Fe–Si system

35 accepted literature values from 3 paper(s) (experimental 16, model 19); 3 calculated phase diagram(s). 2 further extracted value(s) not accepted by the reader-agreement checks are only in the JSON/CSV.

Data: JSON · CSV · interactive explorer · interactive phase diagram · phases (12) · papers (bibliography) · Markdown

Accepted values by evidence class
Evidence class	Values
experimental	16
model	19

Accepted values by property group
Property group	Values
invariant reaction	20
phase transition	6
phase equilibrium	9

Calculated phase diagrams

Binary phase diagrams calculated with pycalphad 0.11.2 from the SGTE binary collection (Hallstedt 2025, CC BY 4.0). Evidence class: model.

Assessments with a calculated phase diagram
TDB file	Assessment	SHA-256	Links
FeSi-14Yua.tdb	Y. Yuan, F. Pan, D. Li, A. Watson, Calphad, 44, 54-61(2014). doi:10.1016/j.calphad.2013.07.007	`b45ac7c1e94df43853b00f85aca124c47a7473ee1e3cfae89ca2cf76d1094d3b`	viewer · TDB · JSON
FeSi-23Wit.tdb	V.T. Witusiewicz, O. Stryzhyboroda, S. Vinke, K. Bobzin, U. Hecht, J. Alloys Compd., 935, 168118(2023). doi:10.1016/j.jallcom.2022.168118	`186057838279687890388d53d0898afaadcb01a9b56baec2b846f197b4ac37b6`	viewer · TDB · JSON
FeSi-91Lac-LB.tdb	J. Lacaze, B. Sundman, Metall. Mater. Trans. A, 22A, 2211-23(1991). Liquid modified by J. Miettinen 1998. doi:10.1007/BF02664987	`b0825ae47e3165133b7f6c7d1bf5c189071c91729f4b9dc42e76ad9d081d4561`	viewer · TDB · JSON

Calculated three-phase invariants (model, mole fraction of the second component)
TDB file	T (K)	Phases at the invariant
FeSi-14Yua.tdb	1667.47	FCC_A1 (x(Si) 0) + B2_BCC (x(Si) 0) + BCC_A2 (x(Si) 0)
FeSi-14Yua.tdb	1485.4	MSI_B20 (x(Si) 0.5) + LIQUID (x(Si) 0.68167) + FESI2_H (x(Si) 0.7)
FeSi-14Yua.tdb	1485.4	MSI_B20 (x(Si) 0.5) + LIQUID (x(Si) 0.68178) + FESI2_H (x(Si) 0.7)
FeSi-14Yua.tdb	1485.4	MSI_B20 (x(Si) 0.5) + LIQUID (x(Si) 0.68183) + FESI2_H (x(Si) 0.7)
FeSi-14Yua.tdb	1483.72	FESI2_H (x(Si) 0.7) + LIQUID (x(Si) 0.72835) + DIAMOND_A4 (x(Si) 1)
FeSi-14Yua.tdb	1483.72	FESI2_H (x(Si) 0.7) + LIQUID (x(Si) 0.72851) + DIAMOND_A4 (x(Si) 1)
FeSi-14Yua.tdb	1477.19	FE2SI (x(Si) 0.33333) + LIQUID (x(Si) 0.35306) + MSI_B20 (x(Si) 0.5)
FeSi-14Yua.tdb	1477	B2_BCC (x(Si) 0.27498) + LIQUID (x(Si) 0.31344) + FE2SI (x(Si) 0.33333)
FeSi-14Yua.tdb	1477	B2_BCC (x(Si) 0.27498) + LIQUID (x(Si) 0.31344) + FE2SI (x(Si) 0.33333)
FeSi-14Yua.tdb	1330.42	FE2SI (x(Si) 0.33333) + M5SI3_D88 (x(Si) 0.375) + MSI_B20 (x(Si) 0.5)
FeSi-14Yua.tdb	1315.83	B2_BCC (x(Si) 0.29971) + FE2SI (x(Si) 0.33333) + M5SI3_D88 (x(Si) 0.375)
FeSi-14Yua.tdb	1315.83	B2_BCC (x(Si) 0.29971) + FE2SI (x(Si) 0.33333) + M5SI3_D88 (x(Si) 0.375)
FeSi-14Yua.tdb	1256.37	MSI_B20 (x(Si) 0.5) + FESI2_L (x(Si) 0.66667) + FESI2_H (x(Si) 0.7)
FeSi-14Yua.tdb	1217.26	FESI2_L (x(Si) 0.66667) + FESI2_H (x(Si) 0.7) + DIAMOND_A4 (x(Si) 1)
FeSi-14Yua.tdb	1184.82	FCC_A1 (x(Si) 0) + B2_BCC (x(Si) 0) + MSI_B20 (x(Si) 0.5)
FeSi-14Yua.tdb	1184.82	B2_BCC (x(Si) 0) + FCC_A1 (x(Si) 0) + MSI_B20 (x(Si) 0.5)
FeSi-14Yua.tdb	1100.15	B2_BCC (x(Si) 0.29885) + M5SI3_D88 (x(Si) 0.375) + MSI_B20 (x(Si) 0.5)
FeSi-14Yua.tdb	1100.15	B2_BCC (x(Si) 0.29885) + M5SI3_D88 (x(Si) 0.375) + MSI_B20 (x(Si) 0.5)
FeSi-23Wit.tdb	1487	MSI_B20 (x(Si) 0.5122) + LIQUID (x(Si) 0.68967) + FESI2_H (x(Si) 0.69809)
FeSi-23Wit.tdb	1485.85	FESI2_H (x(Si) 0.71468) + LIQUID (x(Si) 0.73219) + DIAMOND_A4 (x(Si) 1)
FeSi-23Wit.tdb	1478.35	B2_BCC (x(Si) 0.30775) + LIQUID (x(Si) 0.3242) + FE2SI (x(Si) 0.3344)
FeSi-23Wit.tdb	1478.35	B2_BCC (x(Si) 0.30775) + LIQUID (x(Si) 0.3242) + FE2SI (x(Si) 0.3344)
FeSi-23Wit.tdb	1476.2	FE2SI (x(Si) 0.33872) + LIQUID (x(Si) 0.35296) + MSI_B20 (x(Si) 0.49178)
FeSi-23Wit.tdb	1353.13	FE2SI (x(Si) 0.3392) + M5SI3_D88 (x(Si) 0.375) + MSI_B20 (x(Si) 0.49031)
FeSi-23Wit.tdb	1323.35	B2_BCC (x(Si) 0.31807) + FE2SI (x(Si) 0.33912) + M5SI3_D88 (x(Si) 0.375)
FeSi-23Wit.tdb	1323.35	B2_BCC (x(Si) 0.31807) + FE2SI (x(Si) 0.33912) + M5SI3_D88 (x(Si) 0.375)
FeSi-23Wit.tdb	1255	MSI_B20 (x(Si) 0.50644) + FESI2_L (x(Si) 0.66667) + FESI2_H (x(Si) 0.70096)
FeSi-23Wit.tdb	1209.55	FESI2_L (x(Si) 0.66667) + FESI2_H (x(Si) 0.71045) + DIAMOND_A4 (x(Si) 1)
FeSi-23Wit.tdb	1209.55	FESI2_L (x(Si) 0.66667) + FESI2_H (x(Si) 0.71045) + DIAMOND_A4 (x(Si) 1)
FeSi-23Wit.tdb	1209.55	FESI2_L (x(Si) 0.66667) + FESI2_H (x(Si) 0.71051) + DIAMOND_A4 (x(Si) 1)
FeSi-23Wit.tdb	1194.55	B2_BCC (x(Si) 0.30523) + M5SI3_D88 (x(Si) 0.375) + MSI_B20 (x(Si) 0.48891)
FeSi-23Wit.tdb	1194.55	B2_BCC (x(Si) 0.30523) + M5SI3_D88 (x(Si) 0.375) + MSI_B20 (x(Si) 0.48891)
FeSi-91Lac-LB.tdb	1667.47	FCC_A1 (x(Si) 0) + B2_BCC (x(Si) 0) + BCC_A2 (x(Si) 0)
FeSi-91Lac-LB.tdb	1549.1	B2_BCC (x(Si) 0.20458) + B2_BCC#2 (x(Si) 0.20458) + LIQUID (x(Si) 0.23868)
FeSi-91Lac-LB.tdb	1477.85	FESI2_H (x(Si) 0.7) + LIQUID (x(Si) 0.72588) + DIAMOND_A4 (x(Si) 1)
FeSi-91Lac-LB.tdb	1476.93	MSI_B20 (x(Si) 0.5) + LIQUID (x(Si) 0.67206) + FESI2_H (x(Si) 0.7)
FeSi-91Lac-LB.tdb	1475.66	FE2SI (x(Si) 0.33333) + LIQUID (x(Si) 0.35723) + MSI_B20 (x(Si) 0.5)
FeSi-91Lac-LB.tdb	1475.66	FE2SI (x(Si) 0.33333) + LIQUID (x(Si) 0.35741) + MSI_B20 (x(Si) 0.5)
FeSi-91Lac-LB.tdb	1470.59	B2_BCC (x(Si) 0.27245) + LIQUID (x(Si) 0.30511) + FE2SI (x(Si) 0.33333)
FeSi-91Lac-LB.tdb	1470.59	B2_BCC (x(Si) 0.27245) + LIQUID (x(Si) 0.30511) + FE2SI (x(Si) 0.33333)
FeSi-91Lac-LB.tdb	1364.45	FE2SI (x(Si) 0.33333) + M5SI3_D88 (x(Si) 0.375) + MSI_B20 (x(Si) 0.5)
FeSi-91Lac-LB.tdb	1322.86	B2_BCC (x(Si) 0.29879) + FE2SI (x(Si) 0.33333) + M5SI3_D88 (x(Si) 0.375)
FeSi-91Lac-LB.tdb	1322.86	B2_BCC (x(Si) 0.29879) + FE2SI (x(Si) 0.33333) + M5SI3_D88 (x(Si) 0.375)
FeSi-91Lac-LB.tdb	1275.67	MSI_B20 (x(Si) 0.5) + FESI2_L (x(Si) 0.66667) + FESI2_H (x(Si) 0.7)
FeSi-91Lac-LB.tdb	1232.9	FESI2_L (x(Si) 0.66667) + FESI2_H (x(Si) 0.7) + DIAMOND_A4 (x(Si) 1)
FeSi-91Lac-LB.tdb	1184.82	FCC_A1 (x(Si) 0) + B2_BCC (x(Si) 0) + MSI_B20 (x(Si) 0.5)
FeSi-91Lac-LB.tdb	1184.81	FCC_A1 (x(Si) 0) + B2_BCC (x(Si) 0) + BCC_A2 (x(Si) 0)
FeSi-91Lac-LB.tdb	1098.04	B2_BCC (x(Si) 0.29764) + M5SI3_D88 (x(Si) 0.375) + MSI_B20 (x(Si) 0.5)
FeSi-91Lac-LB.tdb	1098.04	B2_BCC (x(Si) 0.29763) + M5SI3_D88 (x(Si) 0.375) + MSI_B20 (x(Si) 0.5)

Convex hulls: Materials Project DFT hull · OQMD DFT hull · CALPHAD hull FeSi-14Yua · CALPHAD hull FeSi-91Lac-LB

Invariant reactions (literature)

Invariant reactions reported in the literature for the Fe–Si system (20)
T (K)	Reaction / phases	Compositions (mole fraction)	Class	Source	Location
1683	congruent melting: FeSi -> Liquid	FeSi: Si 0.5; Liquid: Si 0.5	model	[1] (ed.) 1998	Table I, p. 219, row 11 report
1488	congruent melting: Fe2Si -> Liquid	Fe2Si: Si 0.333; Liquid: Si 0.333	model	[1] (ed.) 1998	Table I, p. 219, row 10 report
1485	eutectic: L -> FeSi+FeSi2_H	L: Si 0.682; FeSi: Si 0.5; FeSi2_H: Si 0.7	model	[2] Yuan 2014	Table 2, p. 4, row 9 report
1485	eutectic: L -> FeSi+FeSi2_H	L: Si 0.67; FeSi: Si 0.5; FeSi2_H: Si 0.7	experimental	[2] Yuan 2014 cites Kubaschewski 1982	Table 2, p. 4, row 10 report
1483	eutectic: L -> FeSi2_H+(Si)	L: Si 0.728; FeSi2_H: Si 0.7; (Si): Si 1	model	[2] Yuan 2014	Table 2, p. 4, row 13 report
1482	congruent melting: FeSi2-H -> Liquid	FeSi2-H: Si 0.7; Liquid: Si 0.7	model	[1] (ed.) 1998	Table I, p. 219, row 12 report
1480	eutectic: L -> FeSi2_H+(Si)	L: Si 0.73; FeSi2_H: Si 0.7; (Si): Si 1	experimental	[2] Yuan 2014 cites Kubaschewski 1982	Table 2, p. 4, row 14 report
1478.3	eutectic: Liquid -> FeSi2-H + (Si)	Liquid: Si 0.725; FeSi2-H: Si 0.7; (Si): Si 1	model	[1] (ed.) 1998	Table I, p. 219, row 9 report
1477.2	eutectic: Liquid -> FeSi + FeSi2-H	Liquid: Si 0.672; FeSi: Si 0.5; FeSi2-H: Si 0.7	model	[1] (ed.) 1998	Table I, p. 219, row 6 report
1477	eutectic: L -> Fe2Si+FeSi	L: Si 0.353; Fe2Si: Si 0.333333; FeSi: Si 0.5	model	[2] Yuan 2014	Table 2, p. 4, row 5 report
1477	eutectic: L -> BCC_B2+Fe2Si	L: Si 0.318; Fe2Si: Si 0.333333	model	[2] Yuan 2014	Table 2, p. 4, row 1 report
1476	eutectic: L -> Fe2Si+FeSi	L: Si 0.36; Fe2Si: Si 0.333333; FeSi: Si 0.5	experimental	[2] Yuan 2014 cites Kubaschewski 1982	Table 2, p. 4, row 6 report
1475.8	eutectic: Liquid -> Fe2Si + FeSi	Liquid: Si 0.357; Fe2Si: Si 0.333; FeSi: Si 0.5	model	[1] (ed.) 1998	Table I, p. 219, row 5 report
1473	eutectic: L -> BCC_B2+Fe2Si	L: Si 0.32; Fe2Si: Si 0.333333	experimental	[2] Yuan 2014 cites Kubaschewski 1982	Table 2, p. 4, row 2 report
1470.6	eutectic: Liquid -> bcc-B2 + Fe2Si	Liquid: Si 0.273; bcc-B2: Si 0.267; Fe2Si: Si 0.333	model	[1] (ed.) 1998	Table I, p. 219, row 1 report
1364.4	peritectoid: Fe2Si + FeSi -> Fe5Si3	Fe2Si: Si 0.333; FeSi: Si 0.5; Fe5Si3: Si 0.375	model	[1] (ed.) 1998	Table I, p. 219, row 4 report
1322.8	eutectoid: Fe2Si -> bcc-B2 + Fe5Si3	Fe2Si: Si 0.333; bcc-B2: Si 0.299; Fe5Si3: Si 0.375	model	[1] (ed.) 1998	Table I, p. 219, row 2 report
1275.7	peritectoid: FeSi + FeSi2-H -> FeSi2-L	FeSi: Si 0.5; FeSi2-H: Si 0.7; FeSi2-L: Si 0.666	model	[1] (ed.) 1998	Table I, p. 219, row 7 report
1232.9	eutectoid: FeSi2-H -> FeSi2-L + (Si)	FeSi2-H: Si 0.7; FeSi2-L: Si 0.667; (Si): Si 1	model	[1] (ed.) 1998	Table I, p. 219, row 8 report
1097.8	eutectoid: Fe5Si3 -> bcc-B2 + FeSi	Fe5Si3: Si 0.375; bcc-B2: Si 0.298; FeSi: Si 0.5	model	[1] (ed.) 1998	Table I, p. 219, row 3 report

Other properties

Phase transition (6)

Phase transition, Fe–Si system
Property	Value	T (K)	Phases / composition	Class	Source	Location
Phase transition	1484 K	1484	congruent melting: L -> Fe2Si L: Si 0.333333; Fe2Si: Si 0.333333	model	[2] Yuan 2014	Table 2, p. 4, row 3 report
Phase transition	1485 K	1485	congruent melting: L -> Fe2Si L: Si 0.333333; Fe2Si: Si 0.333333	experimental	[2] Yuan 2014 cites Kubaschewski 1982	Table 2, p. 4, row 4 report
Phase transition	1487 K	1487	congruent melting: L -> FeSi2_H L: Si 0.7; FeSi2_H: Si 0.7	model	[2] Yuan 2014	Table 2, p. 4, row 11 report
Phase transition	1493 K	1493	congruent melting: L -> FeSi2_H L: Si 0.7; FeSi2_H: Si 0.7	experimental	[2] Yuan 2014 cites Kubaschewski 1982	Table 2, p. 4, row 12 report
Phase transition	1680 K	1680	congruent melting: L -> FeSi L: Si 0.5; FeSi: Si 0.5	model	[2] Yuan 2014	Table 2, p. 4, row 7 report
Phase transition	1683 K	1683	congruent melting: L -> FeSi L: Si 0.5; FeSi: Si 0.5	experimental	[2] Yuan 2014 cites Kubaschewski 1982	Table 2, p. 4, row 8 report

Phase equilibrium (9)

Phase equilibrium, Fe–Si system
Property	T (K)	Phases / composition	Class	Source	Location
Phase assemblage	973.15	single phase alloy: Fe 0.86, Si 0.14	experimental	[3] Ohnuma 2012	Table 1, p. 2, row 3 report
Phase assemblage	1073.15	single phase alloy: Fe 0.845, Si 0.155	experimental	[3] Ohnuma 2012	Table 1, p. 2, row 2 report
Phase assemblage	1173.15	single phase alloy: Fe 0.83, Si 0.17	experimental	[3] Ohnuma 2012	Table 1, p. 2, row 1 report
Phase composition	873.15	A2 (B2) + D03 + D0₃ A2 (B2): Fe 0.888, Si 0.112; D03: Fe 0.866, Si 0.134; D0₃: Fe 0.866, Si 0.134	experimental	[3] Ohnuma 2012	Table 1, p. 2, row 5 report
Phase composition	923.15	A2 (B2) + D03 + D0₃ A2 (B2): Fe 0.889, Si 0.111; D03: Fe 0.862, Si 0.138; D0₃: Fe 0.862, Si 0.138	experimental	[3] Ohnuma 2012	Table 1, p. 2, row 4 report
Phase composition	973.15	B2 + D03 B2: Fe 0.88, Si 0.12; D03: Fe 0.856, Si 0.144	experimental	[3] Ohnuma 2012	Table 2, p. 3, row 4 report
Phase composition	1073.15	A2/B2 + B2 + D03 A2/B2: Fe 0.875, Si 0.125; B2: Fe 0.849, Si 0.151; D03: Fe 0.842, Si 0.158	experimental	[3] Ohnuma 2012	Table 2, p. 3, row 3 report
Phase composition	1173.15	B2 + D03 B2: Fe 0.835, Si 0.165; D03: Fe 0.83, Si 0.17	experimental	[3] Ohnuma 2012	Table 2, p. 3, row 2 report
Phase composition	1273.15	A2/B2 + B2/ D03 + B2/D03 A2/B2: Fe 0.848, Si 0.152; B2/ D03: Fe 0.816, Si 0.184; B2/D03: Fe 0.816, Si 0.184	experimental	[3] Ohnuma 2012	Table 2, p. 3, row 1 report

Sources

Reporting papers the values were read from (a value cited from another work names that work in its row).

I. Ansara, A. T. Dinsdale, M. H. Rand (eds.), COST 507: Thermochemical database for light metal alloys, Volume 2, EUR 18499 EN, Office for Official Publications of the European Communities, Luxembourg (1998), ISBN 92-828-3902-8.
Yuan Yuan, Fusheng Pan, Dajian Li, Andrew Watson, The re-assessment of the Mg–Zn and Fe–Si systems and their incorporation in thermodynamic descriptions of the Al–Mg–Zn and Fe–Si–Zn systems, Calphad 44, 54-61 (2014). doi:10.1016/j.calphad.2013.07.007
Ikuo Ohnuma, Shinya Abe, Shota Shimenouchi, Toshihiro Omori, Ryosuke Kainuma, Kiyohito Ishida, Experimental and Thermodynamic Studies of the Fe–Si Binary System, ISIJ Int. 52, 540-548 (2012). doi:10.2355/isijinternational.52.540

Please cite

R. Arróyave, J. Saal, D. Shin, ORCHID-Values: thermodynamic and phase-equilibrium values read from the literature (version 2026.10; Version 1, machine-extracted), Zenodo (2026). doi:10.5281/zenodo.23735569
R. Arróyave, J. Saal, D. Shin, ORCHID-Diagrams: calculated binary phase diagrams (version 2026.10), Zenodo (2026). doi:10.5281/zenodo.23735859
R. Arróyave, J. Saal, D. Shin, ORCHID-Hulls: binary convex hulls (Materials Project, OQMD, assessed CALPHAD) (version 2026.10), Zenodo (2026). doi:10.5281/zenodo.23735891
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 the original source of every value you use (paper_citation / paper_doi, and cited_dois for values the paper cites from earlier work); 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). 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_literature_2026,
  author    = {Arr{\'o}yave, Raymundo and Saal, James and Shin, Dongwon},
  title     = {{ORCHID-Values: thermodynamic and phase-equilibrium values read from the literature}},
  version   = {2026.10},
  publisher = {Zenodo},
  year      = {2026},
  doi       = {10.5281/zenodo.23735569},
  url       = {https://doi.org/10.5281/zenodo.23735569},
  note      = {Version 1, machine-extracted}
}

@misc{orchid_phase_diagrams_2026,
  author    = {Arr{\'o}yave, Raymundo and Saal, James and Shin, Dongwon},
  title     = {{ORCHID-Diagrams: calculated binary phase diagrams}},
  version   = {2026.10},
  publisher = {Zenodo},
  year      = {2026},
  doi       = {10.5281/zenodo.23735859},
  url       = {https://doi.org/10.5281/zenodo.23735859}
}

@misc{orchid_hulls_2026,
  author    = {Arr{\'o}yave, Raymundo and Saal, James and Shin, Dongwon},
  title     = {{ORCHID-Hulls: binary convex hulls (Materials Project, OQMD, assessed CALPHAD)}},
  version   = {2026.10},
  publisher = {Zenodo},
  year      = {2026},
  doi       = {10.5281/zenodo.23735891},
  url       = {https://doi.org/10.5281/zenodo.23735891}
}

@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}
}