A strong, machinable, and multifunctional Ti3SiC2-(Ti3SiC2-Cf) composite: Gradient architecture and mechanical properties

Ti 3 SiC 2 , as one of the most typical MAX ceramics, has been extensively studied as a potential high-temperature structural material. However, the restrictive relations between strength and toughness of Ti 3 SiC 2 and Ti 3 SiC 2 -based materials have hampered their industrial applications. Herein, we reported the successful fabrication of Ti 3 SiC 2 –(Ti 3 SiC 2 –C f ) functionally graded materials (FGM) via hot-press sintering Ti 3 SiC 2 and short C f -derived preceramic papers. The microstructure evolution as well as the effect of sintering temperature on phase composition and interfacial reaction were investigated. Flexural strength and fracture toughness from ambient temperature to 1000 °C of the graded composites were determined to evaluate the mechanical performance. The results have shown that chemical reactions occurred between carbon fibers and Ti 3 SiC 2 matrix, which leads to the formation of SiC interfaces with strong covalent bonds . The newly developed Ti 3 SiC 2 –(Ti 3 SiC 2 –C f ) graded composite materials exhibited excellent comprehensive performance as compared to that of monolithic Ti 3 SiC 2 . The flexural strength and fracture toughness of the graded composite at room temperature can be reached to 526 MPa and 7.46 MPa m 1/2 , respectively. However, there is no significant change in flexural strength and fracture toughness from RT to 1000 °C. The fracture micrographs also reveal that fiber breaking、pulling out and debonding are the primary mechanisms that contribute to the superior mechanical properties of composites. The exceptional performance demonstrated in Ti 3 SiC 2 –(Ti 3 SiC 2 –C f ) graded materials also makes them attractive choices for a variety of heatproof devices in aerospace sectors.