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

Fabrication of multi-anionic high-entropy carbonitride ultra-high-temperature ceramics by a green and low-cost process with excellent mechanical properties

“…The bending strength and fracture toughness (SENB) of the HE carbonitride ceramic obtained in this study are higher than the previously reported mechanical properties of HE (TiZrHfNbTa)C carbides and other HE carbides, which may be attributed to the fine grain size leading to more grain boundaries, and the greater hindrance of dislocation movement by the grain boundaries [55]. Meanwhile, the comparison of Vickers hardness and fracture toughness (VIM) with other HE ceramics [25], [26], [29], [30], [57] There is no denying that the hardness and brittleness of ceramic materials are interrelated. To evaluate the correlation between hardness and brittleness of ceramic materials, the brittleness index proposed by Boccaccini is an effective method to quantitatively evaluate the resistance of brittle materials to brittle damage, and the brittleness index B can be expressed by the following Eq.…”

“…The brittleness index of the HECN0.8 ceramic is 2.367 μm −1/2 , which shows a lower brittleness index than the (Hf0.2Zr0.2Ti0.2Ta0.2Nb0.2)C ceramic (4.856 μm −1/2 ) [26], (Hf0.2Zr0.2Ti0.2Ta0.2Nb0.2)N ceramic (4.327 μm −1/2 ) [18] and other HE ceramics calculated from the properties published in literature [24], [29], [30], [57]. The reduction of the brittleness of HE carbonitride ceramic enables them to be used in practical engineering applications with great potential.…”

Dual-Porosity (Ta0.2Nb0.2Ti0.2Zr0.2Hf0.2)C High-Entropy Ceramics with High Compressive Strength and Low Thermal Conductivity Prepared by Pressureless Sintering

“…The emergence of high entropy ceramics (HECs) offers more possibilities to modulate the performance of ultra-high temperature materials and to overcome bottlenecks in material applications [ 29 , 30 , 31 , 32 ]. High-entropy carbides (HECs), such as (Ta 0.2 Nb 0.2 Ti 0.2 Zr 0.2 Hf 0.2 )C, (Ta 0.2 Nb 0.2 Ti 0.2 Zr 0.2 Hf 0.2 )B-2, (Ti, Zr, Nb, Ta, Mo)C, and (Ti, Ta, Nb, Zr, W)(C,N), are considered to be potential UHTCs for TPS because they exhibit lower thermal conductivity, higher mechanical strength, hardness, melting point, and thermal stability than single transition metal carbide components such as ZrC, HfC, NbC, TaC, and TiC [ 33 , 34 , 35 , 36 , 37 ].…”

Design and experimental investigation of potential low-thermal-conductivity high-entropy rare-earth zirconates

“…The reliability of the Rietveld refinement is indicated by Rwp. Rwp was less than 10%, indicating that the refinement results are reliable [40]. The results showed that the synthesised SYLHYb, SCNEG, SYTYbLu, SErTYbLu, and GZ bulk samples had the space group Fm−3m with the defective fluorite structure.…”