Processing, mechanical, corrosion, and wear behavior of ZnO-reinforced Mg and Mg–Zr matrix composites for bioimplant applications

Abstract

The need for efficient biodegradable material for implants has been rising due to issues related to the rate of degradation, toxicity, and osseointegration. This work aims to study the mechanical, corrosion, and wear behavior of ZnO nanoparticles reinforced Mg and Mg–Zr Matrix composites processed using powder metallurgy for bioimplant applications. The magnesium powder with ZnO nanoparticles and Zr microparticles was blended, compacted at 550 MPa, and subsequently sintered at 450 °C for 2 h. The synthesized composites were characterized in terms of structure, microstructure, densification, microhardness, wear, and in vitro corrosion analysis in simulated body fluid. The results showed that ZnO with Zr significantly altered the basal structure of Mg and underwent grain refinement with uniform distribution of ZnO predominantly near grain boundaries. Close to 99 % densification with 50 % enhancement in microhardness was obtained for the Mg–Zr–ZnO composite in comparison to pristine Mg. Moreover, the wear characteristics of the Mg–Zr–ZnO hybrid composite showed enhancement in wear resistance by 35 % relative to pure Mg. Corrosion assessment of the processed Mg composite samples was systematically performed in simulated body fluid (SBF). The obtained results confirmed the enhanced corrosion-resistant performance of Mg–Zr–ZnO samples in SBF medium. The refined microstructure and synergistic impact of Zr and ZnO particles as reinforcement in hybrid Mg composite have improved microhardness, corrosion, and wear characteristics, making it a potential bioimplant material.