微納米力學測試課件

微納米力學測試力學性能

是評價材料質(zhì)量的主要指標，也是進行設(shè)計與計算的主要依據(jù)，不同的應用領(lǐng)域?qū)Σ牧系牧W性能要求也不一樣 鋼材 塑料 橡膠 纖維 膠黏劑 涂層或鍍層模量、硬度、強度、結(jié)合力、摩擦性能 力學性能的評價1、簡單應力狀態(tài)實驗 單軸拉伸、壓縮和扭轉(zhuǎn) 獲得：應力、應變數(shù)據(jù)

由于制樣的局限性只適合尺度在100μm量級的樣品2、復雜應力狀態(tài)的接觸試驗 硬度實驗 表征材料抵抗局部變形的能力，是衡量材料軟硬程度的性能指標

由于只在材料表面局部產(chǎn)生很小的壓痕，使其比較適合微尺度材料常規(guī)硬度測量方法靜態(tài)壓入硬度 通過球體、金剛石椎體或其他椎體經(jīng)載荷施加到被測材料上，使材料發(fā)生塑性形變，再根據(jù)總施加載荷與所產(chǎn)生的壓入面積或深度之間的關(guān)系，給出其硬度值。 宏觀硬度；2N≤P≤30KN 顯微硬度：P≤2N，h≥0.2μ 納米硬度：h≤0.2μ動態(tài)或回彈壓入硬度（載荷與回彈高度，主要用于金屬材料）劃入硬度（法向力、劃痕，材料抗劃入、摩擦、變形、附著力）ComparativeLoadRanges納米壓入和劃入的特點操作方便連續(xù)記錄載荷和壓入深度，從載荷-位移曲線中獲得硬度、模量樣品制備簡單 對樣品的尺寸和形狀無特殊要求，薄膜、涂層、表面改性樣品測量和定位分辨率高 100nN,1nm測試內(nèi)容豐富 硬度、模量、斷裂韌度、應力-應變曲線、高聚物的存儲模量、蠕變特性、疲勞特性、粘附；薄膜的臨界附著力、摩擦系數(shù)等適用范圍廣泛 金屬、陶瓷、高聚物、復合材料、表面工程系統(tǒng)、微系統(tǒng)器件、生物材料TechniquesAvailableTodayLoad,displacement&timeHardnessandModulusContinuousStiffnessMeasurementCreepandStressExponentFractureToughnessStorageandLossModulusScratchandFrictionProfilometry(臺階儀功能）3DImaging(原位成像)ConventionalMicrohardnessApplyaspecificloadonadiamondindenterTheresidualimpressionafterloadremovalisameasureofhardnessLoadConventionalMicrohardnessDiagonal,D,ismeasuredopticallyafterremovalofloadVickers（維氏）:D=7hKnoop（努氏）:D=30.5hWhatisDepth-SensingIndentation?Applyaspecific,quasi-staticordynamic,load-timehistoryonadiamondindenterMeasurethedisplacement-timeresponseUsethesedatatoextractcertainmechanicalpropertiesbasedonanalyticalmodelsHardness,Young’sModulus,Stress-ExponentforCreep,StorageModulus,LossModulus,etc.Hardness&Young’sModulusHardnessisthemeanpressurethematerialwillsupportYoung’smodulusiscalculatedfromthecompositeresponsemodulus,ErThoughnotshownexplicitlyhere,bothHandErequireload,depthandstiffnessforcalculationsLoad-DisplacementBehaviorAluminum（鋁）,typicalofsoftmetallicbehavior,showsverylittledisplacementrecoveryuponunloadingFusedsilica（熔融石英）,typicalofceramicbehavior,showslargeelasticrecoveryuponunloadingAluminumFusedsilicaElastic/PlasticIndentationsForanideallyplasticindentation（塑性壓痕）,hc

（接觸深度）≈ht（穿透深度，最大位移）

Foranelastic/plasticindentation,hc

<htStiffnessFromUnloadinghn,PnModelingtheP-hbehaviorTheunloadingcurve（卸載曲線）followsapowerlawContactstiffness（接觸硬度）istheslopeoftheunloadingcurveContactdepth（接觸深度）isdeterminedfromthedisplacement,load,andcontactstiffnessContactArea(thetipfunction)The“tipfunction”fortheidealBerkovich（玻氏）tipExperimentaltipfunctionArbitraryformCoefficientsdeterminedexperimentallyPolymerthinfilmProblemswithTime-Dependence(粘彈塑性材料)“Conventional”stiffnessdeterminationunreasonableLargeamountsoftime-dependentdeformationLargetime-dependentrecoveryContinuousStiffnessMeasurementTechnique

（連續(xù)剛度測量技術(shù)CSM）PatentedMethodfortheContinuousDeterminationoftheElasticStiffnessofContactBetweenTwoBodies“Frequency-Specific（固定頻率）,Depth-SensingIndentation.”CSM-ForceOscillation（固定頻率的簡諧力）CSM-Elastic&ViscoelasticElasticViscoelastic-2-1012-1-0.500.5101020304050Excitationforce(μN)Responsedisplacement(nm)Time(milliseconds)fDynamicModelA.SampleB.IndenterColumn;mass=mC.LoadApplicationCoilD.IndenterSupportSprings;Stiffness=Ks

E.CapacitiveDisplacementGauge;DampingCoefficient=DiF.LoadFrame;Stiffness=KfABCDEFMass=mK

SsDiKfDsStiffnessCalculationbyCSMTechniqueBenefitsofCSMPropertiesvs.depth---avoidingsubstrateeffect（基底效應）ControllablestrainrateTipcalibrationSurfacecontactdeterminationViscoelasticmaterialsandpropertiesThinFilmTestingwithoutCSMUnloadingdataUnloadsat0.1,0.5and1.0timesthicknessValuesimplyfilmhardnessvarieslinearlywithdepthAlfilmonglass0.511.520200400600800Hardness(GPa)Depth,h(nm)h=th=0.5th=0.1t%offilmthickness020406080100ThinFilmTestingwithCSMCSMdataContinuousdatawiththickness(i.e.,depth)showstruecharacteroffilmAlfilmonglassCSM-AluminumThinFilmsContinuousmeasureofhardnesswithdepthEachcurveisanaverageoftenindentationsFrom10nmto2μmwitheachindentation“Plateaus”inhardnessvarywithfilmthicknessAlfilmsonglassTipCalibration(壓頭校準)–StandardMethodResultsof60indentationsshownLargegapsindataTipCalibration–CSMMethodResultsofsame20indentationsshownMorepointsformoredensedataTipCalibration–ShallowDepthsCSMgiveshigherdatadensityCSMgiveslowernoiseThusCSMgivesmorereliablecalibrationoftipshapeSurfaceContactDetermination（表面探測）

(Criticallyimportantforverythinfilmsandsoftmaterials)

1、擬合函數(shù)，外推法確定零點

2、載荷或接觸剛度的首次增加為零點PointofContact?AccuTip?BerkovichDiamondTipsThesharperthetip,theshalloweranindentcanbemadetogivereliablehardnessvaluesDeepindentrequiredShallowindentpossibleIdealtipAccuTip?BerkovichDiamondTipsOlddiamondtipsFaceangles（中心線與面的夾角）fairlyconsistent,butnotknownwithanyprecisionTipradiustypically~100–150nmNewAccuTip?BerkovichdiamondtipsFaceanglesknownto±0.025?Tipradius≤50nm(typically~40nm)before2007Tipradius≤20nmsince2008OldBerkovichDiamondTipTwodifferentDLCfilms,both20nmthickNosignificantdifferencebetweenthemmeasuredPlasticitydoesnotbeginatashallowenoughindentdepthtoseeasignificanteffectofthefilminthemeasurementTipSharpnessSharptipDulltipHardnessDepthofpenetrationAsharptipisrequiredformakinghardnessmeasurementsatveryshallowindentationdepthsAccuTip?BerkovichdiamondTipTwodifferentDLCfilms,both20nmthick–

samefilmsshowninpreviousslideStatisticallysignificantdifferencebetweenthetwoPlasticitybeginsatashallowerindentdepth–shallowenoughtoseeasignificanteffectofthefilminthemeasurementHardcoating&surfacemodificationIonImplantationofHardChromePlatingTiCCoatedBallBearingsOpticalCoatings-SiloxaneonPCMicroElectronicMachines(MEMS)TheNanoIndenterXPmakesagreatMEMSTesterLFMmicrotensileDoubledogbonemicro-tensileRaytheonRFMEMSSwitchYoung’smodulusofmembraneveryimportantforswitchperformanceNeedtodeflectmembranewithoutcomplicatedstressstatesPublishedbyH.D.Espinosa,M.Fischer,NorthwesternUniversityandE.Herbert,W.C.Oliver,MTSNanoInstrumentsDiamondTipGeometryMoreacutediamondwedgeObtuseanglediamondwedgewilllimitamountofverticaldisplacementpossibleMembraneDeflection（膜偏離）ExperimentsWithdiamondwedgewiderthanmembrane,lineloadisappliedandrelativelysimplestressesandmodelsresultPublishedbyH.D.Espinosa,M.Fischer,NorthwesternUniversityandE.Herbert,W.C.Oliver,MTSNanoInstruments3N/mExperimentalE=52.0Gpa(1isotropicmat’l)E1=73.2Gpa;E2=44.0Gpa

0100020003000048121620Displacement(nm)Force(μN)Lineload(flat)s0=5MPaMembraneDeflectionStiffnessesaslowas2-3N/mweremeasuredquitereproduciblywiththestandardNanoIndenter?XPheadPublishedbyH.D.Espinosa,M.Fischer,NorthwesternUniversityandE.Herbert,W.C.Oliver,MTSNanoInstrumentsAccuTip?DiamondTips

ScratchTesting

劃痕測試ScratchFrictionCoefficientFNFTstindentermaterialMotionofindenterScratchfrictioncoefficient劃痕摩擦系數(shù)Actualfrictioncoefficient實際摩擦系數(shù)(Indentergeometrydependent)(samewithBerkovichandCubeCorner)ScratchtestingwithaBerkovichLowangleofattack（小接觸角）Plasticdeformation（塑性變形）Faceforward面劃入Edgeforward（棱劃入）-1200-1000-800-600-400-200020040060080020304050607080profiledistance(um)profileheight(nm)ahbpFractureInitiation:CriticalLoadMeasurement050010001500200025000100200300400500600700scratchdistance(um)indenterpenetration(nm)Pc=2.5mNhc=1500nmPenetrationunderloadResidualscratchdepthStudyoffracturedamagemechanisms（破裂損壞機理）CubeCornerindenterChippingprocessImportantparameters:Inde