Molybdenum disilicide (MoSi₂) is a novel crack-healing material used in the traditional thermal barrier coating, which reacts with ZrO₂ to attain a corresponding volume expansion of approximately 138%. However, the pre-oxidation of MoSi₂ causes the “pesting” phenomenon, which degrades the microstructure and mechanical properties throughout the service. To address this issue, the aluminum oxide was fabricated on the MoSi₂ surface using the sol-gel method and low-pressure post-heat treatment to prevent oxygen penetration. The orthogonal experiment investigated the effect of pH, temperature, and water amount on sol generation. Because the Zeta potential difference has reached its maximum value (about 27 mV) at pH 4, the aluminum sol was notably adsorbed on the MoSi₂ particles. The modified MoSi₂@Al₂O₃ particles were characterized to understand their morphologies, surface adsorption energy, and crystal structures. The oxygen adsorption energy on the MoSi₂ (103) surface was lower than that on the Mo₅Si₃ (411) surface, which indicated that the oxidization process can be divided into two independent steps. The Al₂O₃ shell was uniformly formed on the MoSi₂ particles, especially in the low-vacuum environment (10 MPa) for 3 h post-treatment. The dense core-shell structure can prevent oxygen penetration into the MoSi₂ surface, thus prolonging the self-healing property of MoSi₂.

二硅化钼（MoSi ₂ ）是一种用于传统热障涂层的新型裂纹修复材料，它与ZrO ₂反应可实现约138%的相应体积膨胀。然而，MoSi ₂的预氧化会导致“腐蚀”现象，从而降低整个使用过程中的微观结构和机械性能。为了解决这个问题，在 MoSi ₂上制造了氧化铝表面采用溶胶-凝胶法和低压后热处理，以防止氧气渗透。正交实验研究了pH、温度和水量对溶胶生成的影响。由于 Zeta 电位差在 pH 4 时已达到最大值（约 27 mV），铝溶胶明显吸附在 MoSi ₂颗粒上。对改性 MoSi ₂ @Al ₂ O ₃颗粒进行了表征，以了解它们的形态、表面吸附能和晶体结构。MoSi ₂ (103) 表面的氧吸附能低于 Mo ₅ Si ₃（411）表面，这表明氧化过程可以分为两个独立的步骤。Al ₂ O ₃壳均匀地形成在MoSi ₂颗粒上，特别是在低真空环境（10 MPa）进行3 h后处理。致密的核壳结构可以防止氧渗透到MoSi ₂表面，从而延长MoSi ₂的自愈性。