Design And Experimental Research Of An In-situ Micra/Nano Indentation Test Device

The research and application of new material and new technology is an important factorto promote the development of science and technology, in order to obtain better performancematerials, people who are working on the properties of materials research gradually from thelevel of mm, to micron level, even the nanometer level. Thus, inventing an instrument whichcould accurate test the material microscopic mechanical behavior, and assess the materialdeformation and damage mechanism under the action of a variety of loads, is very necessary.In this paper, on the basis of consulting a large number of related literature in domesticand abroad, and combined with the project requirements, comparing indentation testingequipment development present situation and existing problems, designing the structure,analyzing the component, researching the control theory and method for the testing device.Besides, using self-made instrument carried out indentation test of typical materials and themaximum penetration depth of in-situ testing. This paper mainly research content is asfollows:(1)This paper analyses the current situation of the development of micro/nanoindentation testing and in-situ testing technology in domestic and abroad, detailed introduceand comprehensively evaluate some indentation test instrument which are widely used on themarket, summarizing the advantages and disadvantages of indentation test equipment.Detailed introduce research status of in-situ testing technology, summarizes the developingtrend of the technology of in-situ test and development bottleneck.(2)In this paper, I choose Oliver&Pharr’s theory as the foundation of Micro/nanoindentation testing method, add and correct the algorithm of contact area.In order to guidethe methods of select the multilayer piezoelectric stack, Detailed classificate commonly usedpiezoelectric materials, point out the advantage and limitation of piezoelectric materials inthis paper.Establish the mathematical model of the the flexible hinge,which is the core partof the micro/nano indentation test equipment,and derive its axial stiffness mathematicalalgorithm,which could provide the basis of simulation.Design and analysis the controlscheme for the control program which could provides a guidance.(3)Under the premise of achieveing full design parameters, in order to preciesly meet the function of micro/nano in-situ indentation test, decorate this device structure and positionreasonably combined with the whole machine structure,combined with the existing testingmethods and equipment,using the micro/nano indentation testing mechanics and the methodof in situ observation, optimize the sensor position detection components combined with theexisting testing methods and equipment. combined with high precision requires, appropriateuse of different power driving and loading, provide accurate velocity and displacement fordevice, so as to realize the specimen of micro/nano indentation testing and in situobservation testing.(4)To ensure and verify the precision, repeatability and stability of the test device, useappropriate calibration method and device, demarcate the force sensor many timesrepeatedly to verify its linearity and stability of the signal. Classifying and analyzing variousfactors that affect the indentation test trial, putting forward solutions,In order to justify theinstrument test results,test of a variety of material under different load test for many times.Besides, test T2copper and N6nickel under maximum depth of in situ test using theinstrument,and analyse the test results based on the materials performance.