Determination of critical parameters for dynamic recrystallization in Ti-6Al-2Zr-1Mo-1V alloy
(College of Materials Science and Engineering, Chongqing University, Chongqing 400044, China)
Abstract: The true stress—strain curves of Ti-6Al-2Zr-1Mo-1V alloy were achieved by a series of isothermal compression tests with height reduction of 60% under the deformation temperatures of 1073-1323 K and the strain rates of 0.01-10 s-1. The critical conditions for the onset of DRX were attained when the value of , where strain hardening rate , reached the minimum which corresponds to an inflection of θ versus σ curve. Thus, two important potential parameters, critical strain and critical stress, were identified, and expressed as εc/εp=0.37-0.60, σc/σp=0.81-0.91. Furthermore, by the regression analysis for conventional hyperbolic sine equation, the main material parameters such as α, β, n, and DRX activation energy, Q, were calculated. In addition, the evolution of Q with strain rate and temperature was revealed as a 3D response surface.
Key words: Ti-6Al-2Zr-1Mo-1V alloy; dynamic recrystallization; flow stress; strain hardening rate; activation energy