Hot deformation behavior of Ti-6.0Al-7.0Nb biomedical alloy by using processing map

Ti-6.0Al-7.0Nb is a dual phase biomedical alloy used for artificial bone. Isothermal compression tests of Ti-6.0Al-7.0Nb biomedical alloy has been taken carried out on a Gleebe 3500 simulator at the strain rates of 0.001-1.0 s1 and temperatures of 750-900 °C. A constitutive equation represented as a function of temperature, strain rate and true strain was developed, and the hot deformation apparent activation energy is calculated about 341 kJ/mol. Processing maps were constructed on the basis of the experimental data for evaluation of the flow instability regime and optimization of processing parameters. Processing maps predict a single flow instability region occurred around the temperature range of 750-770 °C and the strain rate range of 0.03-1.0 s−1. The power dissipation maps at different strains exhibit similar features indicating that the processes involved in hot working have very short transient and are essentially of steady-state type. Ti-6.0Al-7.0Nb biomedical alloy can be deformed at the condition of (Topi: 850 °C, ε̇opi: 1.0 s−1) with the peak η of 0.46 to obtain fine kinked and globular α phase for artificial bone.