Mechanical properties and simulation of thermal gradient formation in GNP-reinforced B₄C-TiB₂ceramics by SPS

Graphene nanoplatelet (GNP)-reinforced B₄C-15 vol% TiB₂ composites were fabricated by spark plasma sintering (SPS) to evaluate the effects of 1, 2, and 3 vol% GNP addition on densification, microstructure, and mechanical properties. The highest relative density (98.23 %) was achieved with 1 vol% GNP, while higher contents led to a slight decrease. Mechanical characterizations revealed peak values of 34.54 ± 0.82 GPa for Vickers hardness and 4.72 ± 0.61 MPa m^1/2for four-point fracture toughness in the 1 vol% GNP-reinforced sample. Furthermore, simulations of the SPS process demonstrated that increasing GNP content reduces temperature gradients within the sintered body due to GNP-facilitated heat transfer. Thermal conductivity decreases with increased GNP content but exceptionally high in-plane heat transfer capability of GNP dominates overall conduction. These findings indicate that controlled GNP incorporation enhances densification and mechanical properties of B₄C-TiB₂ composites while providing new insights into their thermal behavior during SPS.