Titanium Alloys: Thermal Treatment and Thermomechanical Processing

Once the chemistry (composition) is set the mechanical properties of Titanium Alloys depend almost entirely on the size, shape, and distribution of two allotropic phases: the high-temperature b.c.c. s-phase and the low-temperature h.c.p. a-phase. Thermomechanical processing (TMP) – which is a combination of working (deformation) and thermal (heat) treatment – controls the microstructures and, in turn, the mechanical properties. For example, fracture-critical structures perform most efficiently when fabricated from materials processed to achieve a lenticular morphology, i.e., a high fracture toughness. In contrast Ductility is favored by a globular morphology.