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Tantalum carbide (TaC) and hafnium carbide (HfC) have some of the highest melting temperatures among the transition metal carbides, borides, and nitrides, making them promising materials for high‐speed flight and high‐temperature structural applications. Solid solutions of TaC and HfC are of particular interest due to their enhanced oxidation resistance compared to pure TaC or HfC. This study looks at the effect of Hf content on the oxidation resistance of TaC–HfC sintered specimens. Five compositions are fabricated into bulk samples using spark plasma sintering (2173 K, 50 MPa, 10 min hold). Oxidation behavior of a subset of the compositions (100 vol% TaC, 80 vol% TaC + 20 vol% HfC, and 50 vol% TaC + 50 vol% HfC) is analyzed using an oxyacetylene torch for 60 s. The TaC–HfC samples exhibit a reduction in the oxide scale thickness and the mass ablation rate with increasing HfC content. The improved oxidation resistance can be attributed to the formation of a Hf₆Ta₂O₁₇phase. This phase enhances oxidation resistance by reducing oxygen diffusion and serving as a protective layer for the unoxidized material. The superior oxidation resistance of TaC–HfC samples makes these materials strong contenders for the development of high‐speed flight coatings.

We describe the manufacturing of a solid‐oxide fuel cell anode of NiO−8 mol.% Y₂O₃‐stabilized ZrO₂with micro‐scale continuous linear pores (CLPs) and nano‐scale interparticle pore structures, achieved through thermal decomposition of unidirectional amorphous carbon fibers. The CLP structure prepared by this sacrificial templating method is characterized by its controllable uniform size, a tortuosity (ie, uniformity) of 1.003, and a coefficient of variation of 0.59. These highly regular CLPs are expected to minimize Knudsen diffusion, resulting in enhanced mass transport of hydrogen gas at the active sites, known as triple‐phase boundary sites. Simulations using the Lattice Boltzmann Method (LBM) were used to determine the mass transport in the systems. An optimum diameter of 3 µm and an interparticle pore size of 185 nm was shown to maximize the acceleration of mass transport of H₂and maintain the number of TPB sites to minimize concentration overpotential. Thus, the proposed porous design can increase the energy efficiency of a solid‐oxide fuel cell primarily by reducing the concentration overpotential.