A REVIEW OF MICROSTRUCTURE AND CORROSION BEHAVIOR OF CU AL NI SHAPE MEMORY ALLOY

Abstract

The shape memory alloys (SMAs), that consist of Cu-Al-Ni, have been established and developed for the applications used at higher temperature values due to their capability to return to its original shape when heating close to its transformation temperature. Cu-Al-Ni alloy has high value of transformation temperature and show small hysteresis as compared to the other types of SMAs. This work present a general review about how SMAs have developed by adding several metals such as, Ti, Be, B, Mn, and Zr or by changing its content (Ni or Al) by either decreasing or increasing. That might show a significant impact on the phase transition and enhancing the corrosion behavior and mechanical properties of the presented alloys. However, the transformation of the martensite phase is the critical factor that might change the properties of Cu-Al-Ni SMAs. This phase is largely affected by addition of the alloying element mentioned above. A review about effect of addition some alloying elements for enhancing the corrosion characteristics of the alloy and phase transition is presented.