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1、1MaterialsinManufacturingMostengineeringmaterialscanbeclassifiedintooneoffourbasiccategories:1.Metals2.Ceramics3.Polymers4.Composites第1页/共28页第一页，共29页。2ProcessingOperationsThreecategoriesofprocessingoperations:1.Shapingoperations-alterthegeometryofthestartingworkmaterial2.Property enhancingoperations
2、-improvephysicalpropertiesofthematerialwithoutchangingitsshape3.Surfaceprocessingoperations-clean,treat,coat,ordepositmaterialontotheexteriorsurfaceofthework第2页/共28页第二页，共29页。3ShapingFourMainCategoriesSolidificationProcesses-startingmaterialisaheatedliquidthatsolidifiestoformpartgeometryDeformationPr
3、ocesses-startingmaterialisaductilesolidthatisdeformedMaterialRemovalProcesses-startingmaterialisaductile/brittlesolid,fromwhichmaterialisremovedAssemblyProcesses-twoormoreseparatepartsarejoinedtoformanewentity第3页/共28页第三页，共29页。ComparingProcesses4第4页/共28页第四页，共29页。Stress-StrainRelationshipsFigure3.3Typ
4、icalengineeringstressstrainplotinatensiletestofametal.5第5页/共28页第五页，共29页。TrueStress-StrainCurveFigure3.4TruestressstraincurveforthepreviousengineeringstressstrainplotinFigure3.3.6第6页/共28页第六页，共29页。StrainHardeningFigure3.5Truestressstraincurveplottedonloglogscale.7第7页/共28页第七页，共29页。RecrystallizationandG
5、rainGrowth8Scanning electron micrograph taken using backscattered electrons, of a partly recrystallized Al-Zr alloy. The large defect-free recrystallized grains can be seen consuming the deformed cellular microstructure. -50m-第8页/共28页第八页，共29页。PhaseDispersionspeedofquenching9第9页/共28页第九页，共29页。Allotrop
6、icTransformationandTemperingFigure6.4Phasediagramforironcarbonsystem,uptoabout6%carbon.10Tempered MartensiteAustenizingQuenching第10页/共28页第十页，共29页。Figure27.5Precipitationhardening:(a)phasediagramofanalloysystemconsistingofmetalsAandBthatcanbeprecipitationhardened;and(b)heattreatment:(1)solutiontreatm
7、ent,(2)quenching,and(3)precipitationtreatment.Precipitation Hardening - Al 6022 (Mg-Si)11第11页/共28页第十一页，共29页。MachiningRelationships12Machine ToolWorkpieceWorkholding ToolCutting Tool第12页/共28页第十二页，共29页。Highershearplaneanglemeanssmallershearplanewhichmeanslowershearforce,cuttingforces,power,andtemperat
8、ureFigure 21.12 Effect of shear plane angle : (a) higher with a resulting lower shear plane area; (b) smaller with a corresponding larger shear plane area. Note that the rake angle is larger in (a), which tends to increase shear angle according to the Merchant equationEffect of Higher Shear Plane An
9、gle13第13页/共28页第十三页，共29页。14TurningParametersIllustrated第14页/共28页第十四页，共29页。15MachiningCalculations:TurningSpindleSpeed-N(rpm)v=cuttingspeedDo=outerdiameterFeedRate-fr(mm/min-or-in/min)f=feedperrevDepthofCut-d(mm-or-in)Do=outerdiameterDf=finaldiameterMachiningTime-Tm(min)L=lengthofcutMatlRemovalRate-MR
10、R(mm3/min-or-in3/min)第15页/共28页第十五页，共29页。16UnitPowerinMachiningUsefultoconvertpowerintopowerperunitvolumerateofmetalcutCalledtheunitpower,Puorunithorsepower,HPuorToolsharpnessistakenintoaccountmultiplyby1.001.25FeedistakenintoaccountbymultiplyingbyfactorinFigure21.14where MRR = material removal rate第
11、16页/共28页第十六页，共29页。Whatiffeedchanges?17第17页/共28页第十七页，共29页。UnitHorsepowerThesignificanceofHPuisthatitcanbeused:1)todeterminethesizeofthemachinetoolrequiredtoperformaparticularcuttingoperation;and2)thesizeofthecuttingforceontheworkholdingandcuttingtools.18HPu hp/in3/minCf correction factorMRR in3/minFc
12、 lbV ft/minE machine tool efficiency33,000 conversion between ft-lb & hp第18页/共28页第十八页，共29页。ExampleInaturningoperationonstainlesssteelwithhardness=200HB,thecuttingspeed=200m/min,feed=0.25mm/rev,anddepthofcut=7.5mm.Howmuchpowerwillthelathedrawinperformingthisoperationifitsmechanicalefficiency=90%.From
13、Table21.2,U=2.8N-m/mm3=2.8J/mm3Sincefeedis0.25mm/rev,thecorrectionfactoris119第19页/共28页第十九页，共29页。20Example:SolutionMRR=vfd=(200m/min)(103mm/m)(0.25mm)(7.5mm)=375,000mm3/min=6250mm3/sPc=(6250mm3/s)(2.8J/mm3)(1.0)=17,500J/s=17,500W=17.5kWAccountingformechanicalefficiency,Pg=17.5/0.90=19.44kW第20页/共28页第二
14、十页，共29页。21lFlow of Molten Liquid Requires HeatinglHeat Transfer of Liquid in Mold Cavity During and After PouringlSolidification into ComponentCastingCommon process attributes: 第21页/共28页第二十一页，共29页。22GatingSystemChannelthroughwhichmoltenmetalflowsintocavityfromoutsideofmoldConsistsofadownsprue,throug
15、hwhichmetalentersarunnerleadingtothemaincavityAttopofdownsprue,apouringcupisoftenusedtominimizesplashandturbulenceasthemetalflowsintodownsprue第22页/共28页第二十二页，共29页。23PouringCalculationsMinimummoldfillingtime,MFTMFT=V/QQ:volumetricflowrate,cm3/sV:moldcavityvolume,cm3第23页/共28页第二十三页，共29页。ChvorinovsRulewh
16、ereTST=totalsolidificationtime;V=volumeofthecasting;A=surfaceareaofcasting;n=exponentusuallytakentohaveavalue=2;andCmismoldconstant24第24页/共28页第二十四页，共29页。AmountandCompositionFigure6.2Phasediagramforthecoppernickelalloysystem.第25页/共28页第二十五页，共29页。ShrinkageinSolidificationandCoolingFigure10.8Shrinkageof
17、acylindricalcastingduringsolidificationandcooling:(0)startinglevelofmoltenmetalimmediatelyafterpouring;(1)reductioninlevelcausedbyliquidcontractionduringcooling(dimensionalreductionsareexaggeratedforclarity).第26页/共28页第二十六页，共29页。ShrinkageinSolidificationandCoolingFigure10.8(2)reductioninheightandform
18、ationofshrinkagecavitycausedbysolidificationshrinkage;(3)furtherreductioninheightanddiameterduetothermalcontractionduringcoolingofsolidmetal(dimensionalreductionsareexaggeratedforclarity).第27页/共28页第二十七页，共29页。28感谢您的观赏(gunshng)第28页/共28页第二十八页，共29页。内容(nirng)总结1。Feed Rate - fr (mm/min -or- in/min)。Depth of Cut - d (mm -or- in)。Matl Removal Rate - MRR (mm3/min -or- in3/min)。第27页/共28页。感谢您的观赏(gunshng)第二十九页，共29页。
