Why are titanium alloy heat treatments usually performed below the beta transus temperature?

Heat treatments and final mechanical working of titanium alloys are typically performed below the beta transus temperature to ensure the material achieves the desired microstructural phase distribution and grain size.1

The beta transus represents the lowest temperature at which a 100-percent beta phase can exist, a threshold that varies between 700 °C and 1,050 °C depending on the specific composition of the alloy. By maintaining temperatures below this point, processors can better control the balance between the alpha and beta phases, which is essential for optimizing the mechanical properties—such as strength, toughness, and formability—of the final product.1