Study On The Micro-material Mechanical Property Testing Device

With the development of microelectronics,micro-electro-mechanical system, precision optics and biomedical engineering, it has been encountered a lot of mechanical problems inevitably in the process of design, manufacture, performance test and reliability evaluation. The mechanical performance test of these elements are different from traditional test. The main problem is that research methods have not a unified standard and the testing datas are dispersed and precision deficiency. These factors make the study on the mechanical properties of 3d-micro compoments become a hot issue.This paper design a piezoelectric direct drive nano-indentation experimental apparatus and a tesion experimental apparatus, which transmission by right flexible hinge and driveing by a piezo-electric stack. The main contents are presented as follows:1.introductionThe problems of micro-component mechanical properity testing in the development of microelectronics, micro-electro-mechanical system and precision optics are introduced. Particularly give the introduction about the research of testing method of micro-compoment mechanical properity at home and abroad,and then put forward the contents of this paper.2.Basic method and principle of nano mechanical property testingMechanical testing basic methods of micro structures are introduced, and then gives a description of indentation contacting mechanics and nanoindentation testing system.Particularly gives a detail description of classical mechanics method and continuous stiffness measurement. Those founds solid theoretical foundations for the design of nanoindentation experiment device. At last, it gives principle and characteristics of uniaxial tensile method.3.design and anysis of nanoindentation deviceAt first, describes the integral structure and working principle of nanoindentation device as well as points for attention about wire cutting. Then gives a detail introduction about flexure hinge and anysis its advantages and disadvantages. Summarizes the its design principles. Makes a theory analysis of flexure hinge, and gains its stiffness equation, analyses the related size parameters affecting the stiffness. Also gives finite element analysis to flexible hinge.At last, analyses the structure of each part. Gives the function of preloading mechanism and analyses its effect to the output performance of nanoindentation device. Establishes a dynamic model of three parallel-plate flexure hinge, and gives it an analytical solution, from which we get the transfer function and the inherent frequency of the flexure hinge system. What's more, gives finite element statics and modal analysis to transmission flexure hinge, and studys the deformation of first six grades. and studies how the structure factors affect the stiffness and frequency. Finally, finite element simulation is made to fleture hinge which used to test the indentation force and simulation results error was given out.4.Performance testing and analysis of indentation experimental deviceIn this chapter, experimental instruments and system are introduced and output performance of indentation experimental device is tested.1) Stiffness calibration of flexture hinge which used to test indentation force is completed. Actual stiffness was figured out and compared to theoretical value. Then the cause of errors between actual and theoretical stiffness is analysed.2) Output performance of nano-indentation device is tested including the relation of input voltage and output displacement. And the curves of output displacement in loading-unloading process are ploted. It could be obviously found that output performance is affected by piezoelectric stack and exists hysteresis phenomenon.3) re-output accuracy is tested and the curve is ploted. 4) Output displancement resolution is tested. And three times testing are repeated. We can get average value of output displancement accuracy which is 10.3nm.Then we analyse the causes which could affect testing result. At last, observes indentation result under a microscope.5. design and study on the micro-nano tension experimental deviceIn this chapter, compositon and working mode of micro-nano tension experimental device are introduced. Finite element analysis of flexture hinge is made. Output performance of tension device is tested and the curve of volage-displancement relation is ploted in the process of loading and unloading. Then llinear fitting of the points is made and linear correlation coefficient was obtained. Finally, the repetition output accuracy and displacement resolution is tested.6.Conclutation and prospectThe work of this paper is summarized.And the problems and disadvantages in the process of design and experiment are analysed.Then improvement measures are proposed.