Nanomeasurement And Characterization Research Of Mechanics Of Film Based On Nanoindenter

Nanoscience and nanotechnology includes three fields: nanomaterials,nanodevice and nanomeasurement and nanocharacterization. In this study, the mainpurpose is to measure and characterize the nanomechanics properties of nanomaterialsin nanoscale range, which belongs to the basic research and applied basic research.Nanomechanics properties were measured to antibacterial bone china filmincluding nanoindentation and nanoscratch experiments. Nanohardness and elasticmodulus have obvious size effect according to the nanoindentation experiment.Nanohardness versus indentation depth curve of ceramic film with 5% rare earthchanges linearly, while that of 3% increases firstly, then decreases. Pile-up stateindentation of ceramic film with 3% rare earth appears at different max load andhf / hmax <0.7, however that of 5% disappears at the same condition. Nanohardnessof ceramic films between 3% and 5% rare earth content is different greatly, but theelastic modulus is near μNder 8000μN while far over 8000μN. Scratch impression ofceramic film with 3% rare earth is pile-up state with obvious plastic flow, while thatof 5% is sink-in state according to the nanoscratch experiment, so theirnanomechanics property is different. Nanohardness and friction coefficient of ceramicfilm with 5% is 4 times and 1/4 as that of 3%, respectively. It can be drawn fromabove phenomenon that relationship between harness and friction coefficient is closewhile that between elastic modulus and friction coefficient is weak. Nanotribologyproperty of two kinds of ceramic films is stable with the scratch speed and max load.The two kinds of ceramic films have not only antibacterial property, but also tribologyproperty and nanohardness, so it has broad prospect.Nanoindentation of anodic aluminium oxide (AAO) film was also measured. Theresults show that nanohardness and elastic modulus of substrate AAO film andthrough-nanohole AAO film increase as diameter of nanohole grows, respectively.Nanohardness of AAO film with substrate is bigger than that of AAO film withthrough-nanohole at the same nanohole diameter condition. The phenomenon isresulted by the thin barrier layer which strengthens the nanohole network at thebottom of AAO film above the substrate. After the removal of barrier layer,nanohardness of AAO film with through-nanohole reduces. AAO film with 50, 100nmnanohole has small surface roughness, which results that nanohardness and elasticmodulus decreases linearly as load increases. While AAO film with 25nm nanoholehas big surface roughness, which influences the nanomechanics property and resultsthat nanohardness and elastic modulus decreases firstly, then increases.Force measured by nanomeasuring instrument is at the nN order or current nAorder, so sometimes the scanning images of antibacterial bone china film werepolluted unavoidably by the noise. Wavelet transform was applied to the denoising,enhancement and fusion of scanning images. The results show wavelet transform iseffective to the treatment of scanning images of AFM, STM and nanoindenter.AFM will invalidate at measuring the antibacterial bone china with thicksubstrate. To find the failure reason, solid modeling technology was applied to analyzethe fault diagnose. According to the simulation the failure reason is the driving designproblem. Furthermore, a novel eccentric lifting instrument and over-load protectioninstrument were designed, which can avoid the failure problem and enhance thescanning ability.Nanocompression and nanotension experiments are the difficult and key problemin the nanomeasurement field. A novel nanocompression and a nanotensioninstrument were designed with elliptical flexure hinge as locomotive structure andpiezoelectric ceramic as actuator. At present, the calculation theory of ellipticalflexure hinge derived from complex theory is complex, which isn't beneficial for theengineering application. Linear and angular deflection equations were deductedthrough material mechanics theory, which is more concise and is convenient to theengineering application. Nanocompression and nanotension experiments wereconducted by designed instrument cooperated with nanoindenter and AAO film assample, respectively.Plastic deformation occurs at the bigger compression displacement in thenanocompression experiment, which results that nanohardness increases firstly, thendecreases as compression increases, while elastic modulus increases always.The nanotension results show that nanohardness and elastic modulus decreasesvibratively as tension displacement increases at smaller nanoindentation force becauseof the effect of high-frequency vibration of piezoelectric ceramic. In this state,nanoindentation impression after complete unloading has no obvious plasticdeformation. While nanohardness and elastic modulus decreases linearly as tensiondisplacement increases at bigger indentation force and vibration phenomenondisappears, nanoindentation impression after complete unloading exhibits obviousplastic deformation phenomenon.A novel nanopositioning stage was designed according to the scanning propertyof SPM with flexure hinge as kinematic structure and piezoelectric ceramic asactuator. Kinetic precision and X directional area of nanopositioner are 1.55nm and26.4 micron, respectively, which is demonstrated by kinetic analysis and finiteelement method FEM simulation. Designed nanopositioner based on SPM moves at 3dimensions with nanometer scale and its motion of X, Y, and Z directions isdecoupled and isotropic. Furthermore, frame of nanopositioner is simple andmanufacturing is convenient, which will have broad prospect in the field ofnanopositioning and nanotracing.