Ternary layered material MAX/MAB phases have become a highly promising candidate for fourth-generation nuclear energy systems, combining the excellent properties of metals and ceramics. This paper reviewed the irradiation response and resistance mechanisms of Ti/Cr/Zr/Nb/V/Ta-based MAX phases, doped/entropy-enhancing MAX phases, and MAB phases. The performance differences between the MAX/MAB phases under irradiation with neutrons, heavy ions, self-ions, He ions, protons, or electrons were investigated. Studies have confirmed that they possess high damage tolerance and resistance to amorphization. This is manifested in the following aspects: accommodating point defects through antisite defects and Frenkel defects; resisting amorphization via atomic rearrangement and crystalline transformation; capturing He atoms by the low-bond-energy A-layer and restricting the growth of He bubbles through M-X layers or B layers; inhibiting further diffusion and penetration of energetic particles; and achieving defect annihilation and damage recovery during high-temperature irradiation and annealing processes. Finally, scientific research strategies are proposed, including regulating MAX/MAB phases to achieve optimal entropy values, designing component structures based on electronegativity and lattice distortion, and investigating the synergistic effects of multiple irradiation particles. Additionally, prospects for the further development of MAX/MAB phases in nuclear energy systems are presented.
High-temperature corrosion caused by low-melting-point molten salts known as CMAS poses a critical challenge to hot-section components in gas turbine engines. The screening of CMAS corrosion-resistant RE2SiO5 ceramics is crucial for the development of environmental barrier coatings for SiC fiber reinforced SiC composites. Due to varying experimental methods, conditions, and CMAS corrosion evaluation approaches, there has been some controversy regarding the CMAS resistance of RE2SiO5 ceramics. To address this issue, we employed a highthroughput multilayer stacking method to eliminate external influences such as experimental conditions. The CMAS resistance of several rare earth silicate ceramics was investigated, which revealed the influence of rare earth elements on CMAS corrosion. It was found that the smaller the rare earth ionic radius, the less corrosion product formed. Additionally, Er2SiO5 exhibited the best CMAS resistance due to the shallowest penetration depth of CMAS. The results indicate that the evaluation of CMAS corrosion resistance of RE2SiO5 ceramics requires a comprehensive consideration of the formation ability of corrosion products, dissolution of RE2SiO5, and the penetration of CMAS.
With the advancement of modern aeroengines toward higher thrust-to-weight ratios and increased gas temperatures, the control of rotor-stator clearances has become a critical factor influencing engine performance and efficiency. Abradable seal coatings (ASCs), as an effective means of clearance control, have been widely applied to the inner casings of engines. Under high-temperature service conditions ($\ge {1300}^{\circ }\mathrm{C}$≥1300∘C), conventional metalbased ASCs are increasingly exhibiting service performance limitations due to their insufficient thermal stability. In contrast, ceramic-based abradable seal coatings, owing to their excellent high-temperature stability and low thermal conductivity, are considered promising candidates for next-generation high-temperature sealing materials. However, the design of such novel ASCs faces numerous key challenges, including crack propagation, the trade-off between abradability and erosion resistance, and coating failure mechanisms under extremely complex service environments. This review systematically summarizes the recent progress in high-temperature ceramic-based ASCs, with a focus on typical material systems, fabrication techniques, key structural design strategies, and their relationship with performance evolution. Comprehensive analysis reveals significant coupling and trade-offs among abradability, hardness, erosion resistance, thermal shock resistance, and corrosion resistance. Achieving balanced performance requires multiscale structural design and multifunctional synergistic optimization. Finally, this paper summarizes the main challenges currently faced in this field and emphasizes that future research should focus more on understanding the evolution of failure mechanisms under complex service environments and on the design and construction of integrated multifunctional coating architectures.
The development of new ablation-resistant and heat-insulating integrated materials for thermal protection of hypersonic vehicles is extremely important, but significant challenges remain. In this study, zirconium-based phosphate ceramics were developed by mixing a nano powder of the traditional ultra-high temperature ceramic oxidation product ZrO2, which has excellent thermal insulation performance, with an aluminum-chromium phosphate slurry, which provides a certain degree of thermal stability. The zirconium-based phosphate ceramics crosslinked and cured by a polycondensation reaction inherited the high temperature resistance of ZrO2 and the low thermal conductivity of the phosphate material, and simultaneously achieving excellent thermal stability, mechanical properties, and the desired properties. The mass ablation rate and line ablation rate of the zirconiumbased phosphate ceramics were found to be 0.0173 g/s and 0.0114 mm/s, respectively, under oxyacetylene flame ablation at 2527∘C for 30 s. In addition, cooling by up to 2301∘C was achieved over a distance of 10 mm in the thickness direction was achieved. The zirconium-based phosphate ceramics also exhibited remarkable compressive strength (6.23-29.22MPa), good thermal insulation (0.827-1.784 W/m⋅K), excellent thermal stability, and mass loss within 2.2% in thermogravimetric tests from room temperature to 1400∘C. These properties indicate that zirconium-based phosphate ceramics can be utilized in thermal protection systems in hypersonic vehicles, rocket propulsion, and missile launchers.
