Niti Şekil Bellekli Alaşımların Süperelastik Özelliklerinin Termo-Mekanik İşlemlerle İyileştirilmesi

Abstract

Nickel-rich (%50.7.at.) Nickel-Titanium Shape Memory Alloys which were commercially obtained from two different suppliers have been subjected to thermo-mechanical processing for one hour via aging under stress at 450°C both under tension and compression at 120MPa and 250Mpa, respectively. Cyclic loading/unloading tests, with incremental strain values were conducted in order to observe the changes to the superelastic characteristics of the material in both compressive and tensional loads until fracture. These results were then compared to stress-free aged samples at 450°C and homojenized samples at 950°C.In contrast with the given literature, in this work, the aging temperatures were dropped around 50°C to 100°C whereas the compressive and tensional forces were increased upto 1250%. Also, both tensional and compressive forces were applied in order to understand the effects of different force characteristics.