3. Basics of heat treatment of titanium alloys

Before going into the details of heat treatment of titanium alloys, it seems necessary to return to two fundamental principles, particularly important in that they challenge a priori ideas inherited from steel metallurgy.

We will then attempt to justify these principles by crystallographic and thermodynamic considerations, both in terms of equilibria and kinetics. Finally, the consequences for the current state (observed microstructures) and for the future (other hardening processes) will be presented.