Deformation characteristics of Ti-24Al-14Nb-3V-0.5Mo alloy during hot compression

Hot compression tests on samples of the Ti-24Al-14Nb-3V-0.5Mo alloy have been done in the (α₂ + β) phase field. It has been found that the Ti-24Al-14Nb-3V-0.5Mo alloy has good hot workability and hot compression can be applied satisfactorily to deform the alloy within the temperature and strain-rate ranges of 1030-1130°C and 0.001-0.1 s^-1 to ∼ 50% height reduction. The compressive flow stress varied from 13 MPa over the range of conditions used. The compressive pressure required for deformation is strongly dependent on the temperature and the strain-rate. A strain-rate sensitivity exponent (m) of 0.263 and a deformation activation energy of 602 kJ mol^-1 are obtained for the conditions used. It is considered that the deformation mechanism of the Ti-24Al-14Nb-3V-0.5Mo alloy in the (α₂ + β) phase field involves a combination of dynamic recovery and grain-boundary sliding. An empirical power-law equation valid over the range of temperatures and strain-rate investigated has been developed, the equation accurately describing the temperature and strain-rate dependence of the flow stress. © 1998 Elsevier Science S.A.