Superelastic Porous NiTi with Adjustable Porosities Synthesized by Powder Metallurgical Method

Abstract

The effects of cold compaction pressure, TiH₂, and NH₄HCO₃ on the properties of porous NiTi fabricated by capsule-free hot isostatic pressing (CF-HIP) were investigated.  The porosities vary from 20% to 28% depending on the pressure.  Porous NiTi with 42% porosity and irregular pores can be prepared by addition of TiH₂ whereas 48% porosity and circular pores can be achieved by NH₄HCO₃ addition.  All the porous NiTi fabricated by CF-HIP using these three methods exhibit super-elastic behavior that matches human bones.

Keywords: Porous NiTi; Superelastic; Hot isostatic pressing;