Effect of cold rolling ratio on the nanoscale precipitation behavior of TiNiPdCu based high temperature shape memory alloys

The effect of cold rolling ratio on precipitation behavior of an annealed Ti50Ni15Pd25Cu10 alloy was investigated. The change in the cold rolling ratio noticeably affected the precipitation behavior mainly due to the difference in the density of heterogeneous nucleation sites provided by the deformation induced defects. Higher cold rolling ratios caused an increase in the density of precipitates which subsequently caused a decrease in the martensitic transformation temperatures and shape recovery strain. It was confirmed that the prior cold deformation ratio is an important parameter to control the nanoscale precipitation behavior of Ti2Pd and TiPdCu type precipitates, both in terms of their overall density and distribution.