Abnormal sintering behaviors of chromium carbide under high pressure and high temperature

Abstract

Controlling grain behavior during high pressure and high temperature (HPHT) sintering is crucial for synthesizing high-performance bulk ceramic materials. Chromium carbide (Cr3C2), a representative transition metal carbide ceramic, finds extensive industrial applications owing to its exceptional combination of properties. In this study, the intricate grain behaviors in Cr3C2 under 15 GPa/25–1700 °C are revealed by HPHT methods. It is found that the mechanical and elastic properties of Cr3C2 exhibit a significant dependence on temperature-induced grain behavior. Particularly, the mechanical properties of Cr3C2 exhibit abnormal softening at 15 GPa/1200 °C and 15 GPa/1500 °C. Through characterization and analysis of the microstructure, it is confirmed that the significant change in mechanical properties stems from the abnormal sintering behaviors of distinctive competitive behavior of grain refinement and growth. The findings highlight the significant influence of the competitive behavior on microstructural evolution, which exhibits strong correlations with the mechanical properties.