The study of the influence of the cobalt content on the cyclic stability of superelasticity(SE)was carried out in quenched Ni_(44)Fe_(19)Ga_(27)Co_(10)and Ni_(39)Fe_(19)Ga_(27)Co_(15)(at.%)single crystals under compre...The study of the influence of the cobalt content on the cyclic stability of superelasticity(SE)was carried out in quenched Ni_(44)Fe_(19)Ga_(27)Co_(10)and Ni_(39)Fe_(19)Ga_(27)Co_(15)(at.%)single crystals under compression.It is shown that an increase in the cobalt content leads to embrittlement of the material and a decrease in the cyclic stability of SE.In Ni_(44)Fe_(19)Ga_(27)Co_(10)single crystals,during the first 20 loading/unloading cycles,the elastic energy relaxation occurs along with the formation of dislocations and residual martensite,which leads to a decrease in critical stress of martensite formation and in stress hysteresis.During the next 80 cycles,SE becomes more stable.Stabilization is accompanied by a slight change in the parameters.On the contrary,Ni_(39)Fe_(19)Ga_(27)Co_(15)single crystals are characterized by high-strength characteristics,which lead to high SE stability during the first 20 loading/unloading cycles.However,after 20 cycles,a strong degradation of the SE is observed through the formation of microcracks,which ultimately leads to the destruction of the sample.The results of work are replicable for cycling at different temperatures from all temperature ranges of superelasticity.展开更多
基金financially supported by the Russian Science Foundation(No.21-19-00287).
文摘The study of the influence of the cobalt content on the cyclic stability of superelasticity(SE)was carried out in quenched Ni_(44)Fe_(19)Ga_(27)Co_(10)and Ni_(39)Fe_(19)Ga_(27)Co_(15)(at.%)single crystals under compression.It is shown that an increase in the cobalt content leads to embrittlement of the material and a decrease in the cyclic stability of SE.In Ni_(44)Fe_(19)Ga_(27)Co_(10)single crystals,during the first 20 loading/unloading cycles,the elastic energy relaxation occurs along with the formation of dislocations and residual martensite,which leads to a decrease in critical stress of martensite formation and in stress hysteresis.During the next 80 cycles,SE becomes more stable.Stabilization is accompanied by a slight change in the parameters.On the contrary,Ni_(39)Fe_(19)Ga_(27)Co_(15)single crystals are characterized by high-strength characteristics,which lead to high SE stability during the first 20 loading/unloading cycles.However,after 20 cycles,a strong degradation of the SE is observed through the formation of microcracks,which ultimately leads to the destruction of the sample.The results of work are replicable for cycling at different temperatures from all temperature ranges of superelasticity.
