电弧离子镀 NiCrAlY 涂层对镍基单晶合金热腐蚀行为的影响

摘要

采用电弧离子镀技术在镍基单晶合金表面沉积 Ni28Cr11Al0.5Y 涂层，研究镍基单晶合金及其Ni28Cr11Al0.5Y 涂层在900℃的75%Na2SO4+25% K2SO4(质量分数)熔盐中的热腐蚀行为。结果表明：镍基单晶合金受到了严重的热腐蚀，镍基单晶合金内部出现了严重的内硫化和内氧化现象，且内硫化物区域和内氧化物区域出现明显分层结构，与外腐蚀层相邻的区域为内氧化区域，远离外腐蚀层的基体内部形成内硫化区域；而Ni28Cr11Al0.5Y 涂层在热腐蚀过程中，表面生成连续的 Al2O3氧化膜，且随腐蚀时间延长，Al2O3氧化膜的厚度增大，表现出优良的抗热腐蚀性能。%Ni28Cr11Al0.5Y coatings were deposited on a single crystal Ni­base superalloy substrate by arc ion plating. The corrosion behaviors of the superalloy and Ni28Cr11Al0.5Y coatings in molten 75%Na2SO4+25% K2SO4 (mass fraction) at 900 ℃ were studied. The results indicate that the superalloy suffer catastrophic hot corrosion, and serious internal oxidation and internal sulfidation occur in a single crystal Ni­base superalloy. The regions near the layer of the surface are identified as the internal oxidizing zones, and the matrix region far from the layer of the surface is identified as the internal sulfidation zone. During the hot corrosion of Ni28Cr11Al0.5Y, the continuous Al2O3 oxidation film forms, and with the hot corrosion time increasing, the oxidation film becomes thick and has better hot corrosion resistance property.