Thermomechanical processing of Ti-5A1-5Mo-5V-3Cr

The constitutive behaviour and microstructural evolution of the near-P alloy Ti-5Al-5Mo-5V-3Cr in the ct + P condition has been characterised during isothermal subtransus forging at a range of temperatures and strain rates. The results indicate that Ti-5AI-5Mo-5V-3Cr has a shallower approach curve, and therefore, offers a more controllable microstructure than the near-P alloy Ti-10V-2Fe-3Al. Flow softening is small in magnitude in both alloys in the ot + P condition. The steady state flow stresses obey a Norton-Hoff constitutive law with an activation energy of Q = 183 U mol', which is similar to the activation energy for self-diffusion in the 0 phase, suggesting deformation is dominated by dynamic recovery in the P matrix. Good evidence is found for the existence of w phase after both air cooling and water quenching from above the P transus. In addition, dissolution of the ot phase is found to be slow at near-transus temperatures. (c) 2008 Elsevier B.V. All rights reserved.