TCNI: TCS Ni-based Superalloys Database Revision History

• The Effective Bond Energy Formalism (EBEF) is implemented to describe the complex and important topologically close-packed (TCP) sigma (σ) and mu (μ) phases.
  • New Density Functional Theory (DFT) data is used to support the implementation of the EBEF.
  • The five-sublattice (5-SL) model is used to describe both phases, which better reflects their real crystallographic structures.
• Oxygen (O) and sulfur (S) are added in the LIQUID phase (previously only available in the IONIC_LIQ phase) and the IONIC_LIQ is removed from the database.

• The Hf-Pt system is added. Previously the system was incorrectly listed as assessed in the last version of the database, TCNI12.
• The description of phase equilibria involving σ and/or μ phases is improved in several systems.
  • Co-Nb, Co-Ta, Fe-Ta, Nb-Ni, Ni-Ta, Ni-V, Pd-Ta, Pt-Ta, and Re-Ta.

• 2 new ternary systems are assessed: Cr-Ni-Pt and Hf-Ni-Ti.
• The liquidus projection of the Mg–Mn–Ni system is corrected.
• Several improvements are obtained in the description of the σ and μ phases as a result of the implementation of the EBEF. Some examples:
  • σ description in the Cr-Ni-Re, Cr-Fe-Mn, and Mo-Ni-Re.
  • μ description in the Co-Cr-W, Cr-Fe-Nb, and Fe-Mo-Nb.

• Added viscosity, surface tension, and THCD/ELRS descriptions for the above newly added systems.

Elastic Properties

• Added elastic properties for BCC (A2 & B2), FCC (A1 & L12), and HCP (A3) phases.

• Phosphorus (P) is added to make it a 31 element framework.

The following systems are at least partially assessed.

• Al-P, B-P, C-P, Ca-P, Co-P, Cu-P, Cr-P, Fe-P, Mn-P, Mo-P, Nb-P, Ni-P, P-Pd, Pt-P, Ru-P, S-P, Si-P, Ti-P, V-P, and W-P

• Fe-Nb updated, improved MU and C14_LAVES boundaries.
• Nb-Ni, Fe-Si, Nb-Si updated metastable C14_LAVES description.
• Co-W updated so that Co3W D019 is stable to low temperature.
• Fe-Nb-Si added.
• Fe-Nb-Ni updated, improved Laves boundaries.
• Co-Ni-Ti updated to correspond better with available phase diagram data.
• Al-Co-Ni updated to better fit thermodynamic and phase diagram data.
• Al-Co-W updated to destabilize FCC_L12#2 (gamma-prime)
• Co-Ni-W updated metastable FCC_L12 towards an improved description of Al-Co-Ni-W
• Nb-Ni-Ti fixed a bug relating to a slightly destabilized ternary phase.

• Viscosity and Surface tension updated:
  • Viscosity is now described for the ionic liquid phase (IONIC_LIQ)
• Electrical and thermal properties improved:
  • High-temperature trends of THCD are now better for commercial alloys
  • ELRS of Cr-Fe rich Ni-base alloys were before quite over-estimated, now improved.

• AL-FE-SI ternary phases renamed to use their modern Greek letters. ALFESI_ALPHA > ALFESI_ALPHA_TAU5
• D0I_MO2B5 renamed to MO2B5_D8I, correct strukturbericht.
• All phase description updated to our new standardized crystallographic information format.

• Corrected minor typo in the Gibbs energy of the MUFEMO function, used in the MU_PHASE

• Surface tension for the liquid phase is assessed in all unary and binary systems.
• Viscosity for the liquid phase is assessed in all unary and 142 binary systems.
• Nb-Ni metastable BCT_D022 updated to fit data on γ'' solvus temperature in commercial superalloys.
• The solubility of S in γ-Ni has been assessed.
• Bug fixed for metastable BCT_D022 destabilized in Cr-Nb and pure Cr to avoid low-temperature metastable miscibility gaps.

• Al-Co-W system updated to fit better experimental data and no longer have stable L12 at 900 C
• Al-Hf-Ni system revised to better describe liquidus, solidus, and liquid activity as well as γ' boundaries and activity (see references 1-4 at the end of this section).
• Al-Ni-Pt system updated to better describe liquid activity and melting interval data by Copland (2007) (see reference 5 at the end of this section).
• Al-Ni-W system revised to better fit known melting interval and improve liquid/γ partitioning in higher-order alloys
• Co-Hf-Ni liquid and γ phases updated to better describe the melting intervals of high-Co Ni-base alloys. (see reference 6 at the end of this section)
• Co-Ni-W system updated to fit more recent data on the varying ternary solubility of the ALTI3_D019 phase
• Co-Ni-V has been partially assessed by adding Co to BCT-D022, and FCC and liquid have been adjusted to give approximate isothermal and isoplethal sections.
• Nb-Ni-Ti system modified to be closer to the known phase diagram (see reference 7 at the end of this section)

• L12 destabilized in Cr-Ni-W and Cr-Ni-Si
• ALTI3_D019 destabilized in Cr-Ni-W
• Corrected M4SI3 in Cr-Ni-Si, now metastable in Cr-Si and Ni-Si
• Corrected M5Si3_D88 in C-Cr-si
• Al-Cr-Pt extrapolation corrected

• The DATABASE_INFORMATION command accessed via the DATABASE module in Console Mode now includes an exact revision number to make it easier to communicate support questions.
• The additional phase information now contains crystallographic information (if known) for all phases. The command is invoked in the DATABASE module via LIST_SYSTEM and CONSTITUENTS
• The database is automatically validated against a large range of commercial and model alloys to verify that every revision improves solidus, liquidus, γ' solvus and liquid/solid partitioning data. This ensures that no alloy should fall through the cracks.

• ALTI3_DO19 (where O is a letter) has been changed to be named ALTI3_D019 (where 0 is zero), which is consistent with the Strukturbericht designation. Users are advised to update their macros involving this phase.

1. P. Nash, D. R. F. West, Phase equilibria in Ni-rich region of Ni–Al–Hf system. Met. Sci. 15, 347–352 (1981).
2. M. Takeyama, C. T. Liu, Microstructures and mechanical properties of NiAl–Ni 2 AlHf alloys. J. Mater. Res. 5, 1189–1196 (1990).
3. M. Albers, M. Sai Baba, D. Kath, M. Miller, K. Hilpert, Chemical Activities in the Solid Solution of Hf in Ni3Al. Berichte der Bunsengesellschaft für Phys. Chemie. 96, 1663–1668 (1992).
4. S. Miura, Y.-M. Hong, T. Suzuki, Y. Mishima, Liquidus and solidus temperatures of Ni-solid solution in Ni-Al-X (X: Ti, Zr, and Hf) ternary systems. J. Phase Equilibria. 20, 193–198 (1999).
5. E. Copland, Partial Thermodynamic Properties of γ′-(Ni,Pt)3Al in the Ni-Al-Pt system. J. Phase Equilibria Diffus. 28, 38–48 (2007).
6. N. Volz, C. H. Zenk, R. Cherukuri, T. Kalfhaus, M. Weiser, S. K. Makineni, C. Betzing, M. Lenz, B. Gault, S. G. Fries, J. Schreuer, R. Vaßen, S. Virtanen, D. Raabe, E. Spiecker, S. Neumeier, M. Göken, Thermophysical and Mechanical Properties of Advanced Single Crystalline Co-base Superalloys. Metall. Mater. Trans. A. 49, 4099–4109 (2018).
7. K. P. Gupta, The Nb-Ni-Ti (Niobium-Nickel-Titanium) System—Update. J. Phase Equilibria Diffus. 29, 194–197 (2008).