Korean Journal of Metals and Materials (대한금속재료학회지)

The Korean Institute of Metals and Materials (대한금속재료학회)
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Effects of Initial Nucleation Condition at the Start Block on the Grain Size and Growth Direction in Directionally Solidified CM247LC Superalloy

CM247LC 초내열합금에서 일방향응고 스타트 블록의 초기 핵생성 조건에 따른 결정립 성장

  • Yoon, Hye-Young (Dept. of Materials Science and Engineering, Changwon National University) ;
  • Lee, Je-Hyun (Dept. of Materials Science and Engineering, Changwon National University) ;
  • Jung, Hyeong-Min (Dept. of Materials Science and Engineering, Changwon National University) ;
  • Seo, Seong-Moon (High Temperature Materials Lab., Korea Institute of Materials) ;
  • Jo, Chang-Young (High Temperature Materials Lab., Korea Institute of Materials) ;
  • Gwon, Seok-Hwan (R&D Center, Korea Lost Wax Co.) ;
  • Chang, Byeong-Moon (R&D Center, Korea Lost Wax Co.)
  • 윤혜영 (창원대학교 나노신소재공학과) ;
  • 이재현 (창원대학교 나노신소재공학과) ;
  • 정형민 (창원대학교 나노신소재공학과) ;
  • 서성문 (재료연구소 내열재료그룹) ;
  • 조창용 (재료연구소 내열재료그룹) ;
  • 권석환 ((주)한국로스트왁스 기술연구소) ;
  • 장병문 ((주)한국로스트왁스 기술연구소)
  • Received : 2010.09.24
  • Published : 2011.01.25
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Abstract

The grain size and growth direction of a directionally solidified turbine blade were evaluated by the initial nucleation condition at the start block of directional solidification. The initial nucleation condition was controlled by inserting a Ni foil on the directional solidification plate of the directional solidification furnace. Fine grains with good orientation were obtained in the faster cooling condition at the start block. The nucleus number was compared with the cooling rate of the start block by electron back scattered diffraction (EBSD). DSC (differential scanning calorimeter) analysis was performed to compare the melting point and undercooling for nucleation of the coarse nuclei and fine nuclei of the start block. The faster cooling condition at the start block showed more undercooling for nucleation and smaller size of nuclei which resulted in a fine grain with good orientation in the directional turbine blade.

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References

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