The stability of thermoelastic martensite in a Cu-14.84 wt-%Zn-7.75 wt-%Al shape mem-ory alloy with M_s=106°C after direct quenching or stepped quenching has been investigatedby using TEM,X-ray diffroctometer and double electric bridge instrument.The martensiteaged for about 3 h at room temperature after either direct quenching or stepped quenching(150°C,2 rain)is the M18R structure.The martensite just directly quenched is not so stable,both its certain diffraction peaks and specific electric resistivity,change with aging at roomtemperature;whereas it is stable after stepped quenching(150°C.2 min),and its diffractionpeaks and specific electric resistivity change no more with aging at room temperature.Theabove mentioned results seem to be explained by the martensite reordering.
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