Synthesis and Mechanical Characterization of a Ti(C,N)/Mo-Co-Ni/CaF2@Al2O3 Self-Lubricating Cermet

Chuanhao Li; Mingdong Yi; Gaofeng Wei; Chonghai Xu

doi:10.3390/ma12233981

Synthesis and Mechanical Characterization of a Ti(C,N)/Mo-Co-Ni/CaF₂@Al₂O₃ Self-Lubricating Cermet

Materials (Basel). 2019 Nov 30;12(23):3981. doi: 10.3390/ma12233981.

Authors

Chuanhao Li¹, Mingdong Yi¹, Gaofeng Wei¹, Chonghai Xu¹

Affiliation

¹ School of Mechanical and Automotive Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, China.

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 diffusion 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·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.

Keywords: mechanical properties; multilayer core–shell microstructure; residual stress; self-lubricating cermet.

Abstract

Grants and funding