Electrical impedance: an effective technique to detect volumetric and surface microstructural variations in materials

Abstract

In this work, a simple protocol based on electrical impedance measures is implemented to detect changes on chemical composition, the microstructure (percentage and size of pores) and the surface modification treatments of metallic implants. The Hewlett-Packard 4395A Agilent impedance analyzer was employed for these measurements. Discs of commercially pure titanium and the titanium alloy Ti35Nb7Zr5Ta were utilized, manufactured through conventional powder metallurgy at different conditions, along with porous discs obtained through the space holder technique. Some of these discs were treated with femtosecond laser to study how surface modifications affect electrical impedance values. Differences were observed in the measurements obtained for each sample, highlighting the significant role of the manufacturing method in their electrical impedance. However, it has been demonstrated that surface treatments notably affect impedance measurements, with greater changes detected in these cases.