制造业用于提高表面光洁度和减少切削力的抛丸清理机-毕设翻译

./毕业设计〔论文〕英文资料翻译MicroShotBlastingofMachineTools学院：西北工业大学明德学院专业：机械设计制造与自动化班级：161003班__王伟学号：指导2015年6月MicroshotblastingofmachinetoolsforimprovingsurfacefinishandreducingcuttingforcesinmanufacturingD.M.Kennedy*,J.Vahey,D.HanneyFacultyofEngineering,DublinInstituteofTechnology,BoltonStreet,Dublin1,IrelandReceived5January2004;accepted3February2004Availableonline13April2004AbstractMicroblastingofcuttingtipsandtoolsisaveryeffectiveandreliablemethodofadvancingthelifeoftoolsundertheactionofturning,milling,drilling,punchingandcutting.Thispaperoutlinesthewaysinwhichmicroblastedtools,bothcoatedanduncoatedhavebenefitedfromshotblastingandresultedingreaterproductivity,lowercuttingforces,improvedsurfacefinishoftheworkpiecesandlessmachinedowntime.Theprocessofmicroblastingisdiscussedinthepaper.Itseffectivenessdependsonmanyparametersincludingtheshotmediaandsize,themechanicsofimpactandtheapplicationoftheshotviathemicroshotblastingunit.Controloftheprocesstoproviderepeatabilityandreliabilityintheshotblastingunitisdiscussed.Comparisonsbetweentreatedanduntreatedcuttingtoolsaremadeandresultsoftoollifeforthesecuttingtipsoutlined.Theprocesshasshowntobeofmajorbenefittotoollifeimprovement.2004ElsevierLtd.Allrightsreserved.Keywords:Microshotblasting;Surfacefinish;Machinetools1.IntroductionManymoderntechniqueshavebeendevelopedtoenhancethelifeofcomponentsinservice,suchasalloyingadditions,heattreatment,surfaceengineering,surfacecoating,implantationprocesses,lasertreatmentandsurfaceshapedesign.Processessuchasthinfilmtechnology,plasmaspraying,vacuumtechniquesdepositingarangeofmulti-layeredcoatingshavegreatlyenhancedthelife,useandapplicationsofengineeringcomponentsandmachinetools.Bombardmentwithmillionsofmicroshotranginginsizefrom4to50lmwithacontrolledprocesscanleadtodramaticoperatinglifeimprovementsofcomponents.StandardshotpeeningwasfirstusedinaproductionprocesstoextendthelifeofvalvespringsforBuickandCadillacenginesintheearly1930s[1,2]butpriortothisitwasawellknownprocessusedbyblacksmithsandswordmakersovertimetoimprovethetoughnessofthecuttingedgesoftheirtoolsandweapons.Today,cuttingtipsandtoolscanbegreatlyimprovedbytheprocessofmicroshotblastingtheirsurfacestoinducecompressiveresidualstresses.Theoperatinglifeoftoolssuchasdrills,turningtips,millingtips,punches,knifeedges,slicers,blades,andarangeofotherworkingpartscanalsobenefitfromthisprocess.Standardcomponents,suchassprings,dies,shafts,cams,anddynamiccomponentsinmachinesandenginescanbeenhancedbythisprocess.Thefatiguelifeofcompressorcomponentsforexample,treatedbyshotpeeninghaveincreaseddramaticallyasreportedbyEckersleyandFerrelli[3].Otherfactorssuchasimprovedfatigueresistance,microcrackclosure,reducedcorrosionandanimprovedsurfacefinishcanalsobedesignedintocomponentsasaresultofthisthepeeningprocess.Notonlycanimprovementsbemadetothesurfacefinishofthecuttingtipsandtoolsbutalsothesurfacefinishoftheworkpiecesmachinedwiththesetoolshaveimprovedasaresultofthistechnique.Engineeringmaterialssuchastoolssteels,carbides,ceramics,coatedcarbides,throughtopolymersandevenrubbers<elastomers>canbenefit.Thekeyrequirementforthisprocessistodevelopanautomatedmicroblastingprocesstofitinsideasprayboothorstandardshotblastingbooth.Shotmaterial,sizeandmass,operatingpressures,operatingvelocities,kineticenergy,densityandcoveragetimewillneedtobeperfectedandoptimisedforarangeofmaterials.Theprocessisalineofsightmethodbutcanbeappliedtocomplexsurfaceshapessuchasthetipsofdrillbits.2.MethodofoperationOneoftheprimarywaysthatcomponentsfailinerviceisthroughfatigue.Thisiscloselyassociatedwithcyclicstressesandacceleratedbytensilestresses,microcrackpropagationandstresscorrosioncracking.Cracksreducethecrosssectionofamaterialandeventuallyitwillfailtosupporttheappliedloads.Onesimplemethodofreducingfailurebyfatigueistoarrestthesetensilestressesbyinducingcompressivestressesintoasurface.Thebenefitsobtainedwithshotpeeningareadirectresultoftheresidualcompressivestressesproducedinacomponent.AtypicalshotstrikingasurfaceisshowninFig.1.AnyappliedtensileloadswouldhavetoovercometheresidualcompressivestressesbeforeacrackcouldinitiateasdescribedbyAlmen[4].Poormachiningofmaterialscanresultinresidualstressesaccruingatthesurface.Roughsurfaceshavedeepernotches,wherecrackscaninitiateduetotensilestressconcentrationsatthesepoints.Manystandardmachiningprocessessuchasgrinding,milling,turning,andcoatingprocessessuchaselectroplatinginduceresidualtensilestressesinsurfacesandthiscanleadtoearlyfailureofcomponents.Furthertensileloadinginservicewouldleadtoearlyfailureandthiscanbepreventedbyshotpeeningandmicroblastingofcomponentsurfaces.Microshotblastingwillchangethefollowinginamaterialssurface:<i>resistancetofatiguefracture;<ii>resistancetostresscorrosion;<iii>achangeinresidualstresses;<iv>modificationofsurfacefinish.Itisacoldworkingprocessinvolvingbombardingpowderssuchasceramics,glassandmetalsofmainlysphericalshapesagainstsurfacesandcanbeusedinconjunctionwithotherprocesses.Themainstagesinvolvedinthisdynamicprocessincludeelasticrecoveryofthesubstrateafterimpact,someplasticdeformationofthesubstrateiftheimpactpressureexceedstheyieldstress,increasedplasticdeformationduetoanincreaseinimpactpressureandfinallysomereboundoftheshotduetoareleaseofelasticenergy.Somecriticaldesigncharacteristicsofthemicroshotpeeningprocessincludetheshotsize,shape,hardness,density,durability,angleofimpact,velocityandintensity.Alloftheseparameterswillinfluencetheresidualcompressivestressesproducedinthesubstrate.3.ExperimentalworkToolmaterialssuchasTungstenCarbide,HighSpeedSteelsusedinmillingandturningtoolsweresubjectedtothemicropeeningprocessusingdifferentshotmedia<ceramicandglassbead>andshotsize.Testspriortoandfollowingtheblastingprocesswereconductedtoascertainanyimprovementsresultingfromtheprocess.ThemicroshotpeeningunitisshowninPhoto1itincorporatesanairfilter,pressureregulatorandgauge,airflowregulator,pressurisedblastmediacontainerandaventuriblastnozzlefordirectingthestreamofmicroshot.TheunitisPLCcontrolledandasteppermotor,usedtodrivealeadscrew,isusedtomovetheblastnozzleacrossthesampleinordertocontrolmediashotcoverage.Theblastnozzlecanalsoberotatedtoallowshotmediatostrikethesamplesatdifferentangles.Testsundertakenincludesurfacefinishandroughnessmeasurement,machiningtestsonstandardlathesandmills,hardnesstests,cuttingforcesonturningoperations,toolwearandthedeterminationofsurfacefinishoftheworkpiecesmachined.Figs.2and3showatypicalhighspeedsteel<HSS>tippriortoandfollowingthemicroshotpeeningprocessusingceramicbeadatapressureof5.5bar.4.ExperimentalresultsTestingoftreatedanduntreatedcuttingtipsandtoolswasconductedonHSSsforturningandmillingaswellascoatedanduncoatedcarbideinserts.Adynamometerwasusedtomeasurecuttingforcesontheturningtool<Lathe>.Thecuttingprocessconsistedofadepthofcutof2mmonastandardbrightmildsteelspecimenoveralengthof750mmwhilemillingtestsconsistedofmachininga25_25_150mmpieceofmildsteelusingadepthofcutof1mmwithaslotmillingcutterof18mmdiameter.Surfaceroughnessmeasurementswereconductedonthemachinedcomponentspriortoandaftermachiningtoestablishwhetherthetreatedcuttingtipshadsuperiorperformancetotheuntreatedtips.MicroHardnesstestingwasalsocarriedouttoestablishiftherewasanyincreaseinsurfacehardnessduetothemicroshotpeeningprocess.Theimpactangleoftheshotwassetat90_asthisprovidestheoptimumcompressivelayer[5].Theshotvelocityonimpactwithasurfaceislargelydependentonthenozzlesize,theairpressureandthedistancefromthesubstrate.TheexposuretimewasadequatetogivesufficientcoverageofthesubstrateandthiswasdeterminedbytheAlmenstripsaturationtime,workpieceindentationtimeandvisualappearance.Hardermaterialssuchascarbideswillobviouslyrequirelongerexposuretimeorhardershotmedia.Themicropeeningmediausedwasaceramicbeadofapproximately40lmdiameterprovidinghighimpactstrengthandhardness<NFL06-824,approximately60HRc>.4.1.MicrohardnesstestsCombinedVickersmicrohardnesstestsgavetheresultsinTable1.forbothtreatedanduntreatedHSScuttingtips.4.2.SurfaceroughnessvaluesInallsurfaceroughnesstestsconducted,themicroblastedsurfacegaveanimprovedsurfaceroughnessvalue.SurfaceroughnessandprofiletestswerecarriedoutonbothaTalyorHobsonTallysurfinstrumentandanoncontactsurfaceprofileometer.SurfaceroughnessdetailsofatypicaluntreatedHSScuttingtipandatreatedoneareshowninFigs.4and5andTable2showstheresultsofsurfacemeasurementvaluesforothercuttingtipsandtoolsandworkpieces.Fig.6showsanuncoatedcarbidecuttingtipwhichwasnotsubjectedtomicroblasting.Theflankwearwasmeasuredusinganopticalmicroscopeandthevaluerecordedwas150lmafter676sofmachining.Fig.7showsanuncoatedcarbidetipsubjectedtomicroblasting.Theflankwearinthiscaseisonly90lmforthesamemachiningtime.and5andTable2showstheresultsofsurfacemeasurementvaluesforothercuttingtipsandtoolsandworkpieces.Fig.6showsanuncoatedcarbidecuttingtipwhichwasnotsubjectedtomicroblasting.Theflankwearwasmeasuredusinganopticalmicroscopeandthevaluerecordedwas150lmafter676sofmachining.Fig.7showsanuncoatedcarbidetipsubjectedtomicroblasting.Theflankwearinthiscaseisonly90lmforthesamemachiningtime.4.3.DynamometertestsFigs.8and9showthecomparisonforDynamometerresultsforHSSinthetreated<microblasted>anduntreatedstateswithrelevantcomments.Similarprofilesareshownforcoatedanduncoatedturningtipsinboththetreated<microblasted>anduntreatedconditionsinFigs.10–13.Inallcases,themicroblastedtipsprovidedanincreaseincuttingtiplifewithlowercuttingforcesrecorded.5.ConclusionsThisresearchworkhasshownthatmicroshotblastingofcuttingtipsandtoolshasaverypositiveeffectoncomponentsurfacesbyincreasingtoughness,operatinglife,improvinghardnessandsurfacefinish.Fromthetestsconducted,itisobviousthattheprocessaffectstheresidualstressesatornearthesurfaceinabeneficialwaybyinducingcompressivestressesonthesubstratestested.Themicroblastingprocessisverysimpletoapplyandeconomicaltouse.Themechanicalpropertiesofthesubstrateswilldeterminethetypeoftreatment,i.e.shothardness,velocityanddurationofapplicationinordertoobtainmaximumbenefitsfromthisprocess.Insomecases,authorshavereporteda4–10foldimprovementinfatiguelifeinarangeofdynamicmachinepartssubjectedtostandardshotblasting.Furthertestingwillneedtobeconductedatthemicroshotblastingstagetoobtainsimilarbenefits.Otherapplicationsforthemicroblastingprocessarecurrentlybeinginvestigatedandrubberbasedproductsthataresubjectedtofatigueandweararebeingtestedinordertoremovethesurfacevoidsthatactasstressconcentrationsinthesematerials.References[1]Impact.Bloomfield,CT:MetalImprovementCompany;Fall1989.[2]ZimmerliFP.Heattreating,settingandshot-peeningofmechanicalsprings.Metalprocess;June1952.[3]EckersleyJS,FerrelliB.Usingshot-peeningtomultiplythelifeofcompressorcomponents.In:Theshotpeener,Internationalnewsletterforshot-peeningsurfacefinishingindustry,vol.9,IssueNo.1;March1995.[4]AlmenJC.J.O.Almenonhotblasting.Generalmotorstest,USPatent2,350,440.[5]ChampaigneJ.Controlledshotpeening.ElecInc.,Report;1989.制造业用于提高表面光洁度和减少切削力的抛丸清理机摘要在旋转,铣削,钻孔,冲孔和切削运动中,微抛丸切削技巧和工具是一种提高工具寿命的非常高效并且可靠的方法。本文概述了应用微抛丸工具的方式,微抛丸对有无镀膜工件的益处,并且创造了更大的生产力,降低了切应力,提高了工件的表面光洁度,减少了机器的停机时间。本文对微抛丸过程进行了讨论。它的效率取决于包括弹丸媒体和型号在内的许多参数,碰撞力学和通过微抛丸单元的弹丸的应用程序。对控制流程提供的可重复性和可靠性的爆破装置进行了探讨。处理和未经处理的刀具的做出了对比,切割技巧对刀具寿命的影响做出了概述。这个过程体现了提高工具寿命的主要好处。2004爱思唯尔XX保留所有权利。关键词:微喷丸清理,表面光洁度;机床介绍许多现代技术已经开发出来加强服务组件的寿命,例如添加合金,热处理,表面工程,表面涂层,移植过程,激光治疗以与表面外形设计。例如薄膜技术,等离子喷涂,沉淀多层涂料的真空技术都大大加强了寿命,工程和应用程序组件和机床使用。通过控制过程用数以百万计的大小在4到50微米的微抛丸撞击可以显著提高组件的使用寿命。标准喷丸技术首次使用时在20世纪30年代提高别克和凯迪拉克引擎气门弹簧的生产过程中,但在此之前该技术就是被铁匠和刀制造商所熟知的来提高他们工具和武器切削刃韧性的过程。当今,切割技巧和工具可以通过微抛丸清理它们的表面的过程来引导压缩参与应力而被大大提高。钻头,车削头,铣削头,冲头,刀刃,切片机,叶片以与一系列的其他工作部分都可以受益于该过程。机器和引擎中的标准组件,例如离合器,柴油机,轴,凸轮以与动态组件等都可以通过该过程提高。由Eckersley和Ferrelli所述,例如压缩机组件的疲劳寿命通过抛丸处理可以显著增加。其他因素,例如抗疲劳强度,微裂纹闭合,减少腐蚀以与提高表面光洁度都可以被作为喷丸的结果而被设计进组件当中。不仅可以做到切削刀具表面光洁度的提高,而且由这些刀具加工的工件的表面光洁度作为该技术的一个成果也得到了提高。工程材料中,例如工具钢,硬质合金,陶瓷,涂层硬质合金,通过聚合物甚至橡胶〔弹性物〕都可以受益。这个过程的关键要求是开发一个自动化微抛丸的工艺过程来适用于喷漆柜或者标准抛丸位置。抛丸材料,大小和质量,操作压力,操作速度,动能,密度,覆盖时间都要被完美优化一系列材料。这个过程是一种视线方法却可以应用于复杂外形例如钻孔。操作方法服务组件损坏的主要原因之一是疲劳使用。这是与循环应力密切相关,加速了抗拉应力,微裂纹扩展和应力腐蚀开裂。裂纹减少材料的横截面,最终它将无法支持应用加载。减少疲劳的失败的一个简单方法是通过诱导压应力到表面来停止这些拉伸应力。抛丸加工直接产生的好处是一个组件产生的残余压应力。典型的镜头的表面是图1所示。在由阿尔门[4]描述的裂纹出现之前,任何应用拉伸加载将不得不克服残余压应力。不良的加工材料会导致残留表面压力积累。粗糙表面有更深层次的等级,在这些点,由于拉应力会产生裂纹。许多标准磨削,铣削、车削和涂层工艺例如电镀等加工过程,在表面产生残余拉应力,这可能会导致早期失效的组件。进一步拉伸加载服务会导致早期失效,这可以防止喷丸加工和微抛丸组件表面。微抛丸处理将改变以下材料表面：抗疲劳断裂；抗应力腐蚀；