| 摘要 |
PURPOSE:To produce a shape memory alloy with which the fluctuation of the transformation point in the stage of use is less by heating a Ti-Ni shape memory alloy to the temp. at which inverse transformation starts or above then cooling the alloy to the temp. at which martensite transformation starts or below after the final shape memory treatment. CONSTITUTION:A Ti-Ni shape memory alloy is subjected, after the final shape memory treatment, to at least one time or more of the heat cycle consisting of heating the alloy at the temp. at which the inverse transformation starts or above and <=200 deg.C then cooling the same to the temp. at which the martensite transformation starts or below after the final shape memory treatment. The shape memory alloy with which the fluctuation of the transformation point by the heat cycle in the stage of use is decreased is thus obtd. With the above-mentioned treating temp., if the heating temp. is lower than the temp. at which the inverse transformation starts, no transformation arises and therefore the treatment is ineffective. If the temp. exceeds 200 deg.C, the shape memory characteristic is deteriorated. If the cooling temp. is above the temp. at which the martensite transformation starts, no transformation arises and therefore the treatment is ineffective. One heat cycle is substantially effective but repetition of the heat cycle is preferable.
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