Comprehensive study of sub-micron porous titanium-zirconium scaffolds fabricated by liquid metal dealloying

This article investigates the microstructure, mechanical properties and biocompatibility of ultrafine porous titanium-zirconium (TiZr) alloys synthesized by the liquid metal dealloying (LMD) at a temperature of 1023 K for various immersion times. The dealloying of Ti ₂₀Zr ₂₀Cu ₆₀ precursors in molten magnesium causes to self-organize three-dimensional hcp-α structures by surface diffusion mechanism, wherein the ligament size, density and porosity range from 130 to 280 nm, 2.8–3.2 g/cm ³ and 0.43–0.5, respectively. The compression test results of porous products indicate a perfect combination of high compressive strength (415–620 MPa) and low elastic modulus (2.1–3.2 GPa) matching that of the human bone. The maximum ligament size (280 nm), density (3.2 g/cm ³) and compressive strength (620 MPa) corresponds to immersion time of 600 s; thereby, the mechanical characteristics can be tailored by modifying the process parameters. Meanwhile, the elastic modulus and compressive strength enhance almost linearly with increasing the relative density in accordance with the Gibson and Ashby model. The in-vitro experiments with MG-63 osteoblast cells also suggests the immersion time of 600 s to better support the bone tissue ingrowth. The porous TiZr alloy fabricated by the new dealloying method can be considered as a novel biomaterial for dental implants owing to its unique microstructure, compressive features and biocompatibility.