The Effect of Heat Treatment on the Martensitic Transformation in an Cu-Al-Ni Single Crystal

Cu-Al-Ni계 단결정 합금의 마르텐사이트 변태특성에 미치는 열처리의 영향

  • Kim, Y.S. (Dept. of Met. & Mater. Engr., Chosun University) ;
  • Jang, W.Y. (Dept. of Met. & Mater. Engr., Chosun University)
  • 김영삼 (조선대학교 금속.재료공학부, BK21 핵심사업팀) ;
  • 장우양 (조선대학교 금속.재료공학부, BK21 핵심사업팀)
  • Received : 2000.04.26
  • Published : 2000.05.30

Abstract

The effects of betatizing and aging temperatures on the martensitic transformation characteristics in an Cu-13.4wt%Al-4.2wt%Ni single crystal have been studied. Microstructures show that the specimen betatized above $800^{\circ}C$ has only ${{\beta}_1}^{\prime}$ martensite while the specimen betatized of below $700^{\circ}C$ has two phases i.e., ${{\beta}_1}^{\prime}+{\gamma}_2$ When betatizing temperature increase from $600^{\circ}C$ upto $900^{\circ}C$, Ms and As temperatures decrease due to the dissolution of which ${\gamma}_2$ phase depletes Al content in the matrix thereafter makes the both Ms and As temperatures significantly increased. Ms and As temperatures of the specimen aged at $200^{\circ}C$ are relatively stable but those of the specimen aged at $300^{\circ}C$ are shifted rapidly with aging time, especially within the first 30min.

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Acknowledgement

Supported by : 한국학술진흥재단