微纳米力学测试课件.ppt
中山大学环境材料所中山大学环境材料所微纳米力学测试微纳米力学测试中山大学环境材料所中山大学环境材料所力学性能力学性能是评价材料质量的主要指标，也是进行设计与计算的主要依据，不同的应用领域对材料的力学性能要求也不一样钢材塑料橡胶纤维胶黏剂涂层或镀层模量、硬度、强度、结合力、摩擦性能中山大学环境材料所中山大学环境材料所力学性能的评价力学性能的评价1、简单应力状态实验单轴拉伸、压缩和扭转获得：应力、应变数据由于制样的局限性只适合尺度在由于制样的局限性只适合尺度在100100mm量级的样品量级的样品2、复杂应力状态的接触试验硬度实验表征材料抵抗局部变形的能力，是衡量材料软硬程度的性能指标由于只在材料表面局部产生很小的压痕，使其比较适合微由于只在材料表面局部产生很小的压痕，使其比较适合微尺度材料尺度材料中山大学环境材料所中山大学环境材料所常规硬度测量方法常规硬度测量方法静态压入硬度静态压入硬度通过球体、金刚石椎体或其他椎体经载荷施加到被测材料上，使材料发生塑性形变，再根据总施加载荷与所产生的压入面积或深度之间的关系，给出其硬度值。宏观硬度；2NP30KN显微硬度：P2N，h0.2纳米硬度：h0.2动态或回弹压入硬度动态或回弹压入硬度（载荷与回弹高度，主要用于金属材料）划入硬度划入硬度（法向力、划痕，材料抗划入、摩擦、变形、附着力）中山大学环境材料所中山大学环境材料所Comparative Load Ranges中山大学环境材料所中山大学环境材料所纳米压入和划入的特点纳米压入和划入的特点操作方便连续记录载荷和压入深度，从载荷-位移曲线中获得硬度、模量样品制备简单对样品的尺寸和形状无特殊要求，薄膜、涂层、表面改性样品测量和定位分辨率高100nN,1nm测试内容丰富硬度、模量、断裂韧度、应力-应变曲线、高聚物的存储模量、蠕变特性、疲劳特性、粘附；薄膜的临界附着力、摩擦系数等适用范围广泛金属、陶瓷、高聚物、复合材料、表面工程系统、微系统器件、生物材料中山大学环境材料所中山大学环境材料所Techniques Available TodayLoad,displacement&timeHardnessandModulusContinuousStiffnessMeasurementCreepandStressExponentFractureToughnessStorageandLossModulusScratchandFrictionProfilometry(台阶仪功能）3DImaging(原位成像)中山大学环境材料所中山大学环境材料所Conventional MicrohardnessApplyaspecificloadonadiamondindenterTheresidualimpressionafterloadremovalisameasureofhardnessLoad中山大学环境材料所中山大学环境材料所Conventional MicrohardnessDiagonal,D,ismeasuredopticallyafterremovalofloadVickers（维氏）:D=7hKnoop（努氏）:D=30.5h中山大学环境材料所中山大学环境材料所What is Depth-Sensing Indentation?Applyaspecific,quasi-staticordynamic,load-timehistoryonadiamondindenterMeasurethedisplacement-timeresponseUsethesedatatoextractcertainmechanicalpropertiesbasedonanalyticalmodelsHardness,Youngs Modulus,Stress-Exponent for Creep,Storage Modulus,Loss Modulus,etc.中山大学环境材料所中山大学环境材料所Hardness&Youngs ModulusHardnessisthemeanpressurethematerialwillsupportYoungsmodulusiscalculatedfromthecompositeresponsemodulus,ErThoughnotshownexplicitlyhere,bothHandErequireload,depth and stiffness forcalculations中山大学环境材料所中山大学环境材料所Load-Displacement BehaviorAluminum（铝）（铝）,typicalofsoftmetallicbehavior,showsverylittledisplacementrecoveryuponunloadingFused silica（熔融石英）（熔融石英）,typicalofceramicbehavior,showslargeelasticrecoveryuponunloadingAluminumFused silica中山大学环境材料所中山大学环境材料所Elastic/Plastic IndentationsForanideallyplasticindentation（塑性压痕）,hc（接触深度）ht（穿透深度，最大位移）Foranelastic/plasticindentation,hc ht中山大学环境材料所中山大学环境材料所Stiffness From Unloadinghn,Pn中山大学环境材料所中山大学环境材料所Modeling the P-h behaviorThe unloading curve（卸载曲线）（卸载曲线）follows a power lawContact stiffness（接触硬度）（接触硬度）is the slope of the unloading curveContact depth（接触深度）（接触深度）is determined from the displacement,load,and contact stiffness中山大学环境材料所中山大学环境材料所Contact Area(the tip function)The“tip function”for the ideal Berkovich（玻氏）（玻氏）tipExperimental tip functionArbitrary formCoefficients determined experimentally中山大学环境材料所中山大学环境材料所Polymer thin filmProblems with Time-Dependence(粘弹塑性材料粘弹塑性材料)“Conventional”stiffness determination unreasonableLarge amounts of time-dependent deformationLarge time-dependent recovery中山大学环境材料所中山大学环境材料所Continuous Stiffness Measurement Technique（连续刚度测量技术（连续刚度测量技术CSM）PatentedMethodfortheContinuousDeterminationoftheElasticStiffnessofContactBetweenTwoBodies“Frequency-Specific（固定频率）,Depth-SensingIndentation.”中山大学环境材料所中山大学环境材料所CSM-Force Oscillation（固定频率的简谐力）（固定频率的简谐力）中山大学环境材料所中山大学环境材料所CSM-Elastic&ViscoelasticElasticViscoelastic-2-1012-1-0.500.5101020304050Excitationforce(N)Responsedisplacement(nm)Time(milliseconds)f中山大学环境材料所中山大学环境材料所Dynamic ModelA.Sample B.Indenter Column;mass=m C.Load Application Coil D.Indenter Support Springs;Stiffness=Ks E.Capacitive Displacement Gauge;Damping Coefficient=DiF.Load Frame;Stiffness=KfABCDEFMass=mK SsDiKfDs中山大学环境材料所中山大学环境材料所Stiffness Calculation by CSM Technique中山大学环境材料所中山大学环境材料所Benefits of CSMPropertiesvs.depth-avoidingsubstrateeffect（基底效应）ControllablestrainrateTipcalibrationSurfacecontactdeterminationViscoelasticmaterialsandproperties中山大学环境材料所中山大学环境材料所Thin Film Testing without CSMUnloading data Unloads at 0.1,0.5 and 1.0 times thicknessValues imply film hardness varies linearly with depthAl film on glass0.511.520200400600800Hardness(GPa)Depth,h(nm)h=th=0.5th=0.1t%offilmthickness020406080100中山大学环境材料所中山大学环境材料所Thin Film Testing with CSMCSMdataContinuousdatawiththickness(i.e.,depth)showstruecharacteroffilmAl film on glass中山大学环境材料所中山大学环境材料所CSM-Aluminum Thin FilmsContinuous measure of hardness with depthEach curve is an average of ten indentationsFrom 10 nm to 2 m with each indentation“Plateaus”in hardness vary with film thicknessAl films on glass中山大学环境材料所中山大学环境材料所Tip Calibration(压头校准压头校准)Standard MethodResultsof60indentationsshownLargegapsindata中山大学环境材料所中山大学环境材料所Tip Calibration CSM MethodResultsofsame20indentationsshownMorepointsformoredensedata中山大学环境材料所中山大学环境材料所Tip Calibration Shallow DepthsCSMgiveshigherdatadensityCSMgiveslowernoiseThusCSMgivesmorereliablecalibrationoftipshape中山大学环境材料所中山大学环境材料所Surface Contact Determination（表面探测）（表面探测）(Critically important for very thin films and soft materials)1、拟合函数，外推法确定零点、拟合函数，外推法确定零点2、载荷或接触刚度的首次增加为零点、载荷或接触刚度的首次增加为零点PointofContact?中山大学环境材料所中山大学环境材料所AccuTip Berkovich Diamond TipsThesharperthetip,theshalloweranindentcanbemadetogivereliablehardnessvaluesDeep indent requiredShallow indent possibleIdeal tip中山大学环境材料所中山大学环境材料所AccuTip Berkovich Diamond TipsOlddiamondtipsFaceangles（中心线与面的夹角）fairlyconsistent,butnotknownwithanyprecisionTipradiustypically100150nmNewAccuTipBerkovichdiamondtipsFaceanglesknownto0.025Tipradius50nm(typically40nm)before2007Tipradius20nmsince2008中山大学环境材料所中山大学环境材料所Old Berkovich Diamond TipTwo different DLC films,both 20 nm thickNo significant differencebetweenthemmeasuredPlasticitydoesnotbeginatashallowenoughindentdepthtoseeasignificanteffectofthefilminthemeasurement中山大学环境材料所中山大学环境材料所Tip SharpnessSharp tipDull tipHardnessDepth of penetrationAsharptipisrequiredformakinghardnessmeasurementsatveryshallowindentationdepths中山大学环境材料所中山大学环境材料所AccuTip Berkovich diamond TipTwodifferentDLCfilms,both20nmthicksame films shown in previous slideStatisticallysignificant differencebetweenthetwoPlasticitybeginsatashallowerindentdepthshallowenoughtoseeasignificanteffectofthefilminthemeasurement中山大学环境材料所中山大学环境材料所Hard coating&surface modification中山大学环境材料所中山大学环境材料所Ion Implantation of Hard Chrome Plating中山大学环境材料所中山大学环境材料所TiC Coated Ball Bearings中山大学环境材料所中山大学环境材料所Optical Coatings-Siloxane on PC中山大学环境材料所中山大学环境材料所Micro Electronic Machines(MEMS)TheNanoIndenterXPmakesagreatMEMSTesterLFMmicrotensileDoubledogbonemicro-tensile中山大学环境材料所中山大学环境材料所Raytheon RF MEMS SwitchYoungsmodulusofmembraneveryimportantforswitchperformanceNeedtodeflectmembranewithoutcomplicatedstressstatesPublished by H.D.Espinosa,M.Fischer,Northwestern University and E.Herbert,W.C.Oliver,MTS Nano Instruments中山大学环境材料所中山大学环境材料所Diamond Tip GeometryMoreacutediamondwedgeObtuseanglediamondwedgewilllimitamountofverticaldisplacementpossible中山大学环境材料所中山大学环境材料所Membrane Deflection（膜偏离）（膜偏离）ExperimentsWithdiamondwedgewiderthanmembrane,lineloadisappliedandrelativelysimplestressesandmodelsresultPublished by H.D.Espinosa,M.Fischer,Northwestern University and E.Herbert,W.C.Oliver,MTS Nano Instruments中山大学环境材料所中山大学环境材料所3 N/mExperimentalE=52.0 Gpa(1 isotropic matl)E1=73.2 Gpa;E2=44.0 Gpa 0100020003000048121620Displacement(nm)Force(N)Lineload(flat)s0=5MPaMembrane DeflectionStiffnessesaslowas2-3N/mweremeasuredquitereproduciblywiththestandardNanoIndenterXPheadPublished by H.D.Espinosa,M.Fischer,Northwestern University and E.Herbert,W.C.Oliver,MTS Nano Instruments中山大学环境材料所中山大学环境材料所AccuTip Diamond TipsScratch Testing划痕测试划痕测试中山大学环境材料所中山大学环境材料所Scratch Friction CoefficientFNFTstindentermaterialMotion of indenterScratch friction coefficient划痕摩擦系数Actual friction coefficient实际摩擦系数(Indenter geometry dependent)(same with Berkovich and Cube Corner)中山大学环境材料所中山大学环境材料所Scratch testing with a BerkovichLowangleofattack（小接触角）Plasticdeformation（塑性变形）Face forward面划入Edge forward（棱划入）中山大学环境材料所中山大学环境材料所-1200-1000-800-600-400-200020040060080020304050607080profile distance(um)profile height(nm)ahbp中山大学环境材料所中山大学环境材料所Fracture Initiation:Critical Load Measurement050010001500200025000100200300400500600700scratch distance(um)indenter penetration(nm)Pc=2.5 mNhc=1500 nmPenetration under loadResidual scratch depth中山大学环境材料所中山大学环境材料所Study of fracture damage mechanisms（破裂损坏机（破裂损坏机理）理）CubeCornerindenterChippingprocessImportantparameters:Indenter geometryLoad for fracture initiation中山大学环境材料所中山大学环境材料所-600-400-2000200-25-15-551525profile distance(um)profile height(nm)30minafter15daysafter8h40oCBerkovich with face forwardVisco-Plastic Recovery of ScratchesTime and Temperature DependenceAutomotive paint polymer clear coat中山大学环境材料所中山大学环境材料所3D Profilometry&Nanopositioning100 x 100 um travel Resolution:2nm Reproducibility:2nm Linearity error:500um Resolution:0.1nm Closed Loop中山大学环境材料所中山大学环境材料所TopoSurface 3D Profilometry中山大学环境材料所中山大学环境材料所Acquisition of 3D Topographic data中山大学环境材料所中山大学环境材料所Acquisition of 3D Topographic dataTestWorks DataTopoSurf 3D中山大学环境材料所中山大学环境材料所Acquisition of 3D Topographic dataInputsintheTestWorksMethodLengthofscanNumberofpointsperscanDistancebetweenscansNumberofscansOrientationofthescansSetthestartlocationwithmicroscopejustlikeanindent中山大学环境材料所中山大学环境材料所Nanopositioning Capability中山大学环境材料所中山大学环境材料所Nanopositioning Capability中山大学环境材料所中山大学环境材料所Nanopositioning Capability中山大学环境材料所中山大学环境材料所
