The effect of isothermal holding on reversible and irreversible strain in TiNi shape memory alloy. (2017)

• Record Type: Journal Article
• Authors: Resnina, Natalia; Sibirev, Alexey; Belyaev, Sergey; Gracheva, Alena
• Is Part Of: Materials today. Volume 4:Number 3(2017)Part B
• Page Start: 4748
• Page End: 4752
• Publication Date: 2017
• Subjects: Irreversible strain -- Reversible strain -- TiNi -- Shape memory alloy -- Isothermal holding; Materials science -- Congresses -- Periodicals; 620.1
• DOI: 10.1016/j.matpr.2017.04.064
• Languages: English
• ISSNs: 2214-7853

Abstract

Abstract: The influence of the relaxation processes that occurred on holding a Ti50 Ni50 alloy at a high temperature on the accumulation of reversible and irreversible strain on cooling and heating of the sample under a constant stress of 50 MPa through a temperature range of the martensitic transformation was studied. It was found that holding the sample at temperatures that were higher than Af temperature (finish temperature of the reverse transformation) led to an increase in reversible strain, and influenced in a different way the irreversible strain that accumulated in the sample after holding. If the holding temperature was less than 160 °C, an increase in holding duration resulted in a decrease in the irreversible strain that accumulated in the sample on cooling under a stress of 50 MPa. If the holding temperature was equal to 160 °C, the holding of the sample did not influence the irreversible strain. If the holding temperature was larger than 160 °C, the irreversible strain increased with further holding duration. It was assumed that the difference in the dependencies of irreversible stain on the holding duration observed at different holding temperatures was due to thermally activated relaxation and its intensity depended on the holding temperature.