Development and Characterization of Mg-nHAP-GNP Hybrid Composites for Biomedical Applications
Kalyanamanohar Veeramallu, Tarun Kumar Kotteda, Vimala Raghavan, Prabhakar Undre, S. Shailajha, Mishikari Nizamoddin
Quarterly No. 2, 2026 pages 76-87
DOI: https://doi.org/10.62753/ctp.2026.04.2.2
keywords: magnesium, nano hydroxyapatite, graphene nanoplatelets, powder metallurgy, sintering
abstract Traditional metallic materials, including titanium and stainless steel, offer excellent biocompatibility and function widely as orthopaedic implants for fracture fixation. However, their non-biodegradable nature creates a major limitation in long-term biomedical use. Magnesium emerges as a promising alternative for implant applications due to its inherent biodegradability. In the present investigation, nano-hydroxyapatite (nHAP) at 10 wt% together with graphene nanoplatelets (GNP) at 0.1, 0.2, and 0.3 wt% underwent incorporation into magnesium by means of pressureless sintering, then the mechanical and microstructural behaviour of the resulting material was investigated. The phase quality and microstructural features were examined using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The mechanical performance of the Mg hybrid composites was assessed utilising a Vickers micro-hardness tester, a universal tensile testing machine, and a pin-on-disc tribometer. SEM observations revealed uniform dispersion of nHAP across the grains, while GNP predominantly occupied the grain boundaries. A notable increase in tensile strength and hardness emerged with the GNP addition, yielding a hardness value of 66.74 HV1, primarily due to grain refinement. Owing to the self-lubricating nature of GNP, the composite with 0.2 wt% GNP exhibited a reduced wear rate of 0.000793 mm3/Nm in comparison with monolithic Mg. Furthermore, enhanced hardness contributed to lower wear, aligning with Archard’s law.