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Phase decomposition and precipitation of metastable A2 phase in B2 ordered Co–Al–Fe alloys

  • Takao Kozakai EMAIL logo , Toshiyuki Koyama and Minoru Doi
Published/Copyright: January 11, 2022
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International Journal of Materials Research
From the journal International Journal of Materials Research Volume 97 Issue 3

Abstract

Phase decomposition in rapidly solidified Co–Al – Fe B2 alloys during isothermal ageing at 923 K has been investigated by means of X-ray diffraction and transmission electron microscopy. At the early stage of ageing, A2 disordered particles precipitate inside B2 matrix grains, being aligned along the <100> direction of the matrix, and equilibrium A1 phase (α-Co) is also formed mostly on grain boundaries. With further ageing, the plate-like A2 particles increase in size. On the other hand, the A1 phase on grain boundaries increases in size and also spreads into the B2 grain like tree branches as so-called Widmanstätten precipitate. Finally, the A2 phase disappears. The A1 phase remains on grain boundaries and also inside the B2 grains as spherical particles. Using the composition gradient method, the metastable precipitation limit of the A2 phase, that is the metastable phase boundary B2/(A2 + B2), was experimentally determined at 923 K. It extends smoothly into the stable A2 + B2 two-phase field on the Co–Fe side of the ternary Co–Al –Fe system.

Keywords: Supersaturated solid solution; Liquid-quenching; Transmission electron microscopy; Metastable A2 phase; Composition gradient method
Dr. Takao Kozakai Nagoya Institute of Technology Dept. of Materials Science and Engineering Gokiso-cho, Showa-ku, Nagoya 466-8555, Japan Tel.: +81 52 735 5317 Fax: +81 52 735 5317

  1. The authors wish to express their gratitude to Mr. Yoichi Ito (present affiliation: Honda Motor Co., Ltd.) for the preparation of the alloys and the foils for TEM, and Mr. Tadaaki Shikama (present affiliation: Nippon Steel Corporation) for the experiment by the composition gradient method.

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Received: 2005-10-07
Accepted: 2005-11-29
Published Online: 2022-01-11

© 2006 Carl Hanser Verlag, München

Articles in the same Issue

  1. Frontmatter
  2. Professor Dr. Gernot Kostorz 65 years
  3. Dislocation micromechanisms under single slip conditions
  4. Characterisation of short-range order using dislocations
  5. Between microscopic and mesoscopic descriptions of twin–twin interaction
  6. Influence of the thermoelastic effect on the acoustic properties of pure metals at low temperatures
  7. Recent progress in the area of bulk metallic glasses
  8. Formation of the ABC6-type ordered structure in fcc alloys
  9. Short-range order in Fe-21.9 at.% Al
  10. Criteria for developing castable, creep-resistant aluminum-based alloys – A review
  11. Phase decomposition and precipitation of metastable A2 phase in B2 ordered Co–Al–Fe alloys
  12. Atomic migration and ordering phenomena in bulk and thin films of FePd and FePt
  13. Late-stage coarsening of oil droplets of excess oil in microemulsions following a temperature quench
  14. Small-angle scattering from spherical particles on randomly oriented interfaces
  15. Ripening of L12 Ni3Ti precipitates in the framework of the trans-interface diffusion-controlled theory of particle coarsening
  16. Texture evolution in equiaxed polycrystalline L10-ordered FePd during coarsening at 600 °C
  17. Modulated structures in amorphous films of Cr-silicide prepared by electron-beam-deposition
  18. Early stages of nucleation and growth of Guinier –Preston zones in Al–Zn–Mg and Al–Zn–Mg–Cu alloys
  19. Experimental and theoretical characterization of Al3Sc precipitates in Al–Mg–Si–Cu–Sc–Zr alloys
  20. Ag2Al plates in Al–Ag alloys
  21. A critical analysis of the composite model as applied to high-temperature creep of Al and an Al–Mg alloy
  22. Damage behaviour of an Al2O3 particle-reinforced 6061 alloy induced by monotonic and cyclic deformation
  23. Deformation behaviour of ultrafine-grained magnesium with 3 vol.% graphite
  24. Press/Presse
  25. Conferences/Konferenzen
  26. Frontmatter
  27. Editorial
  28. Professor Dr. Gernot Kostorz 65 years
  29. Articles BBasic
  30. Dislocation micromechanisms under single slip conditions
  31. Characterisation of short-range order using dislocations
  32. Between microscopic and mesoscopic descriptions of twin–twin interaction
  33. Influence of the thermoelastic effect on the acoustic properties of pure metals at low temperatures
  34. Recent progress in the area of bulk metallic glasses
  35. Formation of the ABC6-type ordered structure in fcc alloys
  36. Short-range order in Fe-21.9 at.% Al
  37. Criteria for developing castable, creep-resistant aluminum-based alloys – A review
  38. Phase decomposition and precipitation of metastable A2 phase in B2 ordered Co–Al–Fe alloys
  39. Atomic migration and ordering phenomena in bulk and thin films of FePd and FePt
  40. Late-stage coarsening of oil droplets of excess oil in microemulsions following a temperature quench
  41. Small-angle scattering from spherical particles on randomly oriented interfaces
  42. Ripening of L12 Ni3Ti precipitates in the framework of the trans-interface diffusion-controlled theory of particle coarsening
  43. Articles AApplied
  44. Texture evolution in equiaxed polycrystalline L10-ordered FePd during coarsening at 600 °C
  45. Modulated structures in amorphous films of Cr-silicide prepared by electron-beam-deposition
  46. Early stages of nucleation and growth of Guinier –Preston zones in Al–Zn–Mg and Al–Zn–Mg–Cu alloys
  47. Experimental and theoretical characterization of Al3Sc precipitates in Al–Mg–Si–Cu–Sc–Zr alloys
  48. Ag2Al plates in Al–Ag alloys
  49. A critical analysis of the composite model as applied to high-temperature creep of Al and an Al–Mg alloy
  50. Damage behaviour of an Al2O3 particle-reinforced 6061 alloy induced by monotonic and cyclic deformation
  51. Deformation behaviour of ultrafine-grained magnesium with 3 vol.% graphite
  52. Notifications/Mitteilungen
  53. Press/Presse
  54. Conferences/Konferenzen
https://doi.org/10.1515/ijmr-2006-0043
Keywords for this article
Supersaturated solid solution; Liquid-quenching; Transmission electron microscopy; Metastable A2 phase; Composition gradient method

Articles in the same Issue

  1. Frontmatter
  2. Professor Dr. Gernot Kostorz 65 years
  3. Dislocation micromechanisms under single slip conditions
  4. Characterisation of short-range order using dislocations
  5. Between microscopic and mesoscopic descriptions of twin–twin interaction
  6. Influence of the thermoelastic effect on the acoustic properties of pure metals at low temperatures
  7. Recent progress in the area of bulk metallic glasses
  8. Formation of the ABC6-type ordered structure in fcc alloys
  9. Short-range order in Fe-21.9 at.% Al
  10. Criteria for developing castable, creep-resistant aluminum-based alloys – A review
  11. Phase decomposition and precipitation of metastable A2 phase in B2 ordered Co–Al–Fe alloys
  12. Atomic migration and ordering phenomena in bulk and thin films of FePd and FePt
  13. Late-stage coarsening of oil droplets of excess oil in microemulsions following a temperature quench
  14. Small-angle scattering from spherical particles on randomly oriented interfaces
  15. Ripening of L12 Ni3Ti precipitates in the framework of the trans-interface diffusion-controlled theory of particle coarsening
  16. Texture evolution in equiaxed polycrystalline L10-ordered FePd during coarsening at 600 °C
  17. Modulated structures in amorphous films of Cr-silicide prepared by electron-beam-deposition
  18. Early stages of nucleation and growth of Guinier –Preston zones in Al–Zn–Mg and Al–Zn–Mg–Cu alloys
  19. Experimental and theoretical characterization of Al3Sc precipitates in Al–Mg–Si–Cu–Sc–Zr alloys
  20. Ag2Al plates in Al–Ag alloys
  21. A critical analysis of the composite model as applied to high-temperature creep of Al and an Al–Mg alloy
  22. Damage behaviour of an Al2O3 particle-reinforced 6061 alloy induced by monotonic and cyclic deformation
  23. Deformation behaviour of ultrafine-grained magnesium with 3 vol.% graphite
  24. Press/Presse
  25. Conferences/Konferenzen
  26. Frontmatter
  27. Editorial
  28. Professor Dr. Gernot Kostorz 65 years
  29. Articles BBasic
  30. Dislocation micromechanisms under single slip conditions
  31. Characterisation of short-range order using dislocations
  32. Between microscopic and mesoscopic descriptions of twin–twin interaction
  33. Influence of the thermoelastic effect on the acoustic properties of pure metals at low temperatures
  34. Recent progress in the area of bulk metallic glasses
  35. Formation of the ABC6-type ordered structure in fcc alloys
  36. Short-range order in Fe-21.9 at.% Al
  37. Criteria for developing castable, creep-resistant aluminum-based alloys – A review
  38. Phase decomposition and precipitation of metastable A2 phase in B2 ordered Co–Al–Fe alloys
  39. Atomic migration and ordering phenomena in bulk and thin films of FePd and FePt
  40. Late-stage coarsening of oil droplets of excess oil in microemulsions following a temperature quench
  41. Small-angle scattering from spherical particles on randomly oriented interfaces
  42. Ripening of L12 Ni3Ti precipitates in the framework of the trans-interface diffusion-controlled theory of particle coarsening
  43. Articles AApplied
  44. Texture evolution in equiaxed polycrystalline L10-ordered FePd during coarsening at 600 °C
  45. Modulated structures in amorphous films of Cr-silicide prepared by electron-beam-deposition
  46. Early stages of nucleation and growth of Guinier –Preston zones in Al–Zn–Mg and Al–Zn–Mg–Cu alloys
  47. Experimental and theoretical characterization of Al3Sc precipitates in Al–Mg–Si–Cu–Sc–Zr alloys
  48. Ag2Al plates in Al–Ag alloys
  49. A critical analysis of the composite model as applied to high-temperature creep of Al and an Al–Mg alloy
  50. Damage behaviour of an Al2O3 particle-reinforced 6061 alloy induced by monotonic and cyclic deformation
  51. Deformation behaviour of ultrafine-grained magnesium with 3 vol.% graphite
  52. Notifications/Mitteilungen
  53. Press/Presse
  54. Conferences/Konferenzen
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