Evaluation of Thermomechanical Characteristics of NITINOL Shape Memory Alloy

NITINOL 형상기억합금의 열적/기계적 특성 평가

  • ;
  • Sridhar Krishnan (Dept. of Aero. & Astro. Eng., Univ. of Illinois at Urbana-Champaign) ;
  • Scott R. White (Dept. of Aero. & Astro. Eng., Univ. of Illinois at Urbana-Champaign)
  • 윤성호 (금오공과대학교 기계공학부) ;
  • ;
  • Published : 2001.04.01

Abstract

The thermomechanical characteristics of NITINOL shape memory alloy were evaluated using DSC with small samples and DMA with three-point bending specimens. The shape memory alloy of 54.4Ni/45.5Ti wt.% was used so that the austenite finish temperature was in the range of $50~100^{\circ}C$. Two types of sample were tested in the experiments corresponding to as-received and annealed conditions. Simple beam bending theory was used to calculate the dynamic moduli of the shape memory alloy. According to the results, a large discrepancy in transformation temperatures was found between DSC and DMA techniques. Annealing treatment was found to suppress the R-phase transformation during cooling and the secondary plateau in the austenite transformation. Such a heat treatment was also significantly influenced to raise the transformation temperatures and the moduli of the shape memory alloy.

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