Characterization of hot-pressed biodegradable zinc-based nanocomposite implant materials reinforced with 10 wt% Mg, WE43, and AZ91

Abstract

Compared to permanent orthopedic implants for load-bearing applications, biodegradable implants provide the advantage of eliminating the necessity for surgical removal after the healing process. Furthermore, magnesium alloy powder reinforced zinc matrix implant materials have been produced to enhance the mechanical properties, biocompatibility, and a proper degradation rate with the growth rate of new bones. This study aims to fabricate Zn-10 wt% Mg, Zn-10 wt% WE43, and Zn-10 wt% AZ91, and alloys along with pure Zn sample for control purpose, using the powder metallurgy production method. In this context, hot pressing was applied to samples at 200°C and 300°C temperatures, under a constant pressure of 400 MPa in order to optimize the fabrication parameters. Scanning Electron Microscope (SEM), Energy Dispersive Spectrometry (EDS), Vickers macro- and micro-hardness test (HV), and X-Ray Diffraction Spectroscopy (XRD) analyses were performed to investigate the influence of press temperatures on the microstructure, elemental components, and mechanical properties of the fabricated samples. The microstructures of the zinc matrix nanocomposite samples reinforced with magnesium alloys predominantly consist of MgZn₂, Mg₂Zn₁₁, and MgO phases dispersed within the refined zinc matrix. The obtained results clearly indicate that ZnMg alloy nanocomposites hold significant potential as biodegradable orthopedic implant materials, however, it is possible to further improve the properties of the material by optimizing the production parameters.

Keywords: Zn-Mg alloy, Powder metallurgy, Biodegradability, Mechanical properties.