Influence of aluminium and iron contents on the transformation temperatures of Cu-Al-Fe shape memory alloys

Abstract

Copper based shape memory alloys have received much focus in recent times because of their good ductility, ease of production and processing and low cost. Earlier investigations have shown that ductility and other mechanical properties of the Cu-Al based shape memory alloys can significantly be improved by adding ternary elements such as Ni and Mn. While Cu-Al-Ni shape memory alloys have better thermal stability and higher operating temperatures, their practical applications are limited because of their poor workability. Cu-Al-Mn shape memory alloys on the other hand, have good ductility and workability, but their operating temperatures are lower. A similar approach is followed in Ni-Al alloys to overcome their brittleness by the addition of Fe. There is paucity of literature on the role of ternary addition of Fe to Cu-Al shape memory alloys. In the present work, therefore, the effect of aluminium and iron on the transformation temperatures has been studied. As the aluminium content increases the transformation temperatures decrease, while the ternary addition of Fe increases the transformation temperatures. The results are presented and discussed in detail in the paper.