Nb–Ti phases

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 · full JSON · Nb–Ti system page · Markdown · field reference

Phases of the Nb–Ti system (5)
Phase	Structure	Basis	Stability (calculated)	TDB models
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	5
OMEGA_C32 phase:nb-ti:c32-omega	AlB2 · C32 · hP3 · P6/mmm (191)	tier A: standard phase name	not stable in 3 calculated diagram(s)	3
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)	5
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	5
LIQUID phase:nb-ti:liquid	liquid	liquid	stable in 5 of 5 calculated diagram(s): 1155–4000 K, x(Ti) 0–1	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

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: BCC_A2, type code %B, sha256 cc166cb688a0d62e…

32: PHASE BCC_A2 %B 2 1 3 !
33: CONST BCC_A2 : NB% TI% : VA : !

NbTi-16Yan.tdb: BCC_A2, type code %B, sha256 334018575c889441…

31: PHASE BCC_A2 %B 2 1 3 !
32: CONST BCC_A2 : NB% TI% : VA : !

NbTi-18Hu.tdb: BCC_A2, type code %B, sha256 b7a98bf27255bfc2…

31: PHASE BCC_A2 %B 2 1 3 !
32: CONST BCC_A2 : NB% TI% : VA : !

NbTi-94Har.tdb: BCC_A2, type code %B, sha256 09901ed78b749997…

30: PHASE BCC_A2 %B 2 1 3 !
31: CONST BCC_A2 : NB% TI% : VA : !

NbTi-98Sau.tdb: BCC_A2, type code %B, sha256 7e8f7395e69fa0a0…

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 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 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 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 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

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: OMEGA_C32, type code %, sha256 cc166cb688a0d62e…

42: PHASE OMEGA_C32 % 1 1 !
43: CONST OMEGA_C32 : NB TI% : !

NbTi-16Yan.tdb: OMEGA_C32, type code %, sha256 334018575c889441…

41: PHASE OMEGA_C32 % 1 1 !
42: CONST OMEGA_C32 : NB TI : !

NbTi-18Hu.tdb: OMEGA_C32, type code %, sha256 b7a98bf27255bfc2…

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 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 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 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

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: FCC_A1, type code %A, sha256 cc166cb688a0d62e…

27: PHASE FCC_A1 %A 2 1 1 !
28: CONST FCC_A1 : NB TI : VA : !

NbTi-16Yan.tdb: FCC_A1, type code %A, sha256 334018575c889441…

26: PHASE FCC_A1 %A 2 1 1 !
27: CONST FCC_A1 : NB TI : VA : !

NbTi-18Hu.tdb: FCC_A1, type code %A, sha256 b7a98bf27255bfc2…

26: PHASE FCC_A1 %A 2 1 1 !
27: CONST FCC_A1 : NB TI : VA : !

NbTi-94Har.tdb: FCC_A1, type code %A, sha256 09901ed78b749997…

25: PHASE FCC_A1 %A 2 1 1 !
26: CONST FCC_A1 : NB TI : VA : !

NbTi-98Sau.tdb: FCC_A1, type code %A, sha256 7e8f7395e69fa0a0…

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 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 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 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 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

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: HCP_A3, type code %A, sha256 cc166cb688a0d62e…

37: PHASE HCP_A3 %A 2 1 0.5 !
38: CONST HCP_A3 : NB TI% : VA : !

NbTi-16Yan.tdb: HCP_A3, type code %A, sha256 334018575c889441…

36: PHASE HCP_A3 %A 2 1 0.5 !
37: CONST HCP_A3 : NB TI% : VA : !

NbTi-18Hu.tdb: HCP_A3, type code %A, sha256 b7a98bf27255bfc2…

36: PHASE HCP_A3 %A 2 1 0.5 !
37: CONST HCP_A3 : NB TI% : VA : !

NbTi-94Har.tdb: HCP_A3, type code %A, sha256 09901ed78b749997…

35: PHASE HCP_A3 %A 2 1 0.5 !
36: CONST HCP_A3 : NB TI% : VA : !

NbTi-98Sau.tdb: HCP_A3, type code %A, sha256 7e8f7395e69fa0a0…

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 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 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 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 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

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: LIQUID, type code %, sha256 cc166cb688a0d62e…

22: PHASE LIQUID:L % 1 1 !
23: CONST LIQUID:L : NB TI : !

NbTi-16Yan.tdb: LIQUID, type code %, sha256 334018575c889441…

21: PHASE LIQUID:L % 1 1 !
22: CONST LIQUID:L : NB TI : !

NbTi-18Hu.tdb: LIQUID, type code %, sha256 b7a98bf27255bfc2…

21: PHASE LIQUID:L % 1 1 !
22: CONST LIQUID:L : NB TI : !

NbTi-94Har.tdb: LIQUID, type code %, sha256 09901ed78b749997…

20: PHASE LIQUID:L % 1 1 !
21: CONST LIQUID:L : NB TI : !

NbTi-98Sau.tdb: LIQUID, type code %, sha256 7e8f7395e69fa0a0…

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 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 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 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 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). doi: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). doi: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.

@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}
}