A novel solid-state dealloying method to prepare ultrafine ligament nanoporous Ti

Abstract

Nanoporous Titanium (NPT) is an attractive material with high corrosion resistance, good biocompatibility, and large surface area for many new functional applications. The solid dealloying reaction was explored using Ti–Cu and Mg diffusion couples to prepare NPT powders. The dealloying temperature in this novel method was much lower than that in the traditional liquid metal dealloying. In addition, the NPT with finer ligament width below 200 nm was obtained when the temperature was lower than 485 °C. A diffusion growth model was applied to explain the quantitative relationship between the morphology and various dealloying parameters. The coarsening exponent and activation energy were also estimated to reveal the difference between dealloying in Mg melts and Mg solids. The quantity as well as the formation ability of the Mg–Cu liquid phase played a crucial role. The NPT with smaller ligament size and larger surface area exhibits higher electrochemical capacitance performances.