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 s(1) and temperatures of 750-900 degrees 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 degrees 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 (T-opi: 850 degrees C, (epsilon)over dote(opi): 1.0 s(-1)) with the peak eta of 0.46 to obtain fine kinked and globular alpha phase for artificial bone. Crown Copyright (C) 2013 Published by Elsevier B. V. All rights reserved.