Cryotreatment of Nickel-Titanium shape memory alloy

Shape memory alloy has wide range of application in aerospace, medical, actuator, sensor and in biomedical due to its property of superelasticity and shape memory effect. From long time for high precision parts cold treatment is being used for the enhancement of their property. When the cold treatment is done temperature down to -80°C, it is known as cryogenic treatment. And if the cold treatment is done at liquid nitrogen temperature (-196°C), called as deep cryogenic treatment. There are plenty of literature that report the cryogenic treatment of different kinds of steel, ZnO nanowire and pure Zr. But unfortunately there are very rare literature on the cryogenic treatment of Nickel-Titanium shape memory alloy. The precise effect of cryogenic on properties like corrosion and hardness is not clear. Therefore, in this present book we have studied, mechanical properties, morphology as well as the corrosion behaviour of NiTi shape memory alloy. For the Cryotreatment test all the four sample of NiTi was kept inside liquid nitrogen for 6, 12, 24 and 48 hrs. A detailed microstructural analysis of non cryotreated and cryotreated NiTi alloy has been done. XRD and SEM were also carried.