Solvus for Ordered Phase Property Model Settings

Select Conventional phase names (the default) or Explicit phase names.

Select Conventional phase names to limit the list to commonly occurring ordered phases, which are Gamma prime (FCC_L12), Gamma double prime (BCT_D022), Eta (NI3TI_D024), Delta (NI3TA_D0A), and Sigma (SIGMA). You can alternatively select a phase from the full list of Explicit phase names; phases available in the list are based on the selected database.

From the Phase to calculate solvus for list, choose a phase. When Conventional phase names is selected Gamma prime (FCC_L12) is the default.

Phases such as FCC_L12 and BCC_B2 normally exhibit ordering (when used with the TCS Ni-based Superalloys Database (TCNI)).

The Subset of phases setting allows you to select a subset of phases relevant to the material type under investigation. The purpose is to consider only phases relevant to typical commercial Ni-base alloys, for example it excludes the eta and delta phases that are normally thermodynamically stable at heat treatment temperatures but rarely form in practice due to their slow formation. Select one of these options to include the specified phases in the calculation:

• All phases: To include all phases in the current system.
• Gamma and gamma prime only (γ and γ' only): To include only disordered FCC (γ) and L12 ordered FCC (γ').

  For the Coarsening - Ni Property Model, you select Gamma and selected precipitate(s) instead and it still includes only disordered FCC (γ) and L12 ordered FCC (γ').

  For Solvus for Ordered Phases - Ni and Strain-Age Cracking - Ni, this option is Gamma + Gamma Prime.

• Typical Ni-base superalloy: To include phases typically present in Ni-base superalloys, i.e. liquid, gamma (γ), gamma prime (γ'), gamma double prime (γ") and carbides (FCC_L12#3, HCP_A3#1, HCP_A3#2, M23C6, M6C, M7C3) along with some additional phases (BCC_A2, BCC_A2#2, BCC_B2, BCC_B2#2, BCT_D022, NI3B_D011, M2B_TETR, D5A_M3B2, M3B2, MB_B33, MB2_C32, G_PHASE, NI5ZR, NI7ZR2, CR3NI5SI2, CR3NI5SI2, SPINEL, ALPHA_SPINEL, CORUNDUM).
• Typical Ni-base superalloy plus eta and delta: To include the phases listed above for a Typical Ni-base superalloy plus eta (η) (NI3TI_D024) and delta (δ) (NI3TA_D0A) phases.
• Typical Ni-base superalloy plus TCP phases: To include the phases listed above for a Typical Ni-base superalloy plus topologically close packed (TCP) phases. TCP phases are laves (C14_LAVES), sigma (σ) (SIGMA), mu (μ) (MU_PHASE), R (R_PHASE), P (P_PHASE), Z (Z_PHASE) and CR3SI (CR3SI_A15).

The search for the solvus temperature is performed between the upper and lower limits. Enter values for the Upper temperature search limit (K) (default is 2000 K) and Lower temperature search limit (K) (default is 500 K).

Depending on the phase model for the selected phase, different sets of sublattices can be used to model ordering. For example, the ordering of FCC_L12 in the TCS Ni-based Superalloys Database (TCNI) occurs on sublattice 1 and 2. Enter a number for the First sublattice for ordering (default is 1) and Second sublattice for ordering (default is 2).

Ordering reactions may be continuous and it is necessary to set a numerical precision. This is because the difference in site occupancy in ordered and disordered phases may be small. Enter a Number of decimals at which to truncate the site fractions (default is 7).

Limits the number of iterations. Enter any value in the Max. number of iterations field that is greater than 0. The default is 100.