【摘要】 热障涂层（TBCs）是先进航空发动机热端部件核心热防护技术之一。在高温服役环境下，发动机叶片涂层由于受到主要成分为CaO-MgO-Al₂O₃-SiO₂（CMAS）的环境沉积物的侵蚀和损伤，造成叶片涂层早期剥落与失效，引起国内外高温防护领域广泛关注。特别是对于采用电子束物理气相沉积（EB-PVD）方法制备的常用TBCs材料——氧化钇稳定氧化锆（YSZ），熔融态CMAS易通过柱状晶间隙、微裂纹渗入到涂层内部，产生严重腐蚀。着眼于先进航空发动机TBCs高温服役过程中亟待解决的CMAS腐蚀问题，通过成分改性的方法在YSZ材料中掺入适量的Al₂O₃，形成一种Al₂O₃-YSZ复合涂层（AYSZ涂层），采用EB-PVD技术在氧化铝陶瓷片表面分别制备出YSZ涂层与AYSZ/YSZ涂层，研究了涂层物相、显微组织结构演变规律，对比了2种涂层热导率、高温热稳定性以及对熔融CMAS的抵抗能力。结果表明，在AYSZ/YSZ涂层体系中，YSZ涂层微观上呈“羽毛”结构，AYSZ涂层呈“微柱状晶”结构，与YSZ涂层相比，AYSZ涂层的孔隙率下降12.6%，说明AYSZ更致密。AYSZ涂层在1200℃下热导率仅为0.94 W/（m·K），比相同温度下YSZ涂层隔热性能更好，且在1400℃长时间保持相稳定，具有优异的高温稳定性。AYSZ层表现出一定的阻熔融CMAS腐蚀能力，这是因为涂层的致密“微柱状晶”结构以及涂层与熔融CMAS反应形成的含有CaAl₂Si₂O₈、MgAl₂O₄和CaAl₄Si₂O₁₁等高熔点化合物的反应牺牲层，共同阻碍了CMAS熔体向涂层内部渗入。所研制的新型AYSZ陶瓷隔热涂层实现了高效隔热、长时高温稳定性以及抗熔融CMAS腐蚀的功能，为航空发动机长寿命抗腐蚀TBCs的发展提供了理论和技术指导。更多还原

【Abstract】 Thermal barrier coatings（TBCs） are one of the core thermal protection technologies for the hot components of advanced aeroengines. Under high-temperature service conditions, TBCs of engine blades are eroded and damaged by environmental deposits mainly composed of CaO-MgO-Al₂O₃-SiO₂（CMAS）, leading to early spalling and failure of the blade coatings, which has attracted extensive attention in the field of high-temperature protection among the researchers. Especially for the commonly used TBCs material-yttria-stabilized zirconia（YSZ） prepared by electron beam-physical vapor deposition（EB-PVD） method, molten CMAS can easily penetrate into the coatings through the columnar crystal gaps and microcracks, causing severe corrosion. This article focused on the urgent issue of CMAS corrosion in the high-temperature service process of TBCs for advanced aeroengines. A proper amount of Al₂O₃ was doped into the YSZ material by means of composition modification to form an Al₂O₃-YSZ composite coating（AYSZ coating）. YSZ coating and AYSZ/YSZ coating were fabricated on the surface of alumina ceramic plates by EB-PVD technique. The phase composition and microstructure evolution of the coatings were studied. The comparisions of the two coatings were made on their thermal conductivity,high-temperature thermal stability and resistance to molten CMAS. The results show that in the AYSZ/YSZ coating system, YSZ possesses feather structure while AYSZ exhibits "micro columnar crystal" structure at the microscopic level. Compared to YSZ coating,the porosity of AYSZ coating decreased by 12.6%, indicating that AYSZ is denser layer. The thermal conductivity of AYSZ coating at1200℃ is only 0.94 W/（m·K）, which is better than that of YSZ coating at the same temperature. Moreover, it maintains phase stability for a long time at 1400℃ and has excellent high-temperature stability. AYSZ coating exhibits certain resistance to melting CMAS corrosion,which is because of its dense "micro columnar crystal" structure, as well as the reaction sacrificial layer containing high melting point compounds such as CaAl₂Si₂O₈, MgAl₂O₄, and CaAl₄Si₂O₁₁ formed by the reaction between AYSZ coating and CMAS, hindering the penetration of CMAS into the interior of the coatings. The novel developed AYSZ coating has achieved efficient insulation,high-temperature stability, and resistance to molten CMAS corrosion, providing theoretical and technical guidance for the development of long-life and corrosion-resistant TBCs for aeroengines.更多还原