PURPOSE: To produce a shape memory metal alloy product in which plural reversible shapes are memorized by transforming a shape memory metal alloy capable of reversible transformation into an austenitic type in a prescribed shape memorizing state and thereafter transforming it into a martensitic type in an another shape memorizing state. ;CONSTITUTION: A spring 2 composed of a shape memory metal alloy is applied with tension F at an ambient temp. by a supporting tool 6 in such a manner that the shape corresponding to a primary shape memorizing state is taken. This spring 2 is placed in a chamber furnace preliminarily heated to about 750°C and is allowed to execute sufficient austenitic transformation, after that, an austenitic phase obtd. by executing rapid cooling to about 90 to 100°C is fixed, which is held for 10 to 20 hr, and stabilizing treatment is executed. Then, this spring 2 is applied with mechanical compressive stress C by a grade 12, is shaped into a secondary memorizing state, is thereafter rapidly cooled to about 0 to 20°C and is allowed to execute martensitic transformation. Moreover, while the mechanical stress is applied to the spring 2, heating to 90 to 110°C and cooling to 0 to 20°C are alternately repeated for several times to obtain the shape memory alloy product.;COPYRIGHT: (C)1990,JPO
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