A novel strategy for fabricating (Ti,Ta,Nb,Zr,W)(C,N) high-entropy ceramic reinforced with in situ synthesized W2C particles

A new strategy was proposed to prepare in situ W2C particle reinforced (Ti,Ta,Nb,Zr,W)(C,N) high-entropy ceramics by the low chemical affinity between tungsten and nitrogen elements. High-entropy ceramics were prepared by in situ carbothermal reduction-nitridation and spark plasma sintering at elevated temperatures. The inferior chemical affinity between tungsten and nitrogen resulted in the formation of the W2C second phase in high-entropy carbonitrides during the reaction of metal oxides, carbon powder and nitrogen. The diffusion of tungsten and uniformly distributed W2C particles in the high-entropy carbonitride matrix enhanced the mechanical properties due to the high-entropy effect and dispersion strengthening mechanism. The high-entropy ceramic sintered at 2000. C demonstrated a high hardness of 23.46 GPa at 9.8 N and an excellent fracture toughness of 4.59 MPa m1/2. The proposed technique was applicable to various carbonitride ceramic systems to prepare high-performance ceramic materials.

Automated summary

A new strategy for preparing in situ W2C particle reinforced high-entropy ceramics has been proposed, which shows excellent mechanical properties. This technique has great potential in various applications.