Synthesis and mechanical characterization of a Ti(C, N)/Mo-Co-Ni/CaF2@Al2O3 self-lubricating cermet

Abstract

In this paper, an Al2O3 coated CaF2 (CaF2@ Al2O3) 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 CaF2 powder is coated with Al2O3, and when introduced into a Ti(C, N)-Mo-Co-Ni material system, it can utilize the high-temperature liquid phase di_usion mechanism of the metal Mo-Co-Ni phase in the sintering process. The CaF2@ Al2O3@Mo-Co-Ni multilayer core-shell microstructure is formed in the material. Compared with the direct addition of CaF2 and Al2O3, the hardness and fracture toughness of the material are increased by 24.31% and 22.56%, reaching 23.93 GPa and 9.94 MPa•m1/2, respectively. The formation of the multilayer core-shell microstructure is the main reason for the improvement of the mechanical properties of the material.