# Nb–Ti phases > Nb–Ti system: 5 phases (tier A 4, liquid 1); 3 stable in a calculated diagram in the ORCHID phase registry, with names, structure type when the stored evidence supports an assignment under the stated tier rules, calculated stability, verbatim TDB PHASE/CONSTITUENT statements and example references. HTML: https://data.orchid-project.org/phases/pages/NB-TI.html · Markdown: https://data.orchid-project.org/phases/pages/NB-TI.md 5 phases (tier A 4, liquid 1); 3 stable in a calculated diagram. Structure types are assigned only when the stored evidence supports an assignment under the stated tier rules (tier A: standard phase name; tier B: unique Materials Project + OQMD on-hull match, DFT-supported; tier C: one structure stated by the assessment's crystallographic table, assessor-stated); other phases list candidates and are marked needs_review. Stability is from phase diagrams calculated with pycalphad from the SGTE binary collection (evidence class: model). Data: [interactive registry](https://orchid-project.org/phases/?q=NB-TI) · [full JSON](https://data.orchid-project.org/phases/systems/NB-TI.json) · [Nb–Ti system page](https://data.orchid-project.org/systems/NB-TI.html) · [Markdown](https://data.orchid-project.org/phases/pages/NB-TI.md) · [field reference](https://data.orchid-project.org/phases/SCHEMA.md) Table: Phases of the Nb–Ti system (5) | Phase | Structure | Basis | Stability (calculated) | Literature values | TDB models | |---|---|---|---|---:|---:| | [BCC_A2](#phase-nb-ti-bcc-a2); _phase:nb-ti:bcc-a2_ | W · A2 · cI2 · Im-3m (229) | tier A: standard phase name | stable in 5 of 5 calculated diagram(s): 300–2765.99 K, x(Ti) 0–1 | 0 | 5 | | [OMEGA_C32](#phase-nb-ti-c32-omega); _phase:nb-ti:c32-omega_ | AlB2 · C32 · hP3 · P6/mmm (191) | tier A: standard phase name | not stable in 3 calculated diagram(s) | 0 | 3 | | [FCC_A1](#phase-nb-ti-fcc-a1); _phase:nb-ti:fcc-a1_ | Cu · A1 · cF4 · Fm-3m (225) | tier A: standard phase name | not stable in 5 calculated diagram(s) | 0 | 5 | | [HCP_A3](#phase-nb-ti-hcp-a3); _phase:nb-ti:hcp-a3_ | Mg · A3 · hP2 · P6_3/mmc (194) | tier A: standard phase name | stable in 5 of 5 calculated diagram(s): 300–2746.9 K, x(Ti) 0.96931–1 | 0 | 5 | | [LIQUID](#phase-nb-ti-liquid); _phase:nb-ti:liquid_ | liquid | liquid | stable in 5 of 5 calculated diagram(s): 1155–4000 K, x(Ti) 0–1 | 0 | 5 | ## BCC_A2 (Nb–Ti) - Id: `phase:nb-ti:bcc-a2`; status `assigned` - Structure: W · A2 · cI2 · Im-3m (229); type `st:a2-w-ci2`; tier A: standard phase name; confidence high - Stability: stable in 5 of 5 calculated diagram(s): 300–2765.99 K, x(Ti) 0–1 - Literature: 0 values (0 accepted) from 0 papers - Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:nb-ti:bcc-a2) Names (6): _corpus: _corpus:phase:nb-ti:bcc-a2 _tdb: _tdb:NbTi-01Zha-LB.tdb:BCC_A2, tdb:NbTi-16Yan.tdb:BCC_A2, tdb:NbTi-18Hu.tdb:BCC_A2, tdb:NbTi-94Har.tdb:BCC_A2, tdb:NbTi-98Sau.tdb:BCC_A2 ### TDB models of BCC_A2 (5): PHASE and CONSTITUENT statements as written [NbTi-01Zha-LB.tdb](https://orchid-project.org/data/databases/sgte-binary/NbTi-01Zha-LB.tdb): BCC_A2, type code %B, sha256 `cc166cb688a0d62e…` ~~~~text 32: PHASE BCC_A2 %B 2 1 3 ! 33: CONST BCC_A2 : NB% TI% : VA : ! ~~~~ [NbTi-16Yan.tdb](https://orchid-project.org/data/databases/sgte-binary/NbTi-16Yan.tdb): BCC_A2, type code %B, sha256 `334018575c889441…` ~~~~text 31: PHASE BCC_A2 %B 2 1 3 ! 32: CONST BCC_A2 : NB% TI% : VA : ! ~~~~ [NbTi-18Hu.tdb](https://orchid-project.org/data/databases/sgte-binary/NbTi-18Hu.tdb): BCC_A2, type code %B, sha256 `b7a98bf27255bfc2…` ~~~~text 31: PHASE BCC_A2 %B 2 1 3 ! 32: CONST BCC_A2 : NB% TI% : VA : ! ~~~~ [NbTi-94Har.tdb](https://orchid-project.org/data/databases/sgte-binary/NbTi-94Har.tdb): BCC_A2, type code %B, sha256 `09901ed78b749997…` ~~~~text 30: PHASE BCC_A2 %B 2 1 3 ! 31: CONST BCC_A2 : NB% TI% : VA : ! ~~~~ [NbTi-98Sau.tdb](https://orchid-project.org/data/databases/sgte-binary/NbTi-98Sau.tdb): BCC_A2, type code %B, sha256 `7e8f7395e69fa0a0…` ~~~~text 32: PHASE BCC_A2 %B 2 1 3 ! 33: CONST BCC_A2 : NB% TI% : VA : ! ~~~~ Example references (4 of 4; assessments first): - [doi:10.1016/0364-5916(94)90008-6](https://doi.org/10.1016/0364-5916%2894%2990008-6) K.C. Hari Kumar, P. Wollants, L. Delaey, Calphad, 18, 71-79(1994). _assessment that models this phase_ - [doi:10.1016/j.calphad.2018.05.007](https://doi.org/10.1016/j.calphad.2018.05.007) B. Hu, Y. Jiang, J. Wang, B. Yao, F. Min, Y. Du, Calphad, 62, 75-82(2018). _assessment that models this phase_ - [doi:10.1016/j.jallcom.2016.02.251](https://doi.org/10.1016/j.jallcom.2016.02.251) Jia-Yi Yan, G.B. Olson, Computational thermodynamics and kinetics of displacive transformations in titanium-based alloys, Journal of Alloys and Compounds 673, 441-454 (2016). _assessment that models this phase_ - [doi:10.1016/S0364-5916(01)00051-7](https://doi.org/10.1016/S0364-5916%2801%2900051-7) Y. Zhang, H. Liu, Z. Jin, Calphad, 25, 305-17(2001). _assessment that models this phase_ ## OMEGA_C32 (Nb–Ti) - Id: `phase:nb-ti:c32-omega`; status `assigned` - Structure: AlB2 · C32 · hP3 · P6/mmm (191); type `st:c32-alb2-hp3`; tier A: standard phase name; confidence high - Stability: not stable in 3 calculated diagram(s) - Literature: 0 values (0 accepted) from 0 papers - Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:nb-ti:c32-omega) Names (4): _corpus: _corpus:phase:nb-ti:c32-omega _tdb: _tdb:NbTi-01Zha-LB.tdb:OMEGA_C32, tdb:NbTi-16Yan.tdb:OMEGA_C32, tdb:NbTi-18Hu.tdb:OMEGA_C32 ### TDB models of OMEGA_C32 (3): PHASE and CONSTITUENT statements as written [NbTi-01Zha-LB.tdb](https://orchid-project.org/data/databases/sgte-binary/NbTi-01Zha-LB.tdb): OMEGA_C32, type code %, sha256 `cc166cb688a0d62e…` ~~~~text 42: PHASE OMEGA_C32 % 1 1 ! 43: CONST OMEGA_C32 : NB TI% : ! ~~~~ [NbTi-16Yan.tdb](https://orchid-project.org/data/databases/sgte-binary/NbTi-16Yan.tdb): OMEGA_C32, type code %, sha256 `334018575c889441…` ~~~~text 41: PHASE OMEGA_C32 % 1 1 ! 42: CONST OMEGA_C32 : NB TI : ! ~~~~ [NbTi-18Hu.tdb](https://orchid-project.org/data/databases/sgte-binary/NbTi-18Hu.tdb): OMEGA_C32, type code %, sha256 `b7a98bf27255bfc2…` ~~~~text 41: PHASE OMEGA_C32 % 1 1 ! 42: CONST OMEGA_C32 : NB TI% : ! ~~~~ Example references (3 of 3; assessments first): - [doi:10.1016/j.calphad.2018.05.007](https://doi.org/10.1016/j.calphad.2018.05.007) B. Hu, Y. Jiang, J. Wang, B. Yao, F. Min, Y. Du, Calphad, 62, 75-82(2018). _assessment that models this phase_ - [doi:10.1016/j.jallcom.2016.02.251](https://doi.org/10.1016/j.jallcom.2016.02.251) Jia-Yi Yan, G.B. Olson, Computational thermodynamics and kinetics of displacive transformations in titanium-based alloys, Journal of Alloys and Compounds 673, 441-454 (2016). _assessment that models this phase_ - [doi:10.1016/S0364-5916(01)00051-7](https://doi.org/10.1016/S0364-5916%2801%2900051-7) Y. Zhang, H. Liu, Z. Jin, Calphad, 25, 305-17(2001). _assessment that models this phase_ ## FCC_A1 (Nb–Ti) - Id: `phase:nb-ti:fcc-a1`; status `assigned` - Structure: Cu · A1 · cF4 · Fm-3m (225); type `st:a1-cu-cf4`; tier A: standard phase name; confidence high - Stability: not stable in 5 calculated diagram(s) - Literature: 0 values (0 accepted) from 0 papers - Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:nb-ti:fcc-a1) Names (6): _corpus: _corpus:phase:nb-ti:fcc-a1 _tdb: _tdb:NbTi-01Zha-LB.tdb:FCC_A1, tdb:NbTi-16Yan.tdb:FCC_A1, tdb:NbTi-18Hu.tdb:FCC_A1, tdb:NbTi-94Har.tdb:FCC_A1, tdb:NbTi-98Sau.tdb:FCC_A1 ### TDB models of FCC_A1 (5): PHASE and CONSTITUENT statements as written [NbTi-01Zha-LB.tdb](https://orchid-project.org/data/databases/sgte-binary/NbTi-01Zha-LB.tdb): FCC_A1, type code %A, sha256 `cc166cb688a0d62e…` ~~~~text 27: PHASE FCC_A1 %A 2 1 1 ! 28: CONST FCC_A1 : NB TI : VA : ! ~~~~ [NbTi-16Yan.tdb](https://orchid-project.org/data/databases/sgte-binary/NbTi-16Yan.tdb): FCC_A1, type code %A, sha256 `334018575c889441…` ~~~~text 26: PHASE FCC_A1 %A 2 1 1 ! 27: CONST FCC_A1 : NB TI : VA : ! ~~~~ [NbTi-18Hu.tdb](https://orchid-project.org/data/databases/sgte-binary/NbTi-18Hu.tdb): FCC_A1, type code %A, sha256 `b7a98bf27255bfc2…` ~~~~text 26: PHASE FCC_A1 %A 2 1 1 ! 27: CONST FCC_A1 : NB TI : VA : ! ~~~~ [NbTi-94Har.tdb](https://orchid-project.org/data/databases/sgte-binary/NbTi-94Har.tdb): FCC_A1, type code %A, sha256 `09901ed78b749997…` ~~~~text 25: PHASE FCC_A1 %A 2 1 1 ! 26: CONST FCC_A1 : NB TI : VA : ! ~~~~ [NbTi-98Sau.tdb](https://orchid-project.org/data/databases/sgte-binary/NbTi-98Sau.tdb): FCC_A1, type code %A, sha256 `7e8f7395e69fa0a0…` ~~~~text 27: PHASE FCC_A1 %A 2 1 1 ! 28: CONST FCC_A1 : NB TI : VA : ! ~~~~ Example references (4 of 4; assessments first): - [doi:10.1016/0364-5916(94)90008-6](https://doi.org/10.1016/0364-5916%2894%2990008-6) K.C. Hari Kumar, P. Wollants, L. Delaey, Calphad, 18, 71-79(1994). _assessment that models this phase_ - [doi:10.1016/j.calphad.2018.05.007](https://doi.org/10.1016/j.calphad.2018.05.007) B. Hu, Y. Jiang, J. Wang, B. Yao, F. Min, Y. Du, Calphad, 62, 75-82(2018). _assessment that models this phase_ - [doi:10.1016/j.jallcom.2016.02.251](https://doi.org/10.1016/j.jallcom.2016.02.251) Jia-Yi Yan, G.B. Olson, Computational thermodynamics and kinetics of displacive transformations in titanium-based alloys, Journal of Alloys and Compounds 673, 441-454 (2016). _assessment that models this phase_ - [doi:10.1016/S0364-5916(01)00051-7](https://doi.org/10.1016/S0364-5916%2801%2900051-7) Y. Zhang, H. Liu, Z. Jin, Calphad, 25, 305-17(2001). _assessment that models this phase_ ## HCP_A3 (Nb–Ti) - Id: `phase:nb-ti:hcp-a3`; status `assigned` - Structure: Mg · A3 · hP2 · P6_3/mmc (194); type `st:a3-mg-hp2`; tier A: standard phase name; confidence high - Stability: stable in 5 of 5 calculated diagram(s): 300–2746.9 K, x(Ti) 0.96931–1 - Literature: 0 values (0 accepted) from 0 papers - Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:nb-ti:hcp-a3) Names (6): _corpus: _corpus:phase:nb-ti:hcp-a3 _tdb: _tdb:NbTi-01Zha-LB.tdb:HCP_A3, tdb:NbTi-16Yan.tdb:HCP_A3, tdb:NbTi-18Hu.tdb:HCP_A3, tdb:NbTi-94Har.tdb:HCP_A3, tdb:NbTi-98Sau.tdb:HCP_A3 ### TDB models of HCP_A3 (5): PHASE and CONSTITUENT statements as written [NbTi-01Zha-LB.tdb](https://orchid-project.org/data/databases/sgte-binary/NbTi-01Zha-LB.tdb): HCP_A3, type code %A, sha256 `cc166cb688a0d62e…` ~~~~text 37: PHASE HCP_A3 %A 2 1 0.5 ! 38: CONST HCP_A3 : NB TI% : VA : ! ~~~~ [NbTi-16Yan.tdb](https://orchid-project.org/data/databases/sgte-binary/NbTi-16Yan.tdb): HCP_A3, type code %A, sha256 `334018575c889441…` ~~~~text 36: PHASE HCP_A3 %A 2 1 0.5 ! 37: CONST HCP_A3 : NB TI% : VA : ! ~~~~ [NbTi-18Hu.tdb](https://orchid-project.org/data/databases/sgte-binary/NbTi-18Hu.tdb): HCP_A3, type code %A, sha256 `b7a98bf27255bfc2…` ~~~~text 36: PHASE HCP_A3 %A 2 1 0.5 ! 37: CONST HCP_A3 : NB TI% : VA : ! ~~~~ [NbTi-94Har.tdb](https://orchid-project.org/data/databases/sgte-binary/NbTi-94Har.tdb): HCP_A3, type code %A, sha256 `09901ed78b749997…` ~~~~text 35: PHASE HCP_A3 %A 2 1 0.5 ! 36: CONST HCP_A3 : NB TI% : VA : ! ~~~~ [NbTi-98Sau.tdb](https://orchid-project.org/data/databases/sgte-binary/NbTi-98Sau.tdb): HCP_A3, type code %A, sha256 `7e8f7395e69fa0a0…` ~~~~text 37: PHASE HCP_A3 %A 2 1 0.5 ! 38: CONST HCP_A3 : NB TI% : VA : ! ~~~~ Example references (4 of 4; assessments first): - [doi:10.1016/0364-5916(94)90008-6](https://doi.org/10.1016/0364-5916%2894%2990008-6) K.C. Hari Kumar, P. Wollants, L. Delaey, Calphad, 18, 71-79(1994). _assessment that models this phase_ - [doi:10.1016/j.calphad.2018.05.007](https://doi.org/10.1016/j.calphad.2018.05.007) B. Hu, Y. Jiang, J. Wang, B. Yao, F. Min, Y. Du, Calphad, 62, 75-82(2018). _assessment that models this phase_ - [doi:10.1016/j.jallcom.2016.02.251](https://doi.org/10.1016/j.jallcom.2016.02.251) Jia-Yi Yan, G.B. Olson, Computational thermodynamics and kinetics of displacive transformations in titanium-based alloys, Journal of Alloys and Compounds 673, 441-454 (2016). _assessment that models this phase_ - [doi:10.1016/S0364-5916(01)00051-7](https://doi.org/10.1016/S0364-5916%2801%2900051-7) Y. Zhang, H. Liu, Z. Jin, Calphad, 25, 305-17(2001). _assessment that models this phase_ ## LIQUID (Nb–Ti) - Id: `phase:nb-ti:liquid`; status `assigned` - Structure: liquid; type `st:liquid`; liquid; confidence high - Stability: stable in 5 of 5 calculated diagram(s): 1155–4000 K, x(Ti) 0–1 - Literature: 0 values (0 accepted) from 0 papers - Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:nb-ti:liquid) Names (6): _corpus: _corpus:phase:nb-ti:liquid _tdb: _tdb:NbTi-01Zha-LB.tdb:LIQUID, tdb:NbTi-16Yan.tdb:LIQUID, tdb:NbTi-18Hu.tdb:LIQUID, tdb:NbTi-94Har.tdb:LIQUID, tdb:NbTi-98Sau.tdb:LIQUID ### TDB models of LIQUID (5): PHASE and CONSTITUENT statements as written [NbTi-01Zha-LB.tdb](https://orchid-project.org/data/databases/sgte-binary/NbTi-01Zha-LB.tdb): LIQUID, type code %, sha256 `cc166cb688a0d62e…` ~~~~text 22: PHASE LIQUID:L % 1 1 ! 23: CONST LIQUID:L : NB TI : ! ~~~~ [NbTi-16Yan.tdb](https://orchid-project.org/data/databases/sgte-binary/NbTi-16Yan.tdb): LIQUID, type code %, sha256 `334018575c889441…` ~~~~text 21: PHASE LIQUID:L % 1 1 ! 22: CONST LIQUID:L : NB TI : ! ~~~~ [NbTi-18Hu.tdb](https://orchid-project.org/data/databases/sgte-binary/NbTi-18Hu.tdb): LIQUID, type code %, sha256 `b7a98bf27255bfc2…` ~~~~text 21: PHASE LIQUID:L % 1 1 ! 22: CONST LIQUID:L : NB TI : ! ~~~~ [NbTi-94Har.tdb](https://orchid-project.org/data/databases/sgte-binary/NbTi-94Har.tdb): LIQUID, type code %, sha256 `09901ed78b749997…` ~~~~text 20: PHASE LIQUID:L % 1 1 ! 21: CONST LIQUID:L : NB TI : ! ~~~~ [NbTi-98Sau.tdb](https://orchid-project.org/data/databases/sgte-binary/NbTi-98Sau.tdb): LIQUID, type code %, sha256 `7e8f7395e69fa0a0…` ~~~~text 22: PHASE LIQUID:L % 1 1 ! 23: CONST LIQUID:L : NB TI : ! ~~~~ Example references (4 of 4; assessments first): - [doi:10.1016/0364-5916(94)90008-6](https://doi.org/10.1016/0364-5916%2894%2990008-6) K.C. Hari Kumar, P. Wollants, L. Delaey, Calphad, 18, 71-79(1994). _assessment that models this phase_ - [doi:10.1016/j.calphad.2018.05.007](https://doi.org/10.1016/j.calphad.2018.05.007) B. Hu, Y. Jiang, J. Wang, B. Yao, F. Min, Y. Du, Calphad, 62, 75-82(2018). _assessment that models this phase_ - [doi:10.1016/j.jallcom.2016.02.251](https://doi.org/10.1016/j.jallcom.2016.02.251) Jia-Yi Yan, G.B. Olson, Computational thermodynamics and kinetics of displacive transformations in titanium-based alloys, Journal of Alloys and Compounds 673, 441-454 (2016). _assessment that models this phase_ - [doi:10.1016/S0364-5916(01)00051-7](https://doi.org/10.1016/S0364-5916%2801%2900051-7) Y. Zhang, H. Liu, Z. Jin, Calphad, 25, 305-17(2001). _assessment that models this phase_ ## Please cite - R. Arróyave, J. Saal, D. Shin, ORCHID-Registry: phase registry of binary systems (version 2026.10; Version 1, machine-extracted), Zenodo (2026). https://doi.org/10.5281/zenodo.23735970 - R. Arróyave, J. Saal, D. Shin, ORCHID data: umbrella record of the ORCHID datasets (version 2026.10; Version 1, machine-extracted), Zenodo (2026). https://doi.org/10.5281/zenodo.23736065 Also cite B. Hallstedt, The SGTE collection of binary datasets, Calphad 89 (2025) 102833, https://doi.org/10.1016/j.calphad.2025.102833 (CC BY 4.0), and the original assessment named in each file; A. Jain et al., The Materials Project: A materials genome approach to accelerating materials innovation, APL Materials 1 (2013) 011002, https://doi.org/10.1063/1.4812323 (CC BY 4.0); J. E. Saal et al., JOM 65 (2013) 1501, https://doi.org/10.1007/s11837-013-0755-4 and S. Kirklin et al., npj Comput. Mater. 1 (2015) 15010, https://doi.org/10.1038/npjcompumats.2015.10 (CC BY 4.0); the original source of every value you use (paper_citation / paper_doi, and cited_dois for values the paper cites from earlier work). Version 1, machine-extracted: values were read by language-model readers constrained to quote their source and checked automatically, and the release was then audited on the printed pages by adversarial audits, an independent second review of fit-facing records and a preliminary human review of a frozen sample. Flags such as accepted and ESPEI-ready record screening results, not certification; known issues are listed in the release notes. ```bibtex @misc{orchid_phase_registry_2026, author = {Arr{\'o}yave, Raymundo and Saal, James and Shin, Dongwon}, title = {{ORCHID-Registry: phase registry of binary systems}}, version = {2026.10}, publisher = {Zenodo}, year = {2026}, doi = {10.5281/zenodo.23735970}, url = {https://doi.org/10.5281/zenodo.23735970}, note = {Version 1, machine-extracted} } @misc{orchid_data_2026, author = {Arr{\'o}yave, Raymundo and Saal, James and Shin, Dongwon}, title = {{ORCHID data: umbrella record of the ORCHID datasets}}, version = {2026.10}, publisher = {Zenodo}, year = {2026}, doi = {10.5281/zenodo.23736065}, url = {https://doi.org/10.5281/zenodo.23736065}, note = {Version 1, machine-extracted} } ``` --- Derived data CC BY 4.0 ([licence](https://creativecommons.org/licenses/by/4.0/)): cite the ORCHID phase registry and the sources named on the page (TDB assessments, Hallstedt 2025, Materials Project, OQMD). TDB statements are quoted as written; parameter expressions are not reproduced. Field reference: [SCHEMA.md](https://data.orchid-project.org/phases/SCHEMA.md). Machine-readable guide: [llms.txt](https://data.orchid-project.org/llms.txt).