About the Martensite Temperatures - Ti Property Model

The Martensite Temperatures - Ti Property Model, available with the Property Model Calculator and the Titanium Model Library, calculates the martensite start temperature (Ms) and T-Zero temperatures for Ti-base alloys.

You can choose between HCP (alpha, alpha, or alpha double prime) and B19_PRIME or B19_ORTHO as the Martensite phase:

  • The HCP (alpha, alpha, or alpha double prime) is the common choice for alloys such as Ti-6Al-4V and other structural alloys.
  • The B19_PRIME and B19_ORTHO options are intended for TiNi-based shape-memory alloys. In particular, B19_ORTHO is useful for TiNiCu-based shape-memory alloys.

The various forms of alpha martensite HCP (alpha, alpha, or alpha double prime) are not explicitly distinguished and are collectively described by the phase HCP_A3 in terms of thermodynamic properties.

An initial equilibrium is calculated to set the starting composition and internal constitution (in case of ordering) of the parent phase. This should be performed at a temperature that reflects the thermal history of the studied alloy. The starting composition and constitution is held fixed throughout the calculation as it is expected that the alloy cannot equilibrate during a martensitic transformation.

The model then calculates the T0 temperature and the associated offset to the Ms temperature, which occurs due to the thermodynamic barrier for nucleation of martensite. The offset is parameterized using conventional Redlich-Kister polynomials.

To run calculations with the Titanium Models requires a valid maintenance license plus a license for the TCTI (version 6 and newer) database. For some Property Models, additional recommendations for the database version to use is indicated in its description. Also see our website to learn more about the Titanium Model Library.

The input parameters are entered on the Configuration window for the Property Model Calculator. There are also settings on the Plot Renderer where you can choose from the available and relevant axis variables.

See Martensite Temperatures - Ti Property Model Settings.

For an example see PM_Ti_01: Martensite Temperatures for Ti-Zr