Influence of quaternary alloying additions on transformation temperatures and shape memory properties of Cu-Al-Mn shape memory alloy

The transformation temperatures, shape memory effect and superelasticity of Cu-Al-Mn shape memory alloys are highly sensitive to variations in composition. A ternary shape memory alloy Cu-12.5 wt.% Al-5 wt.% Mn was chosen for the present study and different amounts (1, 2 and 3 wt.%) of quaternary elements Zn, Si, Fe, Pb, Ni, Mg, Cr and Ti were added to the ternary (base) alloy. The influence of quaternary additions on shape memory characteristics of these alloys was studied by differential scanning calorimetry, bend and tensile test. Zn and Ni as quaternary additions were found to increase the transformation temperatures, whereas Fe, Cr, Ti, Si and Mg decrease them. These additions were found to increase the extent of strain recovery by shape memory effect, whereas decrease the superelasticity of the alloys.