Structural and Magnetic Transitions in Aged Shape Memory Cu-Al-Mn and Cu-Al-Mn-Fe Alloys

A comparative analysis of the structural and magnetic behavior of Cu-Al-Mn and Cu-Al-Mn-Fe alloys depending on their heat treatment is carried out. The influence of low-temperature aging on the behavior of temperature induced martensitic transformation was established. The difference in magnetic behavior of alloys is a consequence of the formation of the ferromagnetic (Cu,Mn) 3 Al and (Fe,Mn) 3 Al Heusler phases during isothermal aging and the transition to a superparamagnetic state. In alloys doped with iron, antiferromagnetic ordering can prevail over ferromagnetic. The precipitates create a significant cumulative effect on the character and characteristic temperature of thermoelastic martensite transformation (MT), as well as on mechanical and magnetic behavior.