Effects of Working Temperature on Microstructure and Hardness of Ti-6Al-4V Alloy Subjected to Asymmetrical Rolling

In the present study, the microstructural evolution alongside its microhardness evaluation has been emphasized for Ti-6Al-4V alloy sheets subjected to asymmetrical cryorolling, warm rolling, and hot rolling up to 50 and 75% thickness reductions. Cryorolling helps in achieving a unique combination of high strength and ductility after proper heat treatment procedures due to ultrafine grain refinement. Microstructural behaviors show that the average grain size is the lowest for Ti-6Al-4V sheet during cryorolling conditions when the average grain sizes recorded are 497, 369, and 216 nm after 50% thickness reduction, and 301, 253, and 106 nm after 75% thickness reduction due to asymmetrical hot rolling, warm rolling, and cryorolling, respectively. It is also observed that the samples subjected to 75% thickness reduction via cryorolling have the highest hardness (VHN395). Furthermore, phase analysis of the dual-phase Ti-(α + β) alloy has been accomplished which showed the effects of the presence of β-Ti phase and the balance alongside its α-Ti counterpart that dictate its mechanical properties. In conjunction with these studies, a simple FEM simulation has been shown for a conventional rolling process using ABAQUS 2019 software for its better understanding.