Construction of Processing Maps with High Precision for Ti-10V-2Fe-3Al Alloy

Hot deformation behavior of Ti-10V-2Fe-3A1 was evaluated with processing maps. Ti-10V-2Fe-3A1 is a metastable beta-titanium alloy for aerospace application. In developing the maps, we applied the new friction and thermal correction method found by Li et al. and Mataya et al. to make authentic stress-strain curves. The cases for the as hot-forged Ti-10V-2Fe-3A1 alloy and the Ti-10V-2Fe-3A1 alloy annealed at beta-single phase temperature (950 degrees C) were evaluated in this work. Cylindrical specimens were machined and then compression tests were carried out in the temperature range of 700 degrees C -1000 degrees C and in the strain rate range 0. 001-10s(-1) using a computer-aided hot forging simulator (Thermec-Master Z). Microstructure of as-hot forged specimen exhibited a duplex alpha+beta structure. Microstructures of the sample after compression below the beta-transus showed equiaxed alpha+beta structure. On the other hand, microstructures after compression at and above the (beta-transus revealed the almost fully martensite structure especially at higher strain more than 1 s(-1). There was a difference in the peaks in power dissipation maps and the regions in instability maps before and after compensation. Comparing the compressed microstuructures and the processing maps, it was found that the deformation is dominated by dynamic recovery or continuous dynamic recrystallization.