Sintering of Porous TiNi Alloy with a Terraced Morphology of Pore Wall Surface

A specific rough morphology for cell attachment in vitro can facilitate the graft-host auspicious response. Therefore, a well-developed rough terrace-like surface of pore walls will definitely contribute to TiNi biocompatibility. The aim of the study was to fabricate porous TiNi alloy with terrace-like surface of pore walls.

TiNi intermetallic powder prepared by a calcium hydride method was sintered at 1240–1270 ᴼС for 15 min to fabricate samples with terrace-like surface of pore walls. The B19´phase evidenced in the green powder compact, as well as phase-chemical heterogeneity and high surface tension of the eutectic liquid, catalyzes the superficial spatial terraces on pore walls. The terraces occur on sites free of precipitates and spread out across the curved pore topography within one grain. The step height is up to 0.25 µm, whereas the width is of 0.4–0.5 µm. In some places, they seem as hexagonal islets of 1–2 μm in size dispersed between pyramidal martensite crystals. The overall specific surface equaled 0.309 m²/g, where the share of terrace-like surface of pore walls was around 37%. This significant increment is believed to modulate and support the cell viability and proliferation within the porous scaffold.

This study has been funded by the Russian science foundation (Project No. 17-79-10123).