In-situ Testing Of Static Mechanical Behavior Of Ti-6Al-4V Alloy With Different Microstructures

Ti-6Al-4V alloy is the most widely used titanium alloy material because of its high yield strength ratio,non-magnetic,weldability,low density and high corrosion resistance.Ti-6Al-4V alloy components are often used in aerospace engines,marine probes,ship pressure resistant shells,medical devices,etc.The application scenarios of Ti-6Al-4V alloy are diverse,and single and composite loads such as tensile and bending are the common service conditions of Ti-6A1-4V alloy,so its mechanical behavior needs to be investigated in depth.At the present stage,there is a lack of systematic and in-depth tests on the mechanical properties of Ti-6A1-4V alloy with different microstructures under the action of composite loads.Therefore,it is important to conduct in-situ test research on the static mechanical behaviors of Ti-6Al-4V alloy with different microstructures to guide the application of the material in the actual complex service conditions.In this paper,the feasibility and necessity of combining in-situ testing techniques to analyze the mechanical properties of Ti-6Al-4V alloys with different microstructures were clarified by comprehensively analyzing the research status of Ti-6Al-4V alloys and in-situ testing techniques at home and abroad.Using finite element software,the results of tensile,three-point bending and three-point bending tests under pre-stretching conditions were simulated and analyzed to obtain the correlation between the magnitude of pre-stretching load and the deviation displacement from the neutral plane of bending.The measurement results of DIC and conventional extensometer were compared and analyzed,and the accuracy of the former was verified.Using the DIC in-situ testing technique,the pretensile bending mechanical properties of Ti-6Al-4V alloy were analyzed,and the effects of different pretensile load levels on the deviation of the bending neutral plane position of the specimen were investigated,and the actual test results were compared and analyzed with the finite element calculation results.The effects of tensile rate and bending loading rate on the mechanical properties of Ti-6Al-4V alloy specimens with bistatic organization were investigated experimentally,and the correlation between the macroscopic deformation mechanism and the change law of microstructure of Ti-6Al-4V alloy specimens with isometric,bistatic and Weiss organization was studied experimentally by combining optical microscopy techniques,and the effects of pretensile load levels on the mechanical properties of Ti-6Al-4V alloy with different microstructures were obtained.The effects of pretensile load levels on the bending mechanical properties of Ti-6Al-4V alloy with different microstructures were obtained.