Improving Abrasion Resistance of Carbon‐Epoxy Hybrid Composites With Silicon Nitride Fillers

ABSTRACT The impact of micron level silicon nitride (Si 3 N 4 ) filler on the multipass condition two‐body abrasive wear behavior of carbon fabric‐reinforced epoxy (C‐E) composites was examined in this study. Using a Pin‐on‐Disc tribometer, the tribological behavior of the produced composites was evaluated at 5 N and 10 N as well as at different abrasive distances of 25, 50, 75, and 100 m. Silicon carbide abrasive papers were used for the experiments. It was found that when the abrading distance and load were increased, the wear volume loss of the composite samples also increased. Notably, the hybrid composite H3 (containing 6 wt% Si 3 N 4 ) exhibited the lowest specific wear rate (SWR), ranging from 0.2064 × 10 −10 to 0.0074 × 10 −10 m 3 /N m. The addition of Si 3 N 4 improved the composite abrasion resistance considerably; when the content was increased from 2 to 4 wt%, the SWR decreased by 67.3%. A more significant decrease of 96.4% in SWR was attained by increasing to 6 wt% Si 3 N 4 loading, indicating superior wear resistance. In comparison to the unfilled C‐E composite, the C‐E with 6 wt% Si 3 N 4 filled composite demonstrated a 33.1% reduction in wear volume loss at 5 N. The results demonstrate that Si 3 N 4 incorporation significantly enhances the abrasion resistance of C‐E composites by reducing both fiber and matrix wear through the formation of a protective transfer film that prevents large‐scale fragmentation. Scanning electron microscopy analysis revealed the underlying wear mechanisms, while the hybrid composites exhibited a strong correlation between wear volume loss and material hardness. These findings indicate promising applications in automotive brake systems, power plant components, and industrial bearings where superior wear resistance is critical.