Hot workability for as-cast and as-forged TiNiNb alloys

The deformation behavior of as-cast and as-forged TiNiNb alloy was studied at elevated temperature by compressive deformation tests from Gleeble-1500D Thermal Simulator. Based on the analyses, constitutive equations which related the flow stress to temperature, strain rate and strain have been respectively established. Results indicate that the flow stresses of as-cast TiNiNb alloy are slightly higher than that of as-forged alloy under the same condition. The optimum parameter ranges for processing of as-cast TiNiNb alloy are below 0.1 s^-1 for strain rate and below 0.4 for strain, while the optimum parameter ranges for processing of as-forged TiNiNb alloy are below 0.56 s^-1 for strain rate and below 0.5 for strain.