Synthesis and properties characterization of an Al2O3-based ceramic materials with intragranular self-lubricating nanostructure

Abstract

In this study, a novel intragranular self-lubricating nanostructure was proposed for preparing a potential ceramic cutting tool material. Nano-sized CaF2, which meets the requirements of such a material, was prepared and used in the synthesis of ceramic materials with intragranular self-lubricating nanostructure. Based on the obtained results, an Al2O3/TiC/CaF2 intragranular self-lubricating nanostructure ceramic material was prepared by vacuum hot-pressing sintering. As the nano-sized CaF2 content increased, the flexural strength first increased and then decreased, hardness decreased, and fracture toughness increased. The results indicated that the formation of intragranular nanostructures could significantly improve the friction performance of this material. The friction coefficient of this material against a 40Cr steel ball was 0.12–0.25, and decreased as the CaF2 content increased. The wear rate also decreased as the CaF2 content increased from 3.3–10 vol%, but the friction coefficient decreased only slightly. Furthermore, the wear rate increased when 13.3 vol% CaF2 was added.