Two-way shape memory effect of NiTi alloy induced by constraint aging treatment at room temperature

A new optimal training procedure to induce a two-way shape-memory effect (T WSME) in bending mode has been investigated in a Ni-rich NiTi alloy that ha d underwent a preaging heat treatment followed by constraint aging at room temperature. The aim of the present investigation is to develop a new train ing procedure to induce TWSME as well as to examine the relationship betwee n the obtained properties and microstructures of specimens prepared by vari ous preaging temperatures. It is suggested that the R-phase plays an import ant role in the establishment of two-way shape-memory behavior on cooling.