Host lattice and solid solution formation in an octal-cation (NbTaZrTiHfVWMo)C high entropy carbide ceramic

作者：He, Liu; Liu, Longjun; Peng, Fei^*; Zhang, Weidong; Lin, Nan; Zhao, Shijun; Ma, Yi; Wu, Zhenggang^*

来源：Journal of the European Ceramic Society, 2023, 43(14): 5792-5801.

DOI：10.1016/j.jeurceramsoc.2023.06.061

• High entropy carbide ceramics
• Host lattice
• Solid solution formation
• Mechanical properties

High entropy carbide ceramics (HECCs) exhibit property peculiarity, such as higher hardness and higher toughness than conventional binary counterparts. The cation-sites of HECCs consist of 4 or more types of transitional metals with equiatomic ratios. Our work advocates that the individual constituent carbide in HECCs cannot be treated equally; instead, one serves as the host lattice and other metallic elements occupy its cation-site lattice substitutionally. urging sintering before the completion of solid solution, individual carbides tend to bind with each other to form a variety of intermediate products. Specifically, in the octal-cation (NbTaZrTiHfVWMo)C carbide, TaC serves as the host lattice and a few intermediate products, such as (Zr,Hf)C and (Ti,V,W,Mo)C, formed. A dense and single-phase carbide can be obtained through sintering at a low temperature of 2000 degrees C and the so-obtained carbide has a nanohardness of 38.71 GPa and a fracture toughness of similar to 4.67 MPa center dot m(1/2), outweighing a majority of the existing carbides.