Studies On High Temperature Deformation Mechanics Behavior Of Ti-6Al-2Sn Alloy

Hot compression experiment were carried on the Gleeble-3800 thermal simulation machine at the temperature rang of 850~1050℃,deformation rate rang of 0.01~30 s-1 and deformation degree is 70%.In the same time,with the observation of metallography the high temperature thermal deformation behavior and microstructure has been analysised,finally come to the following conclusions:1.Forming characteristics of Ti-6Al-2Sn alloy has been studied by the hot compression experiment,and present the influence of deformation temperature and strain rate to material flow stress. Deformation temperature make a greater impact on true stress - strain curves of Ti-6Al-2Sn alloy, deformation softening mechanism is dynamic recrystallization when temperature less thanβphase transition point temperature,and Softening mechanism is dynamic recovery when temperature more thanβphase transition point temperature.2.With the analysis of true stress - strain curves of Ti-6Al-2Sn alloy,use regression method and computer data processing made the hyperbolic sine constitutive equation of high temperature stable state flow stress in two-phase deformation zone.As a result provides a fundamental basis for parameters isothermal extrusion process and computer simulation.3. Discuss the influence of deformation temperature and strain rate to microstructure of Ti-6Al-2Sn alloy ,and found that when deformation occurred with temperature below phase transition point, lamellar equiaxed,and the higher the deformation temperature, higher the degree of lamellar equiaxed,in the same time texture become more uniform;When deformation occurred with temperature higher than phase transition point,With increasing temperature, grain become coarsening. Deformation rate has less impact on the microstructure in low temperatures,but contrast in high temperature deformation. 4. With the use of deformation resistance, microstructure deformed, dracking case of Sample, provide a basis for hot compression deformation process: should chosen a temperature near theβphase transition point and chosen medium strain rate.In this experiment, the suitable deformation temperature is 950℃～1000℃,and the suitable deformation rate is 1s-1.