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A Study of NiTi Alloy Mechanical and Corrosion Behavior Subjected to Mechanical and Cyclic Thermal Loading in Corrosive Environment

Thursday, 5 October 2017: 14:00
Camellia 2 (Gaylord National Resort and Convention Center)

ABSTRACT WITHDRAWN

The corrosion behavior of a nickel titanium alloy (NiTi) have been investigated. The NiTi alloy is

subjected to cyclic thermal loading in corrosive environments (3.5 wt% NaCl and Ringer

solution).

Thermogravimetric measurement versus temperature is perfumed to obtain forward and

reverse martensitic transformation temperatures.

Electrochemical Avesta cell is used to study corrosion behavior of NiTi alloy under thermal

cycling in absence of mechanical loading. Electrochemical Impedance Spectroscopy and cyclic

voltammetry measurements are used to study corrosion behavior at different temperatures

and phases.

The change in corrosion rate during phase transformations are being investigated. An

equivalent circuit model is used to calculate the electrochemical parameters from EIS

measurements for forward and reverse martensitic transformations. The results shows the

breakdown of passive oxide film on the surface with martensitic transformation. This

breakdown would be an origin for fatigue crack initiation and an explanation for fatigue lifetime

reduction of NiTi in corrosive environments.