The Study On Hot Deformation Behaviour And Heat Treatmentof Ti-Al-V-Fe-O Titanium Alloy

Titanium has advantages of high specific strength, excellent corrosion resistance, great comprehensive mechanical properties and broad prospects in application. The consumption of titanium is changed from aerospace to civil fields, including chemical engineering, automobile and sports goods. The high cost limits its application. This paper is based on the high strength and low cost Ti-Al- V-Fe-O, analyze the rheological behavior of the deformation and microstructure evolution, studies hot deformation, based on the Arrhenius constitutive equations and processing map theory, analyze the solution and aging.Thermal simulation experiments are carried out by Gleeble-1500 D, then choose different deformation temperatures and strain rates. The results show that the flow stress drops with the increase of the temperate, while the decrease of the strain rates. The alloy belongs to negative temperature and normal strain sensitive material. Then built constitutive equations of two phase and single based on Arrhenius model that consider the influence of strain. The processing map is build by DMM and Prasad instability criterion. Then analyze the instability region, ASB easily happen in this region. The sutiable for hot working area is in the strain rates from 0.001s-1 to 0.1-1 and temperature from 875℃ to 925℃.Furthermore, analyze the deformation mechanism and microstructure revolution. The results show that the softening mechanism of two phase is dynamic globularization and DRX, nodularity drops with the increase of temperature and decrease of strain rate. The single phase is dynamic recovery.The solution aging heat treatments are carried on Ti-6Al-2.5V-1.5Fe-0.15 O cast alloy. The results show that the microstructure of the solution treatments are consist of primary α phase, secondaryα phase and unchanged β phase. The decrease of primary α phase and increase of secondaryα phase goes with the rise of solution temperate. The solution of βphase shows that primary α phase disappear,αbundling appear in β grain. When the low aging temperate,nucleation of α phase is low,the diffusion rate is hard to go,the aging α phase nuclease by the dispersed ω phase,therefore the aging phase disperse in grain. The aging α phase grow with the rise of aging temperate. When the treatment is 975℃/1h/WQ+540℃/5h/AC,the alloy obtained a god match of strength and ductility...