Three-dimensional modeling of grain structure growth within ceramic tool material

Abstract

Ceramic cutting tool materials possess specific advantages, including high hardness, excellent wear resistance, and high chemical stability, making them unparalleled in the machining of difficult-to-process materials compared to traditional cutting tools. The mechanical performance of these materials is primarily determined by their microstructure. Therefore, it is necessary to simulate and optimize the microstructure of ceramic cutting tool materials to provide theoretical guidance for further enhancing their fracture toughness. In this paper, a simulation model based on sintering densification theory was proposed, coupling crystal plasticity with a three-dimensional cellular automaton, to investigate the impact of nanoparticle content, sintering temperature, sintering pressure, and holding time on grain growth in composite ceramic materials using spark plasma sintering (SPS). Furthermore, an evolution model for grain growth of TiB2-TiC-SiC nanocomposite ceramic materials in cutting tools is established, and the optimal sintering process parameters are obtained. Finally, SPS experiments were conducted. Under the conditions of a sintering temperature of 1600 °C, holding time of 7 min, and sintering pressure of 40 MPa, optimal mechanical performance composite ceramic cutting tool materials were prepared. The experimental results, including a hardness of 25.6 GPa, fracture toughness of 7.1 MPa·m1/2, and flexural strength of 628.2 MPa, were consistent with the simulation outcomes. This indicates that the designed simulation model for nanocomposite ceramic grain growth reliably reflects the physical process of grain growth in the material and provides valuable guidance for further understanding the mechanisms underlying grain growth.