先进制造技术--施平五单元

1AdvancedManufacturingTechnology先进制造技术施平Part52Contents•1.IntroductiontoAMT•2.Computerandcommunication•3.Computer-aidedengineering•4.Automation•5.Modernmanufacturingtechnologies35.Modernmanufacturingtechnologies•Basictheoryandmoderntechnology–Technologicalchangeinmanufacturingengineeringisphenomenalandspeeding–Basictheories(likemetalcuttingtheory)arethefoundationofthesophisticatedtechnologies45.Modernmanufacturingtechnologies•Precisionengineering–Qualityimprovementsofproductsrequirestheenhancementofprecisionofproductionsystem5.1Modernmanufacturingtechnologies-Precisionengineering55.Modernmanufacturingtechnologies•Basicdefinitions–Accuracy•Aquantitativemeasureofthedegreeofconformancetorecognizednationalorinternationalstandardsofmeasurement–Repeatability•Ameasureoftheabilityofamachinetopositionatoolsequentiallywithrespecttoworkpieceundersimilarconditions–Resolution•Theleastincrementofameasuringdevice•Theleastsignificantbitonadigitalmachine5.1Modernmanufacturingtechnologies-Precisionengineering65.Modernmanufacturingtechnologies•Motion–Slide–Spindle•Rigidelement–Wetreatindividualelementasrigidbody•Flexiblestructure–Thewholestructuremaybeflexibleduetodeflectionsandjoints5.2Modernmanufacturingtechnologies-Precisionengineering75.Modernmanufacturingtechnologies•Rigidbodymotionanderror•Theslide–5constraints(Y,ZmovementalongY,Z,rotationaboutX,Y,Z)–1DOF(movementalongX)–WecontrolX,whiletreatingtheother5DOFsaserrors5.2Modernmanufacturingtechnologies-Precisionengineering85.Modernmanufacturingtechnologies•Categoriesofsourcesoferrorsofamachinetool–Geometricerrors•Causedbylackofstraightnessinslide-ways,staticdeflectionofmachinetool,angularerrors–Dynamicerrors•Causedbymachinetoolvibration(chatter)•Inherentfrequency(avoidthe1st,2nd,…)andresonance•Stiff,lightweight,well-dampedmachinetoolhaslessdynamicerror–Work-pieceeffects•Machinetooldeflectioncausedbyfixingandcuttingforcesduringcuttingprocess•Inertialeffectsduetomotion:over-shootonalinearmotion;periodicdeviationscausedbydynamicunbalanceduetopartasymmetryaboutrotationalaxis(likethespindleaxis)–Thermalerrors•Expansionwhenheated,contractionwhencooled•Temperaturecontrol:air-condition,warming-uptimebeforeoperation5.2Modernmanufacturingtechnologies-PrecisionengineeringPerfectmachinewithouterrorsdoesnotexistAllmachinetoolshavegeometricerrors95.Modernmanufacturingtechnologies•Traditionalfinishingoperations–Honing•Holesurfaceprocessing•Radiallyfloating,axiallyreciprocatingmovement5.3Modernmanufacturingtechnologies-finishingoperation105.Modernmanufacturingtechnologies•Traditionalfinishingoperations–Super-finishing•Pressureforceverylight•Stonestrokeveryshort5.3Modernmanufacturingtechnologies-finishingoperation115.Modernmanufacturingtechnologies•Traditionalfinishingoperations–Lapping•Abrasiveparticlesinaslurry•Surfacefinish0.025~0.1µm–Polishing•Non-traditionalfinishingoperation–Chemicalmechanicalpolishing•Achemicalreactionoccurred(example:siliconwaferpolishing)–Electro-polishing•Electrolyteattackstheprojectionsandpeaksonthework-piecesurfacetogetafinesurface–Polishingprocessusingmagneticfields5.3Modernmanufacturingtechnologies-finishingoperation125.Modernmanufacturingtechnologies•AimofCoatedtools–Tocopewiththeuniquepropertiesofnewmaterials•Highsrength,Toughness,Chemicalproperties•Coatingmaterial–Generalcharacteristics•Highhardness•Chemicalstabilityandinertnesstothework-piecematerial•Lowthermalconductivity•Goodbondingtothesubstratetopreventflaking•Littleornoporosity–commonlyusedcoatingmaterials•TiN,titaniumnitride:lowfrictioncoefficient,highhardness,resistancetohightemperature,goodadhesiontosubstrate.Performswellathighercuttingspeed•TiCtitaniumcarbide:similarproperties•TiCNtitaniumcarbonitride:goodwearresistancewhencuttingcarbonsteel,alloysteel,castiron•Al2O3AluminumOxide:lowthermalconductivity,highhothardness,wearresistance5.3Modernmanufacturingtechnologies-coatedtools135.Modernmanufacturingtechnologies•Substratematerial•HSS,highspeedsteel•Cementedcarbide•Ceramic•Super-hardmaterial•Coatingprocess–CVD,chemicalvapordeposition•ChemicalVaporDepositionischemicalreactionswhichtransformgaseousmolecules,calledprecursor,intoasolidmaterial,intheformofthinfilmorpowder,onthesurfaceofasubstrate•InatypicalCVDprocess,thewafer(substrate)isexposedtooneormorevolatileprecursors,whichreactand/ordecomposeonthesubstratesurfacetoproducethedesireddeposit.Frequently,volatileby-productsarealsoproduced,whichareremovedbygasflowthroughthereactionchamber5.3Modernmanufacturingtechnologies-coatedtools145.Modernmanufacturingtechnologies•PVD,physicalvapordeposition–avarietyofvacuumdepositionandisageneraltermusedtodescribeanyofavarietyofmethodstodepositthinfilmsbythecondensationofavaporizedformofthematerialontovarioussurfaces.Thecoatingmethodinvolvespurelyphysicalprocessessuchashightemperaturevacuumevaporationorplasmasputterbombardmentratherthaninvolvingachemicalreactionatthesurfacetobecoatedasinchemicalvapordeposition5.3Modernmanufacturingtechnologies-coatedtoolscomputersimulationofthebasicphysicalprocessunderlyingphysica