ICAMS / Interdisciplinary Centre for Advanced Materials Simulation


Degradation behavior of the MgO/HA surface ceramic nano-composites in the simulated body fluid and its use as a potential bone implant

V. Khalili, J. Frenzel, G. Eggeler.

Materials Chemistry and Physics, Elsevier BV,, 258, 123965, (2021)

In this work, we studied the effects of hot isostatic pressing and surface anodizing on the behavior of an in-situ surface modified magnesium matrix nano-composite with different wt.% of hydroxyapatite by stir-centrifugal casting. The hot isostatic pressing and anodizing were conducted to reduce the defects and to replace the surface of Mg/HA with a ceramic matrix nano-composite layer of MgO/HA, respectively. The composition of the conversion layer of anodizing was evaluated using energy dispersive spectroscopy and X-ray diffraction. The electrochemical tests were conducted in the simulated body fluid. The results show that the dominant deposition is vertical Mg(OH)2 nano-rods on the hot isostatic pressed-anodized surface during immersion in the simulated body fluid. According to the electrochemical results, a homogeneous distribution of 1.8 wt% nano-hydroxyapatite in the magnesium oxide matrix with a well-arranged nanostructure on the surface, after hot isostatic pressing and anodizing, reduces the H2 release and corrosion rate. Also, the mentioned specimen demonstrates the lowest thermodynamic tendency for corrosion (−1.345 V) and the corrosion rate of 3.8388 mm × year−1 with the highest protection efficiency of 42.26% compared to the as-cast pure magnesium. Therefore, it can be considered as a promising material in designing biomedical bone implants.

Keyword(s): In-situ surface modifying; stir-centrifugal casting; anodizing; ceramic nano-composites of MgO/HA; simulated body fluid
DOI: 10.1016/j.matchemphys.2020.123965
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