High-temperature self-lubricated properties of Al2O3/Mo laminated composites

High-performance self-lubricated alumina composites are regarded as potential candidates for space applications. Complying with the design principle of bionic composites, Al2O3/Mo composites with laminated structure were prepared, and their mechanical and tribological properties were studied. The results show that Al2O3/Mo laminated composites have excellent self-lubricating and mechanical properties. The fracture toughness of the material is 9.14 MPa m1/2, which is much higher than the 5.69 MPa m1/2 of the monolithic Al2O3 ceramics. In addition, the friction coefficient of the material can be reduced to 0.34 at 800 °C, a decrease of approximately 62.6% below the monolithic Al2O3 ceramics. The Al2O3/Mo composite showed good self-lubricating and mechanical performance, which can be attributed to the presence of laminated structure and the formation of MoO3 during the sliding friction at high temperature.

► This paper proposes a new design for ceramic self-lubricating composites in order to overcome the conflict between their mechanical and tribological properties. ► Al2O3/Mo laminated composites have excellent self-lubricating and mechanical properties. ► The fracture toughness of the material is 9.14 MPa m1/2, which is much higher than the 5.69 MPa of the monolithic Al2O3 ceramics. ► The friction coefficient of the material can be reduced to 0.34 at 800 °C, a decrease of approximately 62.6% below the monolithic Al2O3 ceramics.