Fe based degradable alloys for use as temporary orthopaedic fixation devices: preliminary degradation study

MELINA HANKOVITS; JOSEFINA BALLARRE; SILVIA CERÉ

Simposio; 1st PhD Student Symposium on Materials for Energy, Environment and Health; 2021

CENTRO UNIVERSITARIO DE BAVIERA PARA AMERICA LATINA (BAYLAT)

Metals are widely used, due to their excellent mechanical properties, as permanent or temporary prosthetic intracorporeal devices. These metallic materials, when in contact with existing bone, generate an interface that must be biocompatible and also minimize the release of potentially toxic ions to the tissues. Within the traumatology applications of biocompatible materials, the use of biodegradable metals is gaining strength due to their high mechanical performance and the possibility to avoid a second surgical intervention to remove the device. These implants are mainly used as temporary fixation devices to restore bone fractures. That is why this work proposes to analyze and then modify the surface of iron and Fe-Mn alloy substrates, to control their degradation and increase early osseointegration, without losing the integrity and performance of the metallic implant.In the first stages of the project, the in vitro surface and electrochemical characterizations of Fe and Fe-Mn alloys were carried out, with the aim of knowing the starting point for degradation and bioactive behaviour of the bare materials. The experimental setup was specifically designed for simulating oxygen, temperature, inorganic ion concentration and flux as in the human body. Three electrode cell was used to perform direct current essays (corrosion potential and cyclic polarization), and altern current experiments as well (electrochemical impedance spectroscopy), to monitor their degradation and corrosion in simulated body fluid at short periods of time. Also surface degradation was analysed with microscopic and spectroscopic techniques such as Raman microscopy. In a future stage, the surface will be coated with silica based materials, creating protective and/or bioactive systems. The oxides and surface degradation products may have influence not only in the protective and bioactive behaviour of the material, but also, on the future deposition of new silica based coatings.