The Effects of 4% Fe on the Performance of Pure Zinc as Biodegradable Implant Material

The efforts to develop structural materials for biodegradable metal implants have lately shifted their focus from Magnesium and Iron base alloys towards Zinc. This was mainly due to the accelerated corrosion rate of Mg that is accompanied by hydrogen gas evolution, formation of voluminous iron oxide products with reduced degradation rate in the case of Iron implants and the crucial role of Zn in many physiological processes. However the mechanical properties and degradation capabilities of pure zinc in physiological environment are limited and do not comply with the requirements of biodegradable implants. The present study aims at evaluating the effect of 4%Fe on the in-vitro and in-vivo behavior of pure Zinc. This was carried out in order to address the inherent disadvantages of pure zinc in terms of mechanical properties and biodegradability. The results obtained clearly indicate that the biocompatibility and mechanical properties of the new material system was in accord with the prospective requirements of biodegradable implants. However the corrosion degradation of the new alloy in in-vivo conditions was quite similar to that of pure zinc in spite of the significant micro-galvanic effect created by Delta phase Zn₁₁Fe.