Processing of Small Scale Nitinol Billets by Induction Heated Nonconventional Isothermal Extrusion (IHNCIE)

Abstract

This paper describes a novel process designed specifically for extruding small scale billets, between 850°C and 950°C, in very short cycle times of 10 min. Induction heated nonconventional isothermal extrusion (IHNCIE) is used to produce wires of Nitinol and compare its efficacy with wires produced conventionally by hot rolling. With two four to one area reductions, a wire of 3 mm diameter was formed by IHNCIE. The extruded wires showed good superelastic tensile properties. This 3 mm diameter extruded wire exhibited a microstructure with grains of approximately 2 μm without a recrystallization anneal. Our method offers an alternative route for the production of small scale billets into a wire.