Mechanical properties and microstructure of the C-C-SiC, C-C-SiC-Ti3SiC2 and C-C-SiC-Ti3Si(Al)C2 composites

This study is focused on the evaluation of various parameters and their effects on the phase composition and mechanical properties of MAX phase-reinforced C-C-SiC composite, fabricated by liquid silicon infiltration (LSI) method. The results have shown that reduction of TiC particles size, elimination of residual silicon and addition of Al have positive impacts not only on the MAX phase content but also on the mechanical properties of the samples. The bending strength of C-C-SiC-Ti3SiC2 and C-C-SiC-Ti3Si(Al)C2 compared to C-C-SiC composites improved by 59.67% and 103.6%, respectively. Moreover, their interlaminar shear strength enhanced by 30.4% and 41.6% and their fracture toughness increased by 72.27% and 89.1%, respectively. Investigations have clarified that inter-bundle matrix of these composites has more MAX phase proving that it can tolerate various micro-transformation mechanisms such as crack deflection, bending and delamination of lamellae, kink boundary and laminate fracture. These phenomena lead to the toughening of such composites and prohibition of crack propagation. Improved properties of the MAX phase-containing samples reveal the potential of such composites as functional and structural materials.