Equations to Predict the Elastic Modulus of the Individual Gamma and Gamma-Prime Phases in Multi-component Ni-Base Superalloys

Takuma Saito, Makoto Osawa, Tadaharu Yokokawa, Hiroshi Harada, Toshiharu Kobayashi, Kyoko Kawagishi, Shinsuke Suzuki

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Strength of Ni-base single-crystal superalloys under high temperature and low stress creep usually is enhanced by formation of γ/γ′ raft structure and larger aspect ratio of γ′ phase in the γ/γ′ raft structure. Elastic misfit between γ and γ′ phases is one of the most important factors to control the aspect ratio of the γ′ phase in the γ/γ′ raft structure formed under external stress. The aspect ratio of the γ′ phase is controlled by kinetics for the γ/γ′ raft structure formation, which is affected by a strain inhomogeneity caused by this elastic misfit between the γ and γ′ phases under external stress. To realize a new alloy design approach to control the aspect ratio of the γ′ phase in the γ/γ′ raft structure, this research aimed to obtain the regression equations which can predict elastic modulus of the individual γ and γ′ phases for multi-component Ni-base single-crystal superalloys based on measurements of elastic modulus of Ni-base single-crystal alloys. Elastic modulus of the individual γ and γ′ phases of various kinds of Ni-base single-crystal alloys was measured by using rectangular parallelepiped resonance (RPR) method. Using the analyzed and referenced elastic modulus, regression equations for predicting <100> longitudinal elastic modulus of the individual γ and γ′ phases and its temperature and composition dependence were obtained. Detailed analysis of the elastic modulus and its composition dependence was executed to clarify the contribution of each element on the elastic modulus. At 900 °C, Re, Ta, Ti, Al, and Mo reduce the <100> longitudinal elastic modulus in the γ phase. On the other hand, Ru, Re, Ta, Ti, Al, W, and Mo enlarge the elastic modulus in the γ′ phase.

Original languageEnglish
Title of host publicationSuperalloys 2020 - Proceedings of the 14th International Symposium on Superalloys
EditorsSammy Tin, Mark Hardy, Justin Clews, Jonathan Cormier, Qiang Feng, John Marcin, Chris O'Brien, Akane Suzuki
PublisherSpringer Science and Business Media Deutschland GmbH
Pages312-323
Number of pages12
ISBN (Print)9783030518332
DOIs
Publication statusPublished - 2020
Event14th International Symposium on Superalloys, Superalloys 2021 - Seven Springs, United States
Duration: 2021 Sep 122021 Sep 16

Publication series

NameMinerals, Metals and Materials Series
ISSN (Print)2367-1181
ISSN (Electronic)2367-1696

Conference

Conference14th International Symposium on Superalloys, Superalloys 2021
CountryUnited States
CitySeven Springs
Period21/9/1221/9/16

Keywords

  • Alloy design
  • Elastic misfit
  • Elastic modulus
  • Raft structure
  • Single crystal

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Energy Engineering and Power Technology
  • Mechanics of Materials
  • Metals and Alloys
  • Materials Chemistry

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