The effect of Nb/Ti ratio on hardness in high-strength Ni-based superalloys

Research output: Contribution to journalArticlepeer-review

Authors

  • Hiromu Hisazawa
  • Yoshihiro Terada
  • Fauzan Adziman
  • David J. Crudden
  • David E J Armstrong
  • Roger C. Reed

Colleges, School and Institutes

External organisations

  • Tokyo Institute of Technology
  • OXFORD UNIVERSITY

Abstract

The age-hardening behaviour and microstructure development of high strength Ni-based superalloys ABD-D2, D4, and D6 with varying Nb/Ti ratios have been studied. The studied alloys have large volume fractions and multimodal size distributions of the γ precipitates, making them sensitive to cooling conditions following solution heat treatment. Differential scanning calorimetry was conducted with a thermal cycle that replicated a processing heat treatment. The hardness of these alloys was subsequently evaluated by nanoindentation. The Nb/Ti ratio was not observed to influence the size and distribution of primary and secondary γ precipitates; however, the difference in those of tertiary γ and precipitate morphology were observed. The nanoindentation hardness for all alloys reduces once they have been solution-heat-treated. The alloys exhibited specific peak hardness. The alloy with the greatest Nb content was found to have the best increase in hardness among the alloys studied due to its large tertiary γ precipitate.

Details

Original languageEnglish
Article number71
JournalMetals
Volume7
Issue number3
Early online date23 Feb 2017
Publication statusPublished - 1 Mar 2017

Keywords

  • Age-hardening, Nanoindentation, Nb/Ti ratio, Superalloy

ASJC Scopus subject areas