Development of Mg-1Zn-1Ca-xZnO (x = 0 and 2 wt.%) composite using disintegrated melt deposition method for biomedical applications

Magnesium (Mg)-based biodegradable materials have become prominent for use in temporary implant applications. In the present work, the Mg-1Zn-1Ca-xZnO (x = 0 and 2 wt. %) alloy and composite were synthesized using a disintegrated melt deposition (DMD) technique followed by a hot extrusion process, and their microstructure, thermal, and mechanical properties were studied. The average grain size for the Mg-1Zn-1Ca alloy and the Mg-1Zn-1Ca-2ZnO composite obtained is 7.0 µm and 6.3 µm, respectively. The XRD analysis depicted that 10-11 pyramidal planes are dominant, and Mg₂Ca, Mg₂Ca and MgZn phases are formed in the Mg-1Zn-1Ca alloy and the Mg-1Zn-1Ca-2ZnO composite. The modulus of elasticity increased by 3.30 % and the ignition temperature increased by 3.11 % with the addition of 2 wt. % ZnO nanoparticles in the Mg-1Zn-1Ca alloy. The Vickers hardness value increased by 1.70 % while the yield strength increased by 13.77 % after the addition of ZnO nanoparticles (150.3 MPa and 171.0 MPa, respectively, for the monolithic Mg-1Zn-1Ca alloy and Mg-1Zn-1Ca-2ZnO composite materials, both of which exceed the yield strength of natural bone at 60 - 90 MPa). The results demonstrate the efficacy of ZnO nanoparticles for use in biomedical applications with good mechanical properties.