英文翻譯論文(模板)

1、本科生畢業(yè)設(shè)計(jì)（論文）專業(yè)外文翻譯文:Magnesium alloy electric wheel hubmicro-arc oxidation production research譯 文：鎂合金電動(dòng)車輪轂微弧氧化生產(chǎn)研究指導(dǎo)教師：張清郁職稱： 講師學(xué)生姓名：陳孟麗學(xué)號(hào)：1002130301機(jī)械設(shè)計(jì)制造及其自動(dòng)化院（系）機(jī)電工程學(xué)院2015年4月10日Magnesium alloy electric wheel hub micro-arc oxidation production researchMost electric vehicles at home and abroad is con

2、figured to aluminum alloy wheelhub, its quality, energy saving, shock absorption, noise reduction and vehicle dynamics characteristics index is much lower than magnesium alloys. Magnesium alloy is 30% lighter than aluminum alloy, the damping effect is 30 times that of aluminum alloy.Replace the alum

3、inum alloy with magnesium alloy wheel hub, driving the development of magnesium alloy material development and deep processing technology, to reduce electric vehicle weight and power consumption, energy conservation and environmental protection;To reduce vibration and noise; Improve ride comfort and

4、 electric vehicle dynamic characteristics such as objective (transportation quality each reduce 10%, energy consumption will be reduced 8% 10%). But its corrosion resistanceis poor, seriously limits the application. Commonly used chemical oxidation and anode oxidation formation of oxide film on magn

5、esium alloy has certain protective effect, but its corrosion resistance, environmental friendliness, appearance is not satisfactory, be badly in need of the development of new surface treatment. In recent years, people trying to develop a variety of new technologies, such as micro arc oxidation tech

6、nology, the betterOne Micro-arc oxidation mechanismMicro-arc oxidation technology is a new surface treatment technology of greenenvironmental protection, can grow in light metal surface in situ ceramic layer directly. Its technological characteristics, surface treatment, as well as the performance o

7、f the since the technology was invented by the favour of people, its mechanism is to light metals such as aluminum, magnesium, titanium and its alloy put in electrolyte aqueous solution as anode, using the method of electrochemical spark discharge spots on the surface of the material, the thermal ch

8、emistry, plasma chemistry and electrochemistry, under the joint action of metal oxide ceramic layers of a surface modification technologyTwo research methods and technologyThis topic in the research on magnesium alloy electric wheel hub, higher requirements on the toughness of the alloy, so choose A

9、M60B, melt and initial temperature of 468 °C, the melting end temperature is 596 °C, the liquidus temperature range of165 C . The chemical composition as shown in table 1. 0Table 1 AM60B alloy chemical comp osition (WB / %)AlZnMnSiCuNiFe雜質(zhì)余量5.66.4< 0.200.26 0.5< 0.05< 0.008< 0.

10、001< 0.0040.02MgBecause of the mag nesium alloy electric wheel hub surface area is larger, generalabove 0.4 m2, require micro-arc oxidati on po wer supply is bigger, this subject ado pts theIan zhou uni versity of tech no logy in stitute of materials and devel opment of MAO - 300type nc micro-arc

11、 oxidation production device (figure 1) micro-arc oxidation onmagnesium alloy wheel casting processing, its similar to ordinary anodic oxidationequipment, including special high-voltage power supply, micro-arc oxidation alkalinesolutio n of electrolytic tank, mixi ng system, cooli ng system, work pi

12、ece with stai nl ess steelp late for p eer electrode.With micro-arc oxidati on method in sodium silicate and sodium hydroxide electrolytefluid system in the prep arati on of mag nesium alloy wheel cast ing oxide ceramic membra ne,the con crete tech no logical p rocess first set oxidati on p rocess p

13、 arameters and the alkali netank sodium silicate solution, the cleaning after micro-arc oxidation of magnesium alloywheel casti ng into cell 15 - 20 min, clea n with clear water tank 2 - 4 mi n, add hot water inhot water (80 °C , 10 - 15 min), closed, then cool in the cold water tank 2 min, hoi

14、sted outdrain age, drying, exam ine the hub. After micro-arc oxidatio n treatme nt must be closed byhot water, formed by micro-arc oxidati on discharge holes so the distributio n of the cha nneland the surrounding a large number of micro cracks will be closed, prevent oxygen tocause oxidati on. Afte

15、r comp leti on of micro-arc oxidati on, from after micro-arc oxidati onon magn esium alloy wheel cast ing in terce pt film samp le were an alyzed, and to facilitatetest an alysis, request samples made of circular p late, so the sam pie in terce pti on locati onchoice among wheels, most is show n in

16、figure 2. Using sca nning electr on microsc opean alysis of oxide filmFigure 1 MAO - 300 type nc micro-arc oxidati on po wer supply 僉.號(hào)翼:2-. < I I/ -h-l- ?- -* r - "少* %! - - Lt- :卜是 *“.：_ -Figure 2 after micro-arc oxidatio n magn esium alloy wheel hub casti ng andr I J.v h.H u _ I I I 11 I

17、J r r -' n J ,ru- JLHU? I ? r/ 11 . . y-d 坨 CT:已.十卩 "用 ”*2;L- “ n-V.J- i >- I _- p I .d -. A.' - i 宀."?！:>1r.lr- 二EH J - * ".亠in terce pti on of membra ne layer an alysis sampleThree micro-arc oxidati on p rocess p arameters on the quality of the filmBased on the researc

18、h of the sample and an alysis of micro-arc oxidatio n tech no logy is, in fact, the substrate mag nesium mag nesium oxide. Figure 3 for the dime nsion of samples before and after oxidatio n app eara nee schematic simulatio n, which is suitable for ceramic oxide film a outward growth, n amely the in

19、crease of size part, b is the depth of the internal oxidati on to the matrix, a and b in terface for in itial samp le surface po siti on, h for the total thickn ess of oxide film.4Figure 3 samp les dime nsion cha nges before and after micro-arc oxidati on diagramJV J14Larger in flue nee on test has

20、a po sitive voltage, freque ncy, duty cycle, curre nt den sity and oxidation time on the process parameters.Due to the electric casting of magnesium alloy surface area is larger, micro-arc oxidati on micro-arc discharge must be formed in the surface can occur after a certa in thick ness of oxide fil

21、m, so the formati on of the oxide film is n eeded for the voltage does n't n eed much, the curre nt is larger, the oxide film formati on and the p rocess of thicke ning, ofte n acco mpanied by curre nt and voltage mutati on. When the oxide film thick ness reaches a certa in degree, the n eed to

22、in crease the voltage on both ends of the work piece, usually at around 150 V in the micro arc discharge betwee n the work pi ece and the electrolyte. In creased with the in crease of voltage, curre nt, micro-arc den sity is more and more close, more and more bright, and micro-arc con sta ntly beat

23、ing, basically, the curre nt and voltage, li near in crease about 180 V voltage, the den sity of micro-arc basically meet the tech no logical requireme nts, the curre nt growth slowly. Whe n the thick ness of oxide film reaches a certa in electricityFrom electric casti ng magn esium alloys is not ha

24、rd to find in the micro-arc oxidati on test result an alysis, micro-arc oxidati on in the p rocess can be divided in to two ste ps, n amely the oxide film formatio n stage and the stage of micro-arc oxidati on film discharge, the formation of oxide film phase as the initial stage, the stage of the s

25、upply voltage is small, and after the film to produce micro-arc discharge requires high voltage, for magn esium alloy electric cast ing the large work pi ece with micro-arc oxidati on p rocess ing surface area is larger, the film for a long time, to a large extent affected the production efficie ncy

26、.Exp erime ntal results also found that the dc po wer of oxide film faster tha n pu Ise po wer, i n the abse nee of micro arc discharge, oxide film layer is not den se, it can be see nfrom appearance, need again with pulse power supply for micro-arc oxidation discharge, the oxide film become more de

27、nse. In order to improve the production efficiency, to meet the needs of industrial production, suggest early low voltage adjustable dc constant voltage power supply are available to set up the initial oxidation film, forming a complete insulation film in place to ensure that the first phase, and th

28、e oxide film in the late discharge can use digital pulse type adjustable power supply, it can shorten the artifacts of micro-arc oxidation time.The size of the current density in a certain extent reflects the intensity of micro-arc oxidation, strongly affect the resulting performance of the micro ar

29、c oxidation ceramic layer. The duration of oxidation also seriously affects the coating corrosion resistance: oxidation time is too short, although generated mainly the dense layer, but the film is too thin, don't have good corrosion resistance; After oxidation time is too long, at some time, wi

30、th the increase of time, although the overall film thickness increases, but the increase is a loose layer, layer density and thinning trend, does not favor the coating corrosion resistance, also not economic. The density of micro arc also related with the pulse frequency, when the pulse frequency in

31、creases, the density of micro arc also gradually increased. Will have the electric field set up suddenly, can produce micro arc. In the basic process parameters such as electrolyte concentration, duty ratio and pulse number of uncertain, the arc voltage is constant commonly, so when the frequency in

32、creases, the sustain micro-arc voltage frequency increases, the micro-arc density will increaseFour micro-arc oxide film layer structure characteristicsAfter micro-arc oxidation of magnesium alloy wheel hub interception by Mef3 large metallurgical microscope observation of the sample, the micro-arc

33、oxide film surface morphology as shown in figure 4. Can be seen from the figure in the wheel hub surface layer is made up of many tiny "small volcanic cone" (figure protuberant part around the holes) in dendritic combination, constitute the mesh structure. "Small volcanic cone" c

34、enter has a small hole, this is the electrolyte reaction with matrix micro-arc discharge channel, namely when the micro-arc spewed molten oxide channel. In addition, because the current micro area local plasma channel is different that differ by the size of the hole, big hole are also distributed ar

35、ound a large number of micro cracks, the generation of micro cracksoften related to the stress that exist in the film. With SSM Analysis Analysis software 6 to 414Figure 4 mag nesium alloy wheel hub micro-arc oxide film layer surface morp hologyUmJFigure 5 AM60B magn esium alloy micro-arc oxidati on

36、 film sect ion morp hology by SEMan alyze the surface den sity, in clud ing 25 m film for sample, the hole surface area ratio of 18%, that of micro-arc oxidati on film den sity is better.>frg2 '1*»嚴(yán)»zeku xf. eeeFigure 5 is through JMS - 6700 - f field emissi on sca nning electro n m

37、icrosc opy (sem) observed the micro-arc oxide film layer section morphology photos. Figure 5 shows the average film thick ness of about 22 (in clud ing m, the oxide film and substrate with good, deco mp ositi on of a disti net, den sity on the in terface is good, no big holes. By figure 5 can also s

38、ee, micro-arc oxide film by the outermost layer of loose layer, the in side of the tran siti on layer and layer in betwee n den sity of three p arts, the tran siti on al layer is the in terface film layer and substrate, holes and other defects existi ng in the loose layer, dense layer is the key to

39、improve its corrosi on resista nee.Figure 6 is obta ined by P hli p X 'pert X-ray diffractometer AM60B mag nesium alloy wheel hub of micro-arc oxidation film XRD spectrum, according to the intensity of diffracti on p eak accumulati on an alysis shows that the matrix of Mg p eak relatively obviou

40、s, the mai n p hase of micro-arc oxidatio n coat ing is cubic structure of MgO style, surface withMg2Si2O4 and MgAI2O4 spinel phase, according to the test conditions that may also contain SiO2, MgF2 and small amounts of Mg (OH) 2, and the oxide of Al, K and Na.Studies have show n that MgAl2O4 and Mg

41、2Si2O4 can improve the wear resista nee of ceramic layer and MgO style the corrosi on resista nee of ceramic layer p lay a very imp orta nt role. This is the micro-arc oxide film p erforma nee is higher tha n the root cause of the anode oxidation membrane performance.ln addition, micro-arc oxidation

42、 ceramic layers of low po rosity, and to improve the corrosi on resista nceof the coat in gs; Ceramic layer from the substrate on the growth, comb ined with matrix closely, therefore, is not easy to fall off. In additi on, the tech no logy can gen erate uniform film both in side and outside the mate

43、rial surface layer, expand the scope of app licati on of micro-arc oxidati on18000 予loom JIMTO-1000 JFigure 6 AM60B magn esium alloy micro-arc oxidati on film XRD sp ectrumTOFive To detect the corrosi on resista nee of the micro-arc oxide film layerIn order to meet the requireme nts of the use of el

44、ectric cars, micro-arc oxidati on on magn esium alloy electric wheel hub on the corrosi on resista nee test, salt spray test ing mach ine mainly USES the WJ - 90 after micro-arc oxidati on treatme nt of the surface of the wheel hub for salt spray test. After testi ng found that did not use hot water

45、 seal p rocess ing of the surface of the wheel hub 48 h corrosion rate was 0.108%, while only 0.073%, after hot water hole sealing hubs such as chromium than other chemical surface treatment processing of low corrosion rate (0.6%). 9, that magnesium alloy after micro-arc oxidation electric wheel hub

46、 surface corrosion resistance is superior. To evaluate a rough check the appearance of the film, feel is very good, membrane layer uniform light show that membrane surface appearance level is higher. Practice shows that without the micro-arc oxidation of the surface of the magnesium alloy wheel cast

47、ing coating, its poor corrosion resistance, abrasion resistance, in a very short period of time, began to appear on the surface of parts oxidation falls off phenomenon, it is difficult to sell in the market;After micro-arc oxidation treatment, its corrosion resistance, wear-resisting performance is

48、significantSix The conclusion(1) quality of micro-arc oxidation on magnesium alloy electric wheel hub surface influence factor has a positive voltage, frequency, duty cycle, current density and oxidation time on the process parameters.Optimum process parametersfor 150 180 V voltage, current density

49、of 1.1 A/dm2, oxidation time to 20 min, 400 Hz frequency, duty cycle of 20%.(2) the oxide film is divided into two layers of loose layer and dense layer structure, the dense layer is the main body, the film formed by cubic structure of MgO style, the surface is MgO style and MgA12O4, spinel phase mi

50、xture, and combined with matrix and closely for hard ceramic layer and played a key role of the magnesium alloy surface anticorrosion(3) the micro-arc oxidation technology for new surface treatment technology of environmental protection, but its large area needed for the magnesium alloy casting film

51、 for a long time, the production efficiency is low, the mass production to meet the large area of magnesium alloy castings, micro-arc oxidation power supply can be established by using dc power first initial oxidation film layer, then use pulse power arc discharge strengthening oxide film layer, the

52、 ways which are already so dense and hard ceramic oxide film layer can be obtained, also can greatly improve production efficiency. 鎂合金電動(dòng)車輪轂微弧氧化生產(chǎn)研究國(guó)內(nèi)外大多數(shù)電動(dòng)車車輛配置為鋁合金輪轂，其在質(zhì)量、節(jié)能、減震、降噪和車 輛動(dòng)力學(xué)特性等指標(biāo)大大低于鎂合金。鎂合金比鋁合金輕30%，減振效果是鋁合金的30倍。以鎂合金輪轂代替鋁合金輪轂，帶動(dòng)鎂合金材料開發(fā)和深加工技術(shù)發(fā)展， 達(dá)到降低電動(dòng)車自重及用電消耗，節(jié)能環(huán)保；減少振動(dòng)和噪聲；改善駕乘舒適度，提 高電動(dòng)

53、車輛動(dòng)力學(xué)特性等目的（交通工具質(zhì)量每減輕10%，能耗將減少8%10%）。 但它的耐蝕性差，嚴(yán)重限制了其應(yīng)用。常用的化學(xué)氧化和陽(yáng)極氧化形成的氧化膜對(duì)鎂 合金有一定的保護(hù)作用，但是其耐蝕性、環(huán)境友好性、外觀等方面還不能令人滿意， 急需開發(fā)新的表面處理方法。近年來，人們嘗試開發(fā)了各種新技術(shù)，如微弧氧化技術(shù)， 較好滿足了上述要求。微弧氧化又稱為微等離子體氧化，是近年來在普通陽(yáng)極氧化基 礎(chǔ)上開發(fā)的一種新技術(shù)。它采用較高的能量密度，通過熱化學(xué)、等離子體化學(xué)和電化 學(xué)的共同作用，鎂合金表面原位形成陶瓷質(zhì)氧化膜，極大地提高了鎂合金鑄件表面的 耐蝕性能，具有廣闊的應(yīng)用前景。一、微弧氧化機(jī)理微弧氧化技術(shù)是一種綠色

54、環(huán)保的新興表面處理工藝技術(shù)，可直接在輕金屬表面原 位生長(zhǎng)陶瓷層。其工藝特點(diǎn)明顯，表面處理的性能優(yōu)勢(shì)突出，自該技術(shù)被發(fā)明以來， 備受人們的青睞，其機(jī)理是將鋁、鎂、鈦等輕金屬或其合金置于電解質(zhì)水溶液中作為 陽(yáng)極，利用電化學(xué)方法在該材料的表面產(chǎn)生火花放電斑點(diǎn)，在熱化學(xué)、等離子體化學(xué)和電化學(xué)的共同作用下，獲得金屬氧化物陶瓷層的一種表面改性技術(shù)。二、研究方法及工藝本課題的研究對(duì)象是鎂合金電動(dòng)車輪轂， 對(duì)合金的韌性要求較高，故選用AM60B 其熔化初始溫度為468 C,熔化結(jié)束溫度為596 C,固液相線溫度區(qū)間為165 C。 其化學(xué)成分如表1所示。表1 AM60陪金化學(xué)成分（WW %）AlZnMnSiCu

55、NiFe雜質(zhì)余量5.6< 0.200.26 < 0.050.02Mg6.40.50.0080.0010.004由于鎂合金電動(dòng)車輪轂表面積比較大，一般在0.4 m2以上，要求微弧氧化電源較大，本課題采用蘭州理工大學(xué)材料學(xué)院開發(fā)的MAO-300型數(shù)控微弧氧化生產(chǎn)裝置（圖1）對(duì)鎂合金輪轂鑄件進(jìn)行微弧氧化處理，其裝置類似普通陽(yáng)極氧化設(shè)備，包括 微弧氧化專用高壓電源、堿性溶液電解槽、攪拌系統(tǒng)、冷卻系統(tǒng)，工件與不銹鋼板為 對(duì)等電極。用微弧氧化方法在硅酸鈉-氫氧化鈉電解液體系中制備鎂合金輪轂鑄件氧化陶瓷膜，具體工藝流程為先設(shè)定氧化工藝參數(shù)及配制堿性槽硅酸鈉溶液，將清洗后的鎂合金輪轂鑄件吊入電解槽

56、微弧氧化 1520 min，用清水槽清洗24 min，再放入熱水 中進(jìn)行熱水封閉（80 r，1015 min），然后在冷水槽冷卻2 min，吊出輪轂排水、 烘干、清理檢查。微弧氧化處理完后一定要通過熱水封閉， 這樣因微弧氧化放電形成 的小孔通道及周圍分布的大量微裂紋會(huì)封閉，防止氧氣進(jìn)入引起氧化。微弧氧化完成后，從微弧氧化后的鎂合金輪轂鑄件上截取膜層試樣進(jìn)行分析，為便于試驗(yàn)分析，要求試樣做成圓形片狀，故試樣截取位置選擇輪轂中間較大部分處， 如圖2所示。利用 掃描電鏡觀察分析氧化膜的表面和對(duì)試樣進(jìn)行測(cè)量。通過改變電解液的組成、設(shè)備工 藝參數(shù)調(diào)整等形式來改變生成膜層的組織和性能，從而得到適合鎂合金電

57、動(dòng)車輪轂需要的膜層和表面質(zhì)量要求。圖1 MAO-30（型數(shù)控微弧氧化電源圖2微弧氧化后鎂合金輪轂鑄件及截取膜層分析試樣處三、微弧氧化工藝參數(shù)對(duì)膜層質(zhì)量的影響通過對(duì)試樣的研究和分析，微弧氧化技術(shù)實(shí)際上是把基體鎂變?yōu)檠趸V。圖 為氧化前后樣品外形尺寸的變化示意圖的模擬： 其中a為陶瓷氧化膜向外生長(zhǎng)即尺寸 增加部分，b為向基體內(nèi)部氧化的深度，a、b分界面為樣品初始表面位置，h為氧化膜總厚度。!14MeO1圖3微弧氧化前后樣品外形尺寸的變化示意圖對(duì)試驗(yàn)影響較大的有正電壓、電流密度、頻率、占空比以及氧化時(shí)間等工藝參數(shù)。由于鎂合金電動(dòng)車鑄件的表面積比較大，而微弧氧化的微弧放電必須在工件表面形成 一定厚度的

58、氧化膜后才能發(fā)生，故氧化膜的形成所需的正電壓不需要很大， 所需的電 流則較大，在氧化膜形成并增厚的過程中，往往伴隨著電流和正電壓的突變。 當(dāng)氧化 膜厚度達(dá)到一定程度后，則需要增加工件兩端電壓，通常在 150 V左右就會(huì)在工件與電解液間產(chǎn)生微弧放電。隨著電壓的增加，電流不斷增大，微弧密度越來越密，越來 越明亮，且微弧在不停跳動(dòng)，此時(shí)電流與電壓基本上呈線性增加，電壓約為180 V， 微弧密度基本上達(dá)到了工藝的要求， 此時(shí)電流的增長(zhǎng)速度比較緩慢。當(dāng)氧化膜達(dá)到一 定厚度時(shí)，電壓即使增加，電流的增加也很小，基本上趨于恒定，這時(shí)在工件上的微 弧也逐漸稀薄，微弧氧化過程也就可以停止。如果繼續(xù)升高電壓，微弧就會(huì)明顯變大， 工件與電極之間會(huì)出現(xiàn)電弧光，導(dǎo)致氧化膜被坑蝕，甚至在氧化膜表面出現(xiàn)小裂紋， 使工件表面質(zhì)量變差。 微弧是在一定的電場(chǎng)激發(fā)下， 且在氧化膜與內(nèi)層金屬之間產(chǎn)生 的一種放電現(xiàn)象。從鎂合金電動(dòng)車鑄件微弧氧化試驗(yàn)結(jié)果分析中不難發(fā)現(xiàn)， 微弧氧化在工