8. Conclusions

At the end of this overview of heat treatment of titanium alloys, it is worth recalling the main principles:

• the centric cubic → hexagonal compact allotropic transformation is exclusively martensitic (at least for germination) and leads to an acicular structure;

• to obtain the equiaxed structure (slightly more ductile), thermomechanical treatments are required (not described here);

• heat treatment will have a greater or lesser effect on the structures, as well as on the various mechanical characteristics required of the alloy, depending on whether the starting structure is fully equiaxed or fully (or partially) needle-punched;

• Since hardening due to quenching is low, if not zero, other mechanisms must be used; the most commonly used is the precipitation...