Internal friction of B2 → B19′ martensitic transformation of Ti50Ni50 shape memory alloy under isothermal conditions
Journal
Materials Science and Engineering A
Journal Volume
454-455
Pages
379-383
Date Issued
2007
Author(s)
Abstract
The inherent internal friction (IFPT + IFI)B2→B19′ of cold-rolled and annealed Ti50Ni50 alloy that exhibits B2 → B19′ martensitic transformation is studied under isothermal conditions. The tan δ value of (IFPT + IFI)B2→B19′ is proportional to σ0/ν1/2 and its damping mechanism is thus related to stress-assisted martensitic transformation and stress-assisted motion of twin boundaries. The tan δ value of (IFPT + IFI)B2→B19′ is smaller than those of (IFPT + IFI)B2→R and (IFPT + IFI)R→B19′ because the former shows no R-phase. The obliterated dislocations and defects after sufficient annealing can lower the tan δ value of the relaxation peak at about -60 °C. © 2006 Elsevier B.V. All rights reserved.
Type
journal article