Mechanical and tribological response of GFRP composites governed by boron carbide particle size

Glass fibre reinforced polymer (GFRP) composites incorporating ceramic fillers have gained increasing interest for applications requiring enhanced mechanical strength and wear resistance. In this work, the mechanical and tribological responses of GFRP composites as a function of boron carbide (B₄C) particle size are systematically investigated at low filler fractions of 1 and 2 wt%. GFRP laminates were fabricated using the hand lay-up method, followed by cut-through abrasive water jet cutting in accordance with ASTM standards. Tensile tests were performed on specimens with and without a central 10 mm hole, Izod impact tests were performed to assess the impact performance, and dry sliding wear behaviour was evaluated under controlled conditions. The results indicated that the composites with 1 wt% B₄C and fine particle size have higher tensile and impact strength than unfilled GFRP due to the effective load transfer and uniform filler dispersion. Increasing the filler content to 2 wt% causes particle agglomeration and formation of micro voids, which leads to a reduction in ductility and promotes premature failure. Tribological results show that the finer the B₄C particle size, the more it improves the wear rate and increases the surface stability, while the coarse particles will cause more abrasive damage. Scanning electron microscopy shows the particle-size dependency, dispersion behaviour, and damage mechanisms of mechanical and wear response. These results give a mechanistic understanding of particle size-controlled reinforcement effectiveness and wear characteristics of B₄C-filled GFRP composites.