Investigation of the mechanical and corrosion properties of Mg-Hydroxyapatite composite by addition of rare-earth oxide particulates for biomedical applications

Abstract

Magnesium has gained much attention as advanced light-weight material and have been extensively used in orthopedic applications. Its bone-like properties and non-toxic behavior have established it as a splendid bone implant with excellent biodegradability and biocompatibility; however, its corrosion properties have exploited its usage and need to be addressed. The current study emphasized the influence of rare-earth oxide, that is, Neodymium oxide (Nd2O3/NdO) on the mechanical and corrosion properties of Mg-Hydroxyapatite (HAP) composite. In this work, Mg-HAP-xNdO ( x = 1%, 1.5%, and 2%) was fabricated via powder metallurgy route using Box-Behnken design methodology with different sintering temperatures (400°C, 450°C, and 500°C) and sintering time (1, 2, and 3 h). The results showed that the addition of NdO to the composite developed various intermetallic phases such as Mg12Nd and Nd0.5Ca0.5 as analyzed through FESEM, XRD, and EDS techniques, producing refined microstructure. It was formalized that Mg-HAP composites containing 1.5% NdO, sintered at 400°C for 2 h showed the lowest corrosion rates as compared to other samples. Moreover, the secondary β-phase developed provided necessary reinforcement to the Mg-HAP composites and prevented deformation, resulting in improved microhardness (48.50 HV), ultimate compressive (UCS) (116.57 MPa), tensile strength (UTS) (154.23 MPa) at 1.5% NdO (400°C-2 h). In addition, the statistical analysis performed via the ANOVA technique confirmed the experimental results by revealing significant effects of sintering temperature and combination of all the three parameters on the microhardness and compressive strength of the composites. Hence, these findings concluded that the Mg-HAP-NdO composite could be a promising candidate for orthopedic implant applications.