Abstract
Twinning in materials results from one of two different effects. Firstly, thermal changes may give rise to growth twins during solidification, annealing twins during recrystallization, or martensitic twins during solid-state phase transformations. Secondly, shear stresses can activate mechanical twinning as a deformation mode other than dislocation slip. TiNi alloys are unusual in that they exhibit both types of twinning. Due to the submicron dimension of both types of twins, transmission electron microscopy (TEM) is used to characterize the resulting structures.TiNi is well-known for its shape memory properties resulting from a martensitic transformation of the cubic B2 structure to the monoclinic B19' structure upon cooling. Minor concentrations of various third elements can be added to modify different shape memory properties. In the case of TiNiCu ternary alloys, up to 30% Cu is substituted for Ni while retaining the shape memory effect. For small Cu concentrations the B2 austenite phase transforms, upon cooling, to the B19' monoclinic martensite typical of the binary alloy.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Proceedings, annual meeting, Electron Microscopy Society of America
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
