Abstract
The Ti-Ni-Cu shape memory alloys by elemental powders were fabricated using a spark-plasma sintering method. The influence of Cu content in Ti-Ni-Cu alloys on the microstructure, tensile properties and thermo-mechanical properties was examined. The microstructure, tensile properties and thermo-mechanical properties of the sintered-compacts were improved greatly by performing the solution treatment and the shape memory treatment. The yielding behavior due to the stress-induced martensite in stress-strain curves of the alloy, that is similar to that of the cold-worked alloy, took place after elastic deformation at any Cu content. The tensile strength and elongation of the alloy with Cu content around 9at% were more than 400 MPa and 6%, respectively. The alloys of higher Cu contents showed a superelastic-like behavior, and the shape memory characteristics of the alloys were confirmed to be superior. The cyclic deformation characteristics of the alloys were more stable than that of the cold-worked alloy.
