简介：Theeffectofthermalcyclingunderloadingonmartensitictransformationandtwo-wayshapememoryeffectwasinvestigatedforTi-49.8at.pctNialloy.ItisshownthatMsandMftemperatureincreasewithincreasingthenumberofcycles,whileAsandAftemperaturedecreaseduringthermalcycling.Thetotalstrainεtandpermanentstrainεpincreasewithincreasingappliedstressandnumberofcycles.Thetwo-wayshapememoryeffectcanbeimprovedbyproperthermalcyclingtrainingunderloading,whileexcessivelyhighappliedstressresultsinthedeteriorationofTWSME.Thereasonforthechangesinmartensitictransformationcharacteristicsandtwo-wayshapememoryeffectduringthermalcyclingunderloadingisdiscussedbasedontheanalysisofmicrostructurebyTEMobservations.