Hot deformation behavior of ZrTiAlV alloy with a coarse grain structure in the β phase field

摘要

Hot deformation behavior of 47Zr-45Ti-5Al-3V alloy in the β field was studied by compression tests at temperatures from 850 ℃ to 1050 ℃ and strain rates from 10~(-3) to 10~0 s~(-1). The flow curves exhibited complete different shapes depending on deformation conditions. At high strain rates and low deformation temperatures, the flow stress decreased drastically after elastic deformation, and then decreased slowly as the deformation proceeded. The flow curves exhibited typical characteristics of dynamic recrystallization at low strain rates and high deformation temperatures. At deformation temperatures of 1000 ℃ and 1050 ℃ and a strain rate of 0.1 s~(-1), a load drop and secondary yield point appeared in the flow curves. A hyperbolic-sine Arrhenius-type equation was used to characterize the dependence of the flow stress on deformation temperature and strain rate. The activation energy of deformation at different strains was determined to be in the range of 155.8-186.6 kJ/mol, which was higher than the self-diffusion activation energy in β-Zr and the activation energies of other Zr alloys. A dynamic microstructure distribution map was presented to help visualize the microstructure of this alloy under different deformation conditions.