3D honeycomb nanostructure-encapsulated magnesium alloys with superior corrosion resistance and mechanical properties

By Cijun Shuai, Bing Wang, You-wen Yang, S. Peng, Cheng-de Gao. Composites Part B: Engineering, 2019

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Abstract Magnesium (Mg) alloys are promising biodegradable metals for biomedical applications but limited by their too fast degradation rates. In this study, selective laser melting was used to fabricate three-dimensional honeycomb nanostructure-encapsulated Mg alloys, in which the honeycomb nanostructure was constructed by graphene oxide (GO) as a second phase and the grains of Mg alloys were encapsulated in the honeycomb unit. Results showed that GO distributed along the grain boundaries and gradually wrapped ɑ-Mg grains as GO content increasing. It was worth noting that a honeycomb nanostructure was formed with ɑ-Mg grains encapsulated in the honeycomb unit at a certain GO content (1.0 wt% in this study). As a result, the corrosion resistance and mechanical properties were both improved, which might be ascribed to the following mechanisms: (I) ɑ-Mg grains were refined due to the reduced connection and promoted nucleation by GO; (II) Benefiting from the outstanding anti-permeability of GO, the honeycomb nanostructure acted as a tight barrier to restrain the propagation of corrosion; (III) GO reinforced the corrosion layer to prevent it falling off the Mg matrix; (Ⅳ) The oxygen-containing groups on GO facilitated the deposition of bone-like apatite and further hindered the invasion of corrosive medium. These findings demonstrated the multiple defensive roles against corrosion in the honeycomb nanostructure-encapsulated Mg alloys and their great potential in biomedical applications.

Subfields: Biomaterials, Materials Chemistry, Mechanical Engineering

View Paper: https://www.semanticscholar.org/paper/0e819cc78e81035ecabf3f0481c07642d346279a