英文翻译论文模板Word文档下载推荐.docx

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Al

Zn

Mn

Si

Cu

Ni

Fe

杂质

余量

5.6～6.4

≤0.20

0.26～0.5

≤0.05

≤0.008

≤0.001

≤0.004

0.02

Mg

Becauseofthemagnesiumalloyelectricwheelhubsurfaceareaislarger,generalabove0.4m2,requiremicro-arcoxidationpowersupplyisbigger,thissubjectadoptsthelanzhouuniversityoftechnologyinstituteofmaterialsanddevelopmentofMAO-300typencmicro-arcoxidationproductiondevice（figure1）micro-arcoxidationonmagnesiumalloywheelcastingprocessing,itssimilartoordinaryanodicoxidationequipment,includingspecialhigh-voltagepowersupply,micro-arcoxidationalkalinesolutionofelectrolytictank,mixingsystem,coolingsystem,workpiecewithstainlesssteelplateforpeerelectrode.

Withmicro-arcoxidationmethodinsodiumsilicateandsodiumhydroxideelectrolytefluidsysteminthepreparationofmagnesiumalloywheelcastingoxideceramicmembrane,theconcretetechnologicalprocessfirstsetoxidationprocessparametersandthealkalinetanksodiumsilicatesolution,thecleaningaftermicro-arcoxidationofmagnesiumalloywheelcastingintocell15~20min,cleanwithclearwatertank2~4min,addhotwaterinhotwater（80℃,10~15min）,closed,thencoolinthecoldwatertank2min,hoistedoutdrainage,drying,examinethehub.Aftermicro-arcoxidationtreatmentmustbeclosedbyhotwater,formedbymicro-arcoxidationdischargeholessothedistributionofthechannelandthesurroundingalargenumberofmicrocrackswillbeclosed,preventoxygentocauseoxidation.Aftercompletionofmicro-arcoxidation,fromaftermicro-arcoxidationonmagnesiumalloywheelcastinginterceptfilmsamplewereanalyzed,andtofacilitatetestanalysis,requestsamplesmadeofcircularplate,sothesampleinterceptionlocationchoiceamongwheels,mostisshowninfigure2.Usingscanningelectronmicroscopeanalysisofoxidefilm

Figure1MAO-300typencmicro-arcoxidationpowersupply

Figure2aftermicro-arcoxidationmagnesiumalloywheelhubcastingandinterceptionofmembranelayeranalysissample

Threemicro-arcoxidationprocessparametersonthequalityofthefilm

Basedontheresearchofthesampleandanalysisofmicro-arcoxidationtechnologyis,infact,thesubstratemagnesiummagnesiumoxide.Figure3forthedimensionofsamplesbeforeandafteroxidationappearanceschematicsimulation,whichissuitableforceramicoxidefilmaoutwardgrowth,namelytheincreaseofsizepart,bisthedepthoftheinternaloxidationtothematrix,aandbinterfaceforinitialsamplesurfaceposition,hforthetotalthicknessofoxidefilm.

Figure3samplesdimensionchangesbeforeandaftermicro-arcoxidationdiagram

Largerinfluenceontesthasapositivevoltage,frequency,dutycycle,currentdensityandoxidationtimeontheprocessparameters.Duetotheelectriccastingofmagnesiumalloysurfaceareaislarger,micro-arcoxidationmicro-arcdischargemustbeformedinthesurfacecanoccurafteracertainthicknessofoxidefilm,sotheformationoftheoxidefilmisneededforthevoltagedoesn'

tneedmuch,thecurrentislarger,theoxidefilmformationandtheprocessofthickening,oftenaccompaniedbycurrentandvoltagemutation.Whentheoxidefilmthicknessreachesacertaindegree,theneedtoincreasethevoltageonbothendsoftheworkpiece,usuallyataround150Vinthemicroarcdischargebetweentheworkpieceandtheelectrolyte.Increasedwiththeincreaseofvoltage,current,micro-arcdensityismoreandmoreclose,moreandmorebright,andmicro-arcconstantlybeating,basically,thecurrentandvoltage,linearincreaseabout180Vvoltage,thedensityofmicro-arcbasicallymeetthetechnologicalrequirements,thecurrentgrowthslowly.Whenthethicknessofoxidefilmreachesacertainelectricity

Fromelectriccastingmagnesiumalloysisnothardtofindinthemicro-arcoxidationtestresultanalysis,micro-arcoxidationintheprocesscanbedividedintotwosteps,namelytheoxidefilmformationstageandthestageofmicro-arcoxidationfilmdischarge,theformationofoxidefilmphaseastheinitialstage,thestageofthesupplyvoltageissmall,andafterthefilmtoproducemicro-arcdischargerequireshighvoltage,formagnesiumalloyelectriccastingthelargeworkpiecewithmicro-arcoxidationprocessingsurfaceareaislarger,thefilmforalongtime,toalargeextentaffectedtheproductionefficiency.

Experimentalresultsalsofoundthatthedcpowerofoxidefilmfasterthanpulsepower,intheabsenceofmicroarcdischarge,oxidefilmlayerisnotdense,itcanbeseenfromappearance,needagainwithpulsepowersupplyformicro-arcoxidationdischarge,theoxidefilmbecomemoredense.Inordertoimprovetheproductionefficiency,tomeettheneedsofindustrialproduction,suggestearlylowvoltageadjustabledcconstantvoltagepowersupplyareavailabletosetuptheinitialoxidationfilm,formingacompleteinsulationfilminplacetoensurethatthefirstphase,andtheoxidefilminthelatedischargecanusedigitalpulsetypeadjustablepowersupply,itcanshortentheartifactsofmicro-arcoxidationtime.

Thesizeofthecurrentdensityinacertainextentreflectstheintensityofmicro-arcoxidation,stronglyaffecttheresultingperformanceofthemicroarcoxidationceramiclayer.Thedurationofoxidationalsoseriouslyaffectsthecoatingcorrosionresistance:

oxidationtimeistooshort,althoughgeneratedmainlythedenselayer,butthefilmistoothin,don'

thavegoodcorrosionresistance;

Afteroxidationtimeistoolong,atsometime,withtheincreaseoftime,althoughtheoverallfilmthicknessincreases,buttheincreaseisalooselayer,layerdensityandthinningtrend,doesnotfavorthecoatingcorrosionresistance,alsonoteconomic.Thedensityofmicroarcalsorelatedwiththepulsefrequency,whenthepulsefrequencyincreases,thedensityofmicroarcalsograduallyincreased.Willhavetheelectricfieldsetupsuddenly,canproducemicroarc.Inthebasicprocessparameterssuchaselectrolyteconcentration,dutyratioandpulsenumberofuncertain,thearcvoltageisconstantcommonly,sowhenthefrequencyincreases,thesustainmicro-arcvoltagefrequencyincreases,themicro-arcdensitywillincrease

Fourmicro-arcoxidefilmlayerstructurecharacteristics

Aftermicro-arcoxidationofmagnesiumalloywheelhubinterceptionbyMef3largemetallurgicalmicroscopeobservationofthesample,themicro-arcoxidefilmsurfacemorphologyasshowninfigure4.Canbeseenfromthefigureinthewheelhubsurfacelayerismadeupofmanytiny"

smallvolcaniccone"

（figureprotuberantpartaroundtheholes）indendriticcombination,constitutethemeshstructure."

Smallvolcaniccone"

centerhasasmallhole,thisistheelectrolytereactionwithmatrixmicro-arcdischargechannel,namelywhenthemicro-arcspewedmoltenoxidechannel.Inaddition,becausethecurrentmicroarealocalplasmachannelisdifferentthatdifferbythesizeofthehole,bigholearealsodistributedaroundalargenumberofmicrocracks,thegenerationofmicrocracksoftenrelatedtothestressthatexistinthefilm.WithSSMAnalysisAnalysissoftware[6]toanalyzethesurfacedensity,including25mfilmforsample,theholesurfacearearatioof18%,thatofmicro-arcoxidationfilmdensityisbetter.

Figure4magnesiumalloywheelhubmicro-arcoxidefilmlayersurfacemorphology

Figure5AM60Bmagnesiumalloymicro-arcoxidationfilmsectionmorphologybySEM

Figure5isthroughJMS-6700-ffieldemissionscanningelectronmicroscopy（sem）observedthemicro-arcoxidefilmlayersectionmorphologyphotos.Figure5showstheaveragefilmthicknessofabout22（includingm,theoxidefilmandsubstratewithgood,decompositionofadistinct,densityontheinterfaceisgood,nobigholes.Byfigure5canalsosee,micro-arcoxidefilmbytheoutermostlayeroflooselayer,theinsideofthetransitionlayerandlayerinbetweendensityofthreeparts,thetransitionallayeristheinterfacefilmlayerandsubstrate,holesandotherdefectsexistinginthelooselayer,denselayeristhekeytoimproveitscorrosionresistance.

Figure6isobtainedbyPhlipX'

pertX-raydiffractometerAM60Bmagnesiumalloywheelhubofmicro-arcoxidationfilmXRDspectrum,accordingtotheintensityofdiffractionpeakaccumulationanalysisshowsthatthematrixofMgpeakrelativelyobvious,themainphaseofmicro-arcoxidationcoatingiscubicstructureofMgOstyle,surfacewithMg2Si2O4andMgAl2O4spinelphase,accordingtothetestconditionsthatmayalsocontainSiO2,MgF2andsmallamountsofMg（OH）2,andtheoxideofAl,KandNa.StudieshaveshownthatMgAl2O4andMg2Si2O4canimprovethewearresistanceofceramiclayerandMgOstylethecorrosionresistanceofceramiclayerplayaveryimportantrole.Thisisthemicro-arcoxidefilmperformanceishigherthantherootcauseoftheanodeoxidationmembraneperformance.Inaddition,micro-arcoxidationceramiclayersoflowporosity,andtoimprovethecorrosionresistanceofthecoatings;

Ceramiclayerfromthesubstrateonthegrowth,combinedwithmatrixclosely,therefore,isnoteasytofalloff.Inaddition,thetechnologycangenerateuniformfilmbothinsideandoutsidethematerialsurfacelayer,expandthescopeofapplicationofmicro-arcoxidation.

Figure6AM60Bmagnesiumalloymicro-arcoxidationfilmXRDspectrum

FiveTodetectthecorrosionresistanceofthemicro-arcoxidefilmlayer

Inordertomeettherequirementsoftheuseofelectriccars,mic