纳米压痕仪资料.pdf

March 26 2010Combining AFM and instrumented indentation for mechanical characterization at the nanoscaleFlavio Alejandro Bonilla,Staff ScientistMarch 26 2010OutlineBackgroundWhat is nanoindentation:Depth sensing indentationImportance of nanoindentation in nanomechanicsInstrumented Nanoindentation vs.AFM NanoindentationHow does this transducer work?The AFM headAdapting the transducer to the AFMCalibration.Transducer,frame compliance.Area function and the use of AFM:Z-sensor.Indentation DataIndentation in air indentation placement around dentine tubules and polymerIndentation in fluid wear test and indentations in mussel fiberSummary and conclusionsMarch 26 2010What is Nanoindentation?ForceDepthDepth sensing indentationradius of 30 to 50nmFused SilicaScan 2.5 umVert.scale:50 nmStatic IndentationForce,Indentation DepthMarch 26 2010Importance of Indentation in nanomechanicsVersatile technique to investigate mechanical behavior and properties at nanoscale:Elasticity Viscoelasticity Plasticity Dislocation behavior in metals Fracture in ceramics Time dependent Dynamic Indentation methods:acquire Amplitude,Phase,Frequency while doing modulation on any of those signals or force.March 26 2010AFM Cantilever NanoindentationAdvantages:Force Resolution,bandwithLimitation:Results are qualitativeUnintended Displacements and rotationsMarch 26 2010Advantage:Quantitative resultsDisadvantages:Force resolution,bandwidth.Instrumented NanoindentationHigh ratio of vertical to lateral and rotational compliance:No unintended Displacements and rotationsMarch 26 2010OutlineBackgroundWhat is nanoindentation:Depth sensing indentationImportance of nanoindentation in nanomechanicsInstrumented Nanoindentation vs.AFM NanoindentationHow does this transducer work?The AFM headAdapting the transducer to the AFMCalibration.Transducer,frame compliance.Area function and the use of AFM:Z-sensor.Indentation DataIndentation in air indentation placement around dentine tubules and polymerIndentation in fluid wear test and indentations in mussel fiberSummary and conclusionsMarch 26 2010Asylum Research AFM HeadMarch 26 2010NanoIndenterAsylum Research NanoindenterEasily switch between AFM and NanoindentationMarch 26 2010How does it work?Optical Sensor(Force)Mounted to head z-stageMarch 26 2010OutlineBackgroundWhat is nanoindentation:Depth sensing indentationImportance of nanoindentation in nanomechanicsInstrumented Nanoindentation vs.AFM NanoindentationHow does this transducer work?The AFM headAdapting the transducer to the AFMCalibration.Transducer,frame compliance.Area function and the use of AFM:Z-sensor.Indentation DataIndentation in air indentation placement around dentine tubules and polymerIndentation in fluid wear test and indentations in mussel fiberSummary and conclusionsMarch 26 2010Tip Characterization:AFM Metrology of BerkovichHeightAmplitudeArea function calibration with AFM metrology method.Right:AFM tip metrology.Left:Numerically integrated area function;Blue trace is numerically integrated projected area;Red trace is a parabolic fit(Ap=C0*h2+C1*h)to data resulting in C0=25.9 and C1=0.939e-06.Green trace is tip surface area(not used in Oliver Pharr).March 26 2010Fused Silica indentation curvesHeightAmplitudeFused silica indentation force curves for different maximum forces.Arrays of 36 to 64 indentation force curves at different maximum load were performed to calibrate the diamond Berkovich tip used according to the Oliver-Pharr method.March 26 2010Fused Silica tip area function calibrationHeightAmplitudeArea function calibration with Oliver Pharr method.Red markers correspond to the area such that E=72 GPa for individual indentations at different depth.Blue trace is a parabolic fit(Ap=C0*h2+C1*h)to red markers with C0=50.55 and C1=-1.357e-06.Green trace is a Berkovich theoretical C0*h2 area with C0=24.5.March 26 2010Indentation imagingAccurate measurement of contact areas and volumesMetal:Pile-upPolymerSemiconductor:sink-inMarch 26 2010OutlineBackgroundWhat is nanoindentation:Depth sensing indentationImportance of nanoindentation in nanomechanicsInstrumented Nanoindentation vs.AFM NanoindentationHow does this transducer work?The AFM headAdapting the transducer to the AFMCalibration.Transducer,frame compliance.Area function and the use of AFM:Z-sensor.Indentation DataIndentation in air indentation placement around dentine tubules and polymerIndentation in fluid wear test and indentations in mussel fiberSummary and conclusionsMarch 26 2010Polymer Indent,750nm scanCourtesy of Krystyn Van Vliet,MITPolymer IndentationMarch 26 2010Courtesy of Krystyn Van Vliet,MITPolymer IndentationPolymer Indent,750nm scanMarch 26 2010Indentation curves on dentine,100 uN maximum forceSpatial variation of mechanical responseMarch 26 2010Longitudinal cross section of mussel holdfast fiber with indents placed in the protective coating region to investigate elastic modulus and hardness.Wear Test and Indentation in FluidCourtesy of Niels Holten-Andersen and Herbert Waite,UCSBScan10 umScan25 umMarch 26 2010Indentation on human hairApparent variation in mechanical properties correctedScan 14 umMarch 26 2010Cube corner diamond scratch and indent on polymer,12um scan.Scratch and Nano-machiningAccurate cuts in diversity of materialsMarch 26 2010Machining results on epoxyHeightAmplitudeDetail of micromachined pattern.Lithography is possible mantaining constant depth.March 26 2010Machining results on epoxy 2HeightAmplitudeDetail 2 of micromachined pattern.A deeper channel is shown in the superior part of the 22 um scan.Z scale 250 nm.March 26 2010Indentation arraysHeightAmplitudeIndentation array in epoxy.Scan size 6 um.Z scale 100 nm.March 26 2010Indentation arrays 2HeightAmplitudeIndentation array in Epoxy using Berkovich tip at different maximum loads(Inverted image for display:material inside view).Scan size 6 um.Z scale 100 nm.March 26 2010Indentation arrays 3HeightAmplitudeIndentation array in Copper using conical tips at different maximum loads(Inverted image for display:material inside view).Scan size 10 um.Z scale 200 nm.March 26 2010Factors affecting Nanoindentation Data Thermal drift Initial penetration depth Instrument compliance Indenter geometry Piling-Up and Sinking-In Indentation size effect:errors associated with area function vs.reflection of material mechanical response,friction,etc.Surface roughness Tip rounding Residual stresses Specimen preparationMarch 26 2010Summary and Conclusions1.AFM based transducer offers additional levels of control,sensitivity and data acquisition.2.AFM images of nanoindentation are more than pretty pictures:with a sensor for height,data is used for quantification.3.Indentation placement with optics and sample positioning close loop are key.March 26 2010Summary and Conclusions(2)4.User understands the instrumentation.5.Set up is pre-calibrated easier to use,less steps before measurement.March 26 2010Acknowledgements NIST:Jon Pratt and Gordie Shaw MIT:Krystyn Van Vliet and Christine Ortiz UCSB:Niels Holten-Andersen and Herbert Waite UIUC:Scott MacLaren and Ivan Petrov