Título

EFFECTS OF TEMPERATURE AND STRAIN RATE ON THE MECHANICAL BEHAVIOR OF A SUPERELASTIC NITI WIRE

Autoria

Soares, Guilherme Corrêa; Rodrigues, Mariana Carla Mendes; Santos, Leandro de Arruda

DOI

10.5151/1516-392X-27599

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Resumo

The effects of temperature and strain rate on the mechanical behavior of a superelastic NiTi wire were investigated by uniaxial tensile testing. A universal testing machine with an attached heating chamber was used for the tensile tests. Temperature influence was studied through straining of samples until rupture at a fixed strain rate and temperatures of 25, 50, 75, 100, 125, 150, 175 and 200 °C. Strain rate effects were investigated by straining samples until rupture at room temperature and strain rates of 10-2, 5 x10-3 , 10-3, 5 x 10-4 and 10-4 s-1. The effects of temperature and strain rate on NiTi mechanical behavior were discussed in terms of critical stress to induce martensite and austenite yield strength, when applicable; upper plateau stress, transformation plateau length and ultimate plateau stress. It was found that increasing test temperature and strain rate shifted the stress-strain curve upwards, albeit temperature displayed a greater influence. Plateau length increased with temperature, but no significant changes were detected as a result of different strain rates.

 

Palavras-chave

NiTi, Mechanical Behavior, Strain Rate, Temperature

Temperature