畢業(yè)設(shè)計英文翻譯

1、<p><b>　　畢業(yè)設(shè)計英文翻譯</b></p><p>　　This process is ideal for cylindrical products such as pipes and tanks. The process is the same as its counterpart in metal casting (Section 11.3.5). Chopped f

2、ibers combined with liquid resin are poured into a fast-rotating cylindrical mold. Centrifugal force presses the ingredients against the mold wall, where curing takes place. The resulting inner surfaces are quite smooth.

3、 Part shrinkage or use of split molds permits part removal.</p><p>　　此過程是理想的圓筒狀的產(chǎn)品，如管道和坦克。其對應(yīng)的金屬鑄造（第11.3.5節(jié)）的過程是相同的。切碎的纖維結(jié)合液態(tài)樹脂倒入一個快速旋轉(zhuǎn)的圓筒形模具。激振力壓力機(jī)對模具壁，在固化的成分</p><p>　　的地方。產(chǎn)生的內(nèi)表面相當(dāng)光滑。剖分式模具零件的收縮

4、或使用</p><p><b>　　允許部分切除。</b></p><p>　　FRP tubes can be fabricated from prepreg sheets by a rolling technique [7l,shown in Figure 15.13. Such tubes are used in bicycle frames and space

5、 trusses. In the process,a precut prepreg sheet is wrapped around a cylindrical mandrel several times to obtain a tube wall of multiple sheet thicknesses. The rolled sheets are then encased in a heat-shrinking sleeve and

6、 oven cured. As the sleeve contracts, entrapped gases are squeezed out the ends of the tube. When curing is complete, the mandrel is re</p><p>　　different wrapping methods or using a steel mold to enclose th

7、e rolled prepreg tube for better dimensional control.</p><p>　　由軋制技術(shù)[7升的FRP管可以由預(yù)浸料坯片材制造，圖15.13中所示。使用這種管在自行車車架和空間桁架。在這個過程中，預(yù)切割的預(yù)浸料坯片纏繞在一個圓柱形心軸幾次以獲得的管多個工作表壁的厚度。然后，熱軋板是裝在熱收縮套筒和烘烤處理。作為套筒合約，截留的氣體被擠壓的端部管。固化完成時，心軸被

8、除去，得到的軋制的FRP管。 操作很簡單，模具成本低。有變化的過程中，如使用</p><p>　　不同的包裝方法，或使用steel mold，附上更好的熱軋預(yù)浸料管</p><p><b>　　尺寸控制。</b></p><p>　　Chapter 16</p><p>　　Powder Metallurgy 345 p

9、roduction technology. Considerations that make powder metallurgy an important commercial technology include:</p><p>　　PM parts can be mass produced to net shape or near net shape,

10、 eliminating or reducing the need for subsequent processing.</p><p>　　The PM process itself involves very little waste of material; about 97% of the starting powders are converted to product. This compares f

11、avorably with casting processes in which sprues, runners. and risers are wasted material in the production cycle.</p><p>　　Owing to the nature of the starting material in PM, parts having a specified level o

12、f porosity can be made. This feature lends itself to the production of porous metal parts such as filters and oil-impregnated bearings and gears.</p><p>　　Certain metals that are difficult to fabricate by ot

13、her methods can be shaped by powder metallurgy. Tungsten is an example; tungsten filaments used' in incandescent lamp bulbs are made using PM technology.畢業(yè)設(shè)計論文代做平臺 《580畢業(yè)設(shè)計網(wǎng)》 是專業(yè)代做團(tuán)隊 也有大量畢業(yè)設(shè)計成品提供參考 www.bysj580.com

14、 QQ3449649974</p><p>　　Certain metal alloy combinations and cermets can be for rued by PM that cannot be produced by other methods.</p><p>　　PM compares favorably with most casting processes in

15、 terms of dimensional control of the product. Tolerances of +0.13 mm (1-0.005 in) are held routinely.</p><p>　　PM production methods can be automated for economical production.</p><p>　　Powder M

16、etallurgy.This clip contains two segments: powder metal parts production and PM overview.There are limitations and disadvantages associated with PM processing. These include the following: tooling and equipment costs ar

17、e high, metallic powders are expensive, and there are difficulties with storing and handling metal powders (such as degradation of the metal over time, and fire hazards with particular metals). Also, there are limitation

18、s on part geometry because metal powders do not read</p><p>　　Although parts as large as 22 kg (50 lb) can be produced, most PM components are less than 2.2 kg (5 lb). A collection of typical PM parts is sho

19、wn in Figure 16.1. The largest tonnage of metals for PM are alloys of iron. steel, and aluminum. Other PM metals include copper, nickel, and refractory metals such as molybdenum and tungsten. Metallic carbides such as tu

20、ngsten carbide are often included within the scope of powder</p><p>　　metallurgy: however. because these materials are ceramics. we defer their consideration until the next chapter.</p><p>　　The

21、 development of the modern field of powder metallurgy dates back to the 1800s(Historical Note 16.1). The scope of the modern technology includes not only parts production, but also preparation of the starting powders.Suc

22、cess in powder metallurgy depends to a large degree on the characteristics of the starting powders; we discuss this topic in Section 16.1. Later sections describe powder production, pressing, and sintering. There is a cl

23、ose correlation between PM technology and aspects of cera</p><p>　　第16章/粉末冶金345生產(chǎn)技術(shù)。</p><p>　　粉末冶金的一個重要的注意事項。</p><p>　　商業(yè)技術(shù)包括：“粉末冶金零件可以大量生產(chǎn)的凈形狀或近凈形狀，消除或減少后續(xù)處理的需要”。</p><p&

24、gt;　　“PM過程本身涉及的材料，極少有廢棄物，約97％的起始粉末轉(zhuǎn)化為產(chǎn)物。與此相比毫不遜色鑄造過程中，澆口，亞，季軍。和立管被浪費(fèi)了材料在生產(chǎn)循環(huán)”。</p><p>　　由于在PM的原料的性質(zhì)，具有特定水平的零件孔隙率可以。這個功能本身的生產(chǎn)多孔金屬零件，如過濾器和油浸漬的軸承和齒輪?！翱梢酝ㄟ^以下的形狀是通過其他方法難以制造的某些金屬粉末冶金”。鎢是一個例子，使用的鎢絲白熾燈的燈泡采用PM技術(shù)。<

25、/p><p>　　某些金屬合金可以由PM forrued不能被組合和金屬陶瓷由其它方法產(chǎn)生。</p><p>　　PM媲美最鑄造過程中的尺寸控制的產(chǎn)品。舉行例行公差的0.13毫米（1-0.005在）。PM的生產(chǎn)方法可以經(jīng)濟(jì)地生產(chǎn)自動化。</p><p>　　粉末冶金。剪輯包含兩個部分：（1）粉末金屬零件生產(chǎn)（2）下午概述。</p><p>　　有

26、與PM處理相關(guān)聯(lián)的限制和缺點。這些包括以下內(nèi)容：（1）的工具和設(shè)備的成本高，（2）的金屬粉末是昂貴的，和（3）也有困難，存儲和處理的金屬粉末（如降解的金屬隨著時間的推移，和火災(zāi)危害，尤其是金屬）。此外，（4）有金屬粉末零件的幾何形狀的限制，因為不容易流，必須提供在模具壓制過程中，和津貼橫向噴射從模具壓制后的一部分。此外，（5）在材料密度的變化在整個在下午的部分可能是一個問題，尤其是對于復(fù)雜的零件的幾何形狀。</p><

27、;p>　　雖然零件一樣大，可以生產(chǎn)22千克（50磅），大多數(shù)PM組件是小于2.2公斤（5磅）。一個典型的粉末冶金零件的集合，如圖16.1所示。最大金屬PM噸位是鐵的合金。鋼和鋁。其他PM金屬包括銅，鎳，和難熔金屬如鉬和鎢。金屬的碳化物，如碳化鎢經(jīng)常包括的范圍內(nèi)的粉末的冶金：。因為這些材料是陶瓷。我們推遲審議直到下一個章節(jié)。</p><p>　　現(xiàn)代粉末冶金領(lǐng)域的發(fā)展可以追溯到19世紀(jì)（史注16.1）?，F(xiàn)代技

28、術(shù)的范圍不僅包括部件生產(chǎn)，但也準(zhǔn)備的起始粉末S。粉末冶金的成功的原料粉末的特點，在很大的程度上取決于我們討論這個話題</p><p>　　在第16.1節(jié)。后面幾節(jié)描述粉的生產(chǎn)，沖壓，和燒結(jié)。有 PM技術(shù)和陶瓷加工方面有密切的關(guān)系（CHAP-后17）。在陶瓷（除玻璃外的）中，起始原料也是粉末，所以方法粉末特性，在PM的密切相關(guān)的。的形狀形成的幾個方法是相似的。還可以。</p><p&g

29、t;　　Chapter 16/Powder Metallurgy</p><p>　　FIGURE 16.1 </p><p>　　A collection of powder metallurgy parts. (Courtesy of Dorst America, Inc.)</p><p>　　Historical Note 1 6.1 &l

30、t;/p><p>　　Powder metollurgy owders of metals such as gold and copper, as wejI</p><p>　　as some of the metallic oxides, Have been used for decorative purposes since ancient times. The uses included

31、 decorations on pottery, bases for paints, and in cosmetics. It is bejieved that the Egyptians used PM to make tools as far back as 3000 BCE.</p><p>　　The modern field of powder metallurgy dates to the early

32、 nineteenth century, when there was a strong interest in the metal platinum. Around l 81 5, Englishman William Wollaston developed a technique for preparing platinum powders, compacting them under high pressure, and baki

33、ng (sintering) them at red heat. The Wollaston process marks the beginning of powder metallu rgy as it is practiced today.</p><p>　　U.S. patents were issued in 1 870 to S. Gwynn that relate to PM self-lub

34、ricating bearings. He used a mixtu re of gg% powdered tin and l % petroleum, mixing,heating, and finally subjecting the mixture to extreme pressures to form it into tHe desired shape inside a mold cavity.</p><

35、;p>　　By the early 1900s, the incandescent lamp had become an important commercial product. A variety of filament materials had been tried, including carbon, zirconium, vanadium, and osmium; but it was concluded that t

36、ungsten was the best filament material. The problem was that tungsten was difficult to process because of its high melting point and unique properties. In 1908, Wijliam Cooiidge developed a procedure that made production

37、 of tungsten incandescent lamp filaments feasible. In his process, f</p><p>　　In the l 920s, cemented carbide tools (WC-Co) were being fabricated by PM techniques (Historical Note 7.2).Self-Iubricating beari

38、ngs we re produced in large quantities starting in the 1930s. Powder metal gears and other components were mass produced in the 1960s and</p><p>　　1 970s, especially in the automotive industry; and in the

39、1980s, PM parts for aircraft turbine engines were developed.</p><p>　　章16/Powder冶金收集的粉末</p><p>　　粉末冶金零件。（禮貌的多斯特美國公司）歷史注16.1粉末metollurgy的 owders的金屬，如金，銅，作為wejI一些金屬氧化物，已被用于自古以來裝飾的目的。使用包括陶器上的裝

40、飾品，油漆基地，并在化妝品上。這是bejieved，埃及人使用PM早在3000 BCE的工具。</p><p>　　現(xiàn)代粉末冶金領(lǐng)域可追溯至十九世紀(jì)初，當(dāng)有一個強(qiáng)大的在金屬鉑的興趣。 L 81左右，英國人威廉·沃拉斯頓開發(fā)的技術(shù)準(zhǔn)備鉑粉，并在高壓縮壓力，燒成（燒結(jié)）在紅熱。 “</p><p>　　沃拉斯頓過程標(biāo)志著粉末的metallu三色，因為它是沿用至今。美國專利發(fā)行的1 8

41、70 S.格溫與PM自潤滑軸承。他用了一個mixtu重</p><p>　　GG％粉狀錫和1％，石油，混合，加熱，最后將混合物進(jìn)行極端</p><p>　　壓力成所需的形狀的模具內(nèi)，以形成它腔。</p><p>　　到20世紀(jì)初，白熾燈成為一個重要的商業(yè)產(chǎn)品。各種曾經(jīng)嘗試過的燈絲材料，包括 碳，鋯，釩，和鋨，但它是結(jié)論是，鎢是最好的燈絲材料。問題是，鎢是困

42、難 來處理，因為它的高的熔點和獨特的性質(zhì)。 1908年，Wijliam Cooiidg??e開發(fā)的過程，使生產(chǎn)鎢絲白熾燈的燈絲是可行的。在他的過程中，細(xì)粉末的氧化鎢（W03）是降低到金屬粉末，壓制成壓塊，預(yù)燒結(jié)，熱鍛造到回合，燒結(jié)，和終于卷入芯線?？铝⒅ミ^程今天仍然使用使燈絲白熾燈燈泡。</p><p>　　在L 920s，硬質(zhì)合金工具（WC-Co）的正在制作的PM技術(shù)（歷史注7.2）。自助式潤滑軸承，

43、我們再在20世紀(jì)30年代開始的數(shù)量。粉末金屬齒輪，其他組件的大規(guī)模生產(chǎn)在20世紀(jì)60年代，1 970s，尤其是在汽車工業(yè)中，在所述20世紀(jì)80年代，飛機(jī)渦輪發(fā)動機(jī)的粉末冶金零件發(fā)展。</p><p>　　材料11032班 ：劉文 </p><p>　　學(xué)號：1040103218