Development And Application Of In-situ Loading Device Based On EBSD Analysis

Materials science is the foundation of the national economy,and materials science subject represents the foundation of a nation's development.With the development of the society,the requirement of people's life is increasing for material conditions,and materials science has gained great progress.The modern material science are mostly based on the relation between material properties and the composition and microstructure.Therefore,more in-depth understanding of material mechanical performance needs microscopic level characterization analysis technology.The traditional material mechanical performance test is material analysis of the material fracture after tensile/compressive test.With the continuous development of science and technology,traditional mechanical performance test cannot satisfy the requirement of social development.The current development of material mechanical performance test and material characterization analysis technology shows a trend in miniaturization,intelligent,and functionalization.Currently,in-situ loading test is a kind of loading method combined the mechanical properties and material characterization.The requirement of mechanical performance test and surface analysis can be combined in a very good way.In-situ loading test refers to the tensile/compressive experiment of material and real-time observation on the tested sample at the same time,and record the stress-strain curve.The ways combined the change of microstructure and stress-strain curve of materials in in-situ loading can make more in-depth understanding of the concrete reason of material deformation.The SEM backscatter diffraction analysis technology is a kind of surface analysis of materials and is widely applied.This technology,in addition to the microstructure observation in the sample,can analyze the sample crystallography data at the same time.Compared with traditional analysis which separates microscopic morphology and crystallographic analysis,SEM backscatter diffraction analysis greatly improves the analysis technology in depth and enlarges the range of application.Thus,research and development of an in-situ loading device based on SEM electron back scattering diffraction analysis and its test method is necessary.This paper studies deeply the domestic and foreign research progress of in situ tension devices,and system analyzed the key points and problems ofthe in situ tensile device design.In-situ loading device design process includes the following several parts:1.Mechanical design part: Based on the scanning electron microscope electronbackscatter diffraction analysis method,an in-situ loading device designed for SEM microscopic morphology analysis and EBSD grain orientation analysis was designed.The in-situ mechanical loading device is generally placed in the chamber of the inspection instrument,and thusit needs to have the characteristics of small size and compact structure.2.Mechanical simulation: Based on the tensile/compressive loading range of the mechanical loading device,force analysis and simulation of the entire frame,key parts,and screw of the device are performed.Correct some design errors in the mechanical design and optimize it to make the overall mechanical design l the best.3.Circuit Design: Based on the SEM analysis method,the optimal circuit design method is achieved,and the circuit simulation and filter processing are performed for the sensor selection scheme.4.Communication software development: To develop a simple and easy-to-operate communication software for the experimental requirements,the process of material loading is controlled and the microscopic image and crystallographic data are collected in real time.5.Reliability and repeatability test of the in-situ loading device: Tensile tests are performed on the material using the laboratory instron-5944 universal testing machine to obtain the stress-strain curve,and the stress-strain curve of the in-situ tension device is obtained.Simulate the vacuum environment under the scanning electron microscope and test the reliability of the already built up in-situ loading device are carried out,and whether the in situ loading device can work properly in high vacuum environment is conducted.6.Insitu tensile test of dual phase steels: The Mn dual-phase steels were analyzed by SEM in real time for different strain points,and EBSD grain orientation analysis was performed,thereby testing the application of the device.