Journal of Korea Foundry Society (한국주조공학회지)

Korea Foundry Society (한국주조공학회)
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Variation of Alloying Element Distribution and Microstructure due to Microsegregation in Ni-base Superalloy GTD 111

니켈기 초내열 합금 GTD 111에서 편석에 의한 합금원소 분포 및 미세조직 변화

  • Choi, Baig-Gyu (High Temperature Materials Department, Korea Institute of Materials Science) ;
  • Kim, In-Soo (High Temperature Materials Department, Korea Institute of Materials Science) ;
  • Do, Jeong-Hyeon (High Temperature Materials Department, Korea Institute of Materials Science) ;
  • Jung, Joong-Eun (High Temperature Materials Department, Korea Institute of Materials Science) ;
  • Jo, Chang-Yong (High Temperature Materials Department, Korea Institute of Materials Science)
  • 최백규 (재료연구소 내열재료연구실) ;
  • 김인수 (재료연구소 내열재료연구실) ;
  • 도정현 (재료연구소 내열재료연구실) ;
  • 정중은 (재료연구소 내열재료연구실) ;
  • 조창용 (재료연구소 내열재료연구실)
  • Received : 2015.10.30
  • Accepted : 2015.12.04
  • Published : 2015.12.31
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Abstract

Segregation during solidification and homogenization during thermal exposure in GTD 111 were investigated. The microstructures of as-cast, standard heat-treated, and thermally exposed specimens were observed by SEM. A compositional analysis of each specimen was conducted by EDS. The dendrite core was enriched in W and Co, though lower levels of Ti and Ta were observed. An unexpected phase, in this case like the ${\eta}$ phase, was observed due to segregation near the ${\gamma}-{\gamma}^{\prime}$ eutectic in the standard heat-treated specimen. Segregation also induced microstructural evolution near the ${\gamma}-{\gamma}^{\prime}$ eutectic during the standard heat treatment. A quantitative analysis and microstructural observations showed that the thermal exposure at a high temperature enhanced the chemical homogeneity of the alloy.

Keywords

References

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