Restricted Hot Deformation Behavior And Mechanical Property Of TA15 Titanium Alloy

The isothermal forging technique was adopted for restricted hotdeformation.The characteristics and influence factors of restricted hotdeformation behavior of TA15 titanium alloy were investigated.Metallographyanalysis was employed to investigate microstructure of the specimens afteradopted hot deformation and the room-temperature mechnical property of tensilespecimens was tested in instron. The constitutive equation of hot deformation wasconstituted by using the data of hot compression of TA15 alloy.Based on theMSC.Marc software,using the rigid-plastic finite element method(FEM) tosimulate the process of restricted hot deformation experiment.Integration the constitutive equation into the MSC.Marc software.A coupledsimulation of deformation with heat transfer was established for the restricted hotdeformation of TA15 titanium alloy.The effect of deformation temperature,thepunch velocity and the friction on the stress field,strain field and temperaturefield during the restricted hot deformation was calculated.The results show thatthe deformation temperature and the punch velocity have significant effect on theworkpiece forming.This reasarch provides the technique foundation forimplementing process of restricted hot deformation of TA15 titanium alloy.The restricted hot deformation experiment of TA15 titanium alloy wasinvestigated,description the hot deformation behavior and characteristic,analysing the effect of processing parameter(punch velocity, deformationtemperature) on hot deformation.The results show that the resistance ofdeformation in low temperature was larger than high temperature.The formabilityof low temperature was bad compare with high temperature.As the deformationtemperature increase,the maximum load was decrease when the punch strokemove the same displacement.Initial stage,the deformation load was increase withthe deformation temperature's increase.When the punch stroke move somedistance,with the deformation velocity decrease,the deformation load wasincrease.The second invariant of the deviatoric stress tensor(J2) and Lode coefficient (??) were employed for the division of deformation area and metallographyanalysis was employed to investigate microstructure of different deformationarea.The results show that the large area of workpiece was plastically deformationtype and the rigid type located in the bottom circular angle area of lower die. Thelarge area of workpiece was compression deformation type,the elongation strainarea located in the gutter outer zone and in the bottom zone of the lower die.Asthe deformation temperature increase,the percentage composition and theslenderness ratio of primary ? were decrease.The room-temperature tensile-strength and elongation percentage of tensilespecimens was tested in instron.The processing parameter have an importanteffect on tensile-strength and elongation percentage.With the punch velocityincrease,the tensile-strength and elongation percentage were also decrease.