Temperature-driven wear behavior of Si ₃ N ₄ -based ceramic reinforced by in situ formed TiC _0.3 N _0.7 particles

Si ₃ N ₄ as a structural ceramic is desirable for applications in spacecraft, transportation, and energy, but its poor high-temperature properties still do not satisfy the actual requirements. Here, a TiC _0.3 N _0.7 reinforced Si ₃ N ₄ ceramic is successfully designed and fabricated via the high-temperature nitridation of TiC _x . It is found that TiC _0.3 N _0.7 grains with the size of 1-2 μm are uniformly dispersed in the Si ₃ N ₄ matrix and show a firm bond with substrate. Compared with pure Si ₃ N ₄ , the doping of harder TiCN phase can effectively improve ceramic's hardness and fracture toughness at a certain temperature. Importantly, the ceramic material displays extraordinary wear resistance across a wide temperature range (eg, the wear rate of TiC _0.3 N _0.7 containing Si ₃ N ₄ over 63 times and 178 times better than pure Si ₃ N ₄ at 600 and 900°C, respectively). More broadly, a correlation between wear mechanism and temperature is established, and the result shows that the mechanical strength and tribochemical oxidation as two key factors determine the wear behavior of the material. These results developed here can provide a springboard for preparation and optimization of multiphase ceramics that serve under high-temperature conditions.