Stress–strain behavior of porous Ni–Ti shape memory intermetallics synthesized from powder sintering

The microstructure and stress–strain behavior of porous Ni–Ti intermetallics fabricated by powder sintering of Ni, Ti and/or TiH2 are investigated. The pores are small and well distributed in the present porous Ni–Ti alloys and the phase constituent and stress–strain behavior of porous Ni–Ti alloys are significantly influenced by the sintering conditions (sintering temperature and sintering time) and TiH2 additions. With increasing sintering temperature, the pseudoelasticity (PE) increases while the hysteretic width decreases. A second compression also leads to an increase of PE, elastic modulus and related deformation resistance. Further, the stress–strain behavior of porous Ni–Ti alloys is different in some way from that of bulk Ni–Ti alloys and other porous materials.