Novel Co-Ti-V-base superalloys reinforced by L12-ordered γ′ phase

J. J. Ruan, X. J. Liu, S. Y. Yang, W. W. Xu, T. Omori, T. Yang, B. Deng, H. X. Jiang, C. P. Wang, R. Kainuma, K. Ishida

Research output: Contribution to journalArticlepeer-review

24 Citations (Scopus)

Abstract

The influences of alloying elements Al and Ni to a Co-Ti-V master alloy on microstructures, phase stabilities and high-temperature mechanical properties have been investigated. A two-phase microstructure γ/γʹ with ultrahigh γʹ volume fraction was designed in the Co-Ti-V (master alloy), Co-Ti-V-Al (Al-modified) and Co-Ti-V-Ni (Ni-modified) alloys. Al shows a slight tendency to partition into γʹ, while Ni exhibits almost equal distribution between the γ and γʹ phases. Al is found to increase the volume fraction and solvus temperature of γʹ. The solvus temperatures of γʹ in the master alloy, Al-modified and Ni-modified alloys exceed that of Co-9Al-9W alloy (1000 °C) by 91, 112 and 82 °C, respectively. The flow stresses of the designed alloys exhibit an anomalous positive dependence on temperature rising from 600 to 750 °C. The strengths of the master alloy and Ni-modified alloys are not only higher than that of traditional Co-base superalloy MAR-M 302 at the temperature ranging from 700 to 1000 °C, but also comparable with that of the commercial Ni-base superalloy IN-939 between 850 and 1000 °C. In conclusion, the present Co-Ti-V-base alloys reinforced by γʹ are suggested as potential candidates for high-temperature utilizations.

Original languageEnglish
Pages (from-to)126-132
Number of pages7
JournalIntermetallics
Volume92
DOIs
Publication statusPublished - 2018 Jan

Keywords

  • Cobalt-base superalloys
  • Compression test
  • L1 compound
  • Phase diagram

ASJC Scopus subject areas

  • Chemistry(all)
  • Mechanics of Materials
  • Mechanical Engineering
  • Metals and Alloys
  • Materials Chemistry

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