Date of Award
Summer 1989
Document Type
Thesis - Restricted
Degree Name
Master of Science (MS)
Department
Foreign Languages and Literatures
First Advisor
Fournelle, Raymond A.
Second Advisor
Hirthe, Walter
Third Advisor
Brantley, William A.
Abstract
The superelastic behavior of cold drawn and annealed Ti-50.8at.%Ni alloy wire has been investigated by tensile testing, differential scanning calorimetry (DSC) and light microscopy. Annealing of the wire at 400°C has been formed to induce superelastic behavior in it. Annealing at higher temperatures ( 450-600° C) was formed to result in no superelasticity, while annealing at still higher temperatures (650- 750°C) resulted in partial superelasticity. The changes in superelastic behavior with annealing has been associated with the reversion of some or all of the cold worked martensite and R phase in the cold drawn wires to austenite, and with the variation of the austenite finish Af temperature of the reverted austenite with annealing temperature. This variation of Af is related in a complicated way with the residual stresses left in the reverted austenite as well as precipitation of nickel rich compounds (Ti11 Ni14 and Ti2 Ni3) in it. The superelastic behavior, microstructure, and transformation behavior of commercial superelastic orthodontic wires (Sentinol [sic], Ormco and Korean) have also been investigated for comparison. These wires were all found to have superelastic behavior, microstructures, and transformation behavior similar to the Ti-50.8at.%Ni alloy after annealing at 400°C.
Recommended Citation
Leu, Lin-Her, "Effect of Annealing on the Tensile Properties and Transformation Behavior of a 50.8 at.% Ni - 49.2 at.% Ti Alloy" (1989). Master's Theses (1922-2009) Access restricted to Marquette Campus. 5002.
https://epublications.marquette.edu/theses/5002