| In Cu-Tn-Al shape memery alloys, it is necessary for practical application that mechanical properties of the alloys is modified by grain refinement. In present work, grain was refined by adding misch metal, Mn or Ni and mechanical and thermal cycling test have been done. In the case of Mn and Ni effect of grain refinement were small. It was, however, predominated by a factor of 20 in the case of misch metal. The fracture stress and the strain of the refined alloy with size of 50㎛ were increased with 2 and 1.3 times than those of the alloy not to be refined, respectively. Shape memory effect was not affected significantly by decreasing grain size, but fatigue life by thermal cycling in the refined alloy was increased with 1.5 times. |
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