中英文翻译材料制备机械设计理论中的新趋势和新问题.doc

攀枝花学院毕业设计（论文）-45-英文原文NewTrendsandProblemsinMaterialProcessingMachineDesignTheoryWANGAi-lun,DUANJi-an,HUANGMing-hui,ZHONGJue(CollegeofMechanical&ElectronicEngineering,CentralSouthUniversity,Changsha410083,HunanChina)Abstract:Basedonreviewingthehistoricalbackground,prospectingforthedevelopmenttrend,analyzingthecomplicacyandmechanismandsummingupsomeachievementsandexperiencesinscientificresearch,severalnewproblemsandthepossibledirectionofdevelopmentinmaterialprocessingtechnologyandmachineareproposed,suchas,producingnewconceptmaterialspossessingsomespecificandextraovdinarypropertiesbymeansofintegratingandcoalescingconelativefrontierscienceandtechnology；andthereafterabriefdiscussionisgiven.Keywords:interface；extraordinaryphysicalfield；processionmachine；functionmaterial1TheTimeBackgroundofMaterialProcessingMachineInthelongspanofhistoryofhumanprogress,manytools,machinesandmethodswerecreatedandavarietyofmaterialswithdifferentpropertieswereprocessed.Materialsanditsprocessinghavebecomeoneofpillaranddrivingforceofmankindprogress.Inpacewithmulti-polarcompetitionincurrentworldandpeoplesstrivingperseveringlyforhappierlife,materialfunctiongoesbeyondunceasinglymensknowledgeandimagination,forexample,crypticfunctionmaterial,semiconductormaterial,energymaterial,vibration-absorptivematerial,super-strength攀枝花学院毕业设计（论文）-46-aluminumalloyaccountingfor70percentofapplicationofaeronauticsandspace,metalfoilof45m,deepdrawingplatewithanisotropybelow1percent,electronicaluminumfoilwithmicro-orientationupto95percent,heatresistingaluminumalloywithsuperstrongspecificstrengthusedinaeronautics,spaceanddeepsea,etc.1,2Thusseveralimportantdevelopmenttrendswithdistincttimefeaturesinmaterialprocessingdomainareshapedupasfollows:(1)Creatingmaterialprocessingmachinewithextraordinaryphysicalfieldforprocessingmaterialwithspecialtexturestructuresandfunctions.Forexample,applicationsofthermalenergyandmechanicalenergyarebreakingthroughunceasinglytechnologylimit,andsomenon-traditionenergy,suchasmicrowave,chemicalenergy,bioenergy,etc.,areintroducedintomaterialprocessingprocedureoneafteranother,sothatsomematerialprocessingmachineswithextraordinaryenergycircumstanceareproduced.(2)Breakingthroughtraditionalphysicallimitsandintegratingmelting,solidifying,plasticdeformationandheattreatmenttoobtainspecialfunctionofmaterialandcutdownexpenses3.Forexample,near-netshapingmaterialprocessingtechnology,suchasfastrolling,sprayingdeposition,over-plasticmolding,injectionmolding,highenergybeam,etc,isapplied.(3)Materialprocessingprocessisforgedaheadinthedirectionofhighspeed,heavy-dutyandhighaccuracyonlinecontrol,forinstance,therollingspeedgoesupto130m·s-1,thedeformationpressurerisesupto300MPa,accuracyofdimensionupto0.1m,accuracyofshapeupto0.1I,strengthaccuracycomesupto0.1MPa.Forthesereasons,itisnecessaryformaterialprocessingmachinedesigntheorytointegrateandcoalesceingeniouslycorrelativefrontierscienceandtechnologytocreateandproducesomenewconceptmaterialprocessingmachinewithfollowingfunctions.2DueFunctionsofNewConceptMaterialProcessingMachine(1)Tohavetheabilitytoproduceandbearextraordinaryphysical攀枝花学院毕业设计（论文）-47-fieldandtransmitextraordinaryenergyflowwiththeaimofprovidingextraordinaryphysicalcircumstancesnecessaryfornewconceptmaterialprocessing.Forexample,highgradienttemperaturefieldwiththespeedofcool-downofworkinterfacewhichexceeds104106K·s-1,linewaveandpulsecomplexexertedinsolidifying-deformingarea,super-strengthcontactstressfieldofmaterialforminginterface,turbulentflowfieldofmoltenmetalwithverybigflakinessratio,lowfrequencymagneticfieldwithrandomfrequency,microwavefieldforpowdermetalheating,ultrasonicfieldforlargevolumesolidifying,etc.4,areapplied.(2)Tohavetheabilitytoworkincriticalstatesothathighstabilityandidealperformanceofprocessingmachineisensuredunderthecircumstanceofreinforcedtechnologicalconditionandmulti-fieldcouplingoperation.Forexample,chattersuppressingcapabilityoffastultra-thinrollingundertheconditionofboundarylubricatingstate5,thecapabilityofself-excitedvibrationsuppressingundertheconditionofspecialfrictionstate,synergismstabilityanddisturbancestabilityofflexibleconnectingparallelshaftwithmulti-drivingsystem,etc.4,areensured.(3)Tohavetheabilitytoaccuratelycontrolthematerialprocessinginordertoobtainlowloss,highefficiencyandhighqualityofmaterialprocessing.Forexample,super-highaccuracyon-linemonitorofproductsform,onlinemonitorandon-lineadjustmentofproductstextureandproperties,precisioncoordinationcontrolofmulti-procedure,on-linemonitorofmicro-orientationofmetalplasticdeformation,etc.4,areensured.Someproductsaccuracyindexmaybeenumeratedasfollows:dimensionalaccuracycomingto0.1m,microstructureuniformitytocrystallattice,strengtherrorto0.1MPa,etc.4Inshort,onlybynewconceptmaterialprocessingmachinewithextraordinaryfunctionbeingdesignedandmade,canspecialfunctionmaterialbeprocessed.攀枝花学院毕业设计（论文）-48-3ScienceProblemsandStudyContentsofMetalMaterialProcessingMachineUndertheCircumstanceofExtraordinaryPhysicalFieldInviewofthesefactsandbackgroundmentionedabove,severalnewresearchtopicscanbeadvancedasfollows.3.1CouplingHeatTransferMechanismofMulti-PhaseInterfaceTemperature-StressFieldAbrand-newmicrostructurecanbeobtainedthroughcontinuouslylargedeformationandfastsolidifyingwhenmeltingmetalisincriticalstateofliquidsolid.Atthisverymoment,highdensityheatflowanddynamicheatresistancearepresentinmaterialprocessingcircumstance6,7.Abasictheoryproblemofdesigningthiskindofmachineistostudymechanismofheattransmittanceandenergyconversion,andtoestablishmathematicalmodel.3.2FrictionConstraintMechanismofPlasticFlowInterfaceofMaterialProcessingMachineThecouplingbetweenoperationmechanismandworkpieceisverycomplicatedbecauseplasticflowispresentinprocessinginterface.Theinterfacestate,determinedbyvelocity,loadthermodynamicprocess,elasticityofoperationmechanism,plasticityofworkpiece,dynamicbehaviourofinterfacesticking-slidingandpartialhydrodynamiclubrication,etc,affectandformfrictionconstraintsmechanismpeculiartomaterialprocessingmachine,becausetheseconstraintspresentstrongnon-linearity；andundercertaincircumstances,theconstraintsmaybedestroyedormismatchedinstantaneouslyandthusdynamicinstabilityisresultedin.Thusfollowingproblemscanbeputforward:Mechanismof“spectrechatter”arosefromsticking-slidingfrictionandpartialhydrodynamiclubricationinrollinginterface,instabilityconditionandmechanismofconstraintbetweensmoothsurfaceandrotatingbodyunderthecircumstanceofhighspeed,heavy-dutyandboundarylubrication,Lubricationfilmabsorptionmechanismandphysicalchemistrybehaviour