Alloying effects in polycrystalline γ strengthened Co-Al-W base alloys

H. Y. Yan, V. A. Vorontsov, D. Dye

Research output: Contribution to journalArticle

71 Citations (Scopus)

Abstract

A polycrystalline hot working ingot metallurgy processing route for γ/γ Co-Al-W superalloys has been developed. Based on Co-7Al-7W (at%), substitutions of Mo, V, Ti, Ta, Ni, Si, Fe and Cr were examined. The γ solvus was found to follow the same trends as those exhibited by alloys with higher γ fractions considered by other investigators. Excessive Cr additions were found to lead to discontinuous coarsening and eventually, the loss of the γ phase from the microstructures observed. Ni additions were examined, with some success, and found to restore the γ′ phase and raise the solvus temperature. It was found that the addition of 13 at.% Cr improved the oxidation resistance at 800 C by over 40 times.

LanguageEnglish
Pages44-53
Number of pages10
JournalIntermetallics
Volume48
DOIs
Publication statusPublished - 1 May 2014

Fingerprint

Hot working
Oxidation resistance
Coarsening
Metallurgy
Ingots
Superalloys
Alloying
Substitution reactions
Microstructure
Processing
Temperature

Keywords

  • aluminides
  • oxidation
  • phase diagrams
  • precipitates
  • miscellaneous
  • polycrystalline hot working ingot metallurgy

Cite this

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abstract = "A polycrystalline hot working ingot metallurgy processing route for γ/γ′ Co-Al-W superalloys has been developed. Based on Co-7Al-7W (at{\%}), substitutions of Mo, V, Ti, Ta, Ni, Si, Fe and Cr were examined. The γ′ solvus was found to follow the same trends as those exhibited by alloys with higher γ′ fractions considered by other investigators. Excessive Cr additions were found to lead to discontinuous coarsening and eventually, the loss of the γ′ phase from the microstructures observed. Ni additions were examined, with some success, and found to restore the γ′ phase and raise the solvus temperature. It was found that the addition of 13 at.{\%} Cr improved the oxidation resistance at 800 C by over 40 times.",
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Alloying effects in polycrystalline γ strengthened Co-Al-W base alloys. / Yan, H. Y.; Vorontsov, V. A.; Dye, D.

In: Intermetallics, Vol. 48, 01.05.2014, p. 44-53.

Research output: Contribution to journalArticle

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