Effect of Ti/Al Ratio on Precipitation Behavior during Aging of Ni-Cr-Co-Based Superalloys

Dong Ju Chu, Chanhee Park, Joonho Lee, Woo Sang Jung

Research output: Contribution to journalArticlepeer-review


Precipitation behaviors of Ni-Cr-Co-based superalloys with different Ti/Al ratios aged at 750, 800, and 850 °C for up to 10,000 h were investigated using scanning and transmission electron microscopy. The Ti/Al ratio did not significantly affect the diameter of the γ′ phase. However, the volume fraction of the γ′ phase increased with increasing Ti/Al ratios. The η phase was not observed in alloys with a small Ti/Al ratio, whereas it was precipitated after aging at 850 °C for 1000 h in alloys with a Ti/Al ratio greater than 0.80. Higher aging temperatures and higher Ti/Al ratios led to faster η formation kinetics and accelerated the degradation of alloys. It is thought that the increase in hardness with an increase in the Ti/Al ratio is attributed to the effective inhibition of the γ′ phase on dislocation movement due to the increase in the volume fraction of the γ′ phase and an increase in the antiphase boundary (APB) energy.

Original languageEnglish
Article number1959
Issue number12
Publication statusPublished - 2023 Dec

Bibliographical note

Publisher Copyright:
© 2023 by the authors.


  • antiphase boundary energy
  • eta
  • gamma prime
  • nickel-based superalloy
  • precipitation
  • Ti/Al ratio

ASJC Scopus subject areas

  • General Materials Science
  • Metals and Alloys


Dive into the research topics of 'Effect of Ti/Al Ratio on Precipitation Behavior during Aging of Ni-Cr-Co-Based Superalloys'. Together they form a unique fingerprint.

Cite this