Study on the Mechanical and Tribological Properties of Functionally Layered Si ₃ N ₄ /TiN Ceramics

To improve the mechanical and tribological properties of Si ₃ N ₄ ceramics, layered ceramics with layered structure were prepared by imitating the nacre structure of shells. The matrix layer is selected to include 10% TiN in the Si ₃ N ₄ powder, with h‐BN as the main interfacial layer material. The incorporation of 10% TiN facilitates the formation of a robust interfacial bond between Si ₃ N ₄ and TiN, thereby enhancing the ceramic's strength. Concurrently, the introduction of h‐BN as an interfacial layer effectively alters the crack propagation pathway, augmenting fracture energy and consequently enhancing the fracture toughness of the Si ₃ N ₄ ceramics. When the prepared layered ceramics are subjected to dry friction at room temperature, the friction coefficients and wear rates are 0.55, 1.097 × 10 ⁻⁶ mm ³ /(N⋅m), 0.48 and 3.396×10 ⁻⁶ mm ³ /(N⋅m) under low loads of 5N and 10N, respectively. The friction coefficient is 0.51 and the wear rate is 7.276×10 ⁻⁶ mm ³ /(N⋅m) when the high load is 20N.The enhancement of the tribological properties of ceramics is attributed to the presence of TiN with a low coefficient of friction, as well as h‐BN as an interfacial layer with lubricating properties. Additionally, the formation of an oxide film during the friction process further contributes to the improved tribological performance. In this study, a layered ceramic with structure‐function integration was prepared, which has very good application potential in cutting tools and other industries.