Junjie Song

Novel Approach to the Fabrication of an Alumina-MoS2 Self-lubricating Composite via the In-situ Synthesis of Nanosized-MoS2

The fabrication of a self-lubricating ceramic composite with MoS2 as the solid lubricant is extremely difficult given the high temperature sensitivity of MoS2. In this study, a hydrothermal method was utilized for the in situ synthesis of nanosized-MoS2 in Al2O3 ceramic to fabricate an Al2O3-MoS2 self-lubricating composite. The composite exhibited excellent self-lubricating properties with low friction coefficient and wear rate in a high-vacuum environment because of the efficient formation of self-lubricating films from the finely structured MoS2 in the Al2O3 matrix. The results of this study establish a new approach to the fabrication of self-lubricating ceramic composites with temperature-sensitive solid lubricants.

Surface Engineering Design of Alumina-Matrix Composites

The three-dimensional lubricating layer on a ceramic surface realizes the integration of the structure and lubricating function in ceramic materials, which can achieve outstanding lubricating properties and maintain the excellent mechanical properties of ceramics, solving the special lubrication and wear failure in mechanical systems under extreme conditions (e.g., corrosive environment and wide-temperature range condition). In this chapter, two kinds of surface-lubricating structural-laminated ceramics with high reliability were designed and prepared based on experiment research and theoretical simulation. These ceramics can achieve stable and effective lubrication in a water environment and wide-temperature range condition. These materials are Al2O3/Ni- and Al2O3/Mo-laminated composites suitable for use in a water environment and in wide-temperature range conditions, respectively. The relation between the surface microstructure of the prepared materials and their properties (mechanical and tribological) was investigated. Results indicated that the integration of the structure and lubricating function of the ceramic composites is realized through the bionic, surface microstructure, and three-dimensional self-lubricating design of the materials, further improving their lubricating and practical properties. Factors that can influence the tribological behavior and wear failure of the above materials were proposed through the systematic study of the tribological behavior under different environments and test conditions, as well as the relation among the structure, composition, and properties of these two kinds of materials. In addition, theoretical models of the relation between the structural parameters and performance of the materials were built. These methods provided theories and technologies for the preparation and application of high performance lubricating materials that can be used in corrosive and wide-temperature range environments.