3D打印技术资料.docx
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3D打印技术资料
3Dprinting
Formethodsofapplyinga2Dimageona3Dsurface,seepadprinting.Formethodsofprinting2Dparallaxstereogramsthatseem3Dtotheeye,seelenticularprintingandholography.
AnORDbotQuantum3Dprinter.
Timelapsevideoofahyperboloidobject(designedbyGeorgeW.Hart)madeofPLAusingaRepRap"PrusaMendel"3Dprinterformoltenpolymerdeposition.
3DprintingorAdditivemanufacturing[1]isaprocessofmakingathree-dimensionalsolidobjectofvirtuallyanyshapefromadigitalmodel.3Dprintingisachievedusinganadditiveprocess,wheresuccessivelayersofmaterialarelaiddownindifferentshapes.[2]3Dprintingisalsoconsidereddistinctfromtraditionalmachiningtechniques,whichmostlyrelyontheremovalofmaterialbymethodssuchascuttingordrilling(subtractiveprocesses).
A3Dprinterisalimitedtypeofindustrialrobotthatiscapableofcarryingoutanadditiveprocessundercomputercontrol.
While3Dprintingtechnologyhasbeenaroundsincethe1980s,itwasnotuntiltheearly2010sthattheprintersbecamewidelyavailablecommercially.[3]Thefirstworking3Dprinterwascreatedin1984byChuckHullof3DSystemsCorp.[4]Sincethestartofthe21stcenturytherehasbeenalargegrowthinthesalesofthesemachines,andtheirpricehasdroppedsubstantially.[5]AccordingtoWohlersAssociates,aconsultancy,themarketfor3Dprintersandserviceswasworth$2.2 billionworldwidein2012,up29%from2011.[6]
The3Dprintingtechnologyisusedforbothprototypinganddistributedmanufacturingwithapplicationsinarchitecture,construction(AEC),industrialdesign,automotive,aerospace,military,engineering,civilengineering,dentalandmedicalindustries,biotech(humantissuereplacement),fashion,footwear,jewelry,eyewear,education,geographicinformationsystems,food,andmanyotherfields.Onestudyhasfound[7]thatopensource3Dprintingcouldbecomeamassmarketitembecausedomestic3Dprinterscanoffsettheircapitalcostsbyenablingconsumerstoavoidcostsassociatedwithpurchasingcommonhouseholdobjects.[8]
Terminology
Thetermadditivemanufacturingreferstotechnologiesthatcreateobjectsthroughsequentiallayering.Objectsthataremanufacturedadditivelycanbeusedanywherethroughouttheproductlifecycle,frompre-production(i.e.rapidprototyping)tofull-scaleproduction(i.e.rapidmanufacturing),inadditiontotoolingapplicationsandpost-productioncustomization.[9]
Inmanufacturing,andmachininginparticular,subtractivemethodsreferstomoretraditionalmethods.Thetermsubtractivemanufacturingisaretronymdevelopedinrecentyearstodistinguishitfromneweradditivemanufacturingtechniques.Althoughfabricationhasincludedmethodsthatareessentially"additive"forcenturies(suchasjoiningplates,sheets,forgings,androlledworkviariveting,screwing,forgewelding,ornewerkindsofwelding),itdidnotincludetheinformationtechnologycomponentofmodel-baseddefinition.Machining(generatingexactshapeswithhighprecision)hastypicallybeensubtractive,fromfilingandturningtomilling,drillingandgrinding.[9]
ThetermstereolithographywasdefinedbyCharlesW.Hullasa"systemforgeneratingthree-dimensionalobjectsbycreatingacross-sectionalpatternoftheobjecttobeformed"—ina1984patent.[10][11]
Generalprinciples
3Dmodelslicing.
Printing
Toperformaprint,themachinereadsthedesignfromanSTLfileandlaysdownsuccessivelayersofliquid,powder,paperorsheetmaterialtobuildthemodelfromaseriesofcrosssections.Theselayers,whichcorrespondtothevirtualcrosssectionsfromtheCADmodel,arejoinedorautomaticallyfusedtocreatethefinalshape.Theprimaryadvantageofthistechniqueisitsabilitytocreatealmostanyshapeorgeometricfeature.
PrinterresolutiondescribeslayerthicknessandX-Yresolutionindpi(dotsperinch),[citationneeded]ormicrometers.Typicallayerthicknessisaround100?
?
m(250 DPI),althoughsomemachinessuchastheObjetConnexseriesand3DSystems'ProJetseriescanprintlayersasthinas16?
?
m(1,600 DPI).[12]X-Yresolutioniscomparabletothatoflaserprinters.Theparticles(3Ddots)arearound50to100?
?
m(510to250 DPI)indiameter.
Constructionofamodelwithcontemporarymethodscantakeanywherefromseveralhourstoseveraldays,dependingonthemethodusedandthesizeandcomplexityofthemodel.Additivesystemscantypicallyreducethistimetoafewhours,althoughitvarieswidelydependingonthetypeofmachineusedandthesizeandnumberofmodelsbeingproducedsimultaneously.
Traditionaltechniqueslikeinjectionmoldingcanbelessexpensiveformanufacturingpolymerproductsinhighquantities,butadditivemanufacturingcanbefaster,moreflexibleandlessexpensivewhenproducingrelativelysmallquantitiesofparts.3Dprintersgivedesignersandconceptdevelopmentteamstheabilitytoproducepartsandconceptmodelsusingadesktopsizeprinter.
Finishing
Thoughtheprinter-producedresolutionissufficientformanyapplications,printingaslightlyoversizedversionofthedesiredobjectinstandardresolutionandthenremovingmaterialwithahigher-resolutionsubtractiveprocesscanachievegreaterprecision.[citationneeded]
Someadditivemanufacturingtechniquesarecapableofusingmultiplematerialsinthecourseofconstructingparts.Someareabletoprintinmultiplecolorsandcolorcombinationssimultaneously.Somealsoutilizesupportswhenbuilding.Supportsareremovableordissolvableuponcompletionoftheprint,andareusedtosupportoverhangingfeaturesduringconstruction.
Additiveprocesses
Rapidprototypingworldwide2001[13]
TheAudiRSQwasmadewithrapidprototypingindustrialKUKArobots.
Severaldifferent3Dprintingprocesseshavebeeninventedsincethelate1970s.Theprinterswereoriginallylarge,expensive,andhighlylimitedinwhattheycouldproduce.[14]
Alargenumberofadditiveprocessesarenowavailable.Theydifferinthewaylayersaredepositedtocreatepartsandinthematerialsthatcanbeused.Somemethodsmeltorsoftenmaterialtoproducethelayers,e.g.selectivelasermelting(SLM)ordirectmetallasersintering(DMLS),selectivelasersintering(SLS),fuseddepositionmodeling(FDM),whileotherscureliquidmaterialsusingdifferentsophisticatedtechnologies,e.g.stereolithography(SLA).Withlaminatedobjectmanufacturing(LOM),thinlayersarecuttoshapeandjoinedtogether(e.g.paper,polymer,metal).Eachmethodhasitsownadvantagesanddrawbacks,andsomecompaniesconsequentlyofferachoicebetweenpowderandpolymerforthematerialfromwhichtheobjectisbuilt.[15]Somecompaniesusestandard,off-the-shelfbusinesspaperasthebuildmaterialtoproduceadurableprototype.Themainconsiderationsinchoosingamachinearegenerallyspeed,costofthe3Dprinter,costoftheprintedprototype,andcostandchoiceofmaterialsandcolorcapabilities.[16]
Printersthatworkdirectlywithmetalsareexpensive.Insomecases,however,lessexpensiveprinterscanbeusedtomakeamould,whichisthenusedtomakemetalparts.[17]
Type
Technologies
Materials
Extrusion
Fuseddepositionmodeling(FDM)
Thermoplastics(e.g.PLA,ABS),HDPE,eutecticmetals,ediblematerials,Rubber(Sugru),Modellingclay,Plasticine,RTVsilicone,Porcelain,Metalclay(includingPreciousMetalClay)
Wire
ElectronBeamFreeformFabrication(EBF3)
Almostanymetalalloy
Granular
Directmetallasersintering(DMLS)
Almostanymetalalloy
Electron-beammelting(EBM)
Titaniumalloys
Selectivelasermelting(SLM)
Titaniumalloys,CobaltChromealloys,StainlessSteel,Aluminium
Selectiveheatsintering(SHS)[18]
Thermoplasticpowder
Selectivelasersintering(SLS)
Thermoplastics,metalpowders,ceramicpowders
Powderbedandinkjethead3Dprinting
Plaster-based3Dprinting(PP)
Plaster
Laminated
Laminatedobjectmanufacturing(LOM)
Paper,metalfoil,plasticfilm
Lightpolymerised
Stereolithography(SLA)
photopolymer
DigitalLightProcessing(DLP)
photopolymer
Extrusiondeposition
Fuseddepositionmodeling:
1–nozzleejectingmoltenplastic,2–depositedmaterial(modeledpart),3–controlledmovabletable.
Mainarticle:
Fuseddepositionmodeling
Fuseddepositionmodeling(FDM)wasdevelopedbyS.ScottCrumpinthelate1980sandwascommercializedin1990byStratasys.[19]Withtheexpirationofthepatentonthistechnologythereisnowalargeopen-sourcedevelopmentcommunity,aswellascommercialandDIYvariants,whichutilizethistypeof3Dprinter.Thishasledtoatwoordersofmagnitudepricedropsincethistechnology'screation.
Infuseddepositionmodelingthemodelorpartisproducedbyextrudingsmallbeadsofmaterialwhichhardenimmediatelytoformlayers.Athermoplasticfilamentormetalwirethatiswoundonacoilisunreeledtosupplymaterialtoanextrusionnozzlehead.Thenozzleheadheatsthematerialandturnstheflowonandoff.Typicallysteppermotorsorservomotorsareemployedtomovetheextrusionheadandadjusttheflowandtheheadcanbemovedinbothhorizontalandverticaldirections.Controlofthismechanismistypicallydonebyacomputer-aidedmanufacturing(CAM)softwarepackagerunningonamicrocontroller.
Variouspolymersareused,includingacrylonitrilebutadienestyrene(ABS),polycarbonate(PC),polylacticacid(PLA),highdensitypolyethylene(HDPE),PC/ABS,andpolyphenylsulfone(PPSU).Ingeneralthepolymerisintheformofafilament,fabricatedfromvirginresins.Multipleprojectsintheopen-sourcecommunityexistthatareaimedatprocessingpost-consumerplasticwasteintofilament.Theseinvolvemachines