Microstructure and properties evolutions of powder metallurgy TA15 titanium plates by a novel hot rolling method

The combination of powder metallurgy (PM) and hot rolling is one of the effective methods to prepare low-cost and high-alloying titanium plates. In this study, the PM-TA15 sintered billets were hot rolled at 1100-1200 degrees C after 1-2 passes with about 60% reduction in each pass without annealing. The influence of rolling reduction and temperature on the microstructure and mechanical properties of the plates was investigated, and the evolution mechanisms of the microstructure and deformation behavior were analyzed in detail. The results indicated that the grains of PM-TA15 plates were significantly refined and the lamellar structure transformed into basketweave structure or bimodal structure after hot rolling. The plates contained the grains after dynamic recovery (DRV) and dynamic recrystallization (DRX). The tensile strength and plasticity of 1100 degrees C-81% plates at room temperature were 1127 MPa and 15.5%, which were 15-20% and 30-55% higher than those of traditional TA15 plates.