Synthesis and Mechanical Characterization of a Ti(C,N)/Mo–Co–Ni/CaF(2)@Al(2)O(3) Self-Lubricating Cermet

In this paper, an Al(2)O(3) coated CaF(2) (CaF(2)@Al(2)O(3)) nanocomposite powder is used as the additive phase of a Ti(C,N)-based self-lubricating cermet material. A novel self-lubricating ceramic material with a multilayer core–shell microstructure was prepared using a vacuum hot-pressing sintering process. The results show that the surface of the CaF(2) powder is coated with Al(2)O(3), and when introduced into a Ti(C,N)–Mo–Co–Ni material system, it can utilize the high-temperature liquid phase diffusion mechanism of the metal Mo–Co–Ni phase in the sintering process. The CaF(2)@Al(2)O(3)@Mo–Co–Ni multilayer core–shell microstructure is formed in the material. Compared with the direct addition of CaF(2) and Al(2)O(3), the hardness and fracture toughness of the material are increased by 24.31% and 22.56%, reaching 23.93 GPa and 9.94 MPa·m(1/2), respectively. The formation of the multilayer core–shell microstructure is the main reason for the improvement of the mechanical properties of the material.