類一個(gè)古老的處理金屬的過程.其在歷史上的大多數(shù)的時(shí)間,它一直被視為一個(gè)粗淺的藝術(shù)或施工技術(shù). 19世紀(jì)推動(dòng)現(xiàn)代焊接新的發(fā)展而且發(fā)展趨勢(shì)比以往任何時(shí)

4、候都要快. 不同的焊接工藝可以由不同強(qiáng)度的熱源融合.也揭示了許多重要的趨勢(shì)當(dāng)中, 滲透率衡量的比例，深度,寬度（四/瓦特）焊縫截面的急劇增加與熱源強(qiáng)度有關(guān)。這允許較高的焊接速度,使得焊接過程更有效率. 一個(gè)更有效率的過程中在焊接過程中需要較少的熱輸入，從而形成一個(gè)強(qiáng)大的焊縫 . 較小的熱源,移動(dòng)速度更快,也意味著停留時(shí)間在任何特定的點(diǎn)的時(shí)間大大減少. 如果停留時(shí)間太短，在過程中，無法手動(dòng)控制，必須加以自動(dòng)化, 最低的時(shí)間，仍然是可以手動(dòng)

5、控制的對(duì)應(yīng)的電弧焊接（約0.3秒）. 因此，他們只能用自動(dòng)控制熱源更激烈的的焊接. 焊接工藝在更加集中熱源的地方創(chuàng)建一個(gè)較小的熱影響區(qū)（ HAZ組織）和形成較低后焊縫扭曲力. 它可以推斷：所帶來的好處是: 更加集中熱源, 資本設(shè)備的費(fèi)用大約與強(qiáng)度熱源成正比的.</p><p>　　航空業(yè)的特點(diǎn)是：低單位生產(chǎn)，單位成本較高，在營運(yùn)條件極其嚴(yán)重情況下,焊接就十分重要了, 這些特征對(duì)較昂貴的和更集中熱源如等離子弧，激光

6、束和電子束焊接作為焊接進(jìn)程的選擇,是焊接的關(guān)鍵部件的重要選擇</p><p>　　焊接過程在航空業(yè)中的使用.</p><p><b>　　摩擦焊接）</b></p><p>　　在這個(gè)過程中，通過機(jī)械變形加入金屬。既然沒有熔化,就不存在基礎(chǔ)的材料熔化-凝固現(xiàn)象的相關(guān)缺陷. 這個(gè)過程中可以加入鋁起落架組件,組成了一個(gè)比較簡單的橫截面. 性摩擦（微

7、動(dòng)）焊接被認(rèn)為是由通用電氣公司和普惠公司發(fā)明的一種替代，為制造和修理高溫合金盤為噴氣發(fā)動(dòng)機(jī). 雖然沒有透露這些進(jìn)程，他們也會(huì)演變成商業(yè)應(yīng)用.</p><p>　　攪拌摩擦（攪拌摩擦焊）</p><p>　　契維語在1991年發(fā)明了這一焊接方法, 這是一個(gè)堅(jiān)實(shí)的焊接進(jìn)程，通過機(jī)械變形加入金屬, 在這個(gè)過程中,圓柱等工具與異型探頭旋轉(zhuǎn)，慢慢地陷入了聯(lián)合線之間的兩塊資產(chǎn)負(fù)債表或板材，這樣就對(duì)接在

8、一起，這個(gè)過程可以焊接以前報(bào)告鋁合金飛機(jī)結(jié)構(gòu)在使用. 實(shí)力焊縫與弧相比是弧30 ％ 或50 ％ . 在一些小熱影響區(qū)的地方，殘余應(yīng)力，微觀結(jié)構(gòu)也得到了改變. 波音公司出了1500萬美元的投資在使用攪拌摩擦焊焊接助推器為三角洲的范圍的國家運(yùn)載火箭，這是美國的第一生產(chǎn)攪拌摩擦焊的地方. 1998年8月, 在德爾塔II,首次發(fā)射一個(gè)使用攪拌摩火箭. 這一進(jìn)程目前正在考慮加入鋁berilium合金，如2005年，為中央智囊團(tuán)的航天飛機(jī)，就得到了

9、應(yīng)用。鈦合金也有其他航空用途. 作為攪拌摩擦焊的一種,為了更好地使用，它可以取代等離子弧焊（足）和電子束焊接（電子束焊接）,在一些具體的應(yīng)用中用鋁和用鈦是有分別。</p><p><b>　　閃光焊</b></p><p>　　為是一種在熔化過程中, 應(yīng)用一對(duì)焊接接頭焊接在短期的內(nèi)弧和壓力而作用的。這是能夠產(chǎn)生強(qiáng)大的焊縫的基礎(chǔ)材料. 這個(gè)過程可以焊接鋁和表面耐高溫合金

10、使用沒有特別準(zhǔn)備或屏蔽氣體。它可以焊接各種復(fù)雜的截面, 這是用在航空業(yè)加入環(huán)噴氣發(fā)動(dòng)機(jī),主要是出于耐高溫合金和擠壓鋁構(gòu)件的作用而考慮的。</p><p><b>　　氣體金屬弧焊</b></p><p>　　這個(gè)過程中，其中一個(gè)是世界上進(jìn)心最熱門的焊接工藝，因?yàn)樗撵`活性和低成本是呆以廣泛使用在航空業(yè). 缺點(diǎn)是大尺寸的熱源(處理流程，與如電子束焊接，運(yùn)作）的焊縫有著不

11、太好的力學(xué)性能. 這個(gè)過程是在主要的焊接工藝用于建造該燃料和氧化劑坦克火箭（ 2219為第一階段）, 目前應(yīng)用在自動(dòng)焊接的葉片愛國者導(dǎo)彈上. 這些葉片由一個(gè)框架17-4 pH值超級(jí)不銹鋼組成，其中金屬薄板的相同的組成是welded8, 此應(yīng)用程序的好處，從成本降低，而可靠性增強(qiáng)。</p><p>　　鎢極氬弧焊（氬弧焊）</p><p>　　氬弧焊可以使用比的GMAW更激烈的熱源. 因此，

12、它可以產(chǎn)生較小的焊縫，從而降低的成本。對(duì)于大多數(shù)結(jié)構(gòu),在應(yīng)用這一過程中，不能與其他焊接方法如電子束焊接，激光焊接或等離子弧相焊接相單混用。氬弧焊是一起使用的GMAW與焊接在2014年和2219的鋁合金在燃料和氧化劑坦克在土星v rocket7使用. 梅塞施米特bölkow blohm在德國目前使用的GMAW為噴嘴延長鎳，阿麗亞娜發(fā)射vehicles9上也使用過這種焊接. 大部分的焊接主要表現(xiàn)在商用飛機(jī)及對(duì)管道及油管使用焊接.

13、這個(gè)過程也可以用在換熱器的核心上，噴氣發(fā)動(dòng)機(jī)百葉窗和排氣外殼上，不銹鋼和inconel1無論是在商業(yè)和軍事都得到了使用. 不銹鋼葉片在多倫多也用在堵塞焊縫在愛國者導(dǎo)彈也得到了使用. 允許應(yīng)用到航空焊接結(jié)構(gòu)的組成部分包括弧長控制和救濟(jì)的應(yīng)力用散熱器在焊接上, 這項(xiàng)技術(shù)，是由洛克希德馬丁公司在土衛(wèi)六四運(yùn)載火箭上使用的. 它是一種通過測(cè)量電弧電壓來測(cè)量所期望的滲透率.這種技術(shù)在中國 北京航空制造技術(shù)研究所也得到了應(yīng)用. 它已用于噴氣發(fā)動(dòng)機(jī)案件

14、中的耐熱合金和火箭燃料箱的鋁合金。在這方面的技術(shù)，散熱器步道背后的焊接電弧就是這樣</p><p><b>　　等離子弧焊</b></p><p>　　使用constricted弧之間的nonconsumable電極和熔池（轉(zhuǎn)移?。┗蛑g的電極和制約噴嘴（ nontransferred?。? 如果熱強(qiáng)度不夠高，這個(gè)過程是不可以運(yùn)作，類似一個(gè)小孔模式，有人認(rèn)為，激光或電

15、子束焊接，雖然與規(guī)模較小但滲透率最高. 這個(gè)過程是用于焊接的先進(jìn)的固體火箭發(fā)動(dòng)機(jī),使用材料是惠普- 9 - 4 - 30鋼.</p><p>　　其中一個(gè)最新的變化，就是霍巴特兄弟將這個(gè)過程如變極性等離子弧焊焊接（ vppa ）商品化. 這種變化在航空航天工業(yè)焊接較厚路段鋁合金，特別是為外部燃料箱的航天飛機(jī)得到了使用.這個(gè)過程中熔化的是在小孔模式中進(jìn)行的.不好的一部分，是循環(huán)提供了一個(gè)陰極清洗鋁工件，而好的部分，

16、提供了理想的滲透和熔融金屬流. 測(cè)試結(jié)果表明，最佳占空比為這個(gè)過程中涉及的負(fù)序電流15-20 MS和一個(gè)積極的2-5的電流中，一個(gè)積極作用是:當(dāng)前的30-80 1高于負(fù)序電流. 集中供熱原因是為了明顯減少角扭曲力.</p><p><b>　　激光焊接</b></p><p>　　這個(gè)過程, 優(yōu)勢(shì)是電子束焊接技術(shù)可以提供最集中的熱源焊接, 更高的精度,焊縫質(zhì)量和規(guī)模較

17、小的扭曲. 這個(gè)過程是用于焊接噴氣發(fā)動(dòng)機(jī)部件,其由耐熱合金制成，如hastelloy，激光加工燃燒在普惠公司噴氣發(fā)動(dòng)機(jī)jt9d ， pw4000 ， pw2037和F - 100 - ○ – 22019得到了運(yùn)用.</p><p>　　激光焊接將很快取代鉚在空中客車318飛機(jī)中使用. 顯著的優(yōu)點(diǎn)是可以預(yù)期并取得的取代鉚接接頭的不足. 鉚，估計(jì)消費(fèi)占制造業(yè)的40 ％左右 .</p><p>

18、<b>　　電子束焊接</b></p><p>　　如上所述，高強(qiáng)度的電子束產(chǎn)生焊縫與熱影響區(qū)小，這個(gè)過程中的優(yōu)勢(shì)，電子束對(duì)熔融金屬的對(duì)接已沒有問題. 不過，它需要在真空中運(yùn)作. 這一特點(diǎn)在使用這一進(jìn)程中，特別適合焊接鈦合金而不能焊接在一個(gè)開放的氣體中的部件. 鈦合金被廣泛用于軍用飛機(jī)，因?yàn)樗亓枯p，強(qiáng)度高，性能在高溫下也較好. 應(yīng)用電子束焊接，以焊接鈦部件的軍用飛機(jī)一直在不斷擴(kuò)大. 塔員額

19、和機(jī)翼部件在Ti 6Al - 4V和f15戰(zhàn)斗機(jī)也得到了廣泛的應(yīng)用. 機(jī)翼盒舉行可變幾何的翅膀，在旋風(fēng)式戰(zhàn)斗機(jī)，如f14 “雄貓”得到了使用. 在控制系統(tǒng)中,以及在以及在實(shí)施電腦自動(dòng)化中有著顯著的差異. 這項(xiàng)新技術(shù)，使連續(xù)一通焊縫超過曲線和曲面，并通過不同厚度來進(jìn)行. 波音公司的F - 22的關(guān)鍵結(jié)構(gòu)部件現(xiàn)在用鈦電子束焊接這種方式來焊接的. F - 22是第一次飛機(jī)在60年的特點(diǎn)焊接機(jī)進(jìn)行的. 前的前身用了鉚接鋁.將他們焊接在一起. 最

20、近的應(yīng)用的鈦鑄件在F - 22戰(zhàn)斗機(jī)的焊接出現(xiàn)了問題，因此延遲開始生產(chǎn)時(shí)間至少五個(gè)月. 俄羅斯能源火箭應(yīng)用電子束焊接建造該氧氣和油缸. 由于龐大真空，是造成當(dāng)?shù)孛芊馀c鐵電產(chǎn)生影響.</p><p><b>　　擴(kuò)散焊</b></p><p>　　這是一個(gè)固態(tài)焊接,在焊接過程中在焊縫所在處產(chǎn)生應(yīng)用的壓力，在高溫下，該件沒有宏觀變形或相對(duì)變化. 航空業(yè)是主要用戶是dfw,

21、 這個(gè)過程已證明,超塑成形（ SPF ）則鈦合金特別有用相結(jié)合. 在這種情況下，復(fù)雜的幾何形狀可以得到在短短得到應(yīng)用. 在某些情況下替代鉚接鋁構(gòu)件,從而使成本降價(jià). 傳統(tǒng)的制作由500緊固件構(gòu)成的16個(gè)部分,并一起進(jìn)行. 有人建議，以取代設(shè)計(jì)，整體加筋所產(chǎn)生的SPF / dfw會(huì)得到很好的作用. 應(yīng)用的SPF / dfw可以減少了原來的鉚接的鋁材構(gòu)件，來自76個(gè)詳細(xì)的零件和1000緊固件，以鈦金屬版只有14個(gè)細(xì)節(jié)和90緊固件與總成本可節(jié)

22、省30 ％左右. 成功的SPF / dfw鈦刺激了大量的研究與目標(biāo)，完成了類似的過程與鋁焊接過程. dfw鈦和鋁鈦根本區(qū)別是鈦可以解散其氧化物而鋁不可以，因此, 剩余氧化氮在界面形成鋁聯(lián)合,極大地降低了力量的焊接在焊接中的擴(kuò)散. 這個(gè)問題已妨礙了SPF級(jí)/ dfw鋁的普遍采用.</p><p><b>　　結(jié)論</b></p><p>　　驅(qū)動(dòng)的成本和重量的積累，技術(shù)

23、進(jìn)步使得更換鉚釘和緊固件與焊縫得到緊密的結(jié)合. 在商用飛機(jī)中,一些鉚接鋁構(gòu)件由SPF級(jí)/ dfw鈦的替代品（ SPF級(jí)/ dfw鋁仍處于試驗(yàn)階段）形成了一種趨勢(shì). 在不久的將來，空中客車飛機(jī)（ a318和a3xx ）功能將機(jī)身出現(xiàn)激光焊接，以在飛機(jī)上的形成. 展望進(jìn)一步,邁向未來, 這是有可能將攪拌摩擦焊用于對(duì)飛機(jī)結(jié)構(gòu)組件的焊接, 它可以可靠地加入合金系列等材料.</p><p>　　變極性等離子弧焊焊接（ vp

24、pa ） ，原本是設(shè)計(jì)為空間應(yīng)用可能深入飛機(jī)工業(yè)入中的厚度較厚的鋁。實(shí)施計(jì)算機(jī)控制使用電子束焊接鈦合金的應(yīng)用程序在過去是不可行的，制造業(yè)等焊接第一次為噴氣式戰(zhàn)斗機(jī)機(jī)身中使用，電子束焊接鈦在未來的軍用飛機(jī)的運(yùn)用將增加，這種預(yù)期是合理的，在飛機(jī)使用鑄件正在增加，這必將帶來新的挑戰(zhàn)。 </p><p>　　Proceedings of the conference “New Trends for the Manufac

25、turing in the AeronauticIndustry”, Hegan/Inasmet, San Sebastián, Spain, May 24-25, 2000, pp. 21-38.</p><p>　　NEW TRENDS IN WELDING IN THE AERONAUTIC INDUSTRY </p><p>　　Patricio F. Mendez &l

26、t;/p><p>　　Massachusetts Institute of Technology </p><p>　　Cambridge, MA 02139, USA </p><p><b>　　Abstract </b></p><p>　　Welding in the aeronautic industry is e

27、xperiencing exciting developments. The widespread application of computers and the improved knowledge and design of new materials are shaping the way welding is implemented and process and product are being designed. The

28、re is a general trend to reduce the use of rivets in structural components in airplanes. Diffusion welding and laser, and electron beam welding are used to join the materials in these cases. In military airplanes electro

29、n beam welding is con</p><p>　　Introduction </p><p>　　Welding is a process almost as old as the processing of metals by humans. For most of its history it has been regarded as an obscure art or

30、a crude construction technique. New discoveries and the availability of electric energy in the nineteenth century pushed the development of modern welding with an ever-accelerating rate (Figure 1). </p><p>　

31、　The different welding processes can be ordered by the intensity of the heat source used for fusion (Figure 2). This ordering reveals many important trends among them. The penetration measured as the ratio of depth to wi

32、dth (d/w) of the weld cross section increases dramatically with the intensity of the heat source. This makes the welding process more efficient and allows for higher welding speeds. A more efficient process requires less

33、 heat input for the same joint, resulting in a stronger weld,</p><p>　　The nature of welding in the aeronautical industry is characterized by low unit production, high unit cost, extreme reliability, and sev

34、ere operating conditions1. These characteristics point towards the more expensive and more concentrated heat sources such as plasma arc, laser beam and electron beam welding as the processes of choice for welding of crit

35、ical components. </p><p>　　Welding Processes used in the Aeronautic Industry </p><p>　　Friction Welding (FRW) </p><p>　　In this process, the joining of the metals is achieved throug

36、h mechanical deformation. Since there is no melting, defects associated with melting-solidification phenomena are not present and unions as strong as the base material can be made. This process can join components with a

37、 relatively simple cross section. It is used for the joining of aluminum landing gear components. Linear friction (fretting) welding was considered by General Electric and Pratt & Whitney as an alternative for the ma

38、nuf</p><p>　　Friction Stir (FSW) </p><p>　　TWI invented this process in 1991. It is a solid-state process that joins metals through mechanical deformation. In this process a cylindrical, shoulde

39、red tool with a profiled probe is rotated and slowly plunged into the joint line between two pieces of sheet or plate material, which are butted together, as shown in Figure 9. This process can weld previously reported u

40、nweldable aluminum alloys such as the 2xxx and 7xxx series used in aircraft structures. The strength of the weld is 30%50% than </p><p>　　Boeing made a $15 million investment in the use of FSW to weld the b

41、ooster core tanks for the Delta range of space launch vehicles, which was the first production FSW in the USA5. The first launch of a FSW tank in Delta II rocket happened in August 19993. This process is currently being

42、considered for the joining of aluminum–berilium alloys such as 2195 for the central tank of the Space shuttle, and also titanium alloys for other aeronautical uses. As FSW becomes better established, it can repla</p&g

43、t;<p>　　Flash Welding (FW) </p><p>　　FW is a melting and joining process in which a butt joint is welded by the flashing action of a short arc and by the application of pressure. It is capable of prod

44、ucing welds as strong as the base material. This process can weld aluminum and temperature resistant alloys without especial surface preparation or shielding gas. It can join sections with complicated cross sections, and

45、 it is used in the aeronautical industry to join rings for jet engines made out of temperature resistant alloys and e</p><p>　　Gas Metal Arc Welding (GMAW) </p><p>　　This process, one of the mos

46、t popular welding processes in the world because its flexibility and low cost is not used extensively in the aeronautic industry. The drawback for its is that the large size of the heat source (compared with processes su

47、ch as EBW, LW, PAW) causes the welds to have poor mechanical properties. This process was the main welding process used for the construction of the fuel and oxidizer tanks for the Saturn V rocket (2219 aluminum alloy for

48、 the first stage)7. One of the c</p><p>　　Gas Tungsten Arc Welding (GTAW) </p><p>　　GTAW can use a more intense heat source than GMAW, therefore it can produce welds with less distortion at a si

49、milar cost. For most structural critical applications this process cannot compete with other welding methods such as electron beam welding, laser beam welding or plasma arc welding. GTAW was used together with GMAW to we

50、ld the 2014 and 2219 aluminum alloy in the fuel and oxidizer tanks in the Saturn V rocket7. Messerschmitt Bölkow Blohm in Germany currently uses GMAW for the nozzle exten</p><p>　　Plasma Arc Welding (PA

51、W) </p><p>　　PAW uses a constricted arc between a nonconsumable electrode and the weld pool (transferred arc) or between the electrode and the constricting nozzle (nontransferred arc). If the heat intensity

52、of the plasma is high enough, this process can operate in a keyhole mode, similar to that of laser or electron beam welding, although with smaller maximum penetration. A schematic of PAW is shown in Figure 12. This proce

53、ss is used for the welding of the Advanced Solid Rocket Motor (ASRM) for the Space Shu</p><p>　　One of the latest variations of this process is variable-polarity plasma arc welding (VPPA) commercialized by H

54、obart Brothers. This variation was developed by the aerospace industry for welding thicker sections of alloy aluminum, specifically for the external fuel tank of the space shuttle16. In this process the melting is in the

55、 keyhole mode. The negative part of the cycle provides a cathodic cleaning of the aluminum workpiece, while the positive portion provides the desired penetration and mol</p><p>　　Laser Beam Welding (LBW) <

56、;/p><p>　　This process, together with electron beam welding can deliver the most concentrated heat sources for welding, with the advantages of higher accuracy and weld quality and smaller distortions. This proc

57、ess is used for welding and drilling of jet engine components made of heat resistant alloys such as Hastelloy X. Laser-processed combustors are used in the Pratt & Whitney jet engines JT9D, PW4000, PW2037 and F-100-P

58、W-22019 </p><p>　　Laser beam welding will soon replace riveting in the joining of stringers to the skin plate in the Airbus 318 and 3XX aircraft20. A schematic comparing a riveted and a welded stringer is sh

59、own in Figure 14. Significant savings are expected to be made by replacing riveted joints by LBW. Riveting is estimated to consume 40% of the total manufacturing man-hours of the aircraft structure4. </p><p>

60、;　　Electron Beam Welding (EBW) </p><p>　　As mentioned above, the high intensity of the electron beam generates welds with small HAZ and little distortion as shown in Figure 5 and Figure 6. This process prese

61、nts the advantage over LBW that it has no problems with beam reflection on the molten metal; however, it needs to operate in a vacuum. This characteristic makes this process especially suitable for the welding of titaniu

62、m alloys that cannot be welded in an open atmosphere. Titanium alloys are widely used in military aircraft because</p><p>　　A remarkable application of EBW is in the construction of the oxygen and fuel tanks

63、 of the Russian Energia rocket (Figure 17). Due to the large size of the tanks, the vacuum is created locally, and sealed with ferroelectric liquids24. </p><p>　　Diffusion Welding (DFW) </p><p>

64、　　It is a solid-state welding process that produces a weld by the application of pressure at elevated temperature with no macroscopic deformation or relative motion of the pieces. The aeronautic industry is the major use

65、r of DFW25. This process has proven particularly useful when combined with the superplastic forming (SPF) of titanium alloys. In this case, complicated geometries can be obtained in just one manufacturing step as shown i

66、n Figure 18. The quality and low cost of the joint enables in </p><p>　　Conclusions </p><p>　　Driven by cost and weight savings, technological progress is moving in the direction of replacing ri

67、vets and fasteners with welds. In commercial aircraft this trend is already in motion with the replacement of some riveted aluminum components by SPF/DFW titanium substitutes (SPF/DFW of aluminum is still at an experimen

68、tal stage). In the near future, Airbus planes (A318 and A3XX) will feature fuselage stringers laser welded to the airplane skin. Looking further into the future, it is likely that </p><p>　　Variable polarity

69、 plasma arc welding (VPPA), originally designed for space applications might pervade into the airplane industry for the joining of medium thickness sections of aluminum. The implementation of computer control to electron

70、 beam enabled the use of welding of titanium alloys in applications that were no feasible in the past, such as manufacturing a welded fuselage for the first time for a jet fighter (the F-22). It is reasonable to expect t

71、hat the amount and criticality of EBW of ti</p><p>　　References </p><p>　　Shaw, C.B. Welding Research for Aerospace in USA.in International Congress on Welding Research. 1984. Boston, MA. </p

72、><p>　　Irving, B., Sparks Begin to fly in Nonconventional Friction Welding and Surfacing. Welding Journal, May 1993: p. 37-40. </p><p>　　Boeing, http://www.boeing.com , 2000 </p><p>　　

73、4.Welded Aluminium Aircraft Structures Ready for Take Off. Welding and Metal Fabrication, September 1998: </p><p>　　p. 16-17. </p><p>　　The Welding Institute, http://www.twi.co.uk , September,

74、1999 </p><p>　　Kuchuk-Yatsenko, S.I., V.T. Cherednichok, and L.A. Semenov. The Flash-Butt Welding of Aluminium Alloys. in Welding in Space and the Construction of Space Vehicles by Welding. 1991. New Carrolt

75、on, MD: American Welding Society. </p><p>　　Masubuchi, K., Integration of NASA-Sponsored Studies on Aluminum Welding. NASA CR-2064, 1972, NASA, Washington, DC. </p><p>　　Irving, B., GTA Welders

76、Put the Finishing Touches on the Fins for the Patriot Missile. Welding Journal, may 1991: p. 71-74. </p><p>　　Wolf,D.B.and R.C. Nicolay. Welded Nozzle Extension for Ariane Launch Vehicles.in Welding in Space

77、 and the Construction of Space Vehicles by Welding. 1991. New Carrolton, MD: American Welding Society. </p><p>　　Irving, B., EB Welding Joins the Titanium Fuselage of Boeing's F-22 Fighter. Welding Journ