Experimental and numerical study on the influence of graphene reinforcement and processing parameters on the mechanical and tribological behavior of magnesium composites

Abstract

The development of lightweight structural materials with enhanced mechanical and tribological properties is a critical challenge in the automotive, aerospace, and biomedical sectors. While magnesium alloys offer excellent weight-to-strength ratios, their intrinsic limitations—such as low wear resistance and poor formability—restrict their application in demanding environments. Reinforcing magnesium with graphene nanoplatelets (GNPs) has emerged as a promising strategy to overcome these drawbacks due to graphene's exceptional stiffness, strength, and lubricating characteristics. However, achieving optimal performance depends not only on graphene content but also on powder metallurgy processing parameters that influence dispersion, densification, and interfacial bonding. This study systematically investigates the effects of graphene content, sintering temperature, sintering time, and compression pressure on the properties of pure magnesium composites produced by powder metallurgy. The composite containing 0.15 wt.% graphene, sintered at 520°C for 60 min under 600 MPa, exhibited optimal performance with a relative density exceeding 96%, hardness of 44.34 HV, compressive strength of 300 MPa, and wear rate of 8.52 × 10⁻⁴ mm³/N·m. Finite Element Method (FEM) simulations revealed that this reinforcement level enhanced stress distribution and stiffness by introducing effective load-bearing sites. The study underscores the importance of optimising graphene content and processing parameters to achieve well-dispersed reinforcements, thereby significantly improving the performance of magnesium-based composites. This work uniquely integrates multi-parameter process optimisation with FEM-based microstructural modelling and comparison, marking a first in the comprehensive evaluation of Mg-GNP composites.