Production of Nitinol Wire from Elemental Nickel and Titanium Powders Through Spark Plasma Sintering and Extrusion

This study demonstrates the production of highly dense binary NiTi by spark plasma sintering (SPS) of elemental Ni and Ti powders. The sintered billets were extruded to 0.7 mm wire for tensile testing. Excellent mechanical properties and very dense microstructures were obtained in the wires produced in this way. The material demonstrated 4% recoverable strain, 14% elongation at fracture and 630 MPa ultimate tensile stress. Furthermore, a close control of the level of impurities was also possible. This highlights the efficacy of the SPS route in production-capacity manufacture of NiTi products.