Research Progress on the Preparation and Characterization of Ultra Refractory Ta_xHf_1-xC Solid Solution Ceramics

Abstract

TaxHf1-xC solid solution ceramics have been considered as the promising candidates for many important applications which can tolerate temperature above 3000 K due to their high melting point, high hardness, low coefficient of thermal expansion, good resistance to oxidation and ablation. In this paper, the research progress of TaxHf1-xC solid solution ceramics was introduced in terms of preparation methods, microstructure, thermophysical properties, mechanical properties at room temperature, oxidation and ablation resistance. Furthermore, the relationship between the composition, structure and properties of TaxHf1-xC solid solution ceramics was discussed. The remaining challenges and future outlook of TaxHf1-xC solid solution ceramics were also addressed.

Fabrication and mechanical behavior of 2D-C f/Ta x Hf 1− x C–SiC composites by a low-temperature and highly-efficient route

“…In terms of the C f /Ta x Hf 1−x C-SiC composites, there are three main challenges: the difficultly in the batch synthesis of the Ta x Hf 1−x C powders, the efficient fabrication of the composites, and the in-depth analysis of their properties and related failure mechanisms. The synthesis of Ta x Hf 1−x C solid solution mainly includes solid-state method (carbide solid solution [16], carbon reaction solid solution [17], and metal oxide reduction solid solution [18]) and liquid phase method [19,20], where the carbide solution is the most simple and efficient synthesis method, which has been favored by many researchers [21]. Although Ta x Hf 1−x C can be obtained by the solution of TaC and HfC in arbitrary proportion at a temperature exceeding 887 ℃ [22], the synthesis process is usually involved with high temperatures and auxiliary pressures [16].…”

Novel strong and tough Ta/TaHfC2 composites with multi‐scale laminated structure

“…So far, there were dozens of literatures about Ta‐Hf‐C ternary ceramics, but the method to fabricate Ta‐Hf‐C‐based composites with high strength, high toughness, and excellent ablation resistance is still unknown 9 . Although carbon fiber and its fabrics have been proved to own a superior ability in toughening silicon carbide (SiC), 10 the unexpected poor mechanical performance of C f /HfC and C f /TaC composites 11–13 suggest that they are probably not the suitable reinforcement for the Ta‐Hf‐C system.…”

“…So far, there were dozens of literatures about Ta-Hf-C ternary ceramics, but the method to fabricate Ta-Hf-Cbased composites with high strength, high toughness, and excellent ablation resistance is still unknown. 9 Although carbon fiber and its fabrics have been proved to own a superior ability in toughening silicon carbide (SiC), 10 the unexpected poor mechanical performance of C f /HfC and C f /TaC composites [11][12][13] suggest that they are probably not the suitable reinforcement for the Ta-Hf-C system. Meanwhile, limited by the featureless toughening mechanisms of particles, the inorganic nonmetal particles with high melting points such as SiC, 14 carbon nanotube, 15 and graphite, 16 were also found to only have few toughening effects on TaC and HfC.…”

Low‐temperature synthesis and oxidation resistance of random combination of Hf, Nb, and Ta carbides microcuboids

“…However, only carbide solid solutions with limited compositions were investigated. As hypersonic vehicles serve under the extreme environment, TaC‐HfC solid solutions attract much attention due to the high melting point, among which Ta 0.8 Hf 0.2 C is known as with the highest melting point (∼4000°C) 13 , excellent mechanical properties, and good oxidation resistance 14 . Furthermore, (Ta x Hf 1‐x )C solid solutions with a continuous series of compositions (0 ≤ x ≤ 1) can form above 887°C according to their pseudo‐binary phase diagram 15 .…”

“…As hypersonic vehicles serve under the extreme environment, TaC-HfC solid solutions attract much attention due to the high melting point, among which Ta 0.8 Hf 0.2 C is known as with the highest melting point (∼4000 • C) 13 , excellent mechanical properties, and good oxidation resistance. 14 Furthermore, (Ta x Hf 1-x )C solid solutions with a continuous series of compositions (0 ≤ x ≤ 1) can form above 887 • C according to their pseudo-binary phase diagram. 15 Diffusion couples between TaC and HfC were adopted to investigate the diffusion behaviors and the formation mechanism of their solid solutions.…”