Precipitation Behavior of Al-Zn-Mg-Cu-(Sc) Alloy

Al-Zn-Mg-Cu-(Sc) 합금의 석출특성

  • Choi, G.S. (Dept. of Mechanical Engineering, Dongmyong University) ;
  • Mun, H.J. (Technology Develop Group, Steel Making Dept., POSCO) ;
  • Woo, K.D. (Division of Advanced Materials Engineering & The Research Center of Advanced Materials Development, Engineering College, Chonbuk National University)
  • 최갑송 (동명대학교기계공학과) ;
  • 문호정 (포스코 제강부 기술개발그룹) ;
  • 우기도 (전북대학교 신소재공학부)
  • Received : 2006.08.30
  • Accepted : 2006.09.26
  • Published : 2006.09.30

Abstract

Scandium(Sc) in Al-Zn-Mg-Cu based Al alloy on precipitation phenomenon was compared to a 7001(Al-7.2%Zn-3.2%Mg-1.8%Cu) Al alloy. GP zone and ${\eta}^{\prime}$ phases were the main strengthening phases at low aging temperature under $100^{\circ}C$, but ${\eta}^{\prime}$ and $Al_3Sc$ phases were the main strengthening phases at high aging temperature above $1600^{\circ}C$ in Sc added 7000(Al-7.7%Zn-2.0%Mg-1.9%Cu-0.1%Zr) Al alloy. With the addition of 0.1%Sc in 7000 Al alloy, the activation energy for the GP zone, ${\eta}^{\prime}$ and ${\eta}$ phase decreased compared to the 7001 Al alloy. This result indicates that the Sc accelerated the precipitation for the GP zone, ${\eta}^{\prime}$ and ${\eta}$ phases in 7000 Al alloy. Al-7.7%Zn-2.0%Mg-1.9%Cu-0.1%Zr-0.1 Sc alloy has higher strength than 7001 Al alloy, which has high strength.

Acknowledgement

Supported by : 전북대학교 공학연구원

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