Thermal conductivity enhancement of epoxy abrasive composites using hybrid SiC–Al2O3 fillers via experimental, analytical, and FEA approaches

This study investigates the thermal conductivity of epoxy matrix-based abrasive composites through the incorporation of silicon carbide (SiC) and aluminium oxide (Al 2 O 3 ) particles. A goal of such material design is to achieve controlled heat transfer with the potential to increase component lifetimes. Thermal conductivity measurements, infrared thermal imaging, scanning electron microscopy (SEM), analytical modelling, and finite element analysis (FEA) were employed to examine the influence of particle type, particle size, particle loading, and hybrid filler ratios on heat transfer behaviour. The results demonstrated that composites with both SiC and Al2O3 (called hybrid composites) exhibited higher thermal conductivity and longer lifetimes compared to just using Al2O3 alone. Hybrid SiC-filled composites exhibited significantly higher thermal conductivity than the hybrid Al 2 O 3 -filled systems due to improved phonon transport, stronger covalent bonding, and superior particle dispersion. Increasing particle size and filler loading enhanced thermal conductivity, with the highest value of approximately 2.78 W/mK achieved for a hybrid composite containing a 9:1 SiC-to-Al 2 O 3 ratio. In contrast, nano-sized particles showed reduced thermal conductivity at high loadings because of particle agglomeration and increased interfacial thermal resistance. Infrared thermal imaging further confirmed that composites with higher thermal conductivity exhibited improved thermal stability and prolonged operational lifetime during grinding applications. Analytical and FEA models predicted the experimental trends, with a discrepancy observed due to the limitations of the models. The findings highlight the potential of hybrid ceramic-filled epoxy composites for the development of thermally stable and longer life time abrasive materials for demanding industrial applications.