Investigation of microstructure and mechanical properties of nano hydroxyapatite and nano alumina reinforced biodegradable Mg2Zn1Mn alloy produced by powder metallurgy method

In recent years, biodegradable materials have attracted significant attention due to their ability to be resorbed by the body following temporary biomedical applications. These materials offer substantial advantages in implant applications by eliminating the need for secondary surgical procedures and enhancing patient comfort. Among them, magnesium and its alloys stand out as promising biodegradable materials owing to their favorable mechanical properties, biocompatibility, and controlled degradation behavior in physiological environments. In this study, Mg2Zn1Mn magnesium alloy was reinforced with a total of up to 10 wt.% hybrid nano-sized hydroxyapatite (HA) and alumina (Al2O3) particles and produced using the powder metallurgy method. Initially, the powders were blended for 30 minutes using a 3D mixer, followed by mechanical alloying in an attritor mill at 300 rpm for 5 hours. The resulting powder mixture was then cold compacted at 600 MPa and sintered at 560 °C for 1 hour using conventional sintering techniques. The produced nanocomposite samples were subjected to microstructural characterization along with microhardness, nanoindentation, and compressive strength tests. Experimental results demonstrated that increasing the reinforcement content led to improved microstructural homogeneity and significantly enhanced mechanical properties. The highest values of microhardness, nanohardness, and elastic modulus were observed in the MCA10 sample, with values of 74.8 HV0.05, 1.15 GPa, and 21.57 GPa, respectively, corresponding to increases of approximately 51%, 62%, and 188% compared to the base alloy. The highest compressive strength was recorded in the MCA6 sample, reaching 201.1 MPa.