英文翻译论文模板.docx

1、英文翻译论文模板本科生毕业设计专业外文翻译原 文： Magnesium alloy electric wheel hub micro-arc oxidation production research 译 文： 镁合金电动车轮毂微弧氧化生产研究 指导教师 ： 张清郁 职称： 讲师 学生姓名 ： 陈孟丽 学号：1002130301 专 业 ： 机械设计制造及其自动化 院（系） ： 机电工程学院 2015年4月10日Magnesium alloy electric wheel hub micro-arc oxidation production research Most electric veh

2、icles at home and abroad is configured to aluminum alloy wheel hub, 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

3、 aluminum alloy. Replace the aluminum 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 a

4、nd noise; Improve ride comfort and electric vehicle dynamic characteristics such as objective (transportation quality each reduce 10%, energy consumption will be reduced 8% 10%). But its corrosion resistance is poor, seriously limits the application. Commonly used chemical oxidation and anode oxidat

5、ion formation of oxide film on magnesium 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 technologie

6、s, such as micro arc oxidation technology, the betterOne Micro-arc oxidation mechanism Micro-arc oxidation technology is a new surface treatment technology of green environmental protection, can grow in light metal surface in situ ceramic layer directly. Its technological characteristics, surface tr

7、eatment, as well as the performance of 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 su

8、rface of the material, the thermal chemistry, plasma chemistry and electrochemistry, under the joint action of metal oxide ceramic layers of a surface modification technologyTwo research methods and technology This topic in the research on magnesium alloy electric wheel hub, higher requirements on t

9、he toughness of the alloy, so choose AM60B, melt and initial temperature of 468 , the melting end temperature is 596 , the liquidus temperature range of 165 . The chemical composition as shown in table 1.Table 1 AM60B alloy chemical composition (WB / %)AlZnMnSiCuNiFe杂质余量5.66.40.200.260.50.050.0080.0

10、010.0040.02Mg Because of the magnesium alloy electric wheel hub surface area is larger, general above 0.4 m2, require micro-arc oxidation power supply is bigger, this subject adopts the lanzhou university of technology institute of materials and development of MAO - 300 type nc micro-arc oxidation p

11、roduction device (figure 1) micro-arc oxidation on magnesium alloy wheel casting processing, its similar to ordinary anodic oxidation equipment, including special high-voltage power supply, micro-arc oxidation alkaline solution of electrolytic tank, mixing system, cooling system, workpiece with stai

12、nless steel plate for peer electrode.With micro-arc oxidation method in sodium silicate and sodium hydroxide electrolyte fluid system in the preparation of magnesium alloy wheel casting oxide ceramic membrane, the concrete technological process first set oxidation process parameters and the alkaline

13、 tank sodium silicate solution, the cleaning after micro-arc oxidation of magnesium alloy wheel casting into cell 15 20 min, clean with clear water tank 2 4 min, add hot water in hot water (80 , 10 15 min), closed, then cool in the cold water tank 2 min, hoisted out drainage, drying, examine the hub

14、. After micro-arc oxidation treatment must be closed by hot water, formed by micro-arc oxidation discharge holes so the distribution of the channel and the surrounding a large number of micro cracks will be closed, prevent oxygen to cause oxidation. After completion of micro-arc oxidation, from afte

15、r micro-arc oxidation on magnesium alloy wheel casting intercept film sample were analyzed, and to facilitate test analysis, request samples made of circular plate, so the sample interception location choice among wheels, most is shown in figure 2. Using scanning electron microscope analysis of oxid

16、e filmFigure 1 MAO - 300 type nc micro-arc oxidation power supplyFigure 2 after micro-arc oxidation magnesium alloy wheel hub casting and interception of membrane layer analysis sampleThree micro-arc oxidation process parameters on the quality of the filmBased on the research of the sample and analy

17、sis of micro-arc oxidation technology is, in fact, the substrate magnesium magnesium oxide. Figure 3 for the dimension of samples before and after oxidation appearance schematic simulation, which is suitable for ceramic oxide film a outward growth, namely the increase of size part, b is the depth of

18、 the internal oxidation to the matrix, a and b interface for initial sample surface position, h for the total thickness of oxide film.Figure 3 samples dimension changes before and after micro-arc oxidation diagramLarger influence on test has a positive voltage, frequency, duty cycle, current density

19、 and oxidation time on the process parameters. Due to the electric casting of magnesium alloy surface area is larger, micro-arc oxidation micro-arc discharge must be formed in the surface can occur after a certain thickness of oxide film, so the formation of the oxide film is needed for the voltage

20、doesnt need much, the current is larger, the oxide film formation and the process of thickening, often accompanied by current and voltage mutation. When the oxide film thickness reaches a certain degree, the need to increase the voltage on both ends of the workpiece, usually at around 150 V in the m

21、icro arc discharge between the workpiece and the electrolyte. Increased with the increase of voltage, current, micro-arc density is more and more close, more and more bright, and micro-arc constantly beating, basically, the current and voltage, linear increase about 180 V voltage, the density of mic

22、ro-arc basically meet the technological requirements, the current growth slowly. When the thickness of oxide film reaches a certain electricityFrom electric casting magnesium alloys is not hard to find in the micro-arc oxidation test result analysis, micro-arc oxidation in the process can be divided

23、 into two steps, namely the oxide film formation stage and the stage of micro-arc oxidation film discharge, the formation of oxide film phase as the initial stage, the stage of the supply voltage is small, and after the film to produce micro-arc discharge requires high voltage, for magnesium alloy e

24、lectric casting the large workpiece with micro-arc oxidation processing surface area is larger, the film for a long time, to a large extent affected the production efficiency.Experimental results also found that the dc power of oxide film faster than pulse power, in the absence of micro arc discharg

25、e, oxide film layer is not dense, it can be seen from appearance, need again with pulse power supply for micro-arc oxidation discharge, the oxide film become more dense. In order to improve the production efficiency, to meet the needs of industrial production, suggest early low voltage adjustable dc

26、 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 the oxide film in the late discharge can use digital pulse type adjustable power supply, it can shorten the artifacts of micro-arc oxidat

27、ion 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 arc oxidation ceramic layer. The duration of oxidation also seriously affects the coating corrosion resistance: oxidation time is too sho

28、rt, although generated mainly the dense layer, but the film is too thin, dont have good corrosion resistance; After oxidation time is too long, at some time, with the increase of time, although the overall film thickness increases, but the increase is a loose layer, layer density and thinning trend,

29、 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 increases, the density of micro arc also gradually increased. Will have the electric field set up suddenly, can produce micro arc. In the basi

30、c process parameters such as electrolyte concentration, duty ratio and pulse number of uncertain, the arc voltage is constant commonly, so when the frequency increases, the sustain micro-arc voltage frequency increases, the micro-arc density will increaseFour micro-arc oxide film layer structure cha

31、racteristicsAfter micro-arc oxidation of magnesium alloy wheel hub interception by Mef3 large metallurgical microscope observation of the sample, the micro-arc 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

32、 volcanic cone (figure protuberant part around the holes) in dendritic combination, constitute the mesh structure. Small volcanic cone center 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 around a large number of micro cracks, the generation of micro cracks often related to the stress that ex