High Temperature Deformation Behavior And Finite Element Simulation Of Ti6242 Titanium Alloy During Flash Welding

The deformation behavior under high temperature of Ti6242 titanium alloy was studed in this paper. Using finite element simulation software to simulate temperature and stress field of flash welding process. The model of grain growth ofβ Phase at flash welding heat affected zone was builed based on isothermal heating process.Compared the tensile strength and shock absorption function under different process conditions to determine the best welding technology.The hot deformation behavior of Ti6242 alloy was investigated by conducting hot compression deformation tested on Gleeble-3800, at the strain rate of alloys0.01 s-1、0.1 s-1、1 s-1、10 s-1 temperature 900 ℃、950 ℃、1000 ℃、1050 ℃、1100 ℃and 60% height reduction. The hyperbolic-sine equation of Ti6242 alloy was obtained. The flow stress-stain curves of Ti6242 alloy under different deformation condition were plotted. The processing maps were maps were established based on dynamic materials model. The results show that the flow stress of Ti6242 alloy were strongly influenced by deformation temperature and strain rate. Flow stresses decrease with the increase of deformation. Its increase with the strain rate. The activation energy of Ti6242 alloy is about 453.742761 k J/mol, the best hot deformation condition at 1000 ℃ to 1050 ℃ and the strain rate is 0.1s-1.Used the finite element simulation software of ansys simulated temperature field and stress field of flash welding. Compared the result of three different heat source loads method, the temperature of multi-step load method is simila r the actual situation. Taking the temperature place results as load to analyse o f stress field. Compared microstructure of the hot deformation experiment and the flash welding analysis of the the feasibility of finite element simulation.Us ing the finite element simulation software of ansys simulated welding temperatu re field and stress field of the process of flash Flash. Compared the result o f three different heat source loads method of temperature field. Taking the tem perature place results as load to analyse of stress field. Compared microstruct ure of the hot deformation experiment and the flash welding analysis of the the feasibility of finite element simulation.The model of grain growth for Ti6242 titanium alloy was researched in flash welding heat zone, according to the temperature curve of finite element simulation and combining with the results of welding thermal cycle curve mat hematical. The grain growth in β Single Phase of Ti6242 Alloy at the temper ature 1000 ℃,1050 ℃,1100 ℃,1150 ℃ Heating for 10 min, 20 min, 30 min, 60 min have been investigated. Compared microstructure at different strai n rate and temperature. The results showed that the β grain increase with the i ncrease of temperature, and grow up of heating time. The curves of β grain growth are approximatively parabolic type. The grain growth exponent n is 0.28, respectively, and the grain growth activation energy Q is 66.396 k J/mol an d the growth model of Ti6242 is D=98392.5t0.28exp(-66396/RT). Got the grain growth model of weld heat affected zone isGetting the best upset speed in the process of flash welding based on ho t deformation process. Making flash welding experiment plan at the different of the flash current and upset ting force. Observated microstructure of the sa mple under different flash current and upsetting force, compared tensile stren gth and shock absorption function to determine the best welding technology.